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| author | Linus Walleij <linus.walleij@linaro.org> | 2024-10-23 14:05:34 +0200 |
|---|---|---|
| committer | Russell King (Oracle) <rmk+kernel@armlinux.org.uk> | 2024-11-13 09:15:23 +0100 |
| commit | 93ee385254d53849c01dd8ab9bc9d02790ee7f0e (patch) | |
| tree | a7f915fc8ceae2a2c1c5f541995ef3d13dfff019 /arch/arm | |
| parent | ARM: 9430/1: entry: Do a dummy read from VMAP shadow (diff) | |
| download | linux-93ee385254d53849c01dd8ab9bc9d02790ee7f0e.tar.xz linux-93ee385254d53849c01dd8ab9bc9d02790ee7f0e.zip | |
ARM: 9431/1: mm: Pair atomic_set_release() with _read_acquire()
The code for syncing vmalloc memory PGD pointers is using
atomic_read() in pair with atomic_set_release() but the
proper pairing is atomic_read_acquire() paired with
atomic_set_release().
This is done to clearly instruct the compiler to not
reorder the memcpy() or similar calls inside the section
so that we do not observe changes to init_mm. memcpy()
calls should be identified by the compiler as having
unpredictable side effects, but let's try to be on the
safe side.
Cc: stable@vger.kernel.org
Fixes: d31e23aff011 ("ARM: mm: make vmalloc_seq handling SMP safe")
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mm/ioremap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index ff555823cceb..89f1c97f3079 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -141,7 +141,7 @@ void __check_vmalloc_seq(struct mm_struct *mm) int seq; do { - seq = atomic_read(&init_mm.context.vmalloc_seq); + seq = atomic_read_acquire(&init_mm.context.vmalloc_seq); memcpy_pgd(mm, VMALLOC_START, VMALLOC_END); if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { unsigned long start = |