Commit Graph

368 Commits

Author SHA1 Message Date
Peter Zijlstra 2b5a0e425e objtool/idle: Validate __cpuidle code as noinstr
Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org
2023-01-13 11:48:15 +01:00
Nicholas Piggin cad90e5381 objtool: Tolerate STT_NOTYPE symbols at end of section
Hand-written asm often contains non-function symbols in executable
sections. _end symbols for finding the size of instruction blocks
for runtime processing is one such usage.

optprobe_template_end is one example that causes the warning:

  objtool: optprobe_template_end(): can't find starting instruction

This is because the symbol happens to be at the end of the file (and
therefore end of a section in the object file).

So ignore end-of-section STT_NOTYPE symbols instead of bailing out
because an instruction can't be found. While we're here, add a more
descriptive warning for STT_FUNC symbols found at the end of a
section.

[ This also solves a PowerPC regression reported by Sathvika Vasireddy. ]

Reported-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reported-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Sathvika Vasireddy <sv@linux.ibm.com>
Link: https://lore.kernel.org/r/20221220101323.3119939-1-npiggin@gmail.com
2023-01-09 17:53:46 +01:00
Miaoqian Lin 3da73f1023 objtool: Fix memory leak in create_static_call_sections()
strdup() allocates memory for key_name. We need to release the memory in
the following error paths. Add free() to avoid memory leak.

Fixes: 1e7e478838 ("x86/static_call: Add inline static call implementation for x86-64")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20221205080642.558583-1-linmq006@gmail.com
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
2023-01-07 11:45:24 +01:00
Linus Torvalds 5f6e430f93 powerpc updates for 6.2
- Add powerpc qspinlock implementation optimised for large system scalability and
    paravirt. See the merge message for more details.
 
  - Enable objtool to be built on powerpc to generate mcount locations.
 
  - Use a temporary mm for code patching with the Radix MMU, so the writable mapping is
    restricted to the patching CPU.
 
  - Add an option to build the 64-bit big-endian kernel with the ELFv2 ABI.
 
  - Sanitise user registers on interrupt entry on 64-bit Book3S.
 
  - Many other small features and fixes.
 
 Thanks to: Aboorva Devarajan, Angel Iglesias, Benjamin Gray, Bjorn Helgaas, Bo Liu, Chen
 Lifu, Christoph Hellwig, Christophe JAILLET, Christophe Leroy, Christopher M. Riedl, Colin
 Ian King, Deming Wang, Disha Goel, Dmitry Torokhov, Finn Thain, Geert Uytterhoeven,
 Gustavo A. R. Silva, Haowen Bai, Joel Stanley, Jordan Niethe, Julia Lawall, Kajol Jain,
 Laurent Dufour, Li zeming, Miaoqian Lin, Michael Jeanson, Nathan Lynch, Naveen N. Rao,
 Nayna Jain, Nicholas Miehlbradt, Nicholas Piggin, Pali Rohár, Randy Dunlap, Rohan McLure,
 Russell Currey, Sathvika Vasireddy, Shaomin Deng, Stephen Kitt, Stephen Rothwell, Thomas
 Weißschuh, Tiezhu Yang, Uwe Kleine-König, Xie Shaowen, Xiu Jianfeng, XueBing Chen, Yang
 Yingliang, Zhang Jiaming, ruanjinjie, Jessica Yu, Wolfram Sang.
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Merge tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Add powerpc qspinlock implementation optimised for large system
   scalability and paravirt. See the merge message for more details

 - Enable objtool to be built on powerpc to generate mcount locations

 - Use a temporary mm for code patching with the Radix MMU, so the
   writable mapping is restricted to the patching CPU

 - Add an option to build the 64-bit big-endian kernel with the ELFv2
   ABI

 - Sanitise user registers on interrupt entry on 64-bit Book3S

 - Many other small features and fixes

Thanks to Aboorva Devarajan, Angel Iglesias, Benjamin Gray, Bjorn
Helgaas, Bo Liu, Chen Lifu, Christoph Hellwig, Christophe JAILLET,
Christophe Leroy, Christopher M. Riedl, Colin Ian King, Deming Wang,
Disha Goel, Dmitry Torokhov, Finn Thain, Geert Uytterhoeven, Gustavo A.
R. Silva, Haowen Bai, Joel Stanley, Jordan Niethe, Julia Lawall, Kajol
Jain, Laurent Dufour, Li zeming, Miaoqian Lin, Michael Jeanson, Nathan
Lynch, Naveen N. Rao, Nayna Jain, Nicholas Miehlbradt, Nicholas Piggin,
Pali Rohár, Randy Dunlap, Rohan McLure, Russell Currey, Sathvika
Vasireddy, Shaomin Deng, Stephen Kitt, Stephen Rothwell, Thomas
Weißschuh, Tiezhu Yang, Uwe Kleine-König, Xie Shaowen, Xiu Jianfeng,
XueBing Chen, Yang Yingliang, Zhang Jiaming, ruanjinjie, Jessica Yu,
and Wolfram Sang.

* tag 'powerpc-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (181 commits)
  powerpc/code-patching: Fix oops with DEBUG_VM enabled
  powerpc/qspinlock: Fix 32-bit build
  powerpc/prom: Fix 32-bit build
  powerpc/rtas: mandate RTAS syscall filtering
  powerpc/rtas: define pr_fmt and convert printk call sites
  powerpc/rtas: clean up includes
  powerpc/rtas: clean up rtas_error_log_max initialization
  powerpc/pseries/eeh: use correct API for error log size
  powerpc/rtas: avoid scheduling in rtas_os_term()
  powerpc/rtas: avoid device tree lookups in rtas_os_term()
  powerpc/rtasd: use correct OF API for event scan rate
  powerpc/rtas: document rtas_call()
  powerpc/pseries: unregister VPA when hot unplugging a CPU
  powerpc/pseries: reset the RCU watchdogs after a LPM
  powerpc: Take in account addition CPU node when building kexec FDT
  powerpc: export the CPU node count
  powerpc/cpuidle: Set CPUIDLE_FLAG_POLLING for snooze state
  powerpc/dts/fsl: Fix pca954x i2c-mux node names
  cxl: Remove unnecessary cxl_pci_window_alignment()
  selftests/powerpc: Fix resource leaks
  ...
2022-12-19 07:13:33 -06:00
Linus Torvalds 94a855111e - Add the call depth tracking mitigation for Retbleed which has
been long in the making. It is a lighterweight software-only fix for
 Skylake-based cores where enabling IBRS is a big hammer and causes a
 significant performance impact.
 
 What it basically does is, it aligns all kernel functions to 16 bytes
 boundary and adds a 16-byte padding before the function, objtool
 collects all functions' locations and when the mitigation gets applied,
 it patches a call accounting thunk which is used to track the call depth
 of the stack at any time.
 
 When that call depth reaches a magical, microarchitecture-specific value
 for the Return Stack Buffer, the code stuffs that RSB and avoids its
 underflow which could otherwise lead to the Intel variant of Retbleed.
 
 This software-only solution brings a lot of the lost performance back,
 as benchmarks suggest:
 
   https://lore.kernel.org/all/20220915111039.092790446@infradead.org/
 
 That page above also contains a lot more detailed explanation of the
 whole mechanism
 
 - Implement a new control flow integrity scheme called FineIBT which is
 based on the software kCFI implementation and uses hardware IBT support
 where present to annotate and track indirect branches using a hash to
 validate them
 
 - Other misc fixes and cleanups
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Merge tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 core updates from Borislav Petkov:

 - Add the call depth tracking mitigation for Retbleed which has been
   long in the making. It is a lighterweight software-only fix for
   Skylake-based cores where enabling IBRS is a big hammer and causes a
   significant performance impact.

   What it basically does is, it aligns all kernel functions to 16 bytes
   boundary and adds a 16-byte padding before the function, objtool
   collects all functions' locations and when the mitigation gets
   applied, it patches a call accounting thunk which is used to track
   the call depth of the stack at any time.

   When that call depth reaches a magical, microarchitecture-specific
   value for the Return Stack Buffer, the code stuffs that RSB and
   avoids its underflow which could otherwise lead to the Intel variant
   of Retbleed.

   This software-only solution brings a lot of the lost performance
   back, as benchmarks suggest:

       https://lore.kernel.org/all/20220915111039.092790446@infradead.org/

   That page above also contains a lot more detailed explanation of the
   whole mechanism

 - Implement a new control flow integrity scheme called FineIBT which is
   based on the software kCFI implementation and uses hardware IBT
   support where present to annotate and track indirect branches using a
   hash to validate them

 - Other misc fixes and cleanups

* tag 'x86_core_for_v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (80 commits)
  x86/paravirt: Use common macro for creating simple asm paravirt functions
  x86/paravirt: Remove clobber bitmask from .parainstructions
  x86/debug: Include percpu.h in debugreg.h to get DECLARE_PER_CPU() et al
  x86/cpufeatures: Move X86_FEATURE_CALL_DEPTH from bit 18 to bit 19 of word 11, to leave space for WIP X86_FEATURE_SGX_EDECCSSA bit
  x86/Kconfig: Enable kernel IBT by default
  x86,pm: Force out-of-line memcpy()
  objtool: Fix weak hole vs prefix symbol
  objtool: Optimize elf_dirty_reloc_sym()
  x86/cfi: Add boot time hash randomization
  x86/cfi: Boot time selection of CFI scheme
  x86/ibt: Implement FineIBT
  objtool: Add --cfi to generate the .cfi_sites section
  x86: Add prefix symbols for function padding
  objtool: Add option to generate prefix symbols
  objtool: Avoid O(bloody terrible) behaviour -- an ode to libelf
  objtool: Slice up elf_create_section_symbol()
  kallsyms: Revert "Take callthunks into account"
  x86: Unconfuse CONFIG_ and X86_FEATURE_ namespaces
  x86/retpoline: Fix crash printing warning
  x86/paravirt: Fix a !PARAVIRT build warning
  ...
2022-12-14 15:03:00 -08:00
Sathvika Vasireddy 4ca993d498 objtool: Add arch specific function arch_ftrace_match()
Add architecture specific function to look for relocation records
pointing to architecture specific symbols.

Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-15-sv@linux.ibm.com
2022-11-18 19:00:16 +11:00
Sathvika Vasireddy c144973521 objtool: Use macros to define arch specific reloc types
Make relocation types architecture specific.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-14-sv@linux.ibm.com
2022-11-18 19:00:16 +11:00
Sathvika Vasireddy de6fbcedf5 objtool: Read special sections with alts only when specific options are selected
Call add_special_section_alts() only when stackval or orc or uaccess or
noinstr options are passed to objtool.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-13-sv@linux.ibm.com
2022-11-18 19:00:16 +11:00
Sathvika Vasireddy 280981d699 objtool: Add --mnop as an option to --mcount
Some architectures (powerpc) may not support ftrace locations being nop'ed
out at build time. Introduce CONFIG_HAVE_OBJTOOL_NOP_MCOUNT for objtool, as
a means for architectures to enable nop'ing of ftrace locations. Add --mnop
as an option to objtool --mcount, to indicate support for the same.

Also, make sure that --mnop can be passed as an option to objtool only when
--mcount is passed.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-12-sv@linux.ibm.com
2022-11-18 19:00:16 +11:00
Christophe Leroy 86ea7f3615 objtool: Use target file class size instead of a compiled constant
In order to allow using objtool on cross-built kernels,
determine size of long from elf data instead of using
sizeof(long) at build time.

For the time being this covers only mcount.

[Sathvika Vasireddy: Rename variable "size" to "addrsize" and function
"elf_class_size()" to "elf_class_addrsize()", and modify
create_mcount_loc_sections() function to follow reverse christmas tree
format to order local variable declarations.]

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Sathvika Vasireddy <sv@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-11-sv@linux.ibm.com
2022-11-18 19:00:16 +11:00
Christophe Leroy 0646c28b41 objtool: Use target file endianness instead of a compiled constant
Some architectures like powerpc support both endianness, it's
therefore not possible to fix the endianness via arch/endianness.h
because there is no easy way to get the target endianness at
build time.

Use the endianness recorded in the file objtool is working on.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-10-sv@linux.ibm.com
2022-11-18 19:00:15 +11:00
Christophe Leroy efb11fdb3e objtool: Fix SEGFAULT
find_insn() will return NULL in case of failure. Check insn in order
to avoid a kernel Oops for NULL pointer dereference.

Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221114175754.1131267-9-sv@linux.ibm.com
2022-11-18 19:00:15 +11:00
Peter Zijlstra 023f2340f0 objtool: Fix weak hole vs prefix symbol
Boris (and the robot) reported that objtool grew a new complaint about
unreachable instructions. Upon inspection it was immediately clear
the __weak zombie instructions struck again.

For the unweary, the linker will simply remove the symbol for
overriden __weak symbols but leave the instructions in place, creating
unreachable instructions -- and objtool likes to report these.

Commit 4adb236867 ("objtool: Ignore extra-symbol code") was supposed
to have dealt with that, but the new commit 9f2899fe36 ("objtool:
Add option to generate prefix symbols") subtly broke that logic by
created unvisited symbols.

Fixes: 9f2899fe36 ("objtool: Add option to generate prefix symbols")
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-11-05 11:28:02 +01:00
Peter Zijlstra 9a479f766b objtool: Add --cfi to generate the .cfi_sites section
Add the location of all __cfi_##name symbols (as generated by kCFI) to
a section such that we might re-write things at kernel boot.

Notably; boot time re-hashing and FineIBT are the intended use of
this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221027092842.568039454@infradead.org
2022-11-01 13:44:10 +01:00
Peter Zijlstra 9f2899fe36 objtool: Add option to generate prefix symbols
When code is compiled with:

  -fpatchable-function-entry=${PADDING_BYTES},${PADDING_BYTES}

functions will have PADDING_BYTES of NOP in front of them. Unwinders
and other things that symbolize code locations will typically
attribute these bytes to the preceding function.

Given that these bytes nominally belong to the following symbol this
mis-attribution is confusing.

Inspired by the fact that CFI_CLANG emits __cfi_##name symbols to
claim these bytes, allow objtool to emit __pfx_##name symbols to do
the same.

Therefore add the objtool --prefix=N argument, to conditionally place
a __pfx_##name symbol at N bytes ahead of symbol 'name' when: all
these preceding bytes are NOP and name-N is an instruction boundary.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Yujie Liu <yujie.liu@intel.com>
Link: https://lkml.kernel.org/r/20221028194453.526899822@infradead.org
2022-11-01 13:44:09 +01:00
Marco Elver 63646fcba5 objtool, kcsan: Add volatile read/write instrumentation to whitelist
Adds KCSAN's volatile instrumentation to objtool's uaccess whitelist.

Recent kernel change have shown that this was missing from the uaccess
whitelist (since the first upstreamed version of KCSAN):

  mm/gup.o: warning: objtool: fault_in_readable+0x101: call to __tsan_volatile_write1() with UACCESS enabled

Fixes: 75d75b7a4d ("kcsan: Support distinguishing volatile accesses")
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2022-10-18 15:07:33 -07:00
Peter Zijlstra 5a9c361a41 objtool: Allow STT_NOTYPE -> STT_FUNC+0 sibling-calls
Teach objtool about STT_NOTYPE -> STT_FUNC+0 sibling calls. Doing do
allows slightly simpler .S files.

There is a slight complication in that we specifically do not want to
allow sibling calls from symbol holes (previously covered by STT_WEAK
symbols) -- such things exist where a weak function has a .cold
subfunction for example.

Additionally, STT_NOTYPE tail-calls are allowed to happen with a
modified stack frame, they don't need to obey the normal rules after
all.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-10-17 16:41:09 +02:00
Peter Zijlstra dbcdbdfdf1 objtool: Rework instruction -> symbol mapping
Currently insn->func contains a instruction -> symbol link for
STT_FUNC symbols. A NULL value is assumed to mean STT_NOTYPE.
However, there are also instructions not covered by any symbol at all.
This can happen due to __weak symbols for example.

Since the current scheme cannot differentiate between no symbol and
STT_NOTYPE symbol, change things around. Make insn->sym point to any
symbol type such that !insn->sym means no symbol and add a helper
insn_func() that check the sym->type to retain the old functionality.

This then prepares the way to add code that depends on the distinction
between STT_NOTYPE and no symbol at all.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-10-17 16:41:08 +02:00
Peter Zijlstra 08ef8c4011 objtool: Allow symbol range comparisons for IBT/ENDBR
A semi common pattern is where code checks if a code address is
within a specific range. All text addresses require either ENDBR or
ANNOTATE_ENDBR, however the ANNOTATE_NOENDBR past the range is
unnatural.

Instead, suppress this warning when this is exactly at the end of a
symbol that itself starts with either ENDBR/ANNOTATE_ENDBR.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111146.434642471@infradead.org
2022-10-17 16:41:08 +02:00
Peter Zijlstra 0c0a6d8934 objtool: Add --hacks=skylake
Make the call/func sections selectable via the --hacks option.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111146.120821440@infradead.org
2022-10-17 16:41:07 +02:00
Peter Zijlstra 00abd38408 objtool: Add .call_sites section
In preparation for call depth tracking provide a section which collects all
direct calls.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111146.016511961@infradead.org
2022-10-17 16:41:07 +02:00
Peter Zijlstra 6644ee846c objtool: Track init section
For future usage of .init.text exclusion track the init section in the
instruction decoder and use the result in retpoline validation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111145.910334431@infradead.org
2022-10-17 16:41:07 +02:00
Peter Zijlstra 61c6065ef7 objtool: Allow !PC relative relocations
Objtool doesn't currently much like per-cpu usage in alternatives:

arch/x86/entry/entry_64.o: warning: objtool: .altinstr_replacement+0xf: unsupported relocation in alternatives section
  f:   65 c7 04 25 00 00 00 00 00 00 00 80     movl   $0x80000000,%gs:0x0      13: R_X86_64_32S        __x86_call_depth

Since the R_X86_64_32S relocation is location invariant (it's
computation doesn't include P - the address of the location itself),
it can be trivially allowed.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111145.806607235@infradead.org
2022-10-17 16:41:06 +02:00
Linus Torvalds 27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
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Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Linus Torvalds 65f109e199 Objtool changes for v6.1:
- Remove the "ANNOTATE_NOENDBR on ENDBR" warning: it's not
    really useful and only found a non-bug false positive so far.
 
  - Properly decode LOOP/LOOPE/LOOPNE, which were missing from
    the x86 decoder. Because these instructions are rather
    ineffective, they never showed up in compiler output,
    but they are simple enough to support, so add them for
    completeness.
 
  - A bit more cross-arch preparatory work.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - Remove the "ANNOTATE_NOENDBR on ENDBR" warning: it's not really
   useful and only found a non-bug false positive so far.

 - Properly decode LOOP/LOOPE/LOOPNE, which were missing from the x86
   decoder. Because these instructions are rather ineffective, they
   never showed up in compiler output, but they are simple enough to
   support, so add them for completeness.

 - A bit more cross-arch preparatory work.

* tag 'objtool-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool,x86: Teach decode about LOOP* instructions
  objtool: Remove "ANNOTATE_NOENDBR on ENDBR" warning
  objtool: Use arch_jump_destination() in read_intra_function_calls()
2022-10-10 09:56:19 -07:00
Linus Torvalds 0326074ff4 Networking changes for 6.1.
Core
 ----
 
  - Introduce and use a single page frag cache for allocating small skb
    heads, clawing back the 10-20% performance regression in UDP flood
    test from previous fixes.
 
  - Run packets which already went thru HW coalescing thru SW GRO.
    This significantly improves TCP segment coalescing and simplifies
    deployments as different workloads benefit from HW or SW GRO.
 
  - Shrink the size of the base zero-copy send structure.
 
  - Move TCP init under a new slow / sleepable version of DO_ONCE().
 
 BPF
 ---
 
  - Add BPF-specific, any-context-safe memory allocator.
 
  - Add helpers/kfuncs for PKCS#7 signature verification from BPF
    programs.
 
  - Define a new map type and related helpers for user space -> kernel
    communication over a ring buffer (BPF_MAP_TYPE_USER_RINGBUF).
 
  - Allow targeting BPF iterators to loop through resources of one
    task/thread.
 
  - Add ability to call selected destructive functions.
    Expose crash_kexec() to allow BPF to trigger a kernel dump.
    Use CAP_SYS_BOOT check on the loading process to judge permissions.
 
  - Enable BPF to collect custom hierarchical cgroup stats efficiently
    by integrating with the rstat framework.
 
  - Support struct arguments for trampoline based programs.
    Only structs with size <= 16B and x86 are supported.
 
  - Invoke cgroup/connect{4,6} programs for unprivileged ICMP ping
    sockets (instead of just TCP and UDP sockets).
 
  - Add a helper for accessing CLOCK_TAI for time sensitive network
    related programs.
 
  - Support accessing network tunnel metadata's flags.
 
  - Make TCP SYN ACK RTO tunable by BPF programs with TCP Fast Open.
 
  - Add support for writing to Netfilter's nf_conn:mark.
 
 Protocols
 ---------
 
  - WiFi: more Extremely High Throughput (EHT) and Multi-Link
    Operation (MLO) work (802.11be, WiFi 7).
 
  - vsock: improve support for SO_RCVLOWAT.
 
  - SMC: support SO_REUSEPORT.
 
  - Netlink: define and document how to use netlink in a "modern" way.
    Support reporting missing attributes via extended ACK.
 
  - IPSec: support collect metadata mode for xfrm interfaces.
 
  - TCPv6: send consistent autoflowlabel in SYN_RECV state
    and RST packets.
 
  - TCP: introduce optional per-netns connection hash table to allow
    better isolation between namespaces (opt-in, at the cost of memory
    and cache pressure).
 
  - MPTCP: support TCP_FASTOPEN_CONNECT.
 
  - Add NEXT-C-SID support in Segment Routing (SRv6) End behavior.
 
  - Adjust IP_UNICAST_IF sockopt behavior for connected UDP sockets.
 
  - Open vSwitch:
    - Allow specifying ifindex of new interfaces.
    - Allow conntrack and metering in non-initial user namespace.
 
  - TLS: support the Korean ARIA-GCM crypto algorithm.
 
  - Remove DECnet support.
 
 Driver API
 ----------
 
  - Allow selecting the conduit interface used by each port
    in DSA switches, at runtime.
 
  - Ethernet Power Sourcing Equipment and Power Device support.
 
  - Add tc-taprio support for queueMaxSDU parameter, i.e. setting
    per traffic class max frame size for time-based packet schedules.
 
  - Support PHY rate matching - adapting between differing host-side
    and link-side speeds.
 
  - Introduce QUSGMII PHY mode and 1000BASE-KX interface mode.
 
  - Validate OF (device tree) nodes for DSA shared ports; make
    phylink-related properties mandatory on DSA and CPU ports.
    Enforcing more uniformity should allow transitioning to phylink.
 
  - Require that flash component name used during update matches one
    of the components for which version is reported by info_get().
 
  - Remove "weight" argument from driver-facing NAPI API as much
    as possible. It's one of those magic knobs which seemed like
    a good idea at the time but is too indirect to use in practice.
 
  - Support offload of TLS connections with 256 bit keys.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - Microchip KSZ9896 6-port Gigabit Ethernet Switch
    - Renesas Ethernet AVB (EtherAVB-IF) Gen4 SoCs
    - Analog Devices ADIN1110 and ADIN2111 industrial single pair
      Ethernet (10BASE-T1L) MAC+PHY.
    - Rockchip RV1126 Gigabit Ethernet (a version of stmmac IP).
 
  - Ethernet SFPs / modules:
    - RollBall / Hilink / Turris 10G copper SFPs
    - HALNy GPON module
 
  - WiFi:
    - CYW43439 SDIO chipset (brcmfmac)
    - CYW89459 PCIe chipset (brcmfmac)
    - BCM4378 on Apple platforms (brcmfmac)
 
 Drivers
 -------
 
  - CAN:
    - gs_usb: HW timestamp support
 
  - Ethernet PHYs:
    - lan8814: cable diagnostics
 
  - Ethernet NICs:
    - Intel (100G):
      - implement control of FCS/CRC stripping
      - port splitting via devlink
      - L2TPv3 filtering offload
    - nVidia/Mellanox:
      - tunnel offload for sub-functions
      - MACSec offload, w/ Extended packet number and replay
        window offload
      - significantly restructure, and optimize the AF_XDP support,
        align the behavior with other vendors
    - Huawei:
      - configuring DSCP map for traffic class selection
      - querying standard FEC statistics
      - querying SerDes lane number via ethtool
    - Marvell/Cavium:
      - egress priority flow control
      - MACSec offload
    - AMD/SolarFlare:
      - PTP over IPv6 and raw Ethernet
    - small / embedded:
      - ax88772: convert to phylink (to support SFP cages)
      - altera: tse: convert to phylink
      - ftgmac100: support fixed link
      - enetc: standard Ethtool counters
      - macb: ZynqMP SGMII dynamic configuration support
      - tsnep: support multi-queue and use page pool
      - lan743x: Rx IP & TCP checksum offload
      - igc: add xdp frags support to ndo_xdp_xmit
 
  - Ethernet high-speed switches:
    - Marvell (prestera):
      - support SPAN port features (traffic mirroring)
      - nexthop object offloading
    - Microchip (sparx5):
      - multicast forwarding offload
      - QoS queuing offload (tc-mqprio, tc-tbf, tc-ets)
 
  - Ethernet embedded switches:
    - Marvell (mv88e6xxx):
      - support RGMII cmode
    - NXP (felix):
      - standardized ethtool counters
    - Microchip (lan966x):
      - QoS queuing offload (tc-mqprio, tc-tbf, tc-cbs, tc-ets)
      - traffic policing and mirroring
      - link aggregation / bonding offload
      - QUSGMII PHY mode support
 
  - Qualcomm 802.11ax WiFi (ath11k):
    - cold boot calibration support on WCN6750
    - support to connect to a non-transmit MBSSID AP profile
    - enable remain-on-channel support on WCN6750
    - Wake-on-WLAN support for WCN6750
    - support to provide transmit power from firmware via nl80211
    - support to get power save duration for each client
    - spectral scan support for 160 MHz
 
  - MediaTek WiFi (mt76):
    - WiFi-to-Ethernet bridging offload for MT7986 chips
 
  - RealTek WiFi (rtw89):
    - P2P support
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core:

   - Introduce and use a single page frag cache for allocating small skb
     heads, clawing back the 10-20% performance regression in UDP flood
     test from previous fixes.

   - Run packets which already went thru HW coalescing thru SW GRO. This
     significantly improves TCP segment coalescing and simplifies
     deployments as different workloads benefit from HW or SW GRO.

   - Shrink the size of the base zero-copy send structure.

   - Move TCP init under a new slow / sleepable version of DO_ONCE().

  BPF:

   - Add BPF-specific, any-context-safe memory allocator.

   - Add helpers/kfuncs for PKCS#7 signature verification from BPF
     programs.

   - Define a new map type and related helpers for user space -> kernel
     communication over a ring buffer (BPF_MAP_TYPE_USER_RINGBUF).

   - Allow targeting BPF iterators to loop through resources of one
     task/thread.

   - Add ability to call selected destructive functions. Expose
     crash_kexec() to allow BPF to trigger a kernel dump. Use
     CAP_SYS_BOOT check on the loading process to judge permissions.

   - Enable BPF to collect custom hierarchical cgroup stats efficiently
     by integrating with the rstat framework.

   - Support struct arguments for trampoline based programs. Only
     structs with size <= 16B and x86 are supported.

   - Invoke cgroup/connect{4,6} programs for unprivileged ICMP ping
     sockets (instead of just TCP and UDP sockets).

   - Add a helper for accessing CLOCK_TAI for time sensitive network
     related programs.

   - Support accessing network tunnel metadata's flags.

   - Make TCP SYN ACK RTO tunable by BPF programs with TCP Fast Open.

   - Add support for writing to Netfilter's nf_conn:mark.

  Protocols:

   - WiFi: more Extremely High Throughput (EHT) and Multi-Link Operation
     (MLO) work (802.11be, WiFi 7).

   - vsock: improve support for SO_RCVLOWAT.

   - SMC: support SO_REUSEPORT.

   - Netlink: define and document how to use netlink in a "modern" way.
     Support reporting missing attributes via extended ACK.

   - IPSec: support collect metadata mode for xfrm interfaces.

   - TCPv6: send consistent autoflowlabel in SYN_RECV state and RST
     packets.

   - TCP: introduce optional per-netns connection hash table to allow
     better isolation between namespaces (opt-in, at the cost of memory
     and cache pressure).

   - MPTCP: support TCP_FASTOPEN_CONNECT.

   - Add NEXT-C-SID support in Segment Routing (SRv6) End behavior.

   - Adjust IP_UNICAST_IF sockopt behavior for connected UDP sockets.

   - Open vSwitch:
      - Allow specifying ifindex of new interfaces.
      - Allow conntrack and metering in non-initial user namespace.

   - TLS: support the Korean ARIA-GCM crypto algorithm.

   - Remove DECnet support.

  Driver API:

   - Allow selecting the conduit interface used by each port in DSA
     switches, at runtime.

   - Ethernet Power Sourcing Equipment and Power Device support.

   - Add tc-taprio support for queueMaxSDU parameter, i.e. setting per
     traffic class max frame size for time-based packet schedules.

   - Support PHY rate matching - adapting between differing host-side
     and link-side speeds.

   - Introduce QUSGMII PHY mode and 1000BASE-KX interface mode.

   - Validate OF (device tree) nodes for DSA shared ports; make
     phylink-related properties mandatory on DSA and CPU ports.
     Enforcing more uniformity should allow transitioning to phylink.

   - Require that flash component name used during update matches one of
     the components for which version is reported by info_get().

   - Remove "weight" argument from driver-facing NAPI API as much as
     possible. It's one of those magic knobs which seemed like a good
     idea at the time but is too indirect to use in practice.

   - Support offload of TLS connections with 256 bit keys.

  New hardware / drivers:

   - Ethernet:
      - Microchip KSZ9896 6-port Gigabit Ethernet Switch
      - Renesas Ethernet AVB (EtherAVB-IF) Gen4 SoCs
      - Analog Devices ADIN1110 and ADIN2111 industrial single pair
        Ethernet (10BASE-T1L) MAC+PHY.
      - Rockchip RV1126 Gigabit Ethernet (a version of stmmac IP).

   - Ethernet SFPs / modules:
      - RollBall / Hilink / Turris 10G copper SFPs
      - HALNy GPON module

   - WiFi:
      - CYW43439 SDIO chipset (brcmfmac)
      - CYW89459 PCIe chipset (brcmfmac)
      - BCM4378 on Apple platforms (brcmfmac)

  Drivers:

   - CAN:
      - gs_usb: HW timestamp support

   - Ethernet PHYs:
      - lan8814: cable diagnostics

   - Ethernet NICs:
      - Intel (100G):
         - implement control of FCS/CRC stripping
         - port splitting via devlink
         - L2TPv3 filtering offload
      - nVidia/Mellanox:
         - tunnel offload for sub-functions
         - MACSec offload, w/ Extended packet number and replay window
           offload
         - significantly restructure, and optimize the AF_XDP support,
           align the behavior with other vendors
      - Huawei:
         - configuring DSCP map for traffic class selection
         - querying standard FEC statistics
         - querying SerDes lane number via ethtool
      - Marvell/Cavium:
         - egress priority flow control
         - MACSec offload
      - AMD/SolarFlare:
         - PTP over IPv6 and raw Ethernet
      - small / embedded:
         - ax88772: convert to phylink (to support SFP cages)
         - altera: tse: convert to phylink
         - ftgmac100: support fixed link
         - enetc: standard Ethtool counters
         - macb: ZynqMP SGMII dynamic configuration support
         - tsnep: support multi-queue and use page pool
         - lan743x: Rx IP & TCP checksum offload
         - igc: add xdp frags support to ndo_xdp_xmit

   - Ethernet high-speed switches:
      - Marvell (prestera):
         - support SPAN port features (traffic mirroring)
         - nexthop object offloading
      - Microchip (sparx5):
         - multicast forwarding offload
         - QoS queuing offload (tc-mqprio, tc-tbf, tc-ets)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - support RGMII cmode
      - NXP (felix):
         - standardized ethtool counters
      - Microchip (lan966x):
         - QoS queuing offload (tc-mqprio, tc-tbf, tc-cbs, tc-ets)
         - traffic policing and mirroring
         - link aggregation / bonding offload
         - QUSGMII PHY mode support

   - Qualcomm 802.11ax WiFi (ath11k):
      - cold boot calibration support on WCN6750
      - support to connect to a non-transmit MBSSID AP profile
      - enable remain-on-channel support on WCN6750
      - Wake-on-WLAN support for WCN6750
      - support to provide transmit power from firmware via nl80211
      - support to get power save duration for each client
      - spectral scan support for 160 MHz

   - MediaTek WiFi (mt76):
      - WiFi-to-Ethernet bridging offload for MT7986 chips

   - RealTek WiFi (rtw89):
      - P2P support"

* tag 'net-next-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1864 commits)
  eth: pse: add missing static inlines
  once: rename _SLOW to _SLEEPABLE
  net: pse-pd: add regulator based PSE driver
  dt-bindings: net: pse-dt: add bindings for regulator based PoDL PSE controller
  ethtool: add interface to interact with Ethernet Power Equipment
  net: mdiobus: search for PSE nodes by parsing PHY nodes.
  net: mdiobus: fwnode_mdiobus_register_phy() rework error handling
  net: add framework to support Ethernet PSE and PDs devices
  dt-bindings: net: phy: add PoDL PSE property
  net: marvell: prestera: Propagate nh state from hw to kernel
  net: marvell: prestera: Add neighbour cache accounting
  net: marvell: prestera: add stub handler neighbour events
  net: marvell: prestera: Add heplers to interact with fib_notifier_info
  net: marvell: prestera: Add length macros for prestera_ip_addr
  net: marvell: prestera: add delayed wq and flush wq on deinit
  net: marvell: prestera: Add strict cleanup of fib arbiter
  net: marvell: prestera: Add cleanup of allocated fib_nodes
  net: marvell: prestera: Add router nexthops ABI
  eth: octeon: fix build after netif_napi_add() changes
  net/mlx5: E-Switch, Return EBUSY if can't get mode lock
  ...
2022-10-04 13:38:03 -07:00
Linus Torvalds 7db99f01d1 - Print the CPU number at segfault time. The number printed is not
always accurate (preemption is enabled at that time) but the print string
   contains "likely" and after a lot of back'n'forth on this, this was the
   consensus that was reached. See thread starting at:
   https://lore.kernel.org/r/5d62c1d0-7425-d5bb-ecb5-1dc3b4d7d245@intel.com
 
 - After a *lot* of testing and polishing, finally the clear_user()
   improvements to inline REP; STOSB by default
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Merge tag 'x86_cpu_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu updates from Borislav Petkov:

 - Print the CPU number at segfault time.

   The number printed is not always accurate (preemption is enabled at
   that time) but the print string contains "likely" and after a lot of
   back'n'forth on this, this was the consensus that was reached. See
   thread at [1].

 - After a *lot* of testing and polishing, finally the clear_user()
   improvements to inline REP; STOSB by default

Link: https://lore.kernel.org/r/5d62c1d0-7425-d5bb-ecb5-1dc3b4d7d245@intel.com [1]

* tag 'x86_cpu_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Print likely CPU at segfault time
  x86/clear_user: Make it faster
2022-10-04 09:21:30 -07:00
Alexander Potapenko 40b22c9df2 objtool: kmsan: list KMSAN API functions as uaccess-safe
KMSAN inserts API function calls in a lot of places (function entries and
exits, local variables, memory accesses), so they may get called from the
uaccess regions as well.

KMSAN API functions are used to update the metadata (shadow/origin pages)
for kernel memory accesses.  The metadata pages for kernel pointers are
also located in the kernel memory, so touching them is not a problem.  For
userspace pointers, no metadata is allocated.

If an API function is supposed to read or modify the metadata, it does so
for kernel pointers and ignores userspace pointers.  If an API function is
supposed to return a pair of metadata pointers for the instrumentation to
use (like all __msan_metadata_ptr_for_TYPE_SIZE() functions do), it
returns the allocated metadata for kernel pointers and special dummy
buffers residing in the kernel memory for userspace pointers.

As a result, none of KMSAN API functions perform userspace accesses, but
since they might be called from UACCESS regions they use
user_access_save/restore().

Link: https://lkml.kernel.org/r/20220915150417.722975-32-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:23 -07:00
Sami Tolvanen 3c68a92d17 objtool: Disable CFI warnings
The __cfi_ preambles contain a mov instruction that embeds the KCFI
type identifier in the following format:

  ; type preamble
  __cfi_function:
    mov <id>, %eax
  function:
    ...

While the preamble symbols are STT_FUNC and contain valid
instructions, they are never executed and always fall through. Skip
the warning for them.

.kcfi_traps sections point to CFI traps in text sections. Also skip
the warning about them referencing !ENDBR instructions.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220908215504.3686827-18-samitolvanen@google.com
2022-09-26 10:13:15 -07:00
Peter Zijlstra (Intel) 9440155ccb ftrace: Add HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
x86 will shortly start using -fpatchable-function-entry for purposes
other than ftrace, make sure the __patchable_function_entry section
isn't merged in the mcount_loc section.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220903131154.420467-2-jolsa@kernel.org
2022-09-16 22:16:48 +02:00
Linus Torvalds 2f23a7c914 Misc fixes:
- Fix PAT on Xen, which caused i915 driver failures
  - Fix compat INT 80 entry crash on Xen PV guests
  - Fix 'MMIO Stale Data' mitigation status reporting on older Intel CPUs
  - Fix RSB stuffing regressions
  - Fix ORC unwinding on ftrace trampolines
  - Add Intel Raptor Lake CPU model number
  - Fix (work around) a SEV-SNP bootloader bug providing bogus values in
    boot_params->cc_blob_address, by ignoring the value on !SEV-SNP bootups.
  - Fix SEV-SNP early boot failure
  - Fix the objtool list of noreturn functions and annotate snp_abort(),
    which bug confused objtool on gcc-12.
  - Fix the documentation for retbleed
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-urgent-2022-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 fixes from Ingo Molnar:

 - Fix PAT on Xen, which caused i915 driver failures

 - Fix compat INT 80 entry crash on Xen PV guests

 - Fix 'MMIO Stale Data' mitigation status reporting on older Intel CPUs

 - Fix RSB stuffing regressions

 - Fix ORC unwinding on ftrace trampolines

 - Add Intel Raptor Lake CPU model number

 - Fix (work around) a SEV-SNP bootloader bug providing bogus values in
   boot_params->cc_blob_address, by ignoring the value on !SEV-SNP
   bootups.

 - Fix SEV-SNP early boot failure

 - Fix the objtool list of noreturn functions and annotate snp_abort(),
   which bug confused objtool on gcc-12.

 - Fix the documentation for retbleed

* tag 'x86-urgent-2022-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/ABI: Mention retbleed vulnerability info file for sysfs
  x86/sev: Mark snp_abort() noreturn
  x86/sev: Don't use cc_platform_has() for early SEV-SNP calls
  x86/boot: Don't propagate uninitialized boot_params->cc_blob_address
  x86/cpu: Add new Raptor Lake CPU model number
  x86/unwind/orc: Unwind ftrace trampolines with correct ORC entry
  x86/nospec: Fix i386 RSB stuffing
  x86/nospec: Unwreck the RSB stuffing
  x86/bugs: Add "unknown" reporting for MMIO Stale Data
  x86/entry: Fix entry_INT80_compat for Xen PV guests
  x86/PAT: Have pat_enabled() properly reflect state when running on Xen
2022-08-28 10:10:23 -07:00
Borislav Petkov c93c296fff x86/sev: Mark snp_abort() noreturn
Mark both the function prototype and definition as noreturn in order to
prevent the compiler from doing transformations which confuse objtool
like so:

  vmlinux.o: warning: objtool: sme_enable+0x71: unreachable instruction

This triggers with gcc-12.

Add it and sev_es_terminate() to the objtool noreturn tracking array
too. Sort it while at it.

Suggested-by: Michael Matz <matz@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220824152420.20547-1-bp@alien8.de
2022-08-25 15:54:03 +02:00
Josh Poimboeuf 3c6f390080 objtool: Remove "ANNOTATE_NOENDBR on ENDBR" warning
This warning isn't very useful: why would you put ANNOTATE_NOENDBR on
ENDBR, and if you did, what's the harm?

And thus far it's only found one non-bug, where the
'__end_entry_SYSENTER_compat' label happens to land on the ENDBR from
entry_SYSCALL_compat:

  vmlinux.o: warning: objtool: entry_SYSCALL_compat+0x0: ANNOTATE_NOENDBR on ENDBR

.. which is fine.  Just remove the warning.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/142341a5dafdfc788e4c95b9e226a6eefc9b626e.1660839773.git.jpoimboe@kernel.org
2022-08-19 19:47:57 +02:00
Chen Zhongjin 7b3e318690 objtool: Use arch_jump_destination() in read_intra_function_calls()
Use arch_jump_destiation() instead of the open-coded 'offset + len +
immediate' that is x86 specific.

Avoids future trouble with other architectures.

Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220818014553.220261-1-chenzhongjin@huawei.com
2022-08-19 19:47:56 +02:00
Josh Poimboeuf e27e5bea95 x86/ibt, objtool: Add IBT_NOSEAL()
Add a macro which prevents a function from getting sealed if there are
no compile-time references to it.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Message-Id: <20220818213927.e44fmxkoq4yj6ybn@treble>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-08-19 04:05:42 -04:00
Borislav Petkov 0db7058e8e x86/clear_user: Make it faster
Based on a patch by Mark Hemment <markhemm@googlemail.com> and
incorporating very sane suggestions from Linus.

The point here is to have the default case with FSRM - which is supposed
to be the majority of x86 hw out there - if not now then soon - be
directly inlined into the instruction stream so that no function call
overhead is taking place.

Drop the early clobbers from the @size and @addr operands as those are
not needed anymore since we have single instruction alternatives.

The benchmarks I ran would show very small improvements and a PF
benchmark would even show weird things like slowdowns with higher core
counts.

So for a ~6m running the git test suite, the function gets called under
700K times, all from padzero():

  <...>-2536    [006] .....   261.208801: padzero: to: 0x55b0663ed214, size: 3564, cycles: 21900
  <...>-2536    [006] .....   261.208819: padzero: to: 0x7f061adca078, size: 3976, cycles: 17160
  <...>-2537    [008] .....   261.211027: padzero: to: 0x5572d019e240, size: 3520, cycles: 23850
  <...>-2537    [008] .....   261.211049: padzero: to: 0x7f1288dc9078, size: 3976, cycles: 15900
   ...

which is around 1%-ish of the total time and which is consistent with
the benchmark numbers.

So Mel gave me the idea to simply measure how fast the function becomes.
I.e.:

  start = rdtsc_ordered();
  ret = __clear_user(to, n);
  end = rdtsc_ordered();

Computing the mean average of all the samples collected during the test
suite run then shows some improvement:

  clear_user_original:
  Amean: 9219.71 (Sum: 6340154910, samples: 687674)

  fsrm:
  Amean: 8030.63 (Sum: 5522277720, samples: 687652)

That's on Zen3.

The situation looks a lot more confusing on Intel:

Icelake:

  clear_user_original:
  Amean: 19679.4 (Sum: 13652560764, samples: 693750)
  Amean: 19743.7 (Sum: 13693470604, samples: 693562)

(I ran it twice just to be sure.)

  ERMS:
  Amean: 20374.3 (Sum: 13910601024, samples: 682752)
  Amean: 20453.7 (Sum: 14186223606, samples: 693576)

  FSRM:
  Amean: 20458.2 (Sum: 13918381386, sample s: 680331)

The original microbenchmark which people were complaining about:

  for i in $(seq 1 10); do dd if=/dev/zero of=/dev/null bs=1M status=progress count=65536; done 2>&1 | grep copied
  32207011840 bytes (32 GB, 30 GiB) copied, 1 s, 32.2 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.93069 s, 35.6 GB/s
  37597741056 bytes (38 GB, 35 GiB) copied, 1 s, 37.6 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.78017 s, 38.6 GB/s
  62020124672 bytes (62 GB, 58 GiB) copied, 2 s, 31.0 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 2.13716 s, 32.2 GB/s
  60010004480 bytes (60 GB, 56 GiB) copied, 1 s, 60.0 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.14129 s, 60.2 GB/s
  53212086272 bytes (53 GB, 50 GiB) copied, 1 s, 53.2 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.28398 s, 53.5 GB/s
  55698259968 bytes (56 GB, 52 GiB) copied, 1 s, 55.7 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.22507 s, 56.1 GB/s
  55306092544 bytes (55 GB, 52 GiB) copied, 1 s, 55.3 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.23647 s, 55.6 GB/s
  54387539968 bytes (54 GB, 51 GiB) copied, 1 s, 54.4 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.25693 s, 54.7 GB/s
  50566529024 bytes (51 GB, 47 GiB) copied, 1 s, 50.6 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.35096 s, 50.9 GB/s
  58308165632 bytes (58 GB, 54 GiB) copied, 1 s, 58.3 GB/s
  68719476736 bytes (69 GB, 64 GiB) copied, 1.17394 s, 58.5 GB/s

Now the same thing with smaller buffers:

  for i in $(seq 1 10); do dd if=/dev/zero of=/dev/null bs=1M status=progress count=8192; done 2>&1 | grep copied
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.28485 s, 30.2 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.276112 s, 31.1 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.29136 s, 29.5 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.283803 s, 30.3 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.306503 s, 28.0 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.349169 s, 24.6 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.276912 s, 31.0 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.265356 s, 32.4 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.28464 s, 30.2 GB/s
  8589934592 bytes (8.6 GB, 8.0 GiB) copied, 0.242998 s, 35.3 GB/s

is also not conclusive because it all depends on the buffer sizes,
their alignments and when the microcode detects that cachelines can be
aggregated properly and copied in bigger sizes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/CAHk-=wh=Mu_EYhtOmPn6AxoQZyEh-4fo2Zx3G7rBv1g7vwoKiw@mail.gmail.com
2022-08-18 12:36:42 +02:00
Linus Torvalds aad26f55f4 This was a moderately busy cycle for documentation, but nothing all that
earth-shaking:
 
 - More Chinese translations, and an update to the Italian translations.
   The Japanese, Korean, and traditional Chinese translations are
   more-or-less unmaintained at this point, instead.
 
 - Some build-system performance improvements.
 
 - The removal of the archaic submitting-drivers.rst document, with the
   movement of what useful material that remained into other docs.
 
 - Improvements to sphinx-pre-install to, hopefully, give more useful
   suggestions.
 
 - A number of build-warning fixes
 
 Plus the usual collection of typo fixes, updates, and more.
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Merge tag 'docs-6.0' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "This was a moderately busy cycle for documentation, but nothing
  all that earth-shaking:

   - More Chinese translations, and an update to the Italian
     translations.

     The Japanese, Korean, and traditional Chinese translations
     are more-or-less unmaintained at this point, instead.

   - Some build-system performance improvements.

   - The removal of the archaic submitting-drivers.rst document,
     with the movement of what useful material that remained into
     other docs.

   - Improvements to sphinx-pre-install to, hopefully, give more
     useful suggestions.

   - A number of build-warning fixes

  Plus the usual collection of typo fixes, updates, and more"

* tag 'docs-6.0' of git://git.lwn.net/linux: (92 commits)
  docs: efi-stub: Fix paths for x86 / arm stubs
  Docs/zh_CN: Update the translation of sched-stats to 5.19-rc8
  Docs/zh_CN: Update the translation of pci to 5.19-rc8
  Docs/zh_CN: Update the translation of pci-iov-howto to 5.19-rc8
  Docs/zh_CN: Update the translation of usage to 5.19-rc8
  Docs/zh_CN: Update the translation of testing-overview to 5.19-rc8
  Docs/zh_CN: Update the translation of sparse to 5.19-rc8
  Docs/zh_CN: Update the translation of kasan to 5.19-rc8
  Docs/zh_CN: Update the translation of iio_configfs to 5.19-rc8
  doc:it_IT: align Italian documentation
  docs: Remove spurious tag from admin-guide/mm/overcommit-accounting.rst
  Documentation: process: Update email client instructions for Thunderbird
  docs: ABI: correct QEMU fw_cfg spec path
  doc/zh_CN: remove submitting-driver reference from docs
  docs: zh_TW: align to submitting-drivers removal
  docs: zh_CN: align to submitting-drivers removal
  docs: ko_KR: howto: remove reference to removed submitting-drivers
  docs: ja_JP: howto: remove reference to removed submitting-drivers
  docs: it_IT: align to submitting-drivers removal
  docs: process: remove outdated submitting-drivers.rst
  ...
2022-08-02 19:24:24 -07:00
Linus Torvalds ce114c8668 Just when you thought that all the speculation bugs were addressed and
solved and the nightmare is complete, here's the next one: speculating
 after RET instructions and leaking privileged information using the now
 pretty much classical covert channels.
 
 It is called RETBleed and the mitigation effort and controlling
 functionality has been modelled similar to what already existing
 mitigations provide.
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Merge tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 retbleed fixes from Borislav Petkov:
 "Just when you thought that all the speculation bugs were addressed and
  solved and the nightmare is complete, here's the next one: speculating
  after RET instructions and leaking privileged information using the
  now pretty much classical covert channels.

  It is called RETBleed and the mitigation effort and controlling
  functionality has been modelled similar to what already existing
  mitigations provide"

* tag 'x86_bugs_retbleed' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
  x86/speculation: Disable RRSBA behavior
  x86/kexec: Disable RET on kexec
  x86/bugs: Do not enable IBPB-on-entry when IBPB is not supported
  x86/entry: Move PUSH_AND_CLEAR_REGS() back into error_entry
  x86/bugs: Add Cannon lake to RETBleed affected CPU list
  x86/retbleed: Add fine grained Kconfig knobs
  x86/cpu/amd: Enumerate BTC_NO
  x86/common: Stamp out the stepping madness
  KVM: VMX: Prevent RSB underflow before vmenter
  x86/speculation: Fill RSB on vmexit for IBRS
  KVM: VMX: Fix IBRS handling after vmexit
  KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS
  KVM: VMX: Convert launched argument to flags
  KVM: VMX: Flatten __vmx_vcpu_run()
  objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}
  x86/speculation: Remove x86_spec_ctrl_mask
  x86/speculation: Use cached host SPEC_CTRL value for guest entry/exit
  x86/speculation: Fix SPEC_CTRL write on SMT state change
  x86/speculation: Fix firmware entry SPEC_CTRL handling
  x86/speculation: Fix RSB filling with CONFIG_RETPOLINE=n
  ...
2022-07-11 18:15:25 -07:00
Mauro Carvalho Chehab d6a21f2d73 objtool: update objtool.txt references
Changeset a8e35fece4 ("objtool: Update documentation")
renamed: tools/objtool/Documentation/stack-validation.txt
to: tools/objtool/Documentation/objtool.txt.

Update the cross-references accordingly.

Fixes: a8e35fece4 ("objtool: Update documentation")
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/ec285ece6348a5be191aebe45f78d06b3319056b.1656234456.git.mchehab@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-07-07 13:10:00 -06:00
Peter Zijlstra 38e0e4d04d x86/ibt, objtool: Don't discard text references from tracepoint section
On Tue, Jun 28, 2022 at 04:28:58PM +0800, Pengfei Xu wrote:

> # ./ftracetest
> === Ftrace unit tests ===
> [1] Basic trace file check      [PASS]
> [2] Basic test for tracers      [PASS]
> [3] Basic trace clock test      [PASS]
> [4] Basic event tracing check   [PASS]
> [5] Change the ringbuffer size  [PASS]
> [6] Snapshot and tracing setting        [PASS]
> [7] trace_pipe and trace_marker [PASS]
> [8] Test ftrace direct functions against tracers        [UNRESOLVED]
> [9] Test ftrace direct functions against kprobes        [UNRESOLVED]
> [10] Generic dynamic event - add/remove eprobe events   [FAIL]
> [11] Generic dynamic event - add/remove kprobe events
>
> It 100% reproduced in step 11 and then missing ENDBR BUG generated:
> "
> [ 9332.752836] mmiotrace: enabled CPU7.
> [ 9332.788612] mmiotrace: disabled.
> [ 9337.103426] traps: Missing ENDBR: syscall_regfunc+0x0/0xb0

It turns out that while syscall_regfunc() does have an ENDBR when
generated, it gets sealed by objtool's .ibt_endbr_seal list.

Since the only text references to this function:

  $ git grep syscall_regfunc
  include/linux/tracepoint.h:extern int syscall_regfunc(void);
  include/trace/events/syscalls.h:        syscall_regfunc, syscall_unregfunc
  include/trace/events/syscalls.h:        syscall_regfunc, syscall_unregfunc
  kernel/tracepoint.c:int syscall_regfunc(void)

appear in the __tracepoint section which is excluded by objtool.

Fixes: 3c6f9f77e6 ("objtool: Rework ibt and extricate from stack validation")
Reported-by: Pengfei Xu <pengfei.xu@intel.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yrrepdaow4F5kqG0@hirez.programming.kicks-ass.net
2022-07-07 13:26:54 +02:00
Peter Zijlstra f43b9876e8 x86/retbleed: Add fine grained Kconfig knobs
Do fine-grained Kconfig for all the various retbleed parts.

NOTE: if your compiler doesn't support return thunks this will
silently 'upgrade' your mitigation to IBPB, you might not like this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-29 17:43:41 +02:00
Josh Poimboeuf 8faea26e61 objtool: Re-add UNWIND_HINT_{SAVE_RESTORE}
Commit

  c536ed2fff ("objtool: Remove SAVE/RESTORE hints")

removed the save/restore unwind hints because they were no longer
needed. Now they're going to be needed again so re-add them.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27 10:34:00 +02:00
Peter Zijlstra a09a6e2399 objtool: Add entry UNRET validation
Since entry asm is tricky, add a validation pass that ensures the
retbleed mitigation has been done before the first actual RET
instruction.

Entry points are those that either have UNWIND_HINT_ENTRY, which acts
as UNWIND_HINT_EMPTY but marks the instruction as an entry point, or
those that have UWIND_HINT_IRET_REGS at +0.

This is basically a variant of validate_branch() that is
intra-function and it will simply follow all branches from marked
entry points and ensures that all paths lead to ANNOTATE_UNRET_END.

If a path hits RET or an indirection the path is a fail and will be
reported.

There are 3 ANNOTATE_UNRET_END instances:

 - UNTRAIN_RET itself
 - exception from-kernel; this path doesn't need UNTRAIN_RET
 - all early exceptions; these also don't need UNTRAIN_RET

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27 10:34:00 +02:00
Peter Zijlstra 9bb2ec608a objtool: Update Retpoline validation
Update retpoline validation with the new CONFIG_RETPOLINE requirement of
not having bare naked RET instructions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27 10:33:59 +02:00
Peter Zijlstra a149180fbc x86: Add magic AMD return-thunk
Note: needs to be in a section distinct from Retpolines such that the
Retpoline RET substitution cannot possibly use immediate jumps.

ORC unwinding for zen_untrain_ret() and __x86_return_thunk() is a
little tricky but works due to the fact that zen_untrain_ret() doesn't
have any stack ops and as such will emit a single ORC entry at the
start (+0x3f).

Meanwhile, unwinding an IP, including the __x86_return_thunk() one
(+0x40) will search for the largest ORC entry smaller or equal to the
IP, these will find the one ORC entry (+0x3f) and all works.

  [ Alexandre: SVM part. ]
  [ bp: Build fix, massages. ]

Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27 10:33:59 +02:00
Peter Zijlstra 951ddecf43 objtool: Treat .text.__x86.* as noinstr
Needed because zen_untrain_ret() will be called from noinstr code.

Also makes sense since the thunks MUST NOT contain instrumentation nor
be poked with dynamic instrumentation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27 10:33:59 +02:00
Peter Zijlstra d9e9d23006 x86,objtool: Create .return_sites
Find all the return-thunk sites and record them in a .return_sites
section such that the kernel can undo this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27 10:33:58 +02:00
Borislav Petkov 2028a255f4 x86/extable: Annotate ex_handler_msr_mce() as a dead end
Fix

  vmlinux.o: warning: objtool: fixup_exception+0x2d6: unreachable instruction

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220520192729.23969-1-bp@alien8.de
2022-05-27 12:34:45 +02:00
Peter Zijlstra 385bd430c0 objtool: Mark __ubsan_handle_builtin_unreachable() as noreturn
fs/ntfs3/ntfs3.prelink.o: warning: objtool: ni_read_frame() falls through to next function ni_readpage_cmpr.cold()

That is in fact:

000000000000124a <ni_read_frame.cold>:
    124a:       44 89 e0                mov    %r12d,%eax
    124d:       0f b6 55 98             movzbl -0x68(%rbp),%edx
    1251:       48 c7 c7 00 00 00 00    mov    $0x0,%rdi        1254: R_X86_64_32S      .data+0x1380
    1258:       48 89 c6                mov    %rax,%rsi
    125b:       e8 00 00 00 00          call   1260 <ni_read_frame.cold+0x16>   125c: R_X86_64_PLT32    __ubsan_handle_shift_out_of_bounds-0x4
    1260:       48 8d 7d cc             lea    -0x34(%rbp),%rdi
    1264:       e8 00 00 00 00          call   1269 <ni_read_frame.cold+0x1f>   1265: R_X86_64_PLT32    __tsan_read4-0x4
    1269:       8b 45 cc                mov    -0x34(%rbp),%eax
    126c:       e9 00 00 00 00          jmp    1271 <ni_read_frame.cold+0x27>   126d: R_X86_64_PC32     .text+0x19109
    1271:       48 8b 75 a0             mov    -0x60(%rbp),%rsi
    1275:       48 63 d0                movslq %eax,%rdx
    1278:       48 c7 c7 00 00 00 00    mov    $0x0,%rdi        127b: R_X86_64_32S      .data+0x13a0
    127f:       89 45 88                mov    %eax,-0x78(%rbp)
    1282:       e8 00 00 00 00          call   1287 <ni_read_frame.cold+0x3d>   1283: R_X86_64_PLT32    __ubsan_handle_shift_out_of_bounds-0x4
    1287:       8b 45 88                mov    -0x78(%rbp),%eax
    128a:       e9 00 00 00 00          jmp    128f <ni_read_frame.cold+0x45>   128b: R_X86_64_PC32     .text+0x19098
    128f:       48 c7 c7 00 00 00 00    mov    $0x0,%rdi        1292: R_X86_64_32S      .data+0x11f0
    1296:       e8 00 00 00 00          call   129b <ni_readpage_cmpr.cold>     1297: R_X86_64_PLT32    __ubsan_handle_builtin_unreachable-0x4

000000000000129b <ni_readpage_cmpr.cold>:

Tell objtool that __ubsan_handle_builtin_unreachable() is a noreturn.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220502091514.GB479834@worktop.programming.kicks-ass.net
2022-05-27 12:34:43 +02:00
Mikulas Patocka 22682a07ac objtool: Fix objtool regression on x32 systems
Commit c087c6e7b5 ("objtool: Fix type of reloc::addend") failed to
appreciate cross building from ILP32 hosts, where 'int' == 'long' and
the issue persists.

As such, use s64/int64_t/Elf64_Sxword for this field and suffer the
pain that is ISO C99 printf formats for it.

Fixes: c087c6e7b5 ("objtool: Fix type of reloc::addend")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
[peterz: reword changelog, s/long long/s64/]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/alpine.LRH.2.02.2205161041260.11556@file01.intranet.prod.int.rdu2.redhat.com
2022-05-20 12:45:30 +02:00
Josh Poimboeuf 753da4179d objtool: Remove --lto and --vmlinux in favor of --link
The '--lto' option is a confusing way of telling objtool to do stack
validation despite it being a linked object.  It's no longer needed now
that an explicit '--stackval' option exists.  The '--vmlinux' option is
also redundant.

Remove both options in favor of a straightforward '--link' option which
identifies a linked object.

Also, implicitly set '--link' with a warning if the user forgets to do
so and we can tell that it's a linked object.  This makes it easier for
manual vmlinux runs.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/dcd3ceffd15a54822c6183e5766d21ad06082b45.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:05 +02:00
Josh Poimboeuf 22102f4559 objtool: Make noinstr hacks optional
Objtool has some hacks in place to workaround toolchain limitations
which otherwise would break no-instrumentation rules.  Make the hacks
explicit (and optional for other arches) by turning it into a cmdline
option and kernel config option.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/b326eeb9c33231b9dfbb925f194ed7ee40edcd7c.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:04 +02:00
Josh Poimboeuf 4ab7674f59 objtool: Make jump label hack optional
Objtool secretly does a jump label hack to overcome the limitations of
the toolchain.  Make the hack explicit (and optional for other arches)
by turning it into a cmdline option and kernel config option.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/3bdcbfdd27ecb01ddec13c04bdf756a583b13d24.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:04 +02:00
Josh Poimboeuf 26e176896a objtool: Make static call annotation optional
As part of making objtool more modular, put the existing static call
code behind a new '--static-call' option.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/d59ac57ef3d6d8380cdce20322314c9e2e556750.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:03 +02:00
Josh Poimboeuf 7206447496 objtool: Make stack validation frame-pointer-specific
Now that CONFIG_STACK_VALIDATION is frame-pointer specific, do the same
for the '--stackval' option.  Now the '--no-fp' option is redundant and
can be removed.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/f563fa064b3b63d528de250c72012d49e14742a3.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:03 +02:00
Josh Poimboeuf c2bdd61c98 objtool: Extricate sls from stack validation
Extricate sls functionality from validate_branch() so they can be
executed (or ported) independently from each other.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/2545c86ffa5f27497f0d0c542540ad4a4be3c5a5.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:03 +02:00
Josh Poimboeuf 3c6f9f77e6 objtool: Rework ibt and extricate from stack validation
Extricate ibt from validate_branch() so they can be executed (or ported)
independently from each other.

While shuffling code around, simplify and improve the ibt logic:

- Ignore an explicit list of known sections which reference functions
  for reasons other than indirect branching to them.  This helps prevent
  unnnecesary sealing.

- Warn on missing !ENDBR for all other sections, not just .data and
  .rodata.  This finds additional warnings, because there are sections
  other than .[ro]data which reference function pointers.  For example,
  the ksymtab sections which are used for exporting symbols.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/fd1435e46bb95f81031b8fb1fa360f5f787e4316.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:02 +02:00
Josh Poimboeuf 7dce62041a objtool: Make stack validation optional
Make stack validation an explicit cmdline option so that individual
objtool features can be enabled individually by other arches.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/52da143699574d756e65ca4c9d4acaffe9b0fe5f.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:02 +02:00
Josh Poimboeuf b51277eb97 objtool: Ditch subcommands
Objtool has a fairly singular focus.  It runs on object files and does
validations and transformations which can be combined in various ways.
The subcommand model has never been a good fit, making it awkward to
combine and remove options.

Remove the "check" and "orc" subcommands in favor of a more traditional
cmdline option model.  This makes it much more flexible to use, and
easier to port individual features to other arches.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/5c61ebf805e90aefc5fa62bc63468ffae53b9df6.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:01 +02:00
Josh Poimboeuf 2daf7faba7 objtool: Reorganize cmdline options
Split the existing options into two groups: actions, which actually do
something; and options, which modify the actions in some way.

Also there's no need to have short flags for all the non-action options.
Reserve short flags for the more important actions.

While at it:

- change a few of the short flags to be more intuitive

- make option descriptions more consistently descriptive

- sort options in the source like they are when printed

- move options to a global struct

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/9dcaa752f83aca24b1b21f0b0eeb28a0c181c0b0.1650300597.git.jpoimboe@redhat.com
2022-04-22 12:32:01 +02:00
Peter Zijlstra 3398b12d10 Merge branch 'tip/x86/urgent'
Merge the x86/urgent objtool/IBT changes as a base

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-04-22 12:32:01 +02:00
Peter Zijlstra c087c6e7b5 objtool: Fix type of reloc::addend
Elf{32,64}_Rela::r_addend is of type: Elf{32,64}_Sword, that means
that our reloc::addend needs to be long or face tuncation issues when
we do elf_rebuild_reloc_section():

  - 107:  48 b8 00 00 00 00 00 00 00 00   movabs $0x0,%rax        109: R_X86_64_64        level4_kernel_pgt+0x80000067
  + 107:  48 b8 00 00 00 00 00 00 00 00   movabs $0x0,%rax        109: R_X86_64_64        level4_kernel_pgt-0x7fffff99

Fixes: 627fce1480 ("objtool: Add ORC unwind table generation")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20220419203807.596871927@infradead.org
2022-04-22 12:13:55 +02:00
Josh Poimboeuf 08feafe8d1 objtool: Fix function fallthrough detection for vmlinux
Objtool's function fallthrough detection only works on C objects.
The distinction between C and assembly objects no longer makes sense
with objtool running on vmlinux.o.

Now that copy_user_64.S has been fixed up, and an objtool sibling call
detection bug has been fixed, the asm code is in "compliance" and this
hack is no longer needed.  Remove it.

Fixes: ed53a0d971 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/b434cff98eca3a60dcc64c620d7d5d405a0f441c.1649718562.git.jpoimboe@redhat.com
2022-04-19 21:58:53 +02:00
Josh Poimboeuf 34c861e806 objtool: Fix sibling call detection in alternatives
In add_jump_destinations(), sibling call detection requires 'insn->func'
to be valid.  But alternative instructions get their 'func' set in
handle_group_alt(), which runs *after* add_jump_destinations().  So
sibling calls in alternatives code don't get properly detected.

Fix that by changing the initialization order: call
add_special_section_alts() *before* add_jump_destinations().

This also means the special case for a missing 'jump_dest' in
add_jump_destinations() can be removed, as it has already been dealt
with.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/c02e0a0a2a4286b5f848d17c77fdcb7e0caf709c.1649718562.git.jpoimboe@redhat.com
2022-04-19 21:58:53 +02:00
Josh Poimboeuf 26ff604102 objtool: Don't set 'jump_dest' for sibling calls
For most sibling calls, 'jump_dest' is NULL because objtool treats the
jump like a call and sets 'call_dest'.  But there are a few edge cases
where that's not true.  Make it consistent to avoid unexpected behavior.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/8737d6b9d1691831aed73375f444f0f42da3e2c9.1649718562.git.jpoimboe@redhat.com
2022-04-19 21:58:53 +02:00
Josh Poimboeuf 1d08b92fa2 objtool: Use offstr() to print address of missing ENDBR
Fixes: 89bc853eae ("objtool: Find unused ENDBR instructions")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/95d12e800c736a3f7d08d61dabb760b2d5251a8e.1650300597.git.jpoimboe@redhat.com
2022-04-19 21:58:50 +02:00
Josh Poimboeuf 4baae989e6 objtool: Print data address for "!ENDBR" data warnings
When a "!ENDBR" warning is reported for a data section, objtool just
prints the text address of the relocation target twice, without giving
any clues about the location of the original data reference:

  vmlinux.o: warning: objtool: dcbnl_netdevice_event()+0x0: .text+0xb64680: data relocation to !ENDBR: dcbnl_netdevice_event+0x0

Instead, print the address of the data reference, in addition to the
address of the relocation target.

  vmlinux.o: warning: objtool: dcbnl_nb+0x0: .data..read_mostly+0xe260: data relocation to !ENDBR: dcbnl_netdevice_event+0x0

Fixes: 89bc853eae ("objtool: Find unused ENDBR instructions")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/762e88d51300e8eaf0f933a5b0feae20ac033bea.1650300597.git.jpoimboe@redhat.com
2022-04-19 21:58:50 +02:00
Peter Zijlstra d4e5268a08 x86,objtool: Mark cpu_startup_entry() __noreturn
GCC-8 isn't clever enough to figure out that cpu_start_entry() is a
noreturn while objtool is. This results in code after the call in
start_secondary(). Give GCC a hand so that they all agree on things.

  vmlinux.o: warning: objtool: start_secondary()+0x10e: unreachable

Reported-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220408094718.383658532@infradead.org
2022-04-19 21:58:48 +02:00
Peter Zijlstra 7a53f40890 objtool: Fix SLS validation for kcov tail-call replacement
Since not all compilers have a function attribute to disable KCOV
instrumentation, objtool can rewrite KCOV instrumentation in noinstr
functions as per commit:

  f56dae88a8 ("objtool: Handle __sanitize_cov*() tail calls")

However, this has subtle interaction with the SLS validation from
commit:

  1cc1e4c8aa ("objtool: Add straight-line-speculation validation")

In that when a tail-call instrucion is replaced with a RET an
additional INT3 instruction is also written, but is not represented in
the decoded instruction stream.

This then leads to false positive missing INT3 objtool warnings in
noinstr code.

Instead of adding additional struct instruction objects, mark the RET
instruction with retpoline_safe to suppress the warning (since we know
there really is an INT3).

Fixes: 1cc1e4c8aa ("objtool: Add straight-line-speculation validation")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220323230712.GA8939@worktop.programming.kicks-ass.net
2022-04-05 10:24:40 +02:00
Peter Zijlstra d139bca4b8 objtool: Fix IBT tail-call detection
Objtool reports:

  arch/x86/crypto/poly1305-x86_64.o: warning: objtool: poly1305_blocks_avx() falls through to next function poly1305_blocks_x86_64()
  arch/x86/crypto/poly1305-x86_64.o: warning: objtool: poly1305_emit_avx() falls through to next function poly1305_emit_x86_64()
  arch/x86/crypto/poly1305-x86_64.o: warning: objtool: poly1305_blocks_avx2() falls through to next function poly1305_blocks_x86_64()

Which reads like:

0000000000000040 <poly1305_blocks_x86_64>:
	 40:       f3 0f 1e fa             endbr64
	...

0000000000000400 <poly1305_blocks_avx>:
	400:       f3 0f 1e fa             endbr64
	404:       44 8b 47 14             mov    0x14(%rdi),%r8d
	408:       48 81 fa 80 00 00 00    cmp    $0x80,%rdx
	40f:       73 09                   jae    41a <poly1305_blocks_avx+0x1a>
	411:       45 85 c0                test   %r8d,%r8d
	414:       0f 84 2a fc ff ff       je     44 <poly1305_blocks_x86_64+0x4>
	...

These are simple conditional tail-calls and *should* be recognised as
such by objtool, however due to a mistake in commit 08f87a93c8
("objtool: Validate IBT assumptions") this is failing.

Specifically, the jump_dest is +4, this means the instruction pointed
at will not be ENDBR and as such it will fail the second clause of
is_first_func_insn() that was supposed to capture this exact case.

Instead, have is_first_func_insn() look at the previous instruction.

Fixes: 08f87a93c8 ("objtool: Validate IBT assumptions")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220322115125.811582125@infradead.org
2022-04-05 10:24:40 +02:00
Peter Zijlstra 89bc853eae objtool: Find unused ENDBR instructions
Find all ENDBR instructions which are never referenced and stick them
in a section such that the kernel can poison them, sealing the
functions from ever being an indirect call target.

This removes about 1-in-4 ENDBR instructions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.763643193@infradead.org
2022-03-15 10:32:47 +01:00
Peter Zijlstra 08f87a93c8 objtool: Validate IBT assumptions
Intel IBT requires that every indirect JMP/CALL targets an ENDBR
instructions, failing this #CP happens and we die. Similarly, all
exception entries should be ENDBR.

Find all code relocations and ensure they're either an ENDBR
instruction or ANNOTATE_NOENDBR. For the exceptions look for
UNWIND_HINT_IRET_REGS at sym+0 not being ENDBR.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.705110141@infradead.org
2022-03-15 10:32:46 +01:00
Peter Zijlstra 96db4a988d objtool: Read the NOENDBR annotation
Read the new NOENDBR annotation. While there, attempt to not bloat
struct instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.586815435@infradead.org
2022-03-15 10:32:46 +01:00
Peter Zijlstra 0e5b613b4d objtool: Rework ASM_REACHABLE
Currently ASM_REACHABLE only works for UD2 instructions; reorder
things to also allow over-riding dead_end_function().

To that end:

 - Mark INSN_BUG instructions in decode_instructions(), this saves
   having to iterate all instructions yet again.

 - Have add_call_destinations() set insn->dead_end for
   dead_end_function() calls.

 - Move add_dead_ends() *after* add_call_destinations() such that
   ASM_REACHABLE can clear the ->dead_end mark.

 - have validate_branch() only check ->dead_end.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.410010807@infradead.org
2022-03-15 10:32:44 +01:00
Peter Zijlstra 105cd68596 x86: Mark __invalid_creds() __noreturn
vmlinux.o: warning: objtool: ksys_unshare()+0x36c: unreachable instruction

0000 0000000000067040 <ksys_unshare>:
...
0364    673a4:	4c 89 ef             	mov    %r13,%rdi
0367    673a7:	e8 00 00 00 00       	call   673ac <ksys_unshare+0x36c>	673a8: R_X86_64_PLT32	__invalid_creds-0x4
036c    673ac:	e9 28 ff ff ff       	jmp    672d9 <ksys_unshare+0x299>
0371    673b1:	41 bc f4 ff ff ff    	mov    $0xfffffff4,%r12d
0377    673b7:	e9 80 fd ff ff       	jmp    6713c <ksys_unshare+0xfc>

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Yi9gOW9f1GGwwUD6@hirez.programming.kicks-ass.net
2022-03-15 10:32:44 +01:00
Peter Zijlstra eae654f1c2 exit: Mark do_group_exit() __noreturn
vmlinux.o: warning: objtool: get_signal()+0x108: unreachable instruction

0000 000000000007f930 <get_signal>:
...
0103    7fa33:  e8 00 00 00 00          call   7fa38 <get_signal+0x108> 7fa34: R_X86_64_PLT32   do_group_exit-0x4
0108    7fa38:  41 8b 45 74             mov    0x74(%r13),%eax

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.351270711@infradead.org
2022-03-15 10:32:43 +01:00
Peter Zijlstra f9cdf7ca57 x86: Mark stop_this_cpu() __noreturn
vmlinux.o: warning: objtool: smp_stop_nmi_callback()+0x2b: unreachable instruction

0000 0000000000047cf0 <smp_stop_nmi_callback>:
...
0026    47d16:  e8 00 00 00 00          call   47d1b <smp_stop_nmi_callback+0x2b>       47d17: R_X86_64_PLT32   stop_this_cpu-0x4
002b    47d1b:  b8 01 00 00 00          mov    $0x1,%eax

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.290905453@infradead.org
2022-03-15 10:32:43 +01:00
Peter Zijlstra 4adb236867 objtool: Ignore extra-symbol code
There's a fun implementation detail on linking STB_WEAK symbols. When
the linker combines two translation units, where one contains a weak
function and the other an override for it. It simply strips the
STB_WEAK symbol from the symbol table, but doesn't actually remove the
code.

The result is that when objtool is ran in a whole-archive kind of way,
it will encounter *heaps* of unused (and unreferenced) code. All
rudiments of weak functions.

Additionally, when a weak implementation is split into a .cold
subfunction that .cold symbol is left in place, even though completely
unused.

Teach objtool to ignore such rudiments by searching for symbol holes;
that is, code ranges that fall outside the given symbol bounds.
Specifically, ignore a sequence of unreachable instruction iff they
occupy a single hole, additionally ignore any .cold subfunctions
referenced.

Both ld.bfd and ld.lld behave like this. LTO builds otoh can (and do)
properly DCE weak functions.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.232019347@infradead.org
2022-03-15 10:32:43 +01:00
Peter Zijlstra 53f7109ef9 objtool: Rename --duplicate to --lto
In order to prepare for LTO like objtool runs for modules, rename the
duplicate argument to lto.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154319.172584233@infradead.org
2022-03-15 10:32:42 +01:00
Peter Zijlstra 1ffbe4e935 objtool: Default ignore INT3 for unreachable
Ignore all INT3 instructions for unreachable code warnings, similar to NOP.
This allows using INT3 for various paddings instead of NOPs.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.343312938@infradead.org
2022-03-15 10:32:32 +01:00
Sergei Trofimovich 82880283d7 objtool: Fix truncated string warning
On GCC 12, the build fails due to a possible truncated string:

    check.c: In function 'validate_call':
    check.c:2865:58: error: '%d' directive output may be truncated writing between 1 and 10 bytes into a region of size 9 [-Werror=format-truncation=]
     2865 |                 snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx);
          |                                                          ^~

In theory it's a valid bug:

    static char pvname[16];
    int idx;
    ...
    idx = (rel->addend / sizeof(void *));
    snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx);

There are only 7 chars for %d while it could take up to 9, so the
printed "pv_ops[%d]" string could get truncated.

In reality the bug should never happen, because pv_ops only has ~80
entries, so 7 chars for the integer is more than enough.  Still, it's
worth fixing.  Bump the buffer size by 2 bytes to silence the warning.

[ jpoimboe: changed size to 19; massaged changelog ]

Fixes: db2b0c5d7b ("objtool: Support pv_opsindirect calls for noinstr")
Reported-by: Adam Borowski <kilobyte@angband.pl>
Reported-by: Martin Liška <mliska@suse.cz>
Signed-off-by: Sergei Trofimovich <slyich@gmail.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220120233748.2062559-1-slyich@gmail.com
2022-01-24 10:09:06 -08:00
Linus Torvalds 35ce8ae9ae Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull signal/exit/ptrace updates from Eric Biederman:
 "This set of changes deletes some dead code, makes a lot of cleanups
  which hopefully make the code easier to follow, and fixes bugs found
  along the way.

  The end-game which I have not yet reached yet is for fatal signals
  that generate coredumps to be short-circuit deliverable from
  complete_signal, for force_siginfo_to_task not to require changing
  userspace configured signal delivery state, and for the ptrace stops
  to always happen in locations where we can guarantee on all
  architectures that the all of the registers are saved and available on
  the stack.

  Removal of profile_task_ext, profile_munmap, and profile_handoff_task
  are the big successes for dead code removal this round.

  A bunch of small bug fixes are included, as most of the issues
  reported were small enough that they would not affect bisection so I
  simply added the fixes and did not fold the fixes into the changes
  they were fixing.

  There was a bug that broke coredumps piped to systemd-coredump. I
  dropped the change that caused that bug and replaced it entirely with
  something much more restrained. Unfortunately that required some
  rebasing.

  Some successes after this set of changes: There are few enough calls
  to do_exit to audit in a reasonable amount of time. The lifetime of
  struct kthread now matches the lifetime of struct task, and the
  pointer to struct kthread is no longer stored in set_child_tid. The
  flag SIGNAL_GROUP_COREDUMP is removed. The field group_exit_task is
  removed. Issues where task->exit_code was examined with
  signal->group_exit_code should been examined were fixed.

  There are several loosely related changes included because I am
  cleaning up and if I don't include them they will probably get lost.

  The original postings of these changes can be found at:
     https://lkml.kernel.org/r/87a6ha4zsd.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87bl1kunjj.fsf@email.froward.int.ebiederm.org
     https://lkml.kernel.org/r/87r19opkx1.fsf_-_@email.froward.int.ebiederm.org

  I trimmed back the last set of changes to only the obviously correct
  once. Simply because there was less time for review than I had hoped"

* 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (44 commits)
  ptrace/m68k: Stop open coding ptrace_report_syscall
  ptrace: Remove unused regs argument from ptrace_report_syscall
  ptrace: Remove second setting of PT_SEIZED in ptrace_attach
  taskstats: Cleanup the use of task->exit_code
  exit: Use the correct exit_code in /proc/<pid>/stat
  exit: Fix the exit_code for wait_task_zombie
  exit: Coredumps reach do_group_exit
  exit: Remove profile_handoff_task
  exit: Remove profile_task_exit & profile_munmap
  signal: clean up kernel-doc comments
  signal: Remove the helper signal_group_exit
  signal: Rename group_exit_task group_exec_task
  coredump: Stop setting signal->group_exit_task
  signal: Remove SIGNAL_GROUP_COREDUMP
  signal: During coredumps set SIGNAL_GROUP_EXIT in zap_process
  signal: Make coredump handling explicit in complete_signal
  signal: Have prepare_signal detect coredumps using signal->core_state
  signal: Have the oom killer detect coredumps using signal->core_state
  exit: Move force_uaccess back into do_exit
  exit: Guarantee make_task_dead leaks the tsk when calling do_task_exit
  ...
2022-01-17 05:49:30 +02:00
Linus Torvalds 64ad946152 - Get rid of all the .fixup sections because this generates
misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
 LIVEPATCH as the backtrace misses the function which is being fixed up.
 
 - Add Straight Light Speculation mitigation support which uses a new
 compiler switch -mharden-sls= which sticks an INT3 after a RET or an
 indirect branch in order to block speculation after them. Reportedly,
 CPUs do speculate behind such insns.
 
 - The usual set of cleanups and improvements
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Merge tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 core updates from Borislav Petkov:

 - Get rid of all the .fixup sections because this generates
   misleading/wrong stacktraces and confuse RELIABLE_STACKTRACE and
   LIVEPATCH as the backtrace misses the function which is being fixed
   up.

 - Add Straight Line Speculation mitigation support which uses a new
   compiler switch -mharden-sls= which sticks an INT3 after a RET or an
   indirect branch in order to block speculation after them. Reportedly,
   CPUs do speculate behind such insns.

 - The usual set of cleanups and improvements

* tag 'x86_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/entry_32: Fix segment exceptions
  objtool: Remove .fixup handling
  x86: Remove .fixup section
  x86/word-at-a-time: Remove .fixup usage
  x86/usercopy: Remove .fixup usage
  x86/usercopy_32: Simplify __copy_user_intel_nocache()
  x86/sgx: Remove .fixup usage
  x86/checksum_32: Remove .fixup usage
  x86/vmx: Remove .fixup usage
  x86/kvm: Remove .fixup usage
  x86/segment: Remove .fixup usage
  x86/fpu: Remove .fixup usage
  x86/xen: Remove .fixup usage
  x86/uaccess: Remove .fixup usage
  x86/futex: Remove .fixup usage
  x86/msr: Remove .fixup usage
  x86/extable: Extend extable functionality
  x86/entry_32: Remove .fixup usage
  x86/entry_64: Remove .fixup usage
  x86/copy_mc_64: Remove .fixup usage
  ...
2022-01-12 16:31:19 -08:00
Eric W. Biederman 1fb466dff9 objtool: Add a missing comma to avoid string concatenation
Recently the kbuild robot reported two new errors:

>> lib/kunit/kunit-example-test.o: warning: objtool: .text.unlikely: unexpected end of section
>> arch/x86/kernel/dumpstack.o: warning: objtool: oops_end() falls through to next function show_opcodes()

I don't know why they did not occur in my test setup but after digging
it I realized I had accidentally dropped a comma in
tools/objtool/check.c when I renamed rewind_stack_do_exit to
rewind_stack_and_make_dead.

Add that comma back to fix objtool errors.

Link: https://lkml.kernel.org/r/202112140949.Uq5sFKR1-lkp@intel.com
Fixes: 0e25498f8c ("exit: Add and use make_task_dead.")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-15 11:33:22 -06:00
Eric W. Biederman cead185526 exit: Rename complete_and_exit to kthread_complete_and_exit
Update complete_and_exit to call kthread_exit instead of do_exit.

Change the name to reflect this change in functionality.  All of the
users of complete_and_exit are causing the current kthread to exit so
this change makes it clear what is happening.

Move the implementation of kthread_complete_and_exit from
kernel/exit.c to to kernel/kthread.c.  As this function is kthread
specific it makes most sense to live with the kthread functions.

There are no functional change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman ca3574bd65 exit: Rename module_put_and_exit to module_put_and_kthread_exit
Update module_put_and_exit to call kthread_exit instead of do_exit.

Change the name to reflect this change in functionality.  All of the
users of module_put_and_exit are causing the current kthread to exit
so this change makes it clear what is happening.  There is no
functional change.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman bbda86e988 exit: Implement kthread_exit
The way the per task_struct exit_code is used by kernel threads is not
quite compatible how it is used by userspace applications.  The low
byte of the userspace exit_code value encodes the exit signal.  While
kthreads just use the value as an int holding ordinary kernel function
exit status like -EPERM.

Add kthread_exit to clearly separate the two kinds of uses.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Eric W. Biederman 0e25498f8c exit: Add and use make_task_dead.
There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
Peter Zijlstra 82a8954acd objtool: Remove .fixup handling
The .fixup has gone the way of the Dodo, that test will always be
false.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101326.261496792@infradead.org
2021-12-11 09:09:51 +01:00
Marco Elver 0509811952 objtool, kcsan: Remove memory barrier instrumentation from noinstr
Teach objtool to turn instrumentation required for memory barrier
modeling into nops in noinstr text.

The __tsan_func_entry/exit calls are still emitted by compilers even
with the __no_sanitize_thread attribute. The memory barrier
instrumentation will be inserted explicitly (without compiler help), and
thus needs to also explicitly be removed.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:28 -08:00
Marco Elver 0525bd82f6 objtool, kcsan: Add memory barrier instrumentation to whitelist
Adds KCSAN's memory barrier instrumentation to objtool's uaccess
whitelist.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-12-09 16:42:28 -08:00
Peter Zijlstra 1cc1e4c8aa objtool: Add straight-line-speculation validation
Teach objtool to validate the straight-line-speculation constraints:

 - speculation trap after indirect calls
 - speculation trap after RET

Notable: when an instruction is annotated RETPOLINE_SAFE, indicating
  speculation isn't a problem, also don't care about sls for that
  instruction.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134908.023037659@infradead.org
2021-12-08 19:26:50 +01:00
Peter Zijlstra 2105a92748 static_call,x86: Robustify trampoline patching
Add a few signature bytes after the static call trampoline and verify
those bytes match before patching the trampoline. This avoids patching
random other JMPs (such as CFI jump-table entries) instead.

These bytes decode as:

   d:   53                      push   %rbx
   e:   43 54                   rex.XB push %r12

And happen to spell "SCT".

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211030074758.GT174703@worktop.programming.kicks-ass.net
2021-11-11 13:09:31 +01:00
Linus Torvalds 79ef0c0014 Tracing updates for 5.16:
- kprobes: Restructured stack unwinder to show properly on x86 when a stack
   dump happens from a kretprobe callback.
 
 - Fix to bootconfig parsing
 
 - Have tracefs allow owner and group permissions by default (only denying
   others). There's been pressure to allow non root to tracefs in a
   controlled fashion, and using groups is probably the safest.
 
 - Bootconfig memory managament updates.
 
 - Bootconfig clean up to have the tools directory be less dependent on
   changes in the kernel tree.
 
 - Allow perf to be traced by function tracer.
 
 - Rewrite of function graph tracer to be a callback from the function tracer
   instead of having its own trampoline (this change will happen on an arch
   by arch basis, and currently only x86_64 implements it).
 
 - Allow multiple direct trampolines (bpf hooks to functions) be batched
   together in one synchronization.
 
 - Allow histogram triggers to add variables that can perform calculations
   against the event's fields.
 
 - Use the linker to determine architecture callbacks from the ftrace
   trampoline to allow for proper parameter prototypes and prevent warnings
   from the compiler.
 
 - Extend histogram triggers to key off of variables.
 
 - Have trace recursion use bit magic to determine preempt context over if
   branches.
 
 - Have trace recursion disable preemption as all use cases do anyway.
 
 - Added testing for verification of tracing utilities.
 
 - Various small clean ups and fixes.
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Merge tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - kprobes: Restructured stack unwinder to show properly on x86 when a
   stack dump happens from a kretprobe callback.

 - Fix to bootconfig parsing

 - Have tracefs allow owner and group permissions by default (only
   denying others). There's been pressure to allow non root to tracefs
   in a controlled fashion, and using groups is probably the safest.

 - Bootconfig memory managament updates.

 - Bootconfig clean up to have the tools directory be less dependent on
   changes in the kernel tree.

 - Allow perf to be traced by function tracer.

 - Rewrite of function graph tracer to be a callback from the function
   tracer instead of having its own trampoline (this change will happen
   on an arch by arch basis, and currently only x86_64 implements it).

 - Allow multiple direct trampolines (bpf hooks to functions) be batched
   together in one synchronization.

 - Allow histogram triggers to add variables that can perform
   calculations against the event's fields.

 - Use the linker to determine architecture callbacks from the ftrace
   trampoline to allow for proper parameter prototypes and prevent
   warnings from the compiler.

 - Extend histogram triggers to key off of variables.

 - Have trace recursion use bit magic to determine preempt context over
   if branches.

 - Have trace recursion disable preemption as all use cases do anyway.

 - Added testing for verification of tracing utilities.

 - Various small clean ups and fixes.

* tag 'trace-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (101 commits)
  tracing/histogram: Fix semicolon.cocci warnings
  tracing/histogram: Fix documentation inline emphasis warning
  tracing: Increase PERF_MAX_TRACE_SIZE to handle Sentinel1 and docker together
  tracing: Show size of requested perf buffer
  bootconfig: Initialize ret in xbc_parse_tree()
  ftrace: do CPU checking after preemption disabled
  ftrace: disable preemption when recursion locked
  tracing/histogram: Document expression arithmetic and constants
  tracing/histogram: Optimize division by a power of 2
  tracing/histogram: Covert expr to const if both operands are constants
  tracing/histogram: Simplify handling of .sym-offset in expressions
  tracing: Fix operator precedence for hist triggers expression
  tracing: Add division and multiplication support for hist triggers
  tracing: Add support for creating hist trigger variables from literal
  selftests/ftrace: Stop tracing while reading the trace file by default
  MAINTAINERS: Update KPROBES and TRACING entries
  test_kprobes: Move it from kernel/ to lib/
  docs, kprobes: Remove invalid URL and add new reference
  samples/kretprobes: Fix return value if register_kretprobe() failed
  lib/bootconfig: Fix the xbc_get_info kerneldoc
  ...
2021-11-01 20:05:19 -07:00
Peter Zijlstra 134ab5bd18 objtool,x86: Replace alternatives with .retpoline_sites
Instead of writing complete alternatives, simply provide a list of all
the retpoline thunk calls. Then the kernel is free to do with them as
it pleases. Simpler code all-round.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.850007165@infradead.org
2021-10-28 23:25:25 +02:00
Peter Zijlstra c509331b41 objtool: Shrink struct instruction
Any one instruction can only ever call a single function, therefore
insn->mcount_loc_node is superfluous and can use insn->call_node.

This shrinks struct instruction, which is by far the most numerous
structure objtool creates.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.785456706@infradead.org
2021-10-28 23:25:25 +02:00
Peter Zijlstra dd003edeff objtool: Explicitly avoid self modifying code in .altinstr_replacement
Assume ALTERNATIVE()s know what they're doing and do not change, or
cause to change, instructions in .altinstr_replacement sections.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.722511775@infradead.org
2021-10-28 23:25:25 +02:00
Peter Zijlstra 1739c66eb7 objtool: Classify symbols
In order to avoid calling str*cmp() on symbol names, over and over, do
them all once upfront and store the result.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120309.658539311@infradead.org
2021-10-28 23:25:24 +02:00
Peter Zijlstra b08cadbd3b Merge branch 'objtool/urgent'
Fixup conflicts.

# Conflicts:
#	tools/objtool/check.c
2021-10-07 00:40:17 +02:00
Joe Lawrence fe255fe6ad objtool: Remove redundant 'len' field from struct section
The section structure already contains sh_size, so just remove the extra
'len' member that requires extra mirroring and potential confusion.

Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20210822225037.54620-3-joe.lawrence@redhat.com
Cc: Andy Lavr <andy.lavr@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
2021-10-05 12:03:21 -07:00