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jump_label,noinstr: Avoid instrumentation for JUMP_LABEL=n builds 

When building x86_64 with JUMP_LABEL=n it's possible for
instrumentation to sneak into noinstr:

vmlinux.o: warning: objtool: exit_to_user_mode+0x14: call to static_key_count.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: syscall_exit_to_user_mode+0x2d: call to static_key_count.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: irqentry_exit_to_user_mode+0x1b: call to static_key_count.constprop.0() leaves .noinstr.text section

Switch to arch_ prefixed atomic to avoid the explicit instrumentation.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
This commit is contained in:
Peter Zijlstra 2022-05-02 12:30:20 +02:00
parent a6a5eb269f
commit 656d054e0a
1 changed files with 2 additions and 2 deletions
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4
include/linux/jump_label.h
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@ -256,9 +256,9 @@ extern void static_key_disable_cpuslocked(struct static_key *key);
#include <linux/atomic.h>
#include <linux/bug.h>
static inline int static_key_count(struct static_key *key)
static __always_inline int static_key_count(struct static_key *key)
{
return atomic_read(&key->enabled);
return arch_atomic_read(&key->enabled);
}
static __always_inline void jump_label_init(void)