From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Wed, 3 May 2017 16:09:36 +0100 Subject: [PATCH 4/6] arm64: armv8_deprecated: ensure extension of addr In-Reply-To: <1493824178-7399-1-git-send-email-mark.rutland@arm.com> References: <1493824178-7399-1-git-send-email-mark.rutland@arm.com> Message-ID: <1493824178-7399-5-git-send-email-mark.rutland@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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: bd35a4adc4131c53 ("arm64: Port SWP/SWPB emulation support from arm") Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Matthias Kaehlcke Cc: Punit Agrawal Cc: Will Deacon --- arch/arm64/kernel/armv8_deprecated.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c index 657977e..f0e6d71 100644 --- a/arch/arm64/kernel/armv8_deprecated.c +++ b/arch/arm64/kernel/armv8_deprecated.c @@ -306,7 +306,8 @@ static void __init register_insn_emulation_sysctl(struct ctl_table *table) _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(); \ -- 1.9.1