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powerpc/kcsan: Properly instrument arch_spin_unlock()

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The following boottime error is encountered with SMP kernel:

  kcsan: improperly instrumented type=(0): arch_spin_unlock(&arch_spinlock)
  kcsan: improperly instrumented type=(0): spin_unlock(&test_spinlock)
  kcsan: improperly instrumented type=(KCSAN_ACCESS_WRITE): arch_spin_unlock(&arch_spinlock)
  kcsan: improperly instrumented type=(KCSAN_ACCESS_WRITE): spin_unlock(&test_spinlock)
  kcsan: improperly instrumented type=(KCSAN_ACCESS_WRITE | KCSAN_ACCESS_COMPOUND): arch_spin_unlock(&arch_spinlock)
  kcsan: improperly instrumented type=(KCSAN_ACCESS_WRITE | KCSAN_ACCESS_COMPOUND): spin_unlock(&test_spinlock)
  kcsan: selftest: test_barrier failed
  kcsan: selftest: 2/3 tests passed
  Kernel panic - not syncing: selftests failed

Properly instrument arch_spin_unlock() with kcsan_mb().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/57834a703dfa5d6c27c9de0a01329059636e5ab7.1685080579.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2023-05-26 07:57:33 +02:00 committed by Michael Ellerman
parent bcea4f7a70
commit 396f2b0106
1 changed files with 2 additions and 0 deletions
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2
arch/powerpc/include/asm/simple_spinlock.h
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@ -15,6 +15,7 @@
* (the type definitions are in asm/simple_spinlock_types.h)
*/
#include <linux/irqflags.h>
#include <linux/kcsan-checks.h>
#include <asm/paravirt.h>
#include <asm/paca.h>
#include <asm/synch.h>
@ -126,6 +127,7 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
kcsan_mb();
__asm__ __volatile__("# arch_spin_unlock\n\t"
PPC_RELEASE_BARRIER: : :"memory");
lock->slock = 0;