| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.11 146/197] arm64: armv8_deprecated: ensure extension of addr | Date | Tue, 23 May 2017 22:08:27 +0200 |
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4.11-stable review patch. If anyone has any objections, please let me know.
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From: Mark Rutland <mark.rutland@arm.com>
commit 55de49f9aa17b0b2b144dd2af587177b9aadf429 upstream.
Our compat swp emulation holds the compat user address in an unsigned int, which it passes to __user_swpX_asm(). When a 32-bit value is passed in a register, the upper 32 bits of the register are unknown, and we must extend the value to 64 bits before we can use it as a base address.
This patch casts the address to unsigned long to ensure it has been suitably extended, avoiding the potential issue, and silencing a related warning from clang.
Fixes: bd35a4adc413 ("arm64: Port SWP/SWPB emulation support from arm") Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/arm64/kernel/armv8_deprecated.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -306,7 +306,8 @@ do { \ _ASM_EXTABLE(0b, 4b) \ _ASM_EXTABLE(1b, 4b) \ : "=&r" (res), "+r" (data), "=&r" (temp), "=&r" (temp2) \ - : "r" (addr), "i" (-EAGAIN), "i" (-EFAULT), \ + : "r" ((unsigned long)addr), "i" (-EAGAIN), \ + "i" (-EFAULT), \ "i" (__SWP_LL_SC_LOOPS) \ : "memory"); \ uaccess_disable(); \
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