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Subject[PATCH v2] arm64: Fix __range_ok macro
Date
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 on a system started with the
norandmaps kernel parameter.

Signed-off-by: Christopher Covington <cov@codeaurora.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 7ecc2b2..5974459 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -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, #2, cc; cset %0, ls" \
: "=&r" (flag), "=&r" (roksum) \
: "1" (addr), "Ir" (size), \
"r" (current_thread_info()->addr_limit) \
--
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