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authorKristina Martsenko <kristina.martsenko@arm.com>2017-05-03 16:37:46 +0100
committerCatalin Marinas <catalin.marinas@arm.com>2017-05-09 17:26:40 +0100
commit7dcd9dd8cebe9fa626af7e2358d03a37041a70fb (patch)
tree45bbe17e3f608ba637e25fab2d12e39f1dc95cc8 /arch/arm64/include/asm/uaccess.h
parentarm64: traps: fix userspace cache maintenance emulation on a tagged pointer (diff)
downloadlinux-dev-7dcd9dd8cebe9fa626af7e2358d03a37041a70fb.tar.xz
linux-dev-7dcd9dd8cebe9fa626af7e2358d03a37041a70fb.zip
arm64: hw_breakpoint: fix watchpoint matching for tagged pointers
When we take a watchpoint exception, the address that triggered the watchpoint is found in FAR_EL1. We compare it to the address of each configured watchpoint to see which one was hit. The configured watchpoint addresses are untagged, while the address in FAR_EL1 will have an address tag if the data access was done using a tagged address. The tag needs to be removed to compare the address to the watchpoints. Currently we don't remove it, and as a result can report the wrong watchpoint as being hit (specifically, always either the highest TTBR0 watchpoint or lowest TTBR1 watchpoint). This patch removes the tag. Fixes: d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0") Cc: <stable@vger.kernel.org> # 3.12.x- Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to '')
-rw-r--r--arch/arm64/include/asm/uaccess.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 5308d696311b..0221029e27ff 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -106,9 +106,9 @@ static inline void set_fs(mm_segment_t fs)
})
/*
- * When dealing with data aborts or instruction traps we may end up with
- * a tagged userland pointer. Clear the tag to get a sane pointer to pass
- * on to access_ok(), for instance.
+ * When dealing with data aborts, watchpoints, or instruction traps we may end
+ * up with a tagged userland pointer. Clear the tag to get a sane pointer to
+ * pass on to access_ok(), for instance.
*/
#define untagged_addr(addr) sign_extend64(addr, 55)