diff options
| author | Will Deacon <will@kernel.org> | 2020-06-30 16:06:04 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2020-11-10 00:49:34 +0300 |
| commit | 5af76fb4228701bd5377880b09b0216a5fd800ef (patch) | |
| tree | d03a81f28e700510c36cb556ac168b8585bb4018 /arch/arm64/kernel | |
| parent | 364a5a8ae8dc2dd457e2fefb4da3f3fd2c0ba8b1 (diff) | |
| download | linux-5af76fb4228701bd5377880b09b0216a5fd800ef.tar.xz | |
arm64: alternatives: Remove READ_ONCE() usage during patch operation
In preparation for patching the internals of READ_ONCE() itself, replace
its usage on the alternatives patching patch with a volatile variable
instead.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/alternative.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 73039949b5ce..a57cffb752e8 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -21,7 +21,8 @@ #define ALT_ORIG_PTR(a) __ALT_PTR(a, orig_offset) #define ALT_REPL_PTR(a) __ALT_PTR(a, alt_offset) -static int all_alternatives_applied; +/* Volatile, as we may be patching the guts of READ_ONCE() */ +static volatile int all_alternatives_applied; static DECLARE_BITMAP(applied_alternatives, ARM64_NCAPS); @@ -205,7 +206,7 @@ static int __apply_alternatives_multi_stop(void *unused) /* We always have a CPU 0 at this point (__init) */ if (smp_processor_id()) { - while (!READ_ONCE(all_alternatives_applied)) + while (!all_alternatives_applied) cpu_relax(); isb(); } else { @@ -217,7 +218,7 @@ static int __apply_alternatives_multi_stop(void *unused) BUG_ON(all_alternatives_applied); __apply_alternatives(®ion, false, remaining_capabilities); /* Barriers provided by the cache flushing */ - WRITE_ONCE(all_alternatives_applied, 1); + all_alternatives_applied = 1; } return 0; |