From: Amit Daniel Kachhap <amit.kachhap@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org,
Vincenzo Frascino <Vincenzo.Frascino@arm.com>,
Amit Daniel Kachhap <amit.kachhap@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Subject: [PATCH] arm64/traps: Avoid unnecessary kernel/user pointer conversion
Date: Tue, 14 Sep 2021 20:57:42 +0530 [thread overview]
Message-ID: <20210914152742.27047-1-amit.kachhap@arm.com> (raw)
Annotating a pointer from kernel to __user and then back again might
confuse sparse. In call_undef_hook() it can be avoided by not using the
intermediate user pointer variable.
Note: This patch adds no functional changes to code.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
arch/arm64/kernel/traps.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index b03e383d944a..357d10a8bbf5 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -404,7 +404,8 @@ static int call_undef_hook(struct pt_regs *regs)
if (!user_mode(regs)) {
__le32 instr_le;
- if (get_kernel_nofault(instr_le, (__force __le32 *)pc))
+ if (get_kernel_nofault(instr_le,
+ (__le32 *)instruction_pointer(regs)))
goto exit;
instr = le32_to_cpu(instr_le);
} else if (compat_thumb_mode(regs)) {
--
2.17.1
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next reply other threads:[~2021-09-14 15:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-14 15:27 Amit Daniel Kachhap [this message]
2021-09-14 16:00 ` [PATCH] arm64/traps: Avoid unnecessary kernel/user pointer conversion Mark Rutland
2021-09-15 13:56 ` Amit Kachhap
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