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| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-11-08 14:35:59 -0800 |
|---|---|---|
| committer | Josh Poimboeuf <jpoimboe@redhat.com> | 2021-12-21 15:09:46 -0800 |
| commit | dcce50e6cc4d86a63dc0a9a6ee7d4f948ccd53a1 (patch) | |
| tree | 924ef38b1c608d28308f4684364482009d39409a | |
| parent | cb8747b7d2a9e3d687a19a007575071d4b71cd05 (diff) | |
| download | lwn-dcce50e6cc4d86a63dc0a9a6ee7d4f948ccd53a1.tar.gz lwn-dcce50e6cc4d86a63dc0a9a6ee7d4f948ccd53a1.zip | |
compiler.h: Fix annotation macro misplacement with Clang
When building with Clang and CONFIG_TRACE_BRANCH_PROFILING, there are a
lot of unreachable warnings, like:
arch/x86/kernel/traps.o: warning: objtool: handle_xfd_event()+0x134: unreachable instruction
Without an input to the inline asm, 'volatile' is ignored for some
reason and Clang feels free to move the reachable() annotation away from
its intended location.
Fix that by re-adding the counter value to the inputs.
Fixes: f1069a8756b9 ("compiler.h: Avoid using inline asm operand modifiers")
Fixes: c199f64ff93c ("instrumentation.h: Avoid using inline asm operand modifiers")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/0417e96909b97a406323409210de7bf13df0b170.1636410380.git.jpoimboe@redhat.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: x86@kernel.org
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Miroslav Benes <mbenes@suse.cz>
| -rw-r--r-- | include/linux/compiler.h | 4 | ||||
| -rw-r--r-- | include/linux/instrumentation.h | 4 |
2 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 3d5af56337bd..429dcebe2b99 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -121,7 +121,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, asm volatile(__stringify_label(c) ":\n\t" \ ".pushsection .discard.reachable\n\t" \ ".long " __stringify_label(c) "b - .\n\t" \ - ".popsection\n\t"); \ + ".popsection\n\t" : : "i" (c)); \ }) #define annotate_reachable() __annotate_reachable(__COUNTER__) @@ -129,7 +129,7 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, asm volatile(__stringify_label(c) ":\n\t" \ ".pushsection .discard.unreachable\n\t" \ ".long " __stringify_label(c) "b - .\n\t" \ - ".popsection\n\t"); \ + ".popsection\n\t" : : "i" (c)); \ }) #define annotate_unreachable() __annotate_unreachable(__COUNTER__) diff --git a/include/linux/instrumentation.h b/include/linux/instrumentation.h index fa2cd8c63dcc..24359b4a9605 100644 --- a/include/linux/instrumentation.h +++ b/include/linux/instrumentation.h @@ -11,7 +11,7 @@ asm volatile(__stringify(c) ": nop\n\t" \ ".pushsection .discard.instr_begin\n\t" \ ".long " __stringify(c) "b - .\n\t" \ - ".popsection\n\t"); \ + ".popsection\n\t" : : "i" (c)); \ }) #define instrumentation_begin() __instrumentation_begin(__COUNTER__) @@ -50,7 +50,7 @@ asm volatile(__stringify(c) ": nop\n\t" \ ".pushsection .discard.instr_end\n\t" \ ".long " __stringify(c) "b - .\n\t" \ - ".popsection\n\t"); \ + ".popsection\n\t" : : "i" (c)); \ }) #define instrumentation_end() __instrumentation_end(__COUNTER__) #else |