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Subject[PATCH V2 0/9] objtool changes to remove all ANNOTATE_NOSPEC_ALTERNATIVE
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Hi,

This is version v2 of this patchset based on the different comments
received so far. It now uses and includes PeterZ patch to add
UNWIND_HINT_RET_OFFSET. Other changes are described below.

Code like retpoline or RSB stuffing, which is used to mitigate some of
the speculative execution issues, is currently ignored by objtool with
the ANNOTATE_NOSPEC_ALTERNATIVE directive. This series adds support
for intra-function calls to objtool so that it can handle such a code.
With these changes, we can remove all ANNOTATE_NOSPEC_ALTERNATIVE
directives.

Changes:
- replace RETPOLINE_RET with PeterZ UNWIND_HINT_RET_OFFSET
- make objtool intra-function call action architecture dependent
- objtool now automatically detects and validates all intra-function
calls but it issues a warning if the call was not explicitly tagged
- change __FILL_RETURN_BUFFER to work with objtool
- add generic ANNOTATE_INTRA_FUNCTION_CALL macro
- remove all ANNOTATE_SPEC_ALTERNATIVE (even for __FILL_RETURN_BUFFER)

Thanks,

alex.

-----

Alexandre Chartre (8):
objtool: UNWIND_HINT_RET_OFFSET should not check registers
objtool: is_fentry_call() crashes if call has no destination
objtool: Allow branches within the same alternative.
objtool: Add support for intra-function calls
x86/speculation: Change __FILL_RETURN_BUFFER to work with objtool
x86/speculation: Annotate intra-function calls
x86/speculation: Add unwind hint to trampoline return
x86/speculation: Remove all ANNOTATE_NOSPEC_ALTERNATIVE directives

Peter Zijlstra (Intel) (1):
objtool: Introduce HINT_RET_OFFSET

arch/x86/include/asm/nospec-branch.h | 32 ++--
arch/x86/include/asm/orc_types.h | 1 +
arch/x86/include/asm/unwind_hints.h | 10 ++
include/linux/frame.h | 11 ++
tools/arch/x86/include/asm/orc_types.h | 1 +
.../Documentation/stack-validation.txt | 8 +
tools/objtool/arch.h | 2 +
tools/objtool/arch/x86/decode.c | 12 ++
tools/objtool/check.c | 152 ++++++++++++++----
tools/objtool/check.h | 6 +-
10 files changed, 192 insertions(+), 43 deletions(-)

--
2.18.2

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