Commit dcce50e6 authored by Josh Poimboeuf's avatar Josh Poimboeuf

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: f1069a87 ("compiler.h: Avoid using inline asm operand modifiers")
Fixes: c199f64f ("instrumentation.h: Avoid using inline asm operand modifiers")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarJosh 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>
parent cb8747b7
......@@ -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__)
......
......@@ -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
......
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