arm64: Fix __range_ok macro

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>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 6c0f684aca81ce2da8b71c18cf2fb659c62ceaab..3bf8f4e99a511c67a3a2d9c4a739929cedd5889f 100644 (file)
--- 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)               \