[GIT PULL] objtool changes for v6.5

[GIT PULL] objtool changes for v6.5

[Ingo Molnar]

Linus,

Please pull the latest objtool/core git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool-core-2023-06-27

   # HEAD: 301cf77e21317b3465c5e2bb0188df24bbf1c2e2 x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y

objtool changes for v6.5:

- Build footprint & performance improvements:

    - Reduce memory usage with CONFIG_DEBUG_INFO=y

      In the worst case of an allyesconfig+CONFIG_DEBUG_INFO=y kernel, DWARF
      creates almost 200 million relocations, ballooning objtool's peak heap
      usage to 53GB.  These patches reduce that to 25GB.

      On a distro-type kernel with kernel IBT enabled, they reduce objtool's
      peak heap usage from 4.2GB to 2.8GB.

      These changes also improve the runtime significantly.

- Debuggability improvements:

    - Add the unwind_debug command-line option, for more extend unwinding
      debugging output.
    - Limit unreachable warnings to once per function
    - Add verbose option for disassembling affected functions
    - Include backtrace in verbose mode
    - Detect missing __noreturn annotations
    - Ignore exc_double_fault() __noreturn warnings
    - Remove superfluous global_noreturns entries
    - Move noreturn function list to separate file
    - Add __kunit_abort() to noreturns

- Unwinder improvements:

    - Allow stack operations in UNWIND_HINT_UNDEFINED regions
    - drm/vmwgfx: Add unwind hints around RBP clobber

- Cleanups:

    - Move the x86 entry thunk restore code into thunk functions
    - x86/unwind/orc: Use swap() instead of open coding it
    - Remove unnecessary/unused variables

- Fixes for modern stack canary handling

 Thanks,

	Ingo

------------------>
Ingo Molnar (1):
      x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y

Jiapeng Chong (1):
      x86/unwind/orc: Use swap() instead of open coding it

Josh Poimboeuf (36):
      x86/unwind/orc: Add 'unwind_debug' cmdline option
      objtool: Limit unreachable warnings to once per function
      objtool: Add verbose option for disassembling affected functions
      objtool: Include backtrace in verbose mode
      objtool: Detect missing __noreturn annotations
      objtool: Ignore exc_double_fault() __noreturn warnings
      objtool: Remove superfluous global_noreturns entries
      tools/lib/subcmd: Replace NORETURN usage with __noreturn
      objtool: Move noreturn function list to separate file
      objtool: Add __kunit_abort() to noreturns
      Revert "x86/orc: Make it callthunk aware"
      x86/entry: Move thunk restore code into thunk functions
      objtool: Allow stack operations in UNWIND_HINT_UNDEFINED regions
      drm/vmwgfx: Add unwind hints around RBP clobber
      objtool: Tidy elf.h
      objtool: Remove flags argument from elf_create_section()
      objtool: Improve reloc naming
      objtool: Consolidate rel/rela handling
      objtool: Fix reloc_hash size
      objtool: Add mark_sec_changed()
      objtool: Add elf_create_section_pair()
      objtool: Keep GElf_Rel[a] structs synced
      objtool: Don't free memory in elf_close()
      objtool: Add for_each_reloc()
      objtool: Allocate relocs in advance for new rela sections
      objtool: Get rid of reloc->list
      objtool: Get rid of reloc->idx
      objtool: Get rid of reloc->offset
      objtool: Get rid of reloc->type
      objtool: Get rid of reloc->addend
      objtool: Get rid of reloc->jump_table_start
      objtool: Shrink reloc->sym_reloc_entry
      objtool: Shrink elf hash nodes
      objtool: Get rid of reloc->rel[a]
      objtool: Free insns when done
      objtool: Skip reading DWARF section data

Lu Hongfei (1):
      tools: Remove unnecessary variables

Peter Zijlstra (1):
      lkdtm: Avoid objtool/ibt warning

ndesaulniers@google.com (2):
      start_kernel: Add __no_stack_protector function attribute
      start_kernel: Omit prevent_tail_call_optimization() for newer toolchains


 Documentation/admin-guide/kernel-parameters.txt |   6 +
 arch/powerpc/kernel/smp.c                       |   1 +
 arch/x86/entry/thunk_64.S                       |  20 +-
 arch/x86/include/asm/alternative.h              |   5 -
 arch/x86/include/asm/unwind_hints.h             |   9 +
 arch/x86/kernel/callthunks.c                    |   4 +-
 arch/x86/kernel/unwind_orc.c                    |  75 ++-
 drivers/gpu/drm/vmwgfx/vmwgfx_msg_x86.h         |  16 +-
 drivers/misc/lkdtm/bugs.c                       |   1 +
 include/linux/compiler_attributes.h             |  12 +
 init/main.c                                     |   9 +-
 tools/lib/subcmd/parse-options.h                |   8 +-
 tools/lib/subcmd/subcmd-util.h                  |   5 +-
 tools/objtool/Documentation/objtool.txt         |  10 +
 tools/objtool/arch/powerpc/include/arch/elf.h   |  11 +-
 tools/objtool/arch/x86/decode.c                 |   6 +-
 tools/objtool/arch/x86/include/arch/elf.h       |  11 +-
 tools/objtool/arch/x86/special.c                |   6 +-
 tools/objtool/builtin-check.c                   |   5 +
 tools/objtool/check.c                           | 643 ++++++++++++++----------
 tools/objtool/elf.c                             | 537 ++++++++------------
 tools/objtool/include/objtool/builtin.h         |   1 +
 tools/objtool/include/objtool/cfi.h             |   1 +
 tools/objtool/include/objtool/elf.h             | 327 ++++++++----
 tools/objtool/include/objtool/warn.h            |  21 +-
 tools/objtool/noreturns.h                       |  46 ++
 tools/objtool/orc_gen.c                         |   8 +-
 tools/objtool/special.c                         |   4 +-
 28 files changed, 1038 insertions(+), 770 deletions(-)
 create mode 100644 tools/objtool/noreturns.h

Re: [GIT PULL] objtool changes for v6.5

[Ingo Molnar]

* Ingo Molnar <mingo@kernel.org> wrote:

> Linus,
> 
> Please pull the latest objtool/core git tree from:
> 
>    git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool-core-2023-06-27
> 
>    # HEAD: 301cf77e21317b3465c5e2bb0188df24bbf1c2e2 x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y

I forgot to mention that there's a new conflict when you merge this, in 
tools/objtool/check.c, plus a semantic conflict in the new 
tools/objtool/noreturns.h file - to remove the 'btrfs_assertfail' entry 
from the new tools/objtool/noreturns.h file.

Our -tip CI conflict resolution can be double checked here:

    git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/merge

Thanks,

	Ingo

[PATCH] objtool: Remove btrfs_assertfail() from the noreturn exceptions list

[Ingo Molnar]

* Ingo Molnar <mingo@kernel.org> wrote:

> 
> * Ingo Molnar <mingo@kernel.org> wrote:
> 
> > Linus,
> > 
> > Please pull the latest objtool/core git tree from:
> > 
> >    git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool-core-2023-06-27
> > 
> >    # HEAD: 301cf77e21317b3465c5e2bb0188df24bbf1c2e2 x86/orc: Make the is_callthunk() definition depend on CONFIG_BPF_JIT=y
> 
> I forgot to mention that there's a new conflict when you merge this, in 
> tools/objtool/check.c, plus a semantic conflict in the new 
> tools/objtool/noreturns.h file - to remove the 'btrfs_assertfail' entry 
> from the new tools/objtool/noreturns.h file.
> 
> Our -tip CI conflict resolution can be double checked here:
> 
>     git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/merge

I believe the (minor & silent) semantic conflict was overlooked in your 
upstream merge:

      6f612579be9d Merge tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

I've fixed it up with the attached patch.

[ There was no harm done to build correctness or functionality AFAICS, 
  because the extra leftover entry in upstream tools/objtool/noreturns.h is 
  now meaningless, as btrfs_assertfail() has become a macro that will not 
  show up as an ELF symbol. ]

Thanks,

	Ingo

======================>
From: Ingo Molnar <mingo@kernel.org>
Date: Wed, 28 Jun 2023 11:16:03 +0200
Subject: [PATCH] objtool: Remove btrfs_assertfail() from the noreturn
 exceptions list

Upstream merge commit:

  6f612579be9d Merge tag 'objtool-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

... generated a (minor) semantic conflict that was not resolved: the btrfs_assertfail()
entry that was removed from the list in tools/objtool/check.c in:

  b831306b3b7d ("btrfs: print assertion failure report and stack trace from the same line")

... because btrfs_assertfail() was changed from a noreturn function into
a macro.

But the list was moved to a different file, in a different enumeration format:

  6245ce4ab670 ("objtool: Move noreturn function list to separate file")

And has to be removed from tools/objtool/noreturns.h post-merge as well.

Do it explicitly.

Cc: David Sterba <dsterba@suse.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 tools/objtool/noreturns.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h
index 1514e84d5cc4..e45c7cb1d5bc 100644
--- a/tools/objtool/noreturns.h
+++ b/tools/objtool/noreturns.h
@@ -14,7 +14,6 @@ NORETURN(__stack_chk_fail)
 NORETURN(__ubsan_handle_builtin_unreachable)
 NORETURN(arch_call_rest_init)
 NORETURN(arch_cpu_idle_dead)
-NORETURN(btrfs_assertfail)
 NORETURN(cpu_bringup_and_idle)
 NORETURN(cpu_startup_entry)
 NORETURN(do_exit)

Re: [GIT PULL] objtool changes for v6.5

[pr-tracker-bot]

The pull request you sent on Tue, 27 Jun 2023 13:20:57 +0200:

> git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git objtool-core-2023-06-27

has been merged into torvalds/linux.git:
https://git.kernel.org/torvalds/c/6f612579be9d0ff527ca2e517e10bfaf08cc1860

Thank you!

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