From 66c3ec5a712005625437474cf5a04148d7890350 Mon Sep 17 00:00:00 2001 From: Dave Martin Date: Wed, 9 Aug 2017 11:43:28 +0100 Subject: 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 Signed-off-by: Dave Martin Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/simd.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch/arm64/include/asm/simd.h') 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 +#include #include #include #include @@ -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 */ -- cgit v1.2.3-59-g8ed1b