From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Sasha Levin <sashal@kernel.org>,
broonie@kernel.org, keescook@chromium.org,
wangkefeng.wang@huawei.com, christophe.leroy@csgroup.eu,
flaniel@linux.microsoft.com,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 5.15 2/5] arm64: make is_ttbrX_addr() noinstr-safe
Date: Fri, 16 Dec 2022 19:10:35 -0500 [thread overview]
Message-ID: <20221217001038.41355-2-sashal@kernel.org> (raw)
In-Reply-To: <20221217001038.41355-1-sashal@kernel.org>
From: Mark Rutland <mark.rutland@arm.com>
[ 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@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221114144042.3001140-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/include/asm/processor.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
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;
--
2.35.1
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parent reply other threads:[~2022-12-17 0:12 UTC|newest]
Thread overview: expand[flat|nested] mbox.gz Atom feed
[parent not found: <20221217001038.41355-1-sashal@kernel.org>]
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