From: Richard Henderson <richard.henderson@linaro.org>
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 3/6] arm64: uaccess: Untie the input address in __range_ok
Date: Wed, 11 Mar 2020 11:04:13 -0700 [thread overview]
Message-ID: <20200311180416.6509-4-richard.henderson@linaro.org> (raw)
In-Reply-To: <20200311180416.6509-1-richard.henderson@linaro.org>
There's no reason for the input address to match the output
register. Give the register allocator a bit more freedom.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
arch/arm64/include/asm/uaccess.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index ceb1d79eab09..fe3dd70e901e 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -75,7 +75,7 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
asm volatile(
// A + B <= C + 1 for all A,B,C, in four easy steps:
// 1: X = A + B; X' = X % 2^64
- " adds %[addr], %[addr], %[size]\n"
+ " adds %[addr], %[addr_in], %[size]\n"
// 2: Set C = 0 if X > 2^64, to guarantee X' > C in step 4
" csel %[limit], xzr, %[limit], hi\n"
// 3: Set X' = ~0 if X >= 2^64. For X == 2^64, this decrements X'
@@ -88,7 +88,7 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
" sbcs xzr, %[addr], %[limit]\n"
" cset %[addr], ls\n"
: [addr] "=&r" (ret), [limit] "+r" (limit)
- : [size] "Ir" (size), "0" (addr)
+ : [size] "Ir" (size), [addr_in] "r" (addr)
: "cc");
return ret;
--
2.20.1
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next prev parent reply other threads:[~2020-03-11 18:04 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-11 18:04 [PATCH 0/6] arm64: gcc asm flag outputs Richard Henderson
2020-03-11 18:04 ` [PATCH 1/6] arm64: Add asm/ccset.h header Richard Henderson
2020-03-13 10:54 ` Mark Rutland
2020-03-13 16:29 ` Richard Henderson
2020-03-11 18:04 ` [PATCH 2/6] arm64: uaccess: Use named asm operands for __in_range Richard Henderson
2020-03-11 19:08 ` Robin Murphy
2020-03-11 21:48 ` Richard Henderson
2020-03-13 16:14 ` Robin Murphy
2020-03-11 18:04 ` Richard Henderson [this message]
2020-03-11 19:08 ` [PATCH 3/6] arm64: uaccess: Untie the input address in __range_ok Robin Murphy
2020-03-11 18:04 ` [PATCH 4/6] arm64: uaccess: Use asm/ccset.h macros " Richard Henderson
2020-03-12 11:48 ` Robin Murphy
2020-03-13 11:04 ` Mark Rutland
2020-03-13 16:51 ` Robin Murphy
2020-03-13 17:14 ` Mark Rutland
2020-03-11 18:04 ` [PATCH 5/6] arm64: archrandom: Use asm/ccset.h macros in __arm64_rndr Richard Henderson
2020-03-11 18:04 ` [PATCH 6/6] arm64: Hoist CONFIG option out of ALTERNATIVE in uaccess.h Richard Henderson
2020-03-13 10:46 ` Mark Rutland
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