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arm64: armv8_deprecated: ensure extension of addr

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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")
Cc: <stable@vger.kernel.org> # 3.19.x-
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>
This commit is contained in:
Mark Rutland 2017-05-03 16:09:36 +01:00 committed by Greg Kroah-Hartman
parent 51ff10e72f
commit 01ce16f40c
1 changed files with 2 additions and 1 deletions
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arch/arm64/kernel/armv8_deprecated.c
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@ -305,7 +305,8 @@ static void register_insn_emulation_sysctl(struct ctl_table *table)
ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \
CONFIG_ARM64_PAN) \
: "=&r" (res), "+r" (data), "=&r" (temp) \
: "r" (addr), "i" (-EAGAIN), "i" (-EFAULT) \
: "r" ((unsigned long)addr), "i" (-EAGAIN), \
"i" (-EFAULT) \
: "memory")
#define __user_swp_asm(data, addr, res, temp) \