Commit Graph

321 Commits

Author SHA1 Message Date
Jiri Olsa ccf5a89efd ftrace: Add multi direct modify interface
Adding interface to modify registered direct function
for ftrace_ops. Adding following function:

   modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)

The function changes the currently registered direct
function for all attached functions.

Link: https://lkml.kernel.org/r/20211008091336.33616-8-jolsa@kernel.org

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21 14:19:00 -04:00
Jiri Olsa f64dd4627e ftrace: Add multi direct register/unregister interface
Adding interface to register multiple direct functions
within single call. Adding following functions:

  register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
  unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)

The register_ftrace_direct_multi registers direct function (addr)
with all functions in ops filter. The ops filter can be updated
before with ftrace_set_filter_ip calls.

All requested functions must not have direct function currently
registered, otherwise register_ftrace_direct_multi will fail.

The unregister_ftrace_direct_multi unregisters ops related direct
functions.

Link: https://lkml.kernel.org/r/20211008091336.33616-7-jolsa@kernel.org

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-21 14:19:00 -04:00
Steven Rostedt (VMware) 0c0593b45c x86/ftrace: Make function graph use ftrace directly
We don't need special hook for graph tracer entry point,
but instead we can use graph_ops::func function to install
the return_hooker.

This moves the graph tracing setup _before_ the direct
trampoline prepares the stack, so the return_hooker will
be called when the direct trampoline is finished.

This simplifies the code, because we don't need to take into
account the direct trampoline setup when preparing the graph
tracer hooker and we can allow function graph tracer on entries
registered with direct trampoline.

Link: https://lkml.kernel.org/r/20211008091336.33616-4-jolsa@kernel.org

[fixed compile error reported by kernel test robot <lkp@intel.com>]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-20 23:44:43 -04:00
Steven Rostedt (VMware) 34cdd18b8d tracing: Use linker magic instead of recasting ftrace_ops_list_func()
In an effort to enable -Wcast-function-type in the top-level Makefile to
support Control Flow Integrity builds, all function casts need to be
removed.

This means that ftrace_ops_list_func() can no longer be defined as
ftrace_ops_no_ops(). The reason for ftrace_ops_no_ops() is to use that when
an architecture calls ftrace_ops_list_func() with only two parameters
(called from assembly). And to make sure there's no C side-effects, those
archs call ftrace_ops_no_ops() which only has two parameters, as
ftrace_ops_list_func() has four parameters.

Instead of a typecast, use vmlinux.lds.h to define ftrace_ops_list_func() to
arch_ftrace_ops_list_func() that will define the proper set of parameters.

Link: https://lore.kernel.org/r/20200614070154.6039-1-oscar.carter@gmx.com
Link: https://lkml.kernel.org/r/20200617165616.52241bde@oasis.local.home
Link: https://lore.kernel.org/all/20211005053922.GA702049@embeddedor/

Requested-by: Oscar Carter <oscar.carter@gmx.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-10-19 20:33:12 -04:00
Ilya Leoshkevich 67ccddf866 ftrace: Introduce ftrace_need_init_nop()
Implementing live patching on s390 requires each function's prologue to
contain a very special kind of nop, which gcc and clang don't generate.
However, the current code assumes that if CC_USING_NOP_MCOUNT is
defined, then whatever the compiler generates is good enough.

Move the CC_USING_NOP_MCOUNT check into the new ftrace_need_init_nop()
macro, that the architectures can override.

An alternative solution is to disable using -mnop-mcount in the
Makefile, however, this makes the build logic (even) more complicated
and forces the arch-specific code to deal with the useless __fentry__
symbol.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20210728212546.128248-2-iii@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-08-03 14:31:40 +02:00
Ingo Molnar f2cc020d78 tracing: Fix various typos in comments
Fix ~59 single-word typos in the tracing code comments, and fix
the grammar in a handful of places.

Link: https://lore.kernel.org/r/20210322224546.GA1981273@gmail.com
Link: https://lkml.kernel.org/r/20210323174935.GA4176821@gmail.com

Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-03-23 14:08:18 -04:00
Jinyang He a1320e0c2f ftrace: Remove unused ftrace_force_update()
ftrace_force_update() is committed by Commit e1c08bdd9f ("ftrace: force
recording") and removed by Commit cb7be3b2fc ("ftrace: remove daemon").
Remove it in header file.

Link: https://lkml.kernel.org/r/1612409671-8249-1-git-send-email-hejinyang@loongson.cn

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-02-09 12:43:42 -05:00
Steven Rostedt (VMware) 2860cd8a23 livepatch: Use the default ftrace_ops instead of REGS when ARGS is available
When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS is available, the ftrace call
will be able to set the ip of the calling function. This will improve the
performance of live kernel patching where it does not need all the regs to
be stored just to change the instruction pointer.

If all archs that support live kernel patching also support
HAVE_DYNAMIC_FTRACE_WITH_ARGS, then the architecture specific function
klp_arch_set_pc() could be made generic.

It is possible that an arch can support HAVE_DYNAMIC_FTRACE_WITH_ARGS but
not HAVE_DYNAMIC_FTRACE_WITH_REGS and then have access to live patching.

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: live-patching@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13 12:15:28 -05:00
Steven Rostedt (VMware) 02a474ca26 ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default
Currently, the only way to get access to the registers of a function via a
ftrace callback is to set the "FL_SAVE_REGS" bit in the ftrace_ops. But as this
saves all regs as if a breakpoint were to trigger (for use with kprobes), it
is expensive.

The regs are already saved on the stack for the default ftrace callbacks, as
that is required otherwise a function being traced will get the wrong
arguments and possibly crash. And on x86, the arguments are already stored
where they would be on a pt_regs structure to use that code for both the
regs version of a callback, it makes sense to pass that information always
to all functions.

If an architecture does this (as x86_64 now does), it is to set
HAVE_DYNAMIC_FTRACE_WITH_ARGS, and this will let the generic code that it
could have access to arguments without having to set the flags.

This also includes having the stack pointer being saved, which could be used
for accessing arguments on the stack, as well as having the function graph
tracer not require its own trampoline!

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13 12:14:59 -05:00
Steven Rostedt (VMware) d19ad0775d ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs
In preparation to have arguments of a function passed to callbacks attached
to functions as default, change the default callback prototype to receive a
struct ftrace_regs as the forth parameter instead of a pt_regs.

For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they
will now need to get the pt_regs via a ftrace_get_regs() helper call. If
this is called by a callback that their ftrace_ops did not have a
FL_SAVE_REGS flag set, it that helper function will return NULL.

This will allow the ftrace_regs to hold enough just to get the parameters
and stack pointer, but without the worry that callbacks may have a pt_regs
that is not completely filled.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-13 12:14:55 -05:00
Steven Rostedt (VMware) 60602cb549 fgraph: Make overruns 4 bytes in graph stack structure
Inspecting the data structures of the function graph tracer, I found that
the overrun value is unsigned long, which is 8 bytes on a 64 bit machine,
and not only that, the depth is an int (4 bytes). The overrun can be simply
an unsigned int (4 bytes) and pack the ftrace_graph_ret structure better.

The depth is moved up next to the func, as it is used more often with func,
and improves cache locality.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-10 20:39:36 -05:00
Steven Rostedt (VMware) a25d036d93 ftrace: Reverse what the RECURSION flag means in the ftrace_ops
Now that all callbacks are recursion safe, reverse the meaning of the
RECURSION flag and rename it from RECURSION_SAFE to simply RECURSION.
Now only callbacks that request to have recursion protecting it will
have the added trampoline to do so.

Also remove the outdated comment about "PER_CPU" when determining to
use the ftrace_ops_assist_func.

Link: https://lkml.kernel.org/r/20201028115613.742454631@goodmis.org
Link: https://lkml.kernel.org/r/20201106023547.904270143@goodmis.org

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh  Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:42:12 -05:00
Steven Rostedt (VMware) 0264c8c9e1 ftrace: Move the recursion testing into global headers
Currently, if a callback is registered to a ftrace function and its
ftrace_ops does not have the RECURSION flag set, it is encapsulated in a
helper function that does the recursion for it.

Really, all the callbacks should have their own recursion protection for
performance reasons. But they should not all implement their own. Move the
recursion helpers to global headers, so that all callbacks can use them.

Link: https://lkml.kernel.org/r/20201028115612.460535535@goodmis.org
Link: https://lkml.kernel.org/r/20201106023546.166456258@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-06 08:33:23 -05:00
Wei Yang 40dc4a42b9 ftrace: ftrace_global_list is renamed to ftrace_ops_list
Fix the comment to comply with the code.

Link: https://lkml.kernel.org/r/20200831031104.23322-7-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Wei Yang 02dae28f0b ftrace: Simplify the dyn_ftrace->flags macro
All the three macro are defined to be used for ftrace_rec_count(). This
can be achieved by (flags & FTRACE_REF_MAX) directly.

Since no other places would use those macros, remove them for clarity.

Also it fixes a typo in the comment.

Link: https://lkml.kernel.org/r/20200831031104.23322-4-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-10-08 15:29:06 -04:00
Tobias Klauser 54fa9ba564 ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer
Commit 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer. Adjust the
signature of ftrace_enable_sysctl to match ctl_table.proc_handler which
fixes the following sparse warning:

kernel/trace/ftrace.c:7544:43: warning: incorrect type in argument 3 (different address spaces)
kernel/trace/ftrace.c:7544:43:    expected void *
kernel/trace/ftrace.c:7544:43:    got void [noderef] __user *buffer

Link: https://lkml.kernel.org/r/20200907093207.13540-1-tklauser@distanz.ch

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-09-18 13:15:56 -04:00
Adrian Hunter fc0ea795f5 ftrace: Add symbols for ftrace trampolines
Symbols are needed for tools to describe instruction addresses. Pages
allocated for ftrace's purposes need symbols to be created for them.
Add such symbols to be visible via /proc/kallsyms.

Example on x86 with CONFIG_DYNAMIC_FTRACE=y

	# echo function > /sys/kernel/debug/tracing/current_tracer
	# cat /proc/kallsyms | grep '\[__builtin__ftrace\]'
	ffffffffc0238000 t ftrace_trampoline    [__builtin__ftrace]

Note: This patch adds "__builtin__ftrace" as a module name in /proc/kallsyms for
symbols for pages allocated for ftrace's purposes, even though "__builtin__ftrace"
is not a module.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-7-adrian.hunter@intel.com
2020-06-15 14:09:49 +02:00
Linus Torvalds 1c38372662 Merge branch 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull sysctl fixes from Al Viro:
 "Fixups to regressions in sysctl series"

* 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sysctl: reject gigantic reads/write to sysctl files
  cdrom: fix an incorrect __user annotation on cdrom_sysctl_info
  trace: fix an incorrect __user annotation on stack_trace_sysctl
  random: fix an incorrect __user annotation on proc_do_entropy
  net/sysctl: remove leftover __user annotations on neigh_proc_dointvec*
  net/sysctl: use cpumask_parse in flow_limit_cpu_sysctl
2020-06-10 16:05:54 -07:00
Christoph Hellwig 7ff0d4490e trace: fix an incorrect __user annotation on stack_trace_sysctl
No user pointers for sysctls anymore.

Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Reported-by: build test robot <lkp@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-06-08 10:13:56 -04:00
David S. Miller da07f52d3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Move the bpf verifier trace check into the new switch statement in
HEAD.

Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15 13:48:59 -07:00
Steven Rostedt (VMware) 59566b0b62 x86/ftrace: Have ftrace trampolines turn read-only at the end of system boot up
Booting one of my machines, it triggered the following crash:

 Kernel/User page tables isolation: enabled
 ftrace: allocating 36577 entries in 143 pages
 Starting tracer 'function'
 BUG: unable to handle page fault for address: ffffffffa000005c
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0003) - permissions violation
 PGD 2014067 P4D 2014067 PUD 2015063 PMD 7b253067 PTE 7b252061
 Oops: 0003 [#1] PREEMPT SMP PTI
 CPU: 0 PID: 0 Comm: swapper Not tainted 5.4.0-test+ #24
 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS SDBLI944.86P 05/08/2007
 RIP: 0010:text_poke_early+0x4a/0x58
 Code: 34 24 48 89 54 24 08 e8 bf 72 0b 00 48 8b 34 24 48 8b 4c 24 08 84 c0 74 0b 48 89 df f3 a4 48 83 c4 10 5b c3 9c 58 fa 48 89 df <f3> a4 50 9d 48 83 c4 10 5b e9 d6 f9 ff ff
0 41 57 49
 RSP: 0000:ffffffff82003d38 EFLAGS: 00010046
 RAX: 0000000000000046 RBX: ffffffffa000005c RCX: 0000000000000005
 RDX: 0000000000000005 RSI: ffffffff825b9a90 RDI: ffffffffa000005c
 RBP: ffffffffa000005c R08: 0000000000000000 R09: ffffffff8206e6e0
 R10: ffff88807b01f4c0 R11: ffffffff8176c106 R12: ffffffff8206e6e0
 R13: ffffffff824f2440 R14: 0000000000000000 R15: ffffffff8206eac0
 FS:  0000000000000000(0000) GS:ffff88807d400000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffffffa000005c CR3: 0000000002012000 CR4: 00000000000006b0
 Call Trace:
  text_poke_bp+0x27/0x64
  ? mutex_lock+0x36/0x5d
  arch_ftrace_update_trampoline+0x287/0x2d5
  ? ftrace_replace_code+0x14b/0x160
  ? ftrace_update_ftrace_func+0x65/0x6c
  __register_ftrace_function+0x6d/0x81
  ftrace_startup+0x23/0xc1
  register_ftrace_function+0x20/0x37
  func_set_flag+0x59/0x77
  __set_tracer_option.isra.19+0x20/0x3e
  trace_set_options+0xd6/0x13e
  apply_trace_boot_options+0x44/0x6d
  register_tracer+0x19e/0x1ac
  early_trace_init+0x21b/0x2c9
  start_kernel+0x241/0x518
  ? load_ucode_intel_bsp+0x21/0x52
  secondary_startup_64+0xa4/0xb0

I was able to trigger it on other machines, when I added to the kernel
command line of both "ftrace=function" and "trace_options=func_stack_trace".

The cause is the "ftrace=function" would register the function tracer
and create a trampoline, and it will set it as executable and
read-only. Then the "trace_options=func_stack_trace" would then update
the same trampoline to include the stack tracer version of the function
tracer. But since the trampoline already exists, it updates it with
text_poke_bp(). The problem is that text_poke_bp() called while
system_state == SYSTEM_BOOTING, it will simply do a memcpy() and not
the page mapping, as it would think that the text is still read-write.
But in this case it is not, and we take a fault and crash.

Instead, lets keep the ftrace trampolines read-write during boot up,
and then when the kernel executable text is set to read-only, the
ftrace trampolines get set to read-only as well.

Link: https://lkml.kernel.org/r/20200430202147.4dc6e2de@oasis.local.home

Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable@vger.kernel.org
Fixes: 768ae4406a ("x86/ftrace: Use text_poke()")
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-05-12 18:24:34 -04:00
Christoph Hellwig 32927393dc sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27 02:07:40 -04:00
Linus Torvalds 6674fdb25a This contains 3 changes:
- Removal of code I accidentally applied when doing a minor fix up
    to a patch, and then using "git commit -a --amend", which pulled
    in some other changes I was playing with.
 
  - Remove an used variable in trace_events_inject code
 
  - Fix to function graph tracer when it traces a ftrace direct function.
    It will now ignore tracing a function that has a ftrace direct
    tramploine attached. This is needed for eBPF to use the ftrace direct
    code.
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Merge tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Remove code I accidentally applied when doing a minor fix up to a
   patch, and then using "git commit -a --amend", which pulled in some
   other changes I was playing with.

 - Remove an used variable in trace_events_inject code

 - Fix function graph tracer when it traces a ftrace direct function.
   It will now ignore tracing a function that has a ftrace direct
   tramploine attached. This is needed for eBPF to use the ftrace direct
   code.

* tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix function_graph tracer interaction with BPF trampoline
  tracing: remove set but not used variable 'buffer'
  module: Remove accidental change of module_enable_x()
2019-12-11 12:22:38 -08:00
Alexei Starovoitov ff205766db ftrace: Fix function_graph tracer interaction with BPF trampoline
Depending on type of BPF programs served by BPF trampoline it can call original
function. In such case the trampoline will skip one stack frame while
returning. That will confuse function_graph tracer and will cause crashes with
bad RIP. Teach graph tracer to skip functions that have BPF trampoline attached.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-12-10 13:53:59 -05:00
Linus Torvalds 95f1fa9e34 New tracing features:
- PERAMAENT flag to ftrace_ops when attaching a callback to a function
    As /proc/sys/kernel/ftrace_enabled when set to zero will disable all
    attached callbacks in ftrace, this has a detrimental impact on live
    kernel tracing, as it disables all that it patched. If a ftrace_ops
    is registered to ftrace with the PERMANENT flag set, it will prevent
    ftrace_enabled from being disabled, and if ftrace_enabled is already
    disabled, it will prevent a ftrace_ops with PREMANENT flag set from
    being registered.
 
  - New register_ftrace_direct(). As eBPF would like to register its own
    trampolines to be called by the ftrace nop locations directly,
    without going through the ftrace trampoline, this function has been
    added. This allows for eBPF trampolines to live along side of
    ftrace, perf, kprobe and live patching. It also utilizes the ftrace
    enabled_functions file that keeps track of functions that have been
    modified in the kernel, to allow for security auditing.
 
  - Allow for kernel internal use of ftrace instances. Subsystems in
    the kernel can now create and destroy their own tracing instances
    which allows them to have their own tracing buffer, and be able
    to record events without worrying about other users from writing over
    their data.
 
  - New seq_buf_hex_dump() that lets users use the hex_dump() in their
    seq_buf usage.
 
  - Notifications now added to tracing_max_latency to allow user space
    to know when a new max latency is hit by one of the latency tracers.
 
  - Wider spread use of generic compare operations for use of bsearch and
    friends.
 
  - More synthetic event fields may be defined (32 up from 16)
 
  - Use of xarray for architectures with sparse system calls, for the
    system call trace events.
 
 This along with small clean ups and fixes.
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Merge tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "New tracing features:

   - New PERMANENT flag to ftrace_ops when attaching a callback to a
     function.

     As /proc/sys/kernel/ftrace_enabled when set to zero will disable
     all attached callbacks in ftrace, this has a detrimental impact on
     live kernel tracing, as it disables all that it patched. If a
     ftrace_ops is registered to ftrace with the PERMANENT flag set, it
     will prevent ftrace_enabled from being disabled, and if
     ftrace_enabled is already disabled, it will prevent a ftrace_ops
     with PREMANENT flag set from being registered.

   - New register_ftrace_direct().

     As eBPF would like to register its own trampolines to be called by
     the ftrace nop locations directly, without going through the ftrace
     trampoline, this function has been added. This allows for eBPF
     trampolines to live along side of ftrace, perf, kprobe and live
     patching. It also utilizes the ftrace enabled_functions file that
     keeps track of functions that have been modified in the kernel, to
     allow for security auditing.

   - Allow for kernel internal use of ftrace instances.

     Subsystems in the kernel can now create and destroy their own
     tracing instances which allows them to have their own tracing
     buffer, and be able to record events without worrying about other
     users from writing over their data.

   - New seq_buf_hex_dump() that lets users use the hex_dump() in their
     seq_buf usage.

   - Notifications now added to tracing_max_latency to allow user space
     to know when a new max latency is hit by one of the latency
     tracers.

   - Wider spread use of generic compare operations for use of bsearch
     and friends.

   - More synthetic event fields may be defined (32 up from 16)

   - Use of xarray for architectures with sparse system calls, for the
     system call trace events.

  This along with small clean ups and fixes"

* tag 'trace-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (51 commits)
  tracing: Enable syscall optimization for MIPS
  tracing: Use xarray for syscall trace events
  tracing: Sample module to demonstrate kernel access to Ftrace instances.
  tracing: Adding new functions for kernel access to Ftrace instances
  tracing: Fix Kconfig indentation
  ring-buffer: Fix typos in function ring_buffer_producer
  ftrace: Use BIT() macro
  ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured
  ftrace: Rename ftrace_graph_stub to ftrace_stub_graph
  ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization
  ftrace: Add helper find_direct_entry() to consolidate code
  ftrace: Add another check for match in register_ftrace_direct()
  ftrace: Fix accounting bug with direct->count in register_ftrace_direct()
  ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"
  tracing: Increase SYNTH_FIELDS_MAX for synthetic_events
  ftrace/samples: Add a sample module that implements modify_ftrace_direct()
  ftrace: Add modify_ftrace_direct()
  tracing: Add missing "inline" in stub function of latency_fsnotify()
  tracing: Remove stray tab in TRACE_EVAL_MAP_FILE's help text
  tracing: Use seq_buf_hex_dump() to dump buffers
  ...
2019-11-27 11:42:01 -08:00
Enrico Weigelt, metux IT consult b41db13282 ftrace: Use BIT() macro
It's cleaner to use the BIT() macro instead of raw shift operation.

Link: http://lkml.kernel.org/r/20191121133815.15040-1-info@metux.net

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
[ Added BIT() for bits 16 and 17 ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-22 19:41:08 -05:00
Alexei Starovoitov eb01fedc3d ftrace: Return ENOTSUPP when DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not configured
When CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not set it's best to
have the stub functions return ENOTSUPP instead of ENODEV,
otherwise ENODEV is a valid error when ip is incorrect which is
indistinguishable from ftrace not compiled in.

Link: http://lkml.kernel.org/r/CAADnVQ+OzTikM9EhrfsC7NFsVYhATW1SVHxK64w3xn9qpk81pg@mail.gmail.com

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-20 18:52:23 -05:00
Steven Rostedt (VMware) ea806eb3ea ftrace: Add a helper function to modify_ftrace_direct() to allow arch optimization
If a direct ftrace callback is at a location that does not have any other
ftrace helpers attached to it, it is possible to simply just change the
text to call the new caller (if the architecture supports it). But this
requires special architecture code. Currently, modify_ftrace_direct() uses a
trick to add a stub ftrace callback to the location forcing it to call the
ftrace iterator. Then it can change the direct helper to call the new
function in C, and then remove the stub. Removing the stub will have the
location now call the new location that the direct helper is using.

The new helper function does the registering the stub trick, but is a weak
function, allowing an architecture to override it to do something a bit more
direct.

Link: https://lore.kernel.org/r/20191115215125.mbqv7taqnx376yed@ast-mbp.dhcp.thefacebook.com

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-18 11:42:09 -05:00
Steven Rostedt (VMware) 0567d68091 ftrace: Add modify_ftrace_direct()
Add a new function modify_ftrace_direct() that will allow a user to update
an existing direct caller to a new trampoline, without missing hits due to
unregistering one and then adding another.

Link: https://lore.kernel.org/r/20191109022907.6zzo6orhxpt5n2sv@ast-mbp.dhcp.thefacebook.com

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-14 22:45:47 -05:00
Steven Rostedt (VMware) a3ad1a7e39 ftrace/x86: Add a counter to test function_graph with direct
As testing for direct calls from the function graph tracer adds a little
overhead (which is a lot when tracing every function), add a counter that
can be used to test if function_graph tracer needs to test for a direct
caller or not.

It would have been nicer if we could use a static branch, but the static
branch logic fails when used within the function graph tracer trampoline.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00
Steven Rostedt (VMware) 562955fe6a ftrace/x86: Add register_ftrace_direct() for custom trampolines
Enable x86 to allow for register_ftrace_direct(), where a custom trampoline
may be called directly from an ftrace mcount/fentry location.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:49 -05:00
Steven Rostedt (VMware) 013bf0da04 ftrace: Add ftrace_find_direct_func()
As function_graph tracer modifies the return address to insert a trampoline
to trace the return of a function, it must be aware of a direct caller, as
when it gets called, the function's return address may not be at on the
stack where it expects. It may have to see if that return address points to
the a direct caller and adjust if it is.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:48 -05:00
Steven Rostedt (VMware) 763e34e74b ftrace: Add register_ftrace_direct()
Add the start of the functionality to allow other trampolines to use the
ftrace mcount/fentry/nop location. This adds two new functions:

 register_ftrace_direct() and unregister_ftrace_direct()

Both take two parameters: the first is the instruction address of where the
mcount/fentry/nop exists, and the second is the trampoline to have that
location called.

This will handle cases where ftrace is already used on that same location,
and will make it still work, where the registered direct called trampoline
will get called after all the registered ftrace callers are handled.

Currently, it will not allow for IP_MODIFY functions to be called at the
same locations, which include some kprobes and live kernel patching.

At this point, no architecture supports this. This is only the start of
implementing the framework.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-13 09:36:41 -05:00
Mark Rutland a1326b17ac module/ftrace: handle patchable-function-entry
When using patchable-function-entry, the compiler will record the
callsites into a section named "__patchable_function_entries" rather
than "__mcount_loc". Let's abstract this difference behind a new
FTRACE_CALLSITE_SECTION, so that architectures don't have to handle this
explicitly (e.g. with custom module linker scripts).

As parisc currently handles this explicitly, it is fixed up accordingly,
with its custom linker script removed. Since FTRACE_CALLSITE_SECTION is
only defined when DYNAMIC_FTRACE is selected, the parisc module loading
code is updated to only use the definition in that case. When
DYNAMIC_FTRACE is not selected, modules shouldn't have this section, so
this removes some redundant work in that case.

To make sure that this is keep up-to-date for modules and the main
kernel, a comment is added to vmlinux.lds.h, with the existing ifdeffery
simplified for legibility.

I built parisc generic-{32,64}bit_defconfig with DYNAMIC_FTRACE enabled,
and verified that the section made it into the .ko files for modules.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Helge Deller <deller@gmx.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Sven Schnelle <svens@stackframe.org>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: linux-parisc@vger.kernel.org
2019-11-06 14:17:30 +00:00
Mark Rutland fbf6c73c5b ftrace: add ftrace_init_nop()
Architectures may need to perform special initialization of ftrace
callsites, and today they do so by special-casing ftrace_make_nop() when
the expected branch address is MCOUNT_ADDR. In some cases (e.g. for
patchable-function-entry), we don't have an mcount-like symbol and don't
want a synthetic MCOUNT_ADDR, but we may need to perform some
initialization of callsites.

To make it possible to separate initialization from runtime
modification, and to handle cases without an mcount-like symbol, this
patch adds an optional ftrace_init_nop() function that architectures can
implement, which does not pass a branch address.

Where an architecture does not provide ftrace_init_nop(), we will fall
back to the existing behaviour of calling ftrace_make_nop() with
MCOUNT_ADDR.

At the same time, ftrace_code_disable() is renamed to
ftrace_nop_initialize() to make it clearer that it is intended to
intialize a callsite into a disabled state, and is not for disabling a
callsite that has been runtime enabled. The kerneldoc description of rec
arguments is updated to cover non-mcount callsites.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Sven Schnelle <svens@stackframe.org>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
2019-11-06 14:17:13 +00:00
Miroslav Benes 7162431dcf ftrace: Introduce PERMANENT ftrace_ops flag
Livepatch uses ftrace for redirection to new patched functions. It means
that if ftrace is disabled, all live patched functions are disabled as
well. Toggling global 'ftrace_enabled' sysctl thus affect it directly.
It is not a problem per se, because only administrator can set sysctl
values, but it still may be surprising.

Introduce PERMANENT ftrace_ops flag to amend this. If the
FTRACE_OPS_FL_PERMANENT is set on any ftrace ops, the tracing cannot be
disabled by disabling ftrace_enabled. Equally, a callback with the flag
set cannot be registered if ftrace_enabled is disabled.

Link: http://lkml.kernel.org/r/20191016113316.13415-2-mbenes@suse.cz

Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-04 09:33:15 -05:00
Steven Rostedt (VMware) 7375dca164 ftrace: Make enable and update parameters bool when applicable
The code modification functions have "enable" and "update" variables that
are sometimes "int" but used as "bool". Remove the ambiguity and make them
"bool" when they are only used for true or false values.

Link: http://lkml.kernel.org/r/e1429923d9eda92a3cf5ee9e33c7eacce539781d.1558115654.git.naveen.n.rao@linux.vnet.ibm.com

Reported-by: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-25 23:04:42 -04:00
Linus Torvalds d2d8b14604 The major changes in this tracing update includes:
- Removing of non-DYNAMIC_FTRACE from 32bit x86
 
  - Removing of mcount support from x86
 
  - Emulating a call from int3 on x86_64, fixes live kernel patching
 
  - Consolidated Tracing Error logs file
 
 Minor updates:
 
  - Removal of klp_check_compiler_support()
 
  - kdb ftrace dumping output changes
 
  - Accessing and creating ftrace instances from inside the kernel
 
  - Clean up of #define if macro
 
  - Introduction of TRACE_EVENT_NOP() to disable trace events based on config
    options
 
 And other minor fixes and clean ups
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Merge tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "The major changes in this tracing update includes:

   - Removal of non-DYNAMIC_FTRACE from 32bit x86

   - Removal of mcount support from x86

   - Emulating a call from int3 on x86_64, fixes live kernel patching

   - Consolidated Tracing Error logs file

  Minor updates:

   - Removal of klp_check_compiler_support()

   - kdb ftrace dumping output changes

   - Accessing and creating ftrace instances from inside the kernel

   - Clean up of #define if macro

   - Introduction of TRACE_EVENT_NOP() to disable trace events based on
     config options

  And other minor fixes and clean ups"

* tag 'trace-v5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  x86: Hide the int3_emulate_call/jmp functions from UML
  livepatch: Remove klp_check_compiler_support()
  ftrace/x86: Remove mcount support
  ftrace/x86_32: Remove support for non DYNAMIC_FTRACE
  tracing: Simplify "if" macro code
  tracing: Fix documentation about disabling options using trace_options
  tracing: Replace kzalloc with kcalloc
  tracing: Fix partial reading of trace event's id file
  tracing: Allow RCU to run between postponed startup tests
  tracing: Fix white space issues in parse_pred() function
  tracing: Eliminate const char[] auto variables
  ring-buffer: Fix mispelling of Calculate
  tracing: probeevent: Fix to make the type of $comm string
  tracing: probeevent: Do not accumulate on ret variable
  tracing: uprobes: Re-enable $comm support for uprobe events
  ftrace/x86_64: Emulate call function while updating in breakpoint handler
  x86_64: Allow breakpoints to emulate call instructions
  x86_64: Add gap to int3 to allow for call emulation
  tracing: kdb: Allow ftdump to skip all but the last few entries
  tracing: Add trace_total_entries() / trace_total_entries_cpu()
  ...
2019-05-15 16:05:47 -07:00
Steven Rostedt (VMware) e8025bab7b function_graph: Place ftrace_graph_entry_stub() prototype in include/linux/ftrace.h
ftrace_graph_entry_stub() is defined in generic code, its prototype should
be in the generic header and not defined throughout architecture specific
code in order to use it.

Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-29 17:17:22 -04:00
Thomas Gleixner 3d9a807291 tracing: Cleanup stack trace code
- Remove the extra array member of stack_dump_trace[] along with the
  ARRAY_SIZE - 1 initialization for struct stack_trace :: max_entries.

  Both are historical leftovers of no value. The stack tracer never exceeds
  the array and there is no extra storage requirement either.

- Make variables which are only used in trace_stack.c static.

- Simplify the enable/disable logic.

- Rename stack_trace_print() as it's using the stack_trace_ namespace. Free
  the name up for stack trace related functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: kasan-dev@googlegroups.com
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: iommu@lists.linux-foundation.org
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: linux-btrfs@vger.kernel.org
Cc: dm-devel@redhat.com
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: linux-arch@vger.kernel.org
Link: https://lkml.kernel.org/r/20190425094801.230654524@linutronix.de
2019-04-29 12:37:46 +02:00
Linus Torvalds 495d714ad1 Tracing changes for v4.21:
- Rework of the kprobe/uprobe and synthetic events to consolidate all
    the dynamic event code. This will make changes in the future easier.
 
  - Partial rewrite of the function graph tracing infrastructure.
    This will allow for multiple users of hooking onto functions
    to get the callback (return) of the function. This is the ground
    work for having kprobes and function graph tracer using one code base.
 
  - Clean up of the histogram code that will facilitate adding more
    features to the histograms in the future.
 
  - Addition of str_has_prefix() and a few use cases. There currently
    is a similar function strstart() that is used in a few places, but
    only returns a bool and not a length. These instances will be
    removed in the future to use str_has_prefix() instead.
 
  - A few other various clean ups as well.
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Merge tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Rework of the kprobe/uprobe and synthetic events to consolidate all
   the dynamic event code. This will make changes in the future easier.

 - Partial rewrite of the function graph tracing infrastructure. This
   will allow for multiple users of hooking onto functions to get the
   callback (return) of the function. This is the ground work for having
   kprobes and function graph tracer using one code base.

 - Clean up of the histogram code that will facilitate adding more
   features to the histograms in the future.

 - Addition of str_has_prefix() and a few use cases. There currently is
   a similar function strstart() that is used in a few places, but only
   returns a bool and not a length. These instances will be removed in
   the future to use str_has_prefix() instead.

 - A few other various clean ups as well.

* tag 'trace-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits)
  tracing: Use the return of str_has_prefix() to remove open coded numbers
  tracing: Have the historgram use the result of str_has_prefix() for len of prefix
  tracing: Use str_has_prefix() instead of using fixed sizes
  tracing: Use str_has_prefix() helper for histogram code
  string.h: Add str_has_prefix() helper function
  tracing: Make function ‘ftrace_exports’ static
  tracing: Simplify printf'ing in seq_print_sym
  tracing: Avoid -Wformat-nonliteral warning
  tracing: Merge seq_print_sym_short() and seq_print_sym_offset()
  tracing: Add hist trigger comments for variable-related fields
  tracing: Remove hist trigger synth_var_refs
  tracing: Use hist trigger's var_ref array to destroy var_refs
  tracing: Remove open-coding of hist trigger var_ref management
  tracing: Use var_refs[] for hist trigger reference checking
  tracing: Change strlen to sizeof for hist trigger static strings
  tracing: Remove unnecessary hist trigger struct field
  tracing: Fix ftrace_graph_get_ret_stack() to use task and not current
  seq_buf: Use size_t for len in seq_buf_puts()
  seq_buf: Make seq_buf_puts() null-terminate the buffer
  arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack
  ...
2018-12-31 11:46:59 -08:00
Steven Rostedt (VMware) a0572f687f ftrace: Allow ftrace_replace_code() to be schedulable
The function ftrace_replace_code() is the ftrace engine that does the
work to modify all the nops into the calls to the function callback in
all the functions being traced.

The generic version which is normally called from stop machine, but an
architecture can implement a non stop machine version and still use the
generic ftrace_replace_code(). When an architecture does this,
ftrace_replace_code() may be called from a schedulable context, where
it can allow the code to be preemptible, and schedule out.

In order to allow an architecture to make ftrace_replace_code()
schedulable, a new command flag is added called:

 FTRACE_MAY_SLEEP

Which can be or'd to the command that is passed to
ftrace_modify_all_code() that calls ftrace_replace_code() and will have
it call cond_resched() in the loop that modifies the nops into the
calls to the ftrace trampolines.

Link: http://lkml.kernel.org/r/20181204192903.8193-1-anders.roxell@linaro.org
Link: http://lkml.kernel.org/r/20181205183303.828422192@goodmis.org

Reported-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-10 12:22:45 -05:00
Steven Rostedt (VMware) b0e21a61d3 function_graph: Have profiler use new helper ftrace_graph_get_ret_stack()
The ret_stack processing is going to change, and that is going
to break anything that is accessing the ret_stack directly. One user is the
function graph profiler. By using the ftrace_graph_get_ret_stack() helper
function, the profiler can access the ret_stack entry without relying on the
implementation details of the stack itself.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:07 -05:00
Steven Rostedt (VMware) 688f7089d8 fgraph: Add new fgraph_ops structure to enable function graph hooks
Currently the registering of function graph is to pass in a entry and return
function. We need to have a way to associate those functions together where
the entry can determine to run the return hook. Having a structure that
contains both functions will facilitate the process of converting the code
to be able to do such.

This is similar to the way function hooks are enabled (it passes in
ftrace_ops). Instead of passing in the functions to use, a single structure
is passed in to the registering function.

The unregister function is now passed in the fgraph_ops handle. When we
allow more than one callback to the function graph hooks, this will let the
system know which one to remove.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:07 -05:00
Steven Rostedt (VMware) 761efe8a94 function_graph: Remove the use of FTRACE_NOTRACE_DEPTH
The curr_ret_stack is no longer set to a negative value when a function is
not to be traced by the function graph tracer. Remove the usage of
FTRACE_NOTRACE_DEPTH, as it is no longer needed.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-12-08 20:54:06 -05:00
Ingo Molnar df60673198 Linux 4.20-rc5
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Merge tag 'v4.20-rc5' into x86/cleanups, to sync up the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-12-03 10:47:53 +01:00
Steven Rostedt (VMware) 23621fac32 function_graph: Remove unused task_curr_ret_stack()
The static inline function task_curr_ret_stack() is unused, remove it.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-29 23:38:34 -05:00
Steven Rostedt (VMware) d125f3f866 function_graph: Make ftrace_push_return_trace() static
As all architectures now call function_graph_enter() to do the entry work,
no architecture should ever call ftrace_push_return_trace(). Make it static.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-27 20:31:54 -05:00
Steven Rostedt (VMware) 8114865ff8 function_graph: Create function_graph_enter() to consolidate architecture code
Currently all the architectures do basically the same thing in preparing the
function graph tracer on entry to a function. This code can be pulled into a
generic location and then this will allow the function graph tracer to be
fixed, as well as extended.

Create a new function graph helper function_graph_enter() that will call the
hook function (ftrace_graph_entry) and the shadow stack operation
(ftrace_push_return_trace), and remove the need of the architecture code to
manage the shadow stack.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: stable@kernel.org
Fixes: 03274a3ffb ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-11-26 16:18:04 -05:00
Yi Wang 89f579ce99 x86/headers: Fix -Wmissing-prototypes warning
When building the kernel with W=1 we get a lot of -Wmissing-prototypes
warnings, which are trivial in nature and easy to fix - and which may
mask some real future bugs if the prototypes get out of sync with
the function definition.

This patch fixes most of -Wmissing-prototypes warnings which
are in the root directory of arch/x86/kernel, not including
the subdirectories.

These are the warnings fixed in this patch:

  arch/x86/kernel/signal.c:865:17: warning: no previous prototype for ‘sys32_x32_rt_sigreturn’ [-Wmissing-prototypes]
  arch/x86/kernel/signal_compat.c:164:6: warning: no previous prototype for ‘sigaction_compat_abi’ [-Wmissing-prototypes]
  arch/x86/kernel/traps.c:625:46: warning: no previous prototype for ‘sync_regs’ [-Wmissing-prototypes]
  arch/x86/kernel/traps.c:640:24: warning: no previous prototype for ‘fixup_bad_iret’ [-Wmissing-prototypes]
  arch/x86/kernel/traps.c:929:13: warning: no previous prototype for ‘trap_init’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:270:28: warning: no previous prototype for ‘smp_x86_platform_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:301:16: warning: no previous prototype for ‘smp_kvm_posted_intr_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:314:16: warning: no previous prototype for ‘smp_kvm_posted_intr_wakeup_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq.c:328:16: warning: no previous prototype for ‘smp_kvm_posted_intr_nested_ipi’ [-Wmissing-prototypes]
  arch/x86/kernel/irq_work.c:16:28: warning: no previous prototype for ‘smp_irq_work_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/irqinit.c:79:13: warning: no previous prototype for ‘init_IRQ’ [-Wmissing-prototypes]
  arch/x86/kernel/quirks.c:672:13: warning: no previous prototype for ‘early_platform_quirks’ [-Wmissing-prototypes]
  arch/x86/kernel/tsc.c:1499:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes]
  arch/x86/kernel/process.c:653:13: warning: no previous prototype for ‘arch_post_acpi_subsys_init’ [-Wmissing-prototypes]
  arch/x86/kernel/process.c:717:15: warning: no previous prototype for ‘arch_randomize_brk’ [-Wmissing-prototypes]
  arch/x86/kernel/process.c:784:6: warning: no previous prototype for ‘do_arch_prctl_common’ [-Wmissing-prototypes]
  arch/x86/kernel/reboot.c:869:6: warning: no previous prototype for ‘nmi_panic_self_stop’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:176:27: warning: no previous prototype for ‘smp_reboot_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:260:28: warning: no previous prototype for ‘smp_reschedule_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:281:28: warning: no previous prototype for ‘smp_call_function_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/smp.c:291:28: warning: no previous prototype for ‘smp_call_function_single_interrupt’ [-Wmissing-prototypes]
  arch/x86/kernel/ftrace.c:840:6: warning: no previous prototype for ‘arch_ftrace_update_trampoline’ [-Wmissing-prototypes]
  arch/x86/kernel/ftrace.c:934:7: warning: no previous prototype for ‘arch_ftrace_trampoline_func’ [-Wmissing-prototypes]
  arch/x86/kernel/ftrace.c:946:6: warning: no previous prototype for ‘arch_ftrace_trampoline_free’ [-Wmissing-prototypes]
  arch/x86/kernel/crash.c:114:6: warning: no previous prototype for ‘crash_smp_send_stop’ [-Wmissing-prototypes]
  arch/x86/kernel/crash.c:351:5: warning: no previous prototype for ‘crash_setup_memmap_entries’ [-Wmissing-prototypes]
  arch/x86/kernel/crash.c:424:5: warning: no previous prototype for ‘crash_load_segments’ [-Wmissing-prototypes]
  arch/x86/kernel/machine_kexec_64.c:372:7: warning: no previous prototype for ‘arch_kexec_kernel_image_load’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:12:16: warning: no previous prototype for ‘__native_queued_spin_unlock’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:18:6: warning: no previous prototype for ‘pv_is_native_spin_unlock’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:24:16: warning: no previous prototype for ‘__native_vcpu_is_preempted’ [-Wmissing-prototypes]
  arch/x86/kernel/paravirt-spinlocks.c:30:6: warning: no previous prototype for ‘pv_is_native_vcpu_is_preempted’ [-Wmissing-prototypes]
  arch/x86/kernel/kvm.c:258:1: warning: no previous prototype for ‘do_async_page_fault’ [-Wmissing-prototypes]
  arch/x86/kernel/jailhouse.c:200:6: warning: no previous prototype for ‘jailhouse_paravirt’ [-Wmissing-prototypes]
  arch/x86/kernel/check.c:91:13: warning: no previous prototype for ‘setup_bios_corruption_check’ [-Wmissing-prototypes]
  arch/x86/kernel/check.c:139:6: warning: no previous prototype for ‘check_for_bios_corruption’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:32:13: warning: no previous prototype for ‘early_init_dt_scan_chosen_arch’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:42:13: warning: no previous prototype for ‘add_dtb’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:108:6: warning: no previous prototype for ‘x86_of_pci_init’ [-Wmissing-prototypes]
  arch/x86/kernel/devicetree.c:314:13: warning: no previous prototype for ‘x86_dtb_init’ [-Wmissing-prototypes]
  arch/x86/kernel/tracepoint.c:16:5: warning: no previous prototype for ‘trace_pagefault_reg’ [-Wmissing-prototypes]
  arch/x86/kernel/tracepoint.c:22:6: warning: no previous prototype for ‘trace_pagefault_unreg’ [-Wmissing-prototypes]
  arch/x86/kernel/head64.c:113:22: warning: no previous prototype for ‘__startup_64’ [-Wmissing-prototypes]
  arch/x86/kernel/head64.c:262:15: warning: no previous prototype for ‘__startup_secondary_64’ [-Wmissing-prototypes]
  arch/x86/kernel/head64.c:350:12: warning: no previous prototype for ‘early_make_pgtable’ [-Wmissing-prototypes]

[ mingo: rewrote the changelog, fixed build errors. ]

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: akpm@linux-foundation.org
Cc: andy.shevchenko@gmail.com
Cc: anton@enomsg.org
Cc: ard.biesheuvel@linaro.org
Cc: bhe@redhat.com
Cc: bhelgaas@google.com
Cc: bp@alien8.de
Cc: ccross@android.com
Cc: devicetree@vger.kernel.org
Cc: douly.fnst@cn.fujitsu.com
Cc: dwmw@amazon.co.uk
Cc: dyoung@redhat.com
Cc: ebiederm@xmission.com
Cc: frank.rowand@sony.com
Cc: frowand.list@gmail.com
Cc: ivan.gorinov@intel.com
Cc: jailhouse-dev@googlegroups.com
Cc: jan.kiszka@siemens.com
Cc: jgross@suse.com
Cc: jroedel@suse.de
Cc: keescook@chromium.org
Cc: kexec@lists.infradead.org
Cc: konrad.wilk@oracle.com
Cc: kvm@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: luto@kernel.org
Cc: m.mizuma@jp.fujitsu.com
Cc: namit@vmware.com
Cc: oleg@redhat.com
Cc: pasha.tatashin@oracle.com
Cc: pbonzini@redhat.com
Cc: prarit@redhat.com
Cc: pravin.shedge4linux@gmail.com
Cc: rajvi.jingar@intel.com
Cc: rkrcmar@redhat.com
Cc: robh+dt@kernel.org
Cc: robh@kernel.org
Cc: rostedt@goodmis.org
Cc: takahiro.akashi@linaro.org
Cc: thomas.lendacky@amd.com
Cc: tony.luck@intel.com
Cc: up2wing@gmail.com
Cc: virtualization@lists.linux-foundation.org
Cc: zhe.he@windriver.com
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1542852249-19820-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-11-23 07:59:59 +01:00