Commit Graph

239 Commits

Author SHA1 Message Date
Omar Sandoval b9f174c811 x86/unwind/orc: Add ELF section with ORC version identifier
Commits ffb1b4a410 ("x86/unwind/orc: Add 'signal' field to ORC
metadata") and fb799447ae ("x86,objtool: Split UNWIND_HINT_EMPTY in
two") changed the ORC format. Although ORC is internal to the kernel,
it's the only way for external tools to get reliable kernel stack traces
on x86-64. In particular, the drgn debugger [1] uses ORC for stack
unwinding, and these format changes broke it [2]. As the drgn
maintainer, I don't care how often or how much the kernel changes the
ORC format as long as I have a way to detect the change.

It suffices to store a version identifier in the vmlinux and kernel
module ELF files (to use when parsing ORC sections from ELF), and in
kernel memory (to use when parsing ORC from a core dump+symbol table).
Rather than hard-coding a version number that needs to be manually
bumped, Peterz suggested hashing the definitions from orc_types.h. If
there is a format change that isn't caught by this, the hashing script
can be updated.

This patch adds an .orc_header allocated ELF section containing the
20-byte hash to vmlinux and kernel modules, along with the corresponding
__start_orc_header and __stop_orc_header symbols in vmlinux.

1: https://github.com/osandov/drgn
2: https://github.com/osandov/drgn/issues/303

Fixes: ffb1b4a410 ("x86/unwind/orc: Add 'signal' field to ORC metadata")
Fixes: fb799447ae ("x86,objtool: Split UNWIND_HINT_EMPTY in two")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://lkml.kernel.org/r/aef9c8dc43915b886a8c48509a12ec1b006ca1ca.1686690801.git.osandov@osandov.com
2023-06-16 17:17:42 +02:00
Arnd Bergmann f9bb7f6a7e x86/build: Make 64-bit defconfig the default
Running 'make ARCH=x86 defconfig' on anything other than an x86_64
machine currently results in a 32-bit build, which is rarely what
anyone wants these days.

Change the default so that the 64-bit config gets used unless
the user asks for i386_defconfig, uses ARCH=i386 or runs on
a system that "uname -m" identifies as i386/i486/i586/i686.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230215091706.1623070-1-arnd@kernel.org
2023-02-15 14:20:17 +01:00
Nathan Chancellor 27b5de622e x86/build: Move '-mindirect-branch-cs-prefix' out of GCC-only block
LLVM 16 will have support for this flag so move it out of the GCC-only
block to allow LLVM builds to take advantage of it.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1665
Link: 6f867f9102
Link: https://lore.kernel.org/r/20230120165826.2469302-1-nathan@kernel.org
2023-01-22 11:36:45 +01:00
Linus Torvalds 6feb57c2fd Kbuild updates for v6.2
- Support zstd-compressed debug info
 
  - Allow W=1 builds to detect objects shared among multiple modules
 
  - Add srcrpm-pkg target to generate a source RPM package
 
  - Make the -s option detection work for future GNU Make versions
 
  - Add -Werror to KBUILD_CPPFLAGS when CONFIG_WERROR=y
 
  - Allow W=1 builds to detect -Wundef warnings in any preprocessed files
 
  - Raise the minimum supported version of binutils to 2.25
 
  - Use $(intcmp ...) to compare integers if GNU Make >= 4.4 is used
 
  - Use $(file ...) to read a file if GNU Make >= 4.2 is used
 
  - Print error if GNU Make older than 3.82 is used
 
  - Allow modpost to detect section mismatches with Clang LTO
 
  - Include vmlinuz.efi into kernel tarballs for arm64 CONFIG_EFI_ZBOOT=y
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmOeImsVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsG06IP/iVjuWFvnjDZT4X8X6zN8aKp1vtR
 EMkmoRtt5cD4CLb1MG4N7irYHgedQSx4rYceP45MyW1I3egl6Ct14RDyeQ1xSIZb
 XFTLDCZvfl/up3MdiqNAqKRS7x5lk9++7F0t+2SoQxKQyJvm735XreX+VhZ1FeLB
 qcHrmzJ5veky5Ry/3OkNUgKFBjKEAL+qKMc55uvkXqfTb3KoBa2r4VC1OaoYGRru
 R8oF9qQRnGVQAl/LbBVchmgSjxryxPrCvBGiKlK03VkXdzEMHMimEJh3BQ6e0PGo
 gajdk+4liy7z+jQnI7jFhvJjGKzkEP/Bc99M/uS92QX5MgpH6mqpHMoqqPiqW87K
 RmZH37FqRu1Vo8dpibmH6r2K6YD/HHRjaDHk1VuuCQYEn0dsNmokPXOqd/1v0I1i
 TXPjWOw1AID5vMJWllqxFhpeVvf0vx5BT/UNrh68MLqlJZzv2eMVJb4fNy6640ml
 U0NclMnOa3eOmf5z1T7/LqDRTa63Q0kpanRrBpcmVOaqW+ZpQ3SQjh4uBN1PyJHL
 cX3Skc341DyRlFiT54QhGKlm57MEb2gjhBZ3Z4J+b7sEFgvjXH/W8vcOGIKlppmA
 CfYMyres4OV+fJc89ONkWsvLiOP1OeUGPvytm33J5QMKXc8SzOLP0D/F8kjrDflm
 EROKuZ4EA5ej/rOy
 =Ig/Y
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Support zstd-compressed debug info

 - Allow W=1 builds to detect objects shared among multiple modules

 - Add srcrpm-pkg target to generate a source RPM package

 - Make the -s option detection work for future GNU Make versions

 - Add -Werror to KBUILD_CPPFLAGS when CONFIG_WERROR=y

 - Allow W=1 builds to detect -Wundef warnings in any preprocessed files

 - Raise the minimum supported version of binutils to 2.25

 - Use $(intcmp ...) to compare integers if GNU Make >= 4.4 is used

 - Use $(file ...) to read a file if GNU Make >= 4.2 is used

 - Print error if GNU Make older than 3.82 is used

 - Allow modpost to detect section mismatches with Clang LTO

 - Include vmlinuz.efi into kernel tarballs for arm64 CONFIG_EFI_ZBOOT=y

* tag 'kbuild-v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (29 commits)
  buildtar: fix tarballs with EFI_ZBOOT enabled
  modpost: Include '.text.*' in TEXT_SECTIONS
  padata: Mark padata_work_init() as __ref
  kbuild: ensure Make >= 3.82 is used
  kbuild: refactor the prerequisites of the modpost rule
  kbuild: change module.order to list *.o instead of *.ko
  kbuild: use .NOTINTERMEDIATE for future GNU Make versions
  kconfig: refactor Makefile to reduce process forks
  kbuild: add read-file macro
  kbuild: do not sort after reading modules.order
  kbuild: add test-{ge,gt,le,lt} macros
  Documentation: raise minimum supported version of binutils to 2.25
  kbuild: add -Wundef to KBUILD_CPPFLAGS for W=1 builds
  kbuild: move -Werror from KBUILD_CFLAGS to KBUILD_CPPFLAGS
  kbuild: Port silent mode detection to future gnu make.
  init/version.c: remove #include <generated/utsrelease.h>
  firmware_loader: remove #include <generated/utsrelease.h>
  modpost: Mark uuid_le type to be suitable only for MEI
  kbuild: add ability to make source rpm buildable using koji
  kbuild: warn objects shared among multiple modules
  ...
2022-12-19 12:33:32 -06:00
Masahiro Yamada fccb3d3eda kbuild: add test-{ge,gt,le,lt} macros
GNU Make 4.4 introduced $(intcmp ...), which is useful to compare two
integers without forking a new process.

Add test-{ge,gt,le,lt} macros, which work more efficiently with GNU
Make >= 4.4. For older Make versions, they fall back to the 'test'
shell command.

The first two parameters to $(intcmp ...) must not be empty. To avoid
the syntax error, I appended '0' to them. Fortunately, '00' is treated
as '0'. This is needed because CONFIG options may expand to an empty
string when the kernel configuration is not included.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com> # RISC-V
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-12-13 22:21:14 +09:00
Peter Zijlstra 931ab63664 x86/ibt: Implement FineIBT
Implement an alternative CFI scheme that merges both the fine-grained
nature of kCFI but also takes full advantage of the coarse grained
hardware CFI as provided by IBT.

To contrast:

  kCFI is a pure software CFI scheme and relies on being able to read
text -- specifically the instruction *before* the target symbol, and
does the hash validation *before* doing the call (otherwise control
flow is compromised already).

  FineIBT is a software and hardware hybrid scheme; by ensuring every
branch target starts with a hash validation it is possible to place
the hash validation after the branch. This has several advantages:

   o the (hash) load is avoided; no memop; no RX requirement.

   o IBT WAIT-FOR-ENDBR state is a speculation stop; by placing
     the hash validation in the immediate instruction after
     the branch target there is a minimal speculation window
     and the whole is a viable defence against SpectreBHB.

   o Kees feels obliged to mention it is slightly more vulnerable
     when the attacker can write code.

Obviously this patch relies on kCFI, but additionally it also relies
on the padding from the call-depth-tracking patches. It uses this
padding to place the hash-validation while the call-sites are
re-written to modify the indirect target to be 16 bytes in front of
the original target, thus hitting this new preamble.

Notably, there is no hardware that needs call-depth-tracking (Skylake)
and supports IBT (Tigerlake and onwards).

Suggested-by: Joao Moreira (Intel) <joao@overdrivepizza.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221027092842.634714496@infradead.org
2022-11-01 13:44:10 +01:00
Thomas Gleixner bea75b3389 x86/Kconfig: Introduce function padding
Now that all functions are 16 byte aligned, add 16 bytes of NOP
padding in front of each function. This prepares things for software
call stack tracking and kCFI/FineIBT.

This significantly increases kernel .text size, around 5.1% on a
x86_64-defconfig-ish build.

However, per the random access argument used for alignment, these 16
extra bytes are code that wouldn't be used. Performance measurements
back this up by showing no significant performance regressions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111146.950884492@infradead.org
2022-10-17 16:41:10 +02:00
Linus Torvalds 8afc66e8d4 Kbuild updates for v6.1
- Remove potentially incomplete targets when Kbuid is interrupted by
    SIGINT etc. in case GNU Make may miss to do that when stderr is piped
    to another program.
 
  - Rewrite the single target build so it works more correctly.
 
  - Fix rpm-pkg builds with V=1.
 
  - List top-level subdirectories in ./Kbuild.
 
  - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in kallsyms.
 
  - Avoid two different modules in lib/zstd/ having shared code, which
    potentially causes building the common code as build-in and modular
    back-and-forth.
 
  - Unify two modpost invocations to optimize the build process.
 
  - Remove head-y syntax in favor of linker scripts for placing particular
    sections in the head of vmlinux.
 
  - Bump the minimal GNU Make version to 3.82.
 
  - Clean up misc Makefiles and scripts.
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmM+4vcVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGY2IQAInr0JUNnkkxwUSXtOcQuA3IK8RJ
 FbU9HXJRoV9H+7+l3SMlN7mIbrs5eE5fTY3iwQ3CVe139d1+1q7nvTMRv8owywJx
 GBgzswncuu1lk7iQQ//CxiqMwSCG8GJdYn1uDVy4I5jg3o+DtFZJtyq2Wb7pqsMm
 ZhZ4PozRN+idYQJSF6Vx/zEVLHI7quMBwfe4CME8/0Kg2+hnYzbXV/aUf0ED2emq
 zdCMDQgIOK5AhY+8qgMXKYnBUJMTqBp6LoR4p3ApfUkwRFY0sGa0/LK3U/B22OE7
 uWyR4fCUExGyerlcHEVev+9eBfmsLLPyqlchNwpSDOPf5OSdnKmgqJEBR/Cvx0eh
 URerPk7EHxyH3G8yi+cU2GtofNTGc5RHPRgJE2ADsQEi5TAUKGmbXMlsFRL/51Vn
 lTANZObBNa1d4enljF6TfTL5nuccOa+DKvXnH9fQ49t0QdtSikv6J/lGwilwm1Sr
 BctmCsySPuURZfkpI9OQnLuouloMXl9f7Q/+S39haS/tSgvPpyITyO71nxDnXn/s
 BbFObZJUk9QkqOACjBP1hNErTLt83uBxQ9z+rDCw/SbLIe4nw0wyneuygfHI5rI8
 3RZB2DbGauuJHX2Zs6YGS14SLSY33IsLqKR1/Vy3LrPvOHuEvNiOR8LITq5E0YCK
 OffK2Y5cIlXR0QWf
 =DHiN
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Remove potentially incomplete targets when Kbuid is interrupted by
   SIGINT etc in case GNU Make may miss to do that when stderr is piped
   to another program.

 - Rewrite the single target build so it works more correctly.

 - Fix rpm-pkg builds with V=1.

 - List top-level subdirectories in ./Kbuild.

 - Ignore auto-generated __kstrtab_* and __kstrtabns_* symbols in
   kallsyms.

 - Avoid two different modules in lib/zstd/ having shared code, which
   potentially causes building the common code as build-in and modular
   back-and-forth.

 - Unify two modpost invocations to optimize the build process.

 - Remove head-y syntax in favor of linker scripts for placing
   particular sections in the head of vmlinux.

 - Bump the minimal GNU Make version to 3.82.

 - Clean up misc Makefiles and scripts.

* tag 'kbuild-v6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (41 commits)
  docs: bump minimal GNU Make version to 3.82
  ia64: simplify esi object addition in Makefile
  Revert "kbuild: Check if linker supports the -X option"
  kbuild: rebuild .vmlinux.export.o when its prerequisite is updated
  kbuild: move modules.builtin(.modinfo) rules to Makefile.vmlinux_o
  zstd: Fixing mixed module-builtin objects
  kallsyms: ignore __kstrtab_* and __kstrtabns_* symbols
  kallsyms: take the input file instead of reading stdin
  kallsyms: drop duplicated ignore patterns from kallsyms.c
  kbuild: reuse mksysmap output for kallsyms
  mksysmap: update comment about __crc_*
  kbuild: remove head-y syntax
  kbuild: use obj-y instead extra-y for objects placed at the head
  kbuild: hide error checker logs for V=1 builds
  kbuild: re-run modpost when it is updated
  kbuild: unify two modpost invocations
  kbuild: move vmlinux.o rule to the top Makefile
  kbuild: move .vmlinux.objs rule to Makefile.modpost
  kbuild: list sub-directories in ./Kbuild
  Makefile.compiler: replace cc-ifversion with compiler-specific macros
  ...
2022-10-10 12:00:45 -07:00
Masahiro Yamada ce697ccee1 kbuild: remove head-y syntax
Kbuild puts the objects listed in head-y at the head of vmlinux.
Conventionally, we do this for head*.S, which contains the kernel entry
point.

A counter approach is to control the section order by the linker script.
Actually, the code marked as __HEAD goes into the ".head.text" section,
which is placed before the normal ".text" section.

I do not know if both of them are needed. From the build system
perspective, head-y is not mandatory. If you can achieve the proper code
placement by the linker script only, it would be cleaner.

I collected the current head-y objects into head-object-list.txt. It is
a whitelist. My hope is it will be reduced in the long run.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-10-02 18:06:03 +09:00
Miguel Ojeda 094981352c x86: enable initial Rust support
Note that only x86_64 is covered and not all features nor mitigations
are handled, but it is enough as a starting point and showcases
the basics needed to add Rust support for a new architecture.

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: David Gow <davidgow@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 09:02:45 +02:00
Nick Desaulniers a0a12c3ed0 asm goto: eradicate CC_HAS_ASM_GOTO
GCC has supported asm goto since 4.5, and Clang has since version 9.0.0.
The minimum supported versions of these tools for the build according to
Documentation/process/changes.rst are 5.1 and 11.0.0 respectively.

Remove the feature detection script, Kconfig option, and clean up some
fallback code that is no longer supported.

The removed script was also testing for a GCC specific bug that was
fixed in the 4.7 release.

Also remove workarounds for bpftrace using clang older than 9.0.0, since
other BPF backend fixes are required at this point.

Link: https://lore.kernel.org/lkml/CAK7LNATSr=BXKfkdW8f-H5VT_w=xBpT2ZQcZ7rm6JfkdE+QnmA@mail.gmail.com/
Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637
Acked-by: Borislav Petkov <bp@suse.de>
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-08-21 10:06:28 -07:00
Josh Poimboeuf efc72a665a lkdtm: Disable return thunks in rodata.c
The following warning was seen:

  WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:557 apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1))
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.19.0-rc4-00008-gee88d363d156 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014
  RIP: 0010:apply_returns (arch/x86/kernel/alternative.c:557 (discriminator 1))
  Code: ff ff 74 cb 48 83 c5 04 49 39 ee 0f 87 81 fe ff ff e9 22 ff ff ff 0f 0b 48 83 c5 04 49 39 ee 0f 87 6d fe ff ff e9 0e ff ff ff <0f> 0b 48 83 c5 04 49 39 ee 0f 87 59 fe ff ff e9 fa fe ff ff 48 89

The warning happened when apply_returns() failed to convert "JMP
__x86_return_thunk" to RET.  It was instead a JMP to nowhere, due to the
thunk relocation not getting resolved.

That rodata.o code is objcopy'd to .rodata, and later memcpy'd, so
relocations don't work (and are apparently silently ignored).

LKDTM is only used for testing, so the naked RET should be fine.  So
just disable return thunks for that file.

While at it, disable objtool and KCSAN for the file.

Fixes: 0b53c374b9 ("x86/retpoline: Use -mfunction-return")
Reported-by: kernel test robot <oliver.sang@intel.com>
Debugged-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Ys58BxHxoDZ7rfpr@xsang-OptiPlex-9020/
2022-07-20 19:24:53 +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
Peter Zijlstra 0b53c374b9 x86/retpoline: Use -mfunction-return
Utilize -mfunction-return=thunk-extern when available to have the
compiler replace RET instructions with direct JMPs to the symbol
__x86_return_thunk. This does not affect assembler (.S) sources, only C
sources.

-mfunction-return=thunk-extern has been available since gcc 7.3 and
clang 15.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
2022-06-27 10:33:58 +02:00
Linus Torvalds df202b452f Kbuild updates for v5.19
- Add HOSTPKG_CONFIG env variable to allow users to override pkg-config
 
  - Support W=e as a shorthand for KCFLAGS=-Werror
 
  - Fix CONFIG_IKHEADERS build to support toybox cpio
 
  - Add scripts/dummy-tools/pahole to ease distro packagers' life
 
  - Suppress false-positive warnings from checksyscalls.sh for W=2 build
 
  - Factor out the common code of arch/*/boot/install.sh into
    scripts/install.sh
 
  - Support 'kernel-install' tool in scripts/prune-kernel
 
  - Refactor module-versioning to link the symbol versions at the final
    link of vmlinux and modules
 
  - Remove CONFIG_MODULE_REL_CRCS because module-versioning now works in
    an arch-agnostic way
 
  - Refactor modpost, Makefiles
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmKOO2oVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGG54P/3/U5FIP5EoPAVu9HqSUKeeUiBYc
 z1B8d7Wt1xU0xHImPWNjoacfye4MrDMUv8mEWKgHCVusJxbUoS+3Z/kd64NU75Fg
 Cpj+9fP1N8m02IJzraxn6fw0bmfx4zp9Zsa9l2fjwL0emq4qhB7BA9/Nl6Png1IW
 p0TPR6gV0Wgp6ikf/eJ3b1decFSqM7QzDlbo860nPMG164gNpDZmFVf2G4HCRQoY
 GtgoQLEy2pBeOdU7+nJTKl2f5JOhDjRKX8equ7BHW9l7nbUvHd6ys3DGqYO3nvwV
 hZZdHwDtxxO6bJtzClKPREyfL2H9R2AGxq94HzSwdvwdLLoFxrTN+mg88xBg17Rm
 tKHy8jpZT36qh218h5lX5n9ZWcovTA38giZ+S/tkwOvvYGivKHDS23QwzB0HrG8/
 VRd+0rhfIvuIpu0OQaTpTkZr2QVci2Zn6PPnxpyPEsGvWVFRjyx0WyZh4fFXnkQT
 n+GS7j5g1LVMra0qu0y+yp4zy/DVFKIcfry0xU8S5SaSEBBcWUxLS2nnoBVB4vb2
 RpiVD2vaOlvu/Zs2SOgtuMOnTw+Qqrvh7OYm/WyxWrB3JQGa/r+vipMKiFEDi2NN
 pwR8wJT/CW1ycte93m3oO83jiitFqzXtAqo24wKlp4SOqnR/TQ/dx743ku2xvONe
 uynJVW/gZVm4KEUl
 =Y2TB
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add HOSTPKG_CONFIG env variable to allow users to override pkg-config

 - Support W=e as a shorthand for KCFLAGS=-Werror

 - Fix CONFIG_IKHEADERS build to support toybox cpio

 - Add scripts/dummy-tools/pahole to ease distro packagers' life

 - Suppress false-positive warnings from checksyscalls.sh for W=2 build

 - Factor out the common code of arch/*/boot/install.sh into
   scripts/install.sh

 - Support 'kernel-install' tool in scripts/prune-kernel

 - Refactor module-versioning to link the symbol versions at the final
   link of vmlinux and modules

 - Remove CONFIG_MODULE_REL_CRCS because module-versioning now works in
   an arch-agnostic way

 - Refactor modpost, Makefiles

* tag 'kbuild-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (56 commits)
  genksyms: adjust the output format to modpost
  kbuild: stop merging *.symversions
  kbuild: link symbol CRCs at final link, removing CONFIG_MODULE_REL_CRCS
  modpost: extract symbol versions from *.cmd files
  modpost: add sym_find_with_module() helper
  modpost: change the license of EXPORT_SYMBOL to bool type
  modpost: remove left-over cross_compile declaration
  kbuild: record symbol versions in *.cmd files
  kbuild: generate a list of objects in vmlinux
  modpost: move *.mod.c generation to write_mod_c_files()
  modpost: merge add_{intree_flag,retpoline,staging_flag} to add_header
  scripts/prune-kernel: Use kernel-install if available
  kbuild: factor out the common installation code into scripts/install.sh
  modpost: split new_symbol() to symbol allocation and hash table addition
  modpost: make sym_add_exported() always allocate a new symbol
  modpost: make multiple export error
  modpost: dump Module.symvers in the same order of modules.order
  modpost: traverse the namespace_list in order
  modpost: use doubly linked list for dump_lists
  modpost: traverse unresolved symbols in order
  ...
2022-05-26 12:09:50 -07:00
Masahiro Yamada f774f5bb87 kbuild: factor out the common installation code into scripts/install.sh
Many architectures have similar install.sh scripts.

The first half is really generic; it verifies that the kernel image
and System.map exist, then executes ~/bin/${INSTALLKERNEL} or
/sbin/${INSTALLKERNEL} if available.

The second half is kind of arch-specific; it copies the kernel image
and System.map to the destination, but the code is slightly different.

Factor out the generic part into scripts/install.sh.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
2022-05-11 21:45:53 +09:00
Dave Hansen 9b5a7f4a2a x86/configs: Add x86 debugging Kconfig fragment plus docs
The kernel has a wide variety of debugging options to help catch
and squash bugs.  However, new debugging is added all the time and
the existing options can be hard to find.

Add a Kconfig fragment with the debugging options which tip
maintainers expect to be used to test contributions.

This should make it easier for contributors to test their code and
find issues before submission.

  [ bp: Add to "make help" output, fix DEBUG_INFO selection as pointed
        out by Nathan Chancellor <nathan@kernel.org>. ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220331175728.299103A0@davehans-spike.ostc.intel.com
2022-04-06 19:56:29 +02:00
Masahiro Yamada 83a44a4f47 x86: Remove toolchain check for X32 ABI capability
Commit 0bf6276392 ("x32: Warn and disable rather than error if
binutils too old") added a small test in arch/x86/Makefile because
binutils 2.22 or newer is needed to properly support elf32-x86-64. This
check is no longer necessary, as the minimum supported version of
binutils is 2.23, which is enforced at configuration time with
scripts/min-tool-version.sh.

Remove this check and replace all uses of CONFIG_X86_X32 with
CONFIG_X86_X32_ABI, as two symbols are no longer necessary.

[nathan: Rebase, fix up a few places where CONFIG_X86_X32 was still
         used, and simplify commit message to satisfy -tip requirements]

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220314194842.3452-2-nathan@kernel.org
2022-03-15 10:32:48 +01:00
Peter Zijlstra 156ff4a544 x86/ibt: Base IBT bits
Add Kconfig, Makefile and basic instruction support for x86 IBT.

(Ab)use __DISABLE_EXPORTS to disable IBT since it's already employed
to mark compressed and purgatory. Additionally mark realmode with it
as well to avoid inserting ENDBR instructions there. While ENDBR is
technically a NOP, inserting them was causing some grief due to code
growth. There's also a problem with using __noendbr in code compiled
without -fcf-protection=branch.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.519875203@infradead.org
2022-03-15 10:32:33 +01:00
Peter Zijlstra e463a09af2 x86: Add straight-line-speculation mitigation
Make use of an upcoming GCC feature to mitigate
straight-line-speculation for x86:

  https://gcc.gnu.org/g:53a643f8568067d7700a9f2facc8ba39974973d3
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952
  https://bugs.llvm.org/show_bug.cgi?id=52323

It's built tested on x86_64-allyesconfig using GCC-12 and GCC-11.

Maintenance overhead of this should be fairly low due to objtool
validation.

Size overhead of all these additional int3 instructions comes to:

     text	   data	    bss	    dec	    hex	filename
  22267751	6933356	2011368	31212475	1dc43bb	defconfig-build/vmlinux
  22804126	6933356	1470696	31208178	1dc32f2	defconfig-build/vmlinux.sls

Or roughly 2.4% additional text.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134908.140103474@infradead.org
2021-12-09 13:32:25 +01:00
Peter Zijlstra 68cf4f2a72 x86: Use -mindirect-branch-cs-prefix for RETPOLINE builds
In order to further enable commit:

  bbe2df3f6b ("x86/alternative: Try inline spectre_v2=retpoline,amd")

add the new GCC flag -mindirect-branch-cs-prefix:

  https://gcc.gnu.org/g:2196a681d7810ad8b227bf983f38ba716620545e
  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102952
  https://bugs.llvm.org/show_bug.cgi?id=52323

to RETPOLINE=y builds. This should allow fully inlining retpoline,amd
for GCC builds.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lkml.kernel.org/r/20211119165630.276205624@infradead.org
2021-12-08 11:57:04 +01:00
Peter Zijlstra b2f825bfed x86: Move RETPOLINE*_CFLAGS to arch Makefile
Currently, RETPOLINE*_CFLAGS are defined in the top-level Makefile
but only x86 makes use of them. Move them there. If ever another
architecture finds the need, it can be reconsidered.

  [ bp: Massage a bit. ]

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lkml.kernel.org/r/20211119165630.219152765@infradead.org
2021-12-08 11:39:42 +01:00
Linus Torvalds 1e9ed9360f Kbuild updates for v5.16
- Remove the global -isystem compiler flag, which was made possible by
    the introduction of <linux/stdarg.h>
 
  - Improve the Kconfig help to print the location in the top menu level
 
  - Fix "FORCE prerequisite is missing" build warning for sparc
 
  - Add new build targets, tarzst-pkg and perf-tarzst-src-pkg, which generate
    a zstd-compressed tarball
 
  - Prevent gen_init_cpio tool from generating a corrupted cpio when
    KBUILD_BUILD_TIMESTAMP is set to 2106-02-07 or later
 
  - Misc cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmGGkysVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGgZkQAIX4i9Tt6pyl/2xGDGkzUqjprfoH
 QUIo1DoUclLUygoakrrrX3EnZLWrslgPTKjQxdiV6RA6xHfe4cYgNTSq8zM9lsPT
 lu+B4nEDqoXQ5gyLxMlnjS3FRQTNYIeBZEhSAIiW8TENdLKlKc+NYdoj7th50dO0
 SkXRa2dpWHa6t7ZRqHIHMpUWA7gm0w22ZbgQmyUv1CDGO4IHPLqe2b2PMsrzhSZ1
 yypP1l6aQVKuP0hN9aytbTRqDxUd0uOzBf00PK5zx23hjdwZ9wmZrFTKDf9fAu/+
 nR7gBsa5YoYNQh3UkayZXjR5dClmgsCXZ25OXI7YucQp/8OJ5fadfn1NFpJHsw56
 n5cckbHIXgnFUcel5YlkR6qTHjpzdr9vHm90MmiuX99b3oy9czl6pY3qkNfRkllQ
 v7ME5L1qlw3P3ia1KA+H4zW/LIJ8p5cbKBwaY22m3kY3bTx7PiOfMlep4UVqxXSb
 0/OqxSsmYg5LlmwEQ0SSsx45hE0o9nG/cdjkHu1jUOUHxYfpt1T4MTILeGUwmjzd
 TydJym5MZyXBawu4NVB3QLoKm5Jt2BXtyaWOtq74VSrs77roNCdYuQWJ+1aBf2Pg
 0s4CVC2cC7KlxJDImoqswZATGXPMfbiVDcuVSSukYRgBMeCBPUzRhB8YP36BZyD3
 9vFYmqSujtUU7nWb
 =ATFN
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Remove the global -isystem compiler flag, which was made possible by
   the introduction of <linux/stdarg.h>

 - Improve the Kconfig help to print the location in the top menu level

 - Fix "FORCE prerequisite is missing" build warning for sparc

 - Add new build targets, tarzst-pkg and perf-tarzst-src-pkg, which
   generate a zstd-compressed tarball

 - Prevent gen_init_cpio tool from generating a corrupted cpio when
   KBUILD_BUILD_TIMESTAMP is set to 2106-02-07 or later

 - Misc cleanups

* tag 'kbuild-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
  kbuild: use more subdir- for visiting subdirectories while cleaning
  sh: remove meaningless archclean line
  initramfs: Check timestamp to prevent broken cpio archive
  kbuild: split DEBUG_CFLAGS out to scripts/Makefile.debug
  gen_init_cpio: add static const qualifiers
  kbuild: Add make tarzst-pkg build option
  scripts: update the comments of kallsyms support
  sparc: Add missing "FORCE" target when using if_changed
  kconfig: refactor conf_touch_dep()
  kconfig: refactor conf_write_dep()
  kconfig: refactor conf_write_autoconf()
  kconfig: add conf_get_autoheader_name()
  kconfig: move sym_escape_string_value() to confdata.c
  kconfig: refactor listnewconfig code
  kconfig: refactor conf_write_symbol()
  kconfig: refactor conf_write_heading()
  kconfig: remove 'const' from the return type of sym_escape_string_value()
  kconfig: rename a variable in the lexer to a clearer name
  kconfig: narrow the scope of variables in the lexer
  kconfig: Create links to main menu items in search
  ...
2021-11-08 09:15:45 -08:00
Elyes HAOUAS a757ac555c x86/Makefile: Remove unneeded whitespaces before tabs
Align the FDINITRD line to the FDARGS one with tabs.

 [ bp: Commit message. ]

Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211028121021.10384-1-ehaouas@noos.fr
2021-10-28 20:19:13 +02:00
Masahiro Yamada 8212f8986d kbuild: use more subdir- for visiting subdirectories while cleaning
Documentation/kbuild/makefiles.rst suggests to use "archclean" for
cleaning arch/$(SRCARCH)/boot/, but it is not a hard requirement.

Since commit d92cc4d516 ("kbuild: require all architectures to have
arch/$(SRCARCH)/Kbuild"), we can use the "subdir- += boot" trick for
all architectures. This can take advantage of the parallel option (-j)
for "make clean".

I also cleaned up the comments in arch/$(SRCARCH)/Makefile. The "archdep"
target no longer exists.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
2021-10-24 13:49:46 +09:00
Linus Torvalds b250e6d141 Kbuild updates for v5.15
- Add -s option (strict mode) to merge_config.sh to make it fail when
    any symbol is redefined.
 
  - Show a warning if a different compiler is used for building external
    modules.
 
  - Infer --target from ARCH for CC=clang to let you cross-compile the
    kernel without CROSS_COMPILE.
 
  - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.
 
  - Add <linux/stdarg.h> to the kernel source instead of borrowing
    <stdarg.h> from the compiler.
 
  - Add Nick Desaulniers as a Kbuild reviewer.
 
  - Drop stale cc-option tests.
 
  - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
    to handle symbols in inline assembly.
 
  - Show a warning if 'FORCE' is missing for if_changed rules.
 
  - Various cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmExXHoVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGAZwP/iHdEZzuQ4cz2uXUaV0fevj9jjPU
 zJ8wrrNabAiT6f5x861DsARQSR4OSt3zN0tyBNgZwUdotbe7ED5GegrgIUBMWlML
 QskhTEIZj7TexAX/20vx671gtzI3JzFg4c9BuriXCFRBvychSevdJPr65gMDOesL
 vOJnXe+SGXG2+fPWi/PxrcOItNRcveqo2GiWHT3g0Cv/DJUulu81gEkz3hrufnMR
 cjMeSkV0nJJcvI755OQBOUnEuigW64k4m2WxHPG24tU8cQOCqV6lqwOfNQBAn4+F
 OoaCMyPQT9gvGYwGExQMCXGg0wbUt1qnxzOVoA2qFCwbo+MFhqjBvPXab6VJm7CE
 mY3RrTtvxSqBdHI6EGcYeLjhycK9b+LLoJ1qc3S9FK8It6NoFFp4XV0R6ItPBls7
 mWi9VSpyI6k0AwLq+bGXEHvaX/bnnf/vfqn8H+w6mRZdXjFV8EB2DiOSRX/OqjVG
 RnvTtXzWWThLyXvWR3Jox4+7X6728oL7akLemoeZI6oTbJDm7dQgwpz5HbSyHXLh
 d+gUF3Y/6lqxT5N9GSVDxpD1bEMh2I7nGQ4M7WGbGas/3yUemF8wbBqGQo4a+YeD
 d9vGAUxDp2PQTtL2sjFo5Gd4PZEM9g7vwWzRvHe0o5NxKEXcBg25b8cD1hxrN9Y4
 Y1AAnc0kLO+My3PC
 =lw3M
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add -s option (strict mode) to merge_config.sh to make it fail when
   any symbol is redefined.

 - Show a warning if a different compiler is used for building external
   modules.

 - Infer --target from ARCH for CC=clang to let you cross-compile the
   kernel without CROSS_COMPILE.

 - Make the integrated assembler default (LLVM_IAS=1) for CC=clang.

 - Add <linux/stdarg.h> to the kernel source instead of borrowing
   <stdarg.h> from the compiler.

 - Add Nick Desaulniers as a Kbuild reviewer.

 - Drop stale cc-option tests.

 - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG
   to handle symbols in inline assembly.

 - Show a warning if 'FORCE' is missing for if_changed rules.

 - Various cleanups

* tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits)
  kbuild: redo fake deps at include/ksym/*.h
  kbuild: clean up objtool_args slightly
  modpost: get the *.mod file path more simply
  checkkconfigsymbols.py: Fix the '--ignore' option
  kbuild: merge vmlinux_link() between ARCH=um and other architectures
  kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh
  kbuild: merge vmlinux_link() between the ordinary link and Clang LTO
  kbuild: remove stale *.symversions
  kbuild: remove unused quiet_cmd_update_lto_symversions
  gen_compile_commands: extract compiler command from a series of commands
  x86: remove cc-option-yn test for -mtune=
  arc: replace cc-option-yn uses with cc-option
  s390: replace cc-option-yn uses with cc-option
  ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild
  sparc: move the install rule to arch/sparc/Makefile
  security: remove unneeded subdir-$(CONFIG_...)
  kbuild: sh: remove unused install script
  kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y
  kbuild: Switch to 'f' variants of integrated assembler flag
  kbuild: Shuffle blank line to improve comment meaning
  ...
2021-09-03 15:33:47 -07:00
Masahiro Yamada 081551266d x86/build: Move the install rule to arch/x86/Makefile
Currently, the install target in arch/x86/Makefile descends into
arch/x86/boot/Makefile to invoke the shell script, but there is no
good reason to do so.

arch/x86/Makefile can run the shell script directly.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210729140023.442101-2-masahiroy@kernel.org
2021-08-25 11:57:38 +02:00
Masahiro Yamada 6d61b8e66d x86/build: Remove the left-over bzlilo target
Commit

  f279b49f13 ("x86/boot: Modernize genimage script; hdimage+EFI support")

removed the bzlilo target from arch/x86/boot/Makefile.

Remove the left-over from arch/x86/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210729140023.442101-1-masahiroy@kernel.org
2021-08-25 11:49:21 +02:00
Nick Desaulniers 989ceac799 x86/build: Remove stale cc-option checks
cc-option, __cc-option, cc-option-yn, and cc-disable-warning all invoke
the compiler during build time, and can slow down the build when these
checks become stale for our supported compilers, whose minimally
supported versions increases over time.

See Documentation/process/changes.rst for the current supported minimal
versions (GCC 4.9+, clang 10.0.1+). Compiler version support for these
flags may be verified on godbolt.org.

The following flags are supported by all supported versions of GCC and
Clang. Remove their cc-option, __cc-option, and cc-option-yn tests.

  -Wno-address-of-packed-member
  -mno-avx
  -m32
  -mno-80387
  -march=k8
  -march=nocona
  -march=core2
  -march=atom
  -mtune=generic
  -mfentry

[ mingo: Fixed regression on GCC, via partial revert of the stack-boundary changes.  ]

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://github.com/ClangBuiltLinux/linux/issues/1436
Link: https://lkml.kernel.org/r/20210812183848.1519994-1-ndesaulniers@google.com
2021-08-22 10:24:27 +02:00
Masahiro Yamada d828563955 kbuild: do not require sub-make for separate output tree builds
As explained in commit 3204a7fb98 ("kbuild: prefix $(srctree)/ to some
included Makefiles"), I want to stop using --include-dir some day.

I already fixed up the top Makefile, but some arch Makefiles (mips, um,
x86) still include check-in Makefiles without $(srctree)/.

Fix them up so 'need-sub-make := 1' can go away for this case.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-08-10 08:23:39 +09:00
Linus Torvalds 81361b837a Kbuild updates for v5.14
- Increase the -falign-functions alignment for the debug option.
 
  - Remove ugly libelf checks from the top Makefile.
 
  - Make the silent build (-s) more silent.
 
  - Re-compile the kernel if KBUILD_BUILD_TIMESTAMP is specified.
 
  - Various script cleanups
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmDon90VHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGWFUP/RGNwlGD/YV1xg0ZmM0/ynBzzOy2
 3dcr3etJZpipQDeqnHy3jt0esgMVlbkTdrHvP+2hpNaeXFwjF1fDHjhur9m8ZkVD
 efOA6nugOnNwhy2G3BvtCJv+Vhb+KZ0nNLB27z3Bl0LGP6LJdMRNAxFBJMv4k3aR
 F3sABugwCpnT2/YtuprxRl2/3/CyLur5NjY24FD+ugON3JIWfl6ETbHeFmxr1JE4
 mE+zaN5AwYuSuH9LpdRy85XVCcW/FFqP/DwOFllVvCCCNvvS0KWYSNHWfEsKdR75
 hmAAaS/rpi2eaL0vp88sNhAtYnhMSf+uFu0fyfYeWZuJqMt4Xz5xZKAzDsifCdif
 aQ6UEPDjiKABh9gpX26BMd2CXzkGR+L4qZ7iBPfO586Iy7opajrFX9kIj5U7ZtCl
 wsPat/9+18xpVJOTe0sss3idId7Ft4cRoW5FQMEAW2EWJ9fXAG1yDxEREj1V5gFx
 sMXtpmCoQag968qjfARvP08s3MB1P4Ij6tXcioGqHuEWeJLxOMK/KWyafQUg611d
 0kSWNO0OMo+odBj6j/vM+MIIaPhgwtZnPgw2q4uHGMcemzQxaEvGW+G/5a5qEpTv
 SKm8W24wXplNot4tuTGWq5/jANRJcMvVsyC48DYT81OZEOWrIc0kDV4v4qZToTxW
 97jn1NKa2H6L0J1V
 =Za8V
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Increase the -falign-functions alignment for the debug option.

 - Remove ugly libelf checks from the top Makefile.

 - Make the silent build (-s) more silent.

 - Re-compile the kernel if KBUILD_BUILD_TIMESTAMP is specified.

 - Various script cleanups

* tag 'kbuild-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (27 commits)
  scripts: add generic syscallnr.sh
  scripts: check duplicated syscall number in syscall table
  sparc: syscalls: use pattern rules to generate syscall headers
  parisc: syscalls: use pattern rules to generate syscall headers
  nds32: add arch/nds32/boot/.gitignore
  kbuild: mkcompile_h: consider timestamp if KBUILD_BUILD_TIMESTAMP is set
  kbuild: modpost: Explicitly warn about unprototyped symbols
  kbuild: remove trailing slashes from $(KBUILD_EXTMOD)
  kconfig.h: explain IS_MODULE(), IS_ENABLED()
  kconfig: constify long_opts
  scripts/setlocalversion: simplify the short version part
  scripts/setlocalversion: factor out 12-chars hash construction
  scripts/setlocalversion: add more comments to -dirty flag detection
  scripts/setlocalversion: remove workaround for old make-kpkg
  scripts/setlocalversion: remove mercurial, svn and git-svn supports
  kbuild: clean up ${quiet} checks in shell scripts
  kbuild: sink stdout from cmd for silent build
  init: use $(call cmd,) for generating include/generated/compile.h
  kbuild: merge scripts/mkmakefile to top Makefile
  sh: move core-y in arch/sh/Makefile to arch/sh/Kbuild
  ...
2021-07-10 11:01:38 -07:00
Linus Torvalds 1b98ed0e83 Modernize the genimage.sh script, add a 'hdimage' target and EFI support.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmDZeRARHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1jEdw/9GB7W8EE4DBdvrNALhw/5xZEVQvYuHFV9
 FKXhP5BBWaNzRy8Ak/5CRJ/+RWjn6HQuliDEzGEsrwkKo5jgOiMRhNCi0tEkkYBR
 UOlmBmrW4h4uqoBvBBrUtZm0rCq5uNMKYc+aXj6qtd3MNaFpN31QsKhH+oHh+dW1
 nMNsdjEj8oNNc9IaPSRdS+RzxnJ+XxakbfEq4d6b+PI56G3J/L6//4tjtcX17G7u
 A3vdlALiCb7LG1eYHBrd8S1D1fHXi8drtS3yKSUu+eEYOmtBlZ/GZ79XaRKixFbC
 1CEjzgEt9W4luGIqRPkj5llAmAYtcJFzMrZJuaIm3WFmSExvbcUbmlloKjLcL5Jt
 LxIdn+mALR8M616MqBYgKpX2fz/kXjVuNJbVk81DjpmQJv513NZgwJgIdKWlf3RM
 M0HrnP+HpHFQ65gQNRBRCvj+UnPXtISm9sd7+wscuSQ1mkl5C4v28diCsKLdpc2N
 MLQpCi1Q5A3ClWnRKoSuXRvmRo9iEI+g/pxXuVYZLTbRk4b5EMNzGKOsr2d0Bs/x
 ns26Iu10A9OeTmt6cca2WQYtbikBIJ7VBATCSGw2gU98XKFbsTqmJRQgmR7FQTFc
 96eRuM9D6hBTl105Gx0QHOmbzu0x62a1S8rOWDRolEy0UYViOMlqCiHjRlSDSLmN
 Tq8ocC3B3yQ=
 =r3pr
 -----END PGP SIGNATURE-----

Merge tag 'x86-boot-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 boot update from Ingo Molnar:
 "Modernize the genimage.sh script, add a 'hdimage' target and EFI
  support"

* tag 'x86-boot-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Modernize genimage script; hdimage+EFI support
2021-06-28 13:05:09 -07:00
Tor Vic 2398ce8015 x86, lto: Pass -stack-alignment only on LLD < 13.0.0
Since LLVM commit 3787ee4, the '-stack-alignment' flag has been dropped
[1], leading to the following error message when building a LTO kernel
with Clang-13 and LLD-13:

    ld.lld: error: -plugin-opt=-: ld.lld: Unknown command line argument
    '-stack-alignment=8'.  Try 'ld.lld --help'
    ld.lld: Did you mean '--stackrealign=8'?

It also appears that the '-code-model' flag is not necessary anymore
starting with LLVM-9 [2].

Drop '-code-model' and make '-stack-alignment' conditional on LLD < 13.0.0.

These flags were necessary because these flags were not encoded in the
IR properly, so the link would restart optimizations without them. Now
there are properly encoded in the IR, and these flags exposing
implementation details are no longer necessary.

[1] https://reviews.llvm.org/D103048
[2] https://reviews.llvm.org/D52322

Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1377
Signed-off-by: Tor Vic <torvic9@mailbox.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/f2c018ee-5999-741e-58d4-e482d5246067@mailbox.org
2021-06-11 10:33:45 -07:00
Masahiro Yamada d92cc4d516 kbuild: require all architectures to have arch/$(SRCARCH)/Kbuild
arch/$(SRCARCH)/Kbuild is useful for Makefile cleanups because you can
use the obj-y syntax.

Add an empty file if it is missing in arch/$(SRCARCH)/.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-05-26 23:10:37 +09:00
Nathan Chancellor 0024430e92 x86/build: Fix location of '-plugin-opt=' flags
Commit b33fff07e3 ("x86, build: allow LTO to be selected") added a
couple of '-plugin-opt=' flags to KBUILD_LDFLAGS because the code model
and stack alignment are not stored in LLVM bitcode.

However, these flags were added to KBUILD_LDFLAGS prior to the
emulation flag assignment, which uses ':=', so they were overwritten
and never added to $(LD) invocations.

The absence of these flags caused misalignment issues in the
AMDGPU driver when compiling with CONFIG_LTO_CLANG, resulting in
general protection faults.

Shuffle the assignment below the initial one so that the flags are
properly passed along and all of the linker flags stay together.

At the same time, avoid any future issues with clobbering flags by
changing the emulation flag assignment to '+=' since KBUILD_LDFLAGS is
already defined with ':=' in the main Makefile before being exported for
modification here as a result of commit:

  ce99d0bf31 ("kbuild: clear LDFLAGS in the top Makefile")

Fixes: b33fff07e3 ("x86, build: allow LTO to be selected")
Reported-by: Anthony Ruhier <aruhier@mailbox.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Anthony Ruhier <aruhier@mailbox.org>
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1374
Link: https://lore.kernel.org/r/20210518190106.60935-1-nathan@kernel.org
2021-05-19 13:05:53 +02:00
H. Peter Anvin (Intel) f279b49f13 x86/boot: Modernize genimage script; hdimage+EFI support
The image generation scripts in arch/x86/boot are pretty out of date,
except for the isoimage target. Update and clean up the
genimage.sh script, and make it support an arbitrary number of
initramfs files in the image.

Add a "hdimage" target, which can be booted by either BIOS or
EFI (if the kernel is compiled with the EFI stub.) For EFI to be able
to pass the command line to the kernel, we need the EFI shell, but the
firmware builtin EFI shell, if it even exists, is pretty much always
the last resort boot option, so search for OVMF or EDK2 and explicitly
include a copy of the EFI shell.

To make this all work, use bash features in the script.  Furthermore,
this version of the script makes use of some mtools features,
especially mpartition, that might not exist in very old version of
mtools, but given all the other dependencies on this script this
doesn't seem such a big deal.

Finally, put a volume label ("LINUX_BOOT") on all generated images.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210510082840.628372-1-hpa@zytor.com
2021-05-10 12:27:50 +02:00
Linus Torvalds b0030af53a Kbuild updates for v5.13
- Evaluate $(call cc-option,...) etc. only for build targets
 
  - Add CONFIG_VMLINUX_MAP to generate .map file when linking vmlinux
 
  - Remove unnecessary --gcc-toolchains Clang flag because the --prefix
    flag finds the toolchains
 
  - Do not pass Clang's --prefix flag when using the integrated as
 
  - Check the assembler version in Kconfig time
 
  - Add new CONFIG options, AS_VERSION, AS_IS_GNU, AS_IS_LLVM to clean up
    some dependencies in Kconfig
 
  - Fix invalid Module.symvers creation when building only modules without
    vmlinux
 
  - Fix false-positive modpost warnings when CONFIG_TRIM_UNUSED_KSYMS is
    set, but there is no module to build
 
  - Refactor module installation Makefile
 
  - Support zstd for module compression
 
  - Convert alpha and ia64 to use generic shell scripts to generate the
    syscall headers
 
  - Add a new elfnote to indicate if the kernel was built with LTO, which
    will be used by pahole
 
  - Flatten the directory structure under include/config/ so CONFIG options
    and filenames match
 
  - Change the deb source package name from linux-$(KERNELRELEASE) to
    linux-upstream
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmCKOLUVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGdq8P/2z+saxIWGXVWt0ggavR0vimcY4e
 NQIKGu9uZpo/lfoC78UG8HO+XvzvPUrcRuOX+WIVr2GfScgVnweDukexUAY0/2oi
 4UvqhndJ0sjEwRj8mXXJ0O+PED+OtgrqrbhkLq9wHQd/jpSD4XEWXwn1g1XVrTZu
 WbwP6b1G/Rnjp2lz3HKC017rPkmfsCFQB7r+hbJGKhT0rCaceheUuBvGa/XqLknr
 IOyaUAY76u3Gtj6fVY1rk70kQgDMF8+LJPgdSSZ/XPCvbNJQAeop36EeRNfmxGIh
 vQhFJRJeqy+K5MhCpdGtTGYDawlmQVn/f/99SkDw9F04S4ZL2Xnaaqw4L1QDhjTh
 xBlckbPvmq36F4xSqWd5kYF3iwS+LsEJROwZKFLEVDb3zMsRQPEGQM/556QmrBi2
 5KXzwOYEJKuobWr1hQ3PwLumJKTPGLvGEFB3Bq2eG8LrgpOAHPI4ejC2EBu0vCez
 QbskP2lPlMj3MbL5iZg+6ZRlOChZ7RUrSDj6+iTeOcinmXHqQONCL6qy+um4Rfcb
 zUkfwTlqM9d88u6AbO2VvQMOobMjvp4bvmqi/Xv8IiTukLHco4tc8zTuySmZwSyI
 rd3RKYn367qWztX5YyaoGRPVmlMG7ssbRc4fkXiV13vfeZebNfVwlX/CHv9+IWwN
 RVnMhYBhUZR68h6z
 =ti9L
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Evaluate $(call cc-option,...) etc. only for build targets

 - Add CONFIG_VMLINUX_MAP to generate .map file when linking vmlinux

 - Remove unnecessary --gcc-toolchains Clang flag because the --prefix
   flag finds the toolchains

 - Do not pass Clang's --prefix flag when using the integrated as

 - Check the assembler version in Kconfig time

 - Add new CONFIG options, AS_VERSION, AS_IS_GNU, AS_IS_LLVM to clean up
   some dependencies in Kconfig

 - Fix invalid Module.symvers creation when building only modules
   without vmlinux

 - Fix false-positive modpost warnings when CONFIG_TRIM_UNUSED_KSYMS is
   set, but there is no module to build

 - Refactor module installation Makefile

 - Support zstd for module compression

 - Convert alpha and ia64 to use generic shell scripts to generate the
   syscall headers

 - Add a new elfnote to indicate if the kernel was built with LTO, which
   will be used by pahole

 - Flatten the directory structure under include/config/ so CONFIG
   options and filenames match

 - Change the deb source package name from linux-$(KERNELRELEASE) to
   linux-upstream

* tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (42 commits)
  kbuild: Add $(KBUILD_HOSTLDFLAGS) to 'has_libelf' test
  kbuild: deb-pkg: change the source package name to linux-upstream
  tools: do not include scripts/Kbuild.include
  kbuild: redo fake deps at include/config/*.h
  kbuild: remove TMPO from try-run
  MAINTAINERS: add pattern for dummy-tools
  kbuild: add an elfnote for whether vmlinux is built with lto
  ia64: syscalls: switch to generic syscallhdr.sh
  ia64: syscalls: switch to generic syscalltbl.sh
  alpha: syscalls: switch to generic syscallhdr.sh
  alpha: syscalls: switch to generic syscalltbl.sh
  sysctl: use min() helper for namecmp()
  kbuild: add support for zstd compressed modules
  kbuild: remove CONFIG_MODULE_COMPRESS
  kbuild: merge scripts/Makefile.modsign to scripts/Makefile.modinst
  kbuild: move module strip/compression code into scripts/Makefile.modinst
  kbuild: refactor scripts/Makefile.modinst
  kbuild: rename extmod-prefix to extmod_prefix
  kbuild: check module name conflict for external modules as well
  kbuild: show the target directory for depmod log
  ...
2021-04-29 14:24:39 -07:00
Linus Torvalds c6536676c7 - turn the stack canary into a normal __percpu variable on 32-bit which
gets rid of the LAZY_GS stuff and a lot of code.
 
 - Add an insn_decode() API which all users of the instruction decoder
 should preferrably use. Its goal is to keep the details of the
 instruction decoder away from its users and simplify and streamline how
 one decodes insns in the kernel. Convert its users to it.
 
 - kprobes improvements and fixes
 
 - Set the maximum DIE per package variable on Hygon
 
 - Rip out the dynamic NOP selection and simplify all the machinery around
 selecting NOPs. Use the simplified NOPs in objtool now too.
 
 - Add Xeon Sapphire Rapids to list of CPUs that support PPIN
 
 - Simplify the retpolines by folding the entire thing into an
 alternative now that objtool can handle alternatives with stack
 ops. Then, have objtool rewrite the call to the retpoline with the
 alternative which then will get patched at boot time.
 
 - Document Intel uarch per models in intel-family.h
 
 - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the
 exception on Intel.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmCHyJQACgkQEsHwGGHe
 VUpjiRAAwPZdwwp08ypZuMHR4EhLNru6gYhbAoALGgtYnQjLtn5onQhIeieK+R4L
 cmZpxHT9OFp5dXHk4kwygaQBsD4pPOiIpm60kye1dN3cSbOORRdkwEoQMpKMZ+5Y
 kvVsmn7lrwRbp600KdE4G6L5+N6gEgr0r6fMFWWGK3mgVAyCzPexVHgydcp131ch
 iYMo6/pPDcNkcV/hboVKgx7GISdQ7L356L1MAIW/Sxtw6uD/X4qGYW+kV2OQg9+t
 nQDaAo7a8Jqlop5W5TQUdMLKQZ1xK8SFOSX/nTS15DZIOBQOGgXR7Xjywn1chBH/
 PHLwM5s4XF6NT5VlIA8tXNZjWIZTiBdldr1kJAmdDYacrtZVs2LWSOC0ilXsd08Z
 EWtvcpHfHEqcuYJlcdALuXY8xDWqf6Q2F7BeadEBAxwnnBg+pAEoLXI/1UwWcmsj
 wpaZTCorhJpYo2pxXckVdHz2z0LldDCNOXOjjaWU8tyaOBKEK6MgAaYU7e0yyENv
 mVc9n5+WuvXuivC6EdZ94Pcr/KQsd09ezpJYcVfMDGv58YZrb6XIEELAJIBTu2/B
 Ua8QApgRgetx+1FKb8X6eGjPl0p40qjD381TADb4rgETPb1AgKaQflmrSTIik+7p
 O+Eo/4x/GdIi9jFk3K+j4mIznRbUX0cheTJgXoiI4zXML9Jv94w=
 =bm4S
 -----END PGP SIGNATURE-----

Merge tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 updates from Borislav Petkov:

 - Turn the stack canary into a normal __percpu variable on 32-bit which
   gets rid of the LAZY_GS stuff and a lot of code.

 - Add an insn_decode() API which all users of the instruction decoder
   should preferrably use. Its goal is to keep the details of the
   instruction decoder away from its users and simplify and streamline
   how one decodes insns in the kernel. Convert its users to it.

 - kprobes improvements and fixes

 - Set the maximum DIE per package variable on Hygon

 - Rip out the dynamic NOP selection and simplify all the machinery
   around selecting NOPs. Use the simplified NOPs in objtool now too.

 - Add Xeon Sapphire Rapids to list of CPUs that support PPIN

 - Simplify the retpolines by folding the entire thing into an
   alternative now that objtool can handle alternatives with stack ops.
   Then, have objtool rewrite the call to the retpoline with the
   alternative which then will get patched at boot time.

 - Document Intel uarch per models in intel-family.h

 - Make Sub-NUMA Clustering topology the default and Cluster-on-Die the
   exception on Intel.

* tag 'x86_core_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
  x86, sched: Treat Intel SNC topology as default, COD as exception
  x86/cpu: Comment Skylake server stepping too
  x86/cpu: Resort and comment Intel models
  objtool/x86: Rewrite retpoline thunk calls
  objtool: Skip magical retpoline .altinstr_replacement
  objtool: Cache instruction relocs
  objtool: Keep track of retpoline call sites
  objtool: Add elf_create_undef_symbol()
  objtool: Extract elf_symbol_add()
  objtool: Extract elf_strtab_concat()
  objtool: Create reloc sections implicitly
  objtool: Add elf_create_reloc() helper
  objtool: Rework the elf_rebuild_reloc_section() logic
  objtool: Fix static_call list generation
  objtool: Handle per arch retpoline naming
  objtool: Correctly handle retpoline thunk calls
  x86/retpoline: Simplify retpolines
  x86/alternatives: Optimize optimize_nops()
  x86: Add insn_decode_kernel()
  x86/kprobes: Move 'inline' to the beginning of the kprobe_is_ss() declaration
  ...
2021-04-27 17:45:09 -07:00
Linus Torvalds ca53fb2c7c A bunch of clang build fixes and a Kconfig highmem selection fix for
486SX.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmCGm0QACgkQEsHwGGHe
 VUpWgQ//X5ArCvi1KvVSA0TpxO1u6V1y3VARWsWvL3xKos57u9NyeRBUqqvAUcdW
 bGqoddOneBsMNwnLuj4grQVYfRtXBPKbsgnhvYKD7X0NNcULABL/h3GRGM6QHLCw
 0n6xpXzr6x6s80McUYnQIEcJmzEnsXKXmPWWOerjd37U79ruxAcJCLV7wIHPQG4A
 hKIXCMF7dmY9wRWkZ9yNN/F+bOXqbLO80wx59u4l8AgLLVASYOLdicutltE6CiRH
 KU4p8trViujtswK2d4q2RO66pwAqFqRmGT1HXJvQE4b3YUqJbI4O2iZGOJTen6N/
 F9yywdjXPGA466id5PoZJVRm5QpzFctfdjXUA1BGBmYu8TsqJecXstLXlMoqhaIj
 DBttl0/0MId9+UqVLBY6P1LWiWUUgIt0uwC7WltiVf2gPKqLNkS7dEZpVadESQTb
 imnEUNNfzh9JMX+e8jjFq3cl3igY1My39/edUoQIWdPuFnFs/Ni+Qu/PztFunEIT
 8nRAr9Hxbvj5tK0OeOTod5i7ZEPyG2OcmEPZnhDUHgz0oaeLKLVfXRBz6lle6Z3N
 WoF/qbPm0nqMOd20H2NWIBdCs9+8sHvp+tlY9hta8lVYzY27qEa21s5xyIZRU3Ia
 /BperJ+J8qyuNCvnaai3pUur+NM7ck/EBTRkxCtwgi6xFxeaFp4=
 =Ic77
 -----END PGP SIGNATURE-----

Merge tag 'x86_build_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 build updates from Borislav Petkov:
 "A bunch of clang build fixes and a Kconfig highmem selection fix for
  486SX"

* tag 'x86_build_for_v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Disable HIGHMEM64G selection for M486SX
  efi/libstub: Add $(CLANG_FLAGS) to x86 flags
  x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS
  x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS)
2021-04-26 09:32:35 -07:00
Masahiro Yamada e3456056f1 kbuild: remove TMPO from try-run
TMPO is only used by arch/x86/Makefile.

Change arch/x86/Makefile to use $$TMPO.o and remove TMPO from
scripts/Makefile.compiler.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-04-25 05:25:56 +09:00
Ingo Molnar e855e80d00 Linux 5.12-rc5
-----BEGIN PGP SIGNATURE-----
 
 iQFRBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmBhB7AeHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGCPUH+KKkSoOlN2YNu1oc
 iy2nznwZoSQTk5ZLz7PypO/WWmmtgzudkObG7yqIURdrncsAkHR17Wu2P7rdBr1j
 Ma+VhF9MQ+xx+r86upH7c3gYfhyfdUMvzuLy0rwLQ1Yrzrb7xFcVkj3BHk54TAQA
 w05sRPuVJ3/c/HPYV2iXkkdnnMbXSTCebeDDwjFb9D3qagr4vcd/PjDHmGbfNF8R
 o6gLpbK5Ly6ww1nth9gGGUjzrW95yVItvcroP6vQWljxhuy+NE1lXRm8LsGhxqtW
 foFFptJup5nhSNJXWtQt/U3huVD6mZ3W3y9cOThPjXZRy2wva3I1IpBKoEFReUpG
 /Tq8EA==
 =tPUY
 -----END PGP SIGNATURE-----

Merge tag 'v5.12-rc5' into WIP.x86/core, to pick up recent NOP related changes

In particular we want to have this upstream commit:

  b90829704780: ("bpf: Use NOP_ATOMIC5 instead of emit_nops(&prog, 5) for BPF_TRAMP_F_CALL_ORIG")

... before merging in x86/cpu changes and the removal of the NOP optimizations, and
applying PeterZ's !retpoline objtool series.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-04-02 12:33:16 +02:00
John Millikin 8abe7fc26a x86/build: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS)
When cross-compiling with Clang, the `$(CLANG_FLAGS)' variable
contains additional flags needed to build C and assembly sources
for the target platform. Normally this variable is automatically
included in `$(KBUILD_CFLAGS)' via the top-level Makefile.

The x86 real-mode makefile builds `$(REALMODE_CFLAGS)' from a
plain assignment and therefore drops the Clang flags. This causes
Clang to not recognize x86-specific assembler directives:

  arch/x86/realmode/rm/header.S:36:1: error: unknown directive
  .type real_mode_header STT_OBJECT ; .size real_mode_header, .-real_mode_header
  ^

Explicit propagation of `$(CLANG_FLAGS)' to `$(REALMODE_CFLAGS)',
which is inherited by real-mode make rules, fixes cross-compilation
with Clang for x86 targets.

Relevant flags:

* `--target' sets the target architecture when cross-compiling. This
  flag must be set for both compilation and assembly (`KBUILD_AFLAGS')
  to support architecture-specific assembler directives.

* `-no-integrated-as' tells clang to assemble with GNU Assembler
  instead of its built-in LLVM assembler. This flag is set by default
  unless `LLVM_IAS=1' is set, because the LLVM assembler can't yet
  parse certain GNU extensions.

Signed-off-by: John Millikin <john@john-millikin.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Link: https://lkml.kernel.org/r/20210326000435.4785-2-nathan@kernel.org
2021-03-26 11:32:47 +01:00
Arnd Bergmann 9fcb51c14d x86/build: Turn off -fcf-protection for realmode targets
The new Ubuntu GCC packages turn on -fcf-protection globally,
which causes a build failure in the x86 realmode code:

  cc1: error: ‘-fcf-protection’ is not compatible with this target

Turn it off explicitly on compilers that understand this option.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210323124846.1584944-1-arnd@kernel.org
2021-03-23 16:36:01 +01:00
Andy Lutomirski 3fb0fdb3bb x86/stackprotector/32: Make the canary into a regular percpu variable
On 32-bit kernels, the stackprotector canary is quite nasty -- it is
stored at %gs:(20), which is nasty because 32-bit kernels use %fs for
percpu storage.  It's even nastier because it means that whether %gs
contains userspace state or kernel state while running kernel code
depends on whether stackprotector is enabled (this is
CONFIG_X86_32_LAZY_GS), and this setting radically changes the way
that segment selectors work.  Supporting both variants is a
maintenance and testing mess.

Merely rearranging so that percpu and the stack canary
share the same segment would be messy as the 32-bit percpu address
layout isn't currently compatible with putting a variable at a fixed
offset.

Fortunately, GCC 8.1 added options that allow the stack canary to be
accessed as %fs:__stack_chk_guard, effectively turning it into an ordinary
percpu variable.  This lets us get rid of all of the code to manage the
stack canary GDT descriptor and the CONFIG_X86_32_LAZY_GS mess.

(That name is special.  We could use any symbol we want for the
 %fs-relative mode, but for CONFIG_SMP=n, gcc refuses to let us use any
 name other than __stack_chk_guard.)

Forcibly disable stackprotector on older compilers that don't support
the new options and turn the stack canary into a percpu variable. The
"lazy GS" approach is now used for all 32-bit configurations.

Also makes load_gs_index() work on 32-bit kernels. On 64-bit kernels,
it loads the GS selector and updates the user GSBASE accordingly. (This
is unchanged.) On 32-bit kernels, it loads the GS selector and updates
GSBASE, which is now always the user base. This means that the overall
effect is the same on 32-bit and 64-bit, which avoids some ifdeffery.

 [ bp: Massage commit message. ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/c0ff7dba14041c7e5d1cae5d4df052f03759bef3.1613243844.git.luto@kernel.org
2021-03-08 13:19:05 +01:00
Linus Torvalds 414eece95b clang-lto for v5.12-rc1 (part2)
- Generate __mcount_loc in objtool (Peter Zijlstra)
 - Support running objtool against vmlinux.o (Sami Tolvanen)
 - Clang LTO enablement for x86 (Sami Tolvanen)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmA1fn8ACgkQiXL039xt
 wCbswQ//Zmnq912Ubyn5uPe9SOS/kumGDoqtxGzlZwo/pSB3qFArhD6G07sJ49XD
 nu/05ZcOda760wubnhcuK91n2fY5i/eGLXMSjfgtdVcco4Q67nPQydc+LGdhuDco
 FlhL8TAIwqYN1f2nJK1IggZpZFxz5r/r1Pq8q1S0oQRqDenxDBQwNtBba4B1OIxw
 /FE/1Hp3xwRnuJEP2jREBeY1yQ+Y1n859pZcDgSOWlTArcp8EVUi5hIWJ9DwIe73
 mqnx6PcFWEYB0zLNZmZz2gpEac+ncGyme6ChayeuQfInbL5dhx97jFGt3S6/+NSY
 mF2zyaR/+JsGGuM8dVqH3izKCJXCEAGirrdMO1ndb9HdwS3KnYEiag2ciNWL0wm3
 UEM4r0i2B14sU3pkyotKgsJdOSgorMKkQUPb2wW+OUfnkZNEWKLqylMgNXBD80l4
 WG5vYQRwwFN9jRBik6Z5YFGnwGsNIoGg1F1GRNMjh6h51adYQeBN/1QJE1FJ5L4D
 iKzmZYqimKUINXWfI6TNyqiv9TctOt65pxnRyq+MHxfTDzHGyc3MUeCeCiR1a1yI
 S5QhcgfSnC/NjDA0+oYC6yRlcBtfhjtUqFTGoZ4q4q/LF1BVU1bPyIXZrROLc05s
 LNMMBcWbJetJxFtm/gYfiVFuNitYtxbBV1krVtsWznCA2nKGJ9w=
 =htKJ
 -----END PGP SIGNATURE-----

Merge tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull more clang LTO updates from Kees Cook:
 "Clang LTO x86 enablement.

  Full disclosure: while this has _not_ been in linux-next (since it
  initially looked like the objtool dependencies weren't going to make
  v5.12), it has been under daily build and runtime testing by Sami for
  quite some time. These x86 portions have been discussed on lkml, with
  Peter, Josh, and others helping nail things down.

  The bulk of the changes are to get objtool working happily. The rest
  of the x86 enablement is very small.

  Summary:

   - Generate __mcount_loc in objtool (Peter Zijlstra)

   - Support running objtool against vmlinux.o (Sami Tolvanen)

   - Clang LTO enablement for x86 (Sami Tolvanen)"

Link: https://lore.kernel.org/lkml/20201013003203.4168817-26-samitolvanen@google.com/
Link: https://lore.kernel.org/lkml/cover.1611263461.git.jpoimboe@redhat.com/

* tag 'clang-lto-v5.12-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kbuild: lto: force rebuilds when switching CONFIG_LTO
  x86, build: allow LTO to be selected
  x86, cpu: disable LTO for cpu.c
  x86, vdso: disable LTO only for vDSO
  kbuild: lto: postpone objtool
  objtool: Split noinstr validation from --vmlinux
  x86, build: use objtool mcount
  tracing: add support for objtool mcount
  objtool: Don't autodetect vmlinux.o
  objtool: Fix __mcount_loc generation with Clang's assembler
  objtool: Add a pass for generating __mcount_loc
2021-02-23 15:13:45 -08:00
Sami Tolvanen b33fff07e3 x86, build: allow LTO to be selected
Pass code model and stack alignment to the linker as these are not
stored in LLVM bitcode, and allow CONFIG_LTO_CLANG* to be enabled.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2021-02-23 12:46:58 -08:00
Linus Torvalds 24880bef41 Remove oprofile and dcookies support
The "oprofile" user-space tools don't use the kernel OPROFILE support any more,
 and haven't in a long time. User-space has been converted to the perf
 interfaces.
 
 The dcookies stuff is only used by the oprofile code. Now that oprofile's
 support is getting removed from the kernel, there is no need for dcookies as
 well.
 
 Remove kernel's old oprofile and dcookies support.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJgJMEVAAoJENK5HDyugRIcL8YP/jkmXH5CZT80ntcqrJGWKcG7
 lWbach7uNeQteht7B1ZPKvojxizTkmfrN2sClX0B2hbGkc5TiWUQ2ZSnvnfWDZ8+
 z2qQcEB11G/ReL2vvRk1fJlWdAOyUfrPee/44AkemnLRv+Niw/8PqnGd87yDQGsK
 qy5E1XXfbjUq6Y/uMiLOX3+21I6w6o2Q6I3NNXC93s0wS3awqnft8n0XBC7iAPBj
 eowRJxpdRU2Vcuj8UOzzOI7gQlwdjwYImyLPbRy/V8NawC8a+FHrPrf5/GCYlVzl
 7TGFBsDQSmzvrBChUfoGz1Rq/VZ1a357p5rhRqemfUrdkjW+vyzelnD8I1W/hb2o
 SmBXoPoyl3+UkFHNyJI0mI7obaV+2PzyXMV0JIQUj+IiX/mfeFv0nF4XfZD2IkRt
 6xhaYj775Zrx32iBdGZIvvLg5Gh9ZkZmR5vJ7Fi/EIZFe6Z+bZnPKUROnAgS/o0z
 +UkSygOhgo/1XbqrzZVk1iweWeu+EUMbY4YQv2qVnFhpvsq4ieThcUGQpWcxGjjH
 WP8O0n1yq1slsnpUtxhiTsm46ENajx9zZp6Iv6Ws+NM0RUqjND8BdF1co9WGD3LS
 cnZMFBs4Bg/V1HICL/D4s6L7t1ofrEXIgJH1y3iF0HeECq03mU4CgA/qly9Aebqg
 UxPF3oNlVOPlds9FzsU2
 =I2Ac
 -----END PGP SIGNATURE-----

Merge tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux

Pull oprofile and dcookies removal from Viresh Kumar:
 "Remove oprofile and dcookies support

  The 'oprofile' user-space tools don't use the kernel OPROFILE support
  any more, and haven't in a long time. User-space has been converted to
  the perf interfaces.

  The dcookies stuff is only used by the oprofile code. Now that
  oprofile's support is getting removed from the kernel, there is no
  need for dcookies as well.

  Remove kernel's old oprofile and dcookies support"

* tag 'oprofile-removal-5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/linux:
  fs: Remove dcookies support
  drivers: Remove CONFIG_OPROFILE support
  arch: xtensa: Remove CONFIG_OPROFILE support
  arch: x86: Remove CONFIG_OPROFILE support
  arch: sparc: Remove CONFIG_OPROFILE support
  arch: sh: Remove CONFIG_OPROFILE support
  arch: s390: Remove CONFIG_OPROFILE support
  arch: powerpc: Remove oprofile
  arch: powerpc: Stop building and using oprofile
  arch: parisc: Remove CONFIG_OPROFILE support
  arch: mips: Remove CONFIG_OPROFILE support
  arch: microblaze: Remove CONFIG_OPROFILE support
  arch: ia64: Remove rest of perfmon support
  arch: ia64: Remove CONFIG_OPROFILE support
  arch: hexagon: Don't select HAVE_OPROFILE
  arch: arc: Remove CONFIG_OPROFILE support
  arch: arm: Remove CONFIG_OPROFILE support
  arch: alpha: Remove CONFIG_OPROFILE support
2021-02-21 10:40:34 -08:00
Linus Torvalds 26a30ffff9 - Treat R_386_PLT32 relocations like R_386_PC32 ones when building.
- Add documentation about "make kvm_guest/xen.config" in "make help" output.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmAqasIACgkQEsHwGGHe
 VUqdDg//WjB6ZW0ZC0DnXpuiXR3r+8YE/z8lvnbbyX/SZQiBIkOfEHiDBVyC1bMZ
 QZP5Ps7fculAZ4/CjTV+1JdTFrK8oGa27oE54ufEX6f7/7A8sOG37HENizQaOksm
 6YDeaarpBV5XdU7RtaT4Id0vHNMxG8q7SVlNz0L8sQ46QOWBzrtuXp4sZbHKN0Za
 TxSKQEHcY+paIAa+wvz6700eejq/mPgRoIvwal1JQzifoDZMYzLkqNI3L+Jm+Q3O
 DA60u2hgZUjr4lA5Me96EqhMFyuMBFBvoDld7q0yKVELAlX4HhB0cGQ0Jet/eX39
 bVYsMurI2sYPoZFer0UnqCpjPadxAUPf9Cr4NUCWGZ7f4uqPPwwr5ivgIBfpeDGX
 CeWYlcU4O6DodIoShZnueFyBtGYR9dNDvaFR47hZqTnUAxUt/NXxcJ8ngjMKKYJk
 OgQFhESwerDp1VQi4B2+qCCDQ+0Z7wWYKliRr02OFusS6ARFUcIcldUDFZupMx1j
 QktEQt6y2P+9C+3+wY/i9DMl52+0BjDT6eDyPaosoAJ339uBq/9mB7jO4X4cfWhT
 Kd5MjcVA4/iuJfQjPq9TaA0ks+opCkL1jbzhAKYq2JpWmEOEe0T2RBl2ZwV1F1Hx
 ffPDf6yiPx715XUXzXxAxV6Q4PbYi4B8u20YpcgbY2dvR6/RJhs=
 =SlDj
 -----END PGP SIGNATURE-----

Merge tag 'x86_build_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 build updates from Borislav Petkov:

 - Treat R_386_PLT32 relocations like R_386_PC32 ones when building

 - Add documentation about "make kvm_guest/xen.config" in "make help"
   output

* tag 'x86_build_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Treat R_386_PLT32 relocation as R_386_PC32
  x86/build: Realign archhelp
  x86/build: Add {kvm_guest,xen}.config targets to make help's output
2021-02-20 20:44:37 -08:00
Borislav Petkov 256b92af78 x86/build: Disable CET instrumentation in the kernel for 32-bit too
Commit

  20bf2b3787 ("x86/build: Disable CET instrumentation in the kernel")

disabled CET instrumentation which gets added by default by the Ubuntu
gcc9 and 10 by default, but did that only for 64-bit builds. It would
still fail when building a 32-bit target. So disable CET for all x86
builds.

Fixes: 20bf2b3787 ("x86/build: Disable CET instrumentation in the kernel")
Reported-by: AC <achirvasub@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: AC <achirvasub@gmail.com>
Link: https://lkml.kernel.org/r/YCCIgMHkzh/xT4ex@arch-chirva.localdomain
2021-02-09 11:23:47 +01:00
Josh Poimboeuf 20bf2b3787 x86/build: Disable CET instrumentation in the kernel
With retpolines disabled, some configurations of GCC, and specifically
the GCC versions 9 and 10 in Ubuntu will add Intel CET instrumentation
to the kernel by default. That breaks certain tracing scenarios by
adding a superfluous ENDBR64 instruction before the fentry call, for
functions which can be called indirectly.

CET instrumentation isn't currently necessary in the kernel, as CET is
only supported in user space. Disable it unconditionally and move it
into the x86's Makefile as CET/CFI... enablement should be a per-arch
decision anyway.

 [ bp: Massage and extend commit message. ]

Fixes: 29be86d7f9 ("kbuild: add -fcf-protection=none when using retpoline flags")
Reported-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Cc: <stable@vger.kernel.org>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: https://lkml.kernel.org/r/20210128215219.6kct3h2eiustncws@treble
2021-01-29 18:41:06 +01:00