This is a note to let you know that I've just added the patch titled arm64: make is_ttbrX_addr() noinstr-safe to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-make-is_ttbrx_addr-noinstr-safe.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 42633bfd09029e6b843d56c4e257f88edaaaf40e Author: Mark Rutland <mark.rutland@xxxxxxx> Date: Mon Nov 14 14:40:42 2022 +0000 arm64: make is_ttbrX_addr() noinstr-safe [ Upstream commit d8c1d798a2e5091128c391c6dadcc9be334af3f5 ] We use is_ttbr0_addr() in noinstr code, but as it's only marked as inline, it's theoretically possible for the compiler to place it out-of-line and instrument it, which would be problematic. Mark is_ttbr0_addr() as __always_inline such that that can safely be used from noinstr code. For consistency, do the same to is_ttbr1_addr(). Note that while is_ttbr1_addr() calls arch_kasan_reset_tag(), this is a macro (and its callees are either macros or __always_inline), so there is not a risk of transient instrumentation. Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221114144042.3001140-1-mark.rutland@xxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index d9bf3d12a2b8..7364530de0a7 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -240,13 +240,13 @@ static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc, } #endif -static inline bool is_ttbr0_addr(unsigned long addr) +static __always_inline bool is_ttbr0_addr(unsigned long addr) { /* entry assembly clears tags for TTBR0 addrs */ return addr < TASK_SIZE; } -static inline bool is_ttbr1_addr(unsigned long addr) +static __always_inline bool is_ttbr1_addr(unsigned long addr) { /* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */ return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;