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| author |   Dave Martin <Dave.Martin@arm.com> | 2017-08-09 11:43:28 +0100 |
|---|---|---|
| committer |   Catalin Marinas <catalin.marinas@arm.com> | 2017-08-09 15:05:59 +0100 |
| commit | 66c3ec5a712005625437474cf5a04148d7890350 (patch) | |
| tree | 38274244ae2d7531ce45045cbfb2b64201dd69fb | |
| parent | arm64: neon: Export kernel_neon_busy to loadable modules (diff) | |
| download | linux-dev-66c3ec5a712005625437474cf5a04148d7890350.tar.xz linux-dev-66c3ec5a712005625437474cf5a04148d7890350.zip | |
arm64: neon: Forbid when irqs are disabled
Currently, may_use_simd() can return true if IRQs are disabled. If
the caller goes ahead and calls kernel_neon_begin(), this can
result in use of local_bh_enable() in an unsafe context.
In particular, __efi_fpsimd_begin() may do this when calling EFI as
part of system shutdown.
This patch ensures that callers don't think they can use
kernel_neon_begin() in such a context.
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| -rw-r--r-- | arch/arm64/include/asm/simd.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/simd.h b/arch/arm64/include/asm/simd.h index 5a1a927b74a2..fa8b3fe932e6 100644 --- a/arch/arm64/include/asm/simd.h +++ b/arch/arm64/include/asm/simd.h @@ -10,6 +10,7 @@ #define __ASM_SIMD_H #include <linux/compiler.h> +#include <linux/irqflags.h> #include <linux/percpu.h> #include <linux/preempt.h> #include <linux/types.h> @@ -40,7 +41,8 @@ static __must_check inline bool may_use_simd(void) * can't migrate to another CPU and spuriously see it become * false. */ - return !in_irq() && !in_nmi() && !raw_cpu_read(kernel_neon_busy); + return !in_irq() && !irqs_disabled() && !in_nmi() && + !raw_cpu_read(kernel_neon_busy); } #else /* ! CONFIG_KERNEL_MODE_NEON */ |