Messages in this thread Patch in this message | | | From | Christopher Covington <> | Subject | [RFC PATCH] arm64: Fix __addr_ok and __range_ok macros | Date | Wed, 5 Mar 2014 17:41:28 -0500 |
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Without this, the following scenario is incorrectly determined to be invalid.
addr 0x7f_ffffe000 size 8192 addr_limit 0x80_00000000
This behavior was observed while trying to vmsplice the stack as part of a CRIU dump of a process.
Signed-off-by: Christopher Covington <cov@codeaurora.org> --- arch/arm64/include/asm/uaccess.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index edb3d5c..9309024 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -66,12 +66,12 @@ static inline void set_fs(mm_segment_t fs) #define segment_eq(a,b) ((a) == (b)) /* - * Return 1 if addr < current->addr_limit, 0 otherwise. + * Return 1 if addr <= current->addr_limit, 0 otherwise. */ #define __addr_ok(addr) \ ({ \ unsigned long flag; \ - asm("cmp %1, %0; cset %0, lo" \ + asm("cmp %1, %0; cset %0, ls" \ : "=&r" (flag) \ : "r" (addr), "0" (current_thread_info()->addr_limit) \ : "cc"); \ @@ -83,7 +83,7 @@ static inline void set_fs(mm_segment_t fs) * Returns 1 if the range is valid, 0 otherwise. * * This is equivalent to the following test: - * (u65)addr + (u65)size < (u65)current->addr_limit + * (u65)addr + (u65)size <= current->addr_limit * * This needs 65-bit arithmetic. */ @@ -91,7 +91,7 @@ static inline void set_fs(mm_segment_t fs) ({ \ unsigned long flag, roksum; \ __chk_user_ptr(addr); \ - asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, cc" \ + asm("adds %1, %1, %3; ccmp %1, %4, #3, cc; cset %0, ls" \ : "=&r" (flag), "=&r" (roksum) \ : "1" (addr), "Ir" (size), \ "r" (current_thread_info()->addr_limit) \ -- Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by the Linux Foundation.
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