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Subject[PATCH 3.16 34/63] arm64/kernel: fix incorrect EL0 check in inv_entry macro
3.16.81-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ard Biesheuvel <ard.biesheuvel@linaro.org>

commit b660950c60a7278f9d8deb7c32a162031207c758 upstream.

The implementation of macro inv_entry refers to its 'el' argument without
the required leading backslash, which results in an undefined symbol
'el' to be passed into the kernel_entry macro rather than the index of
the exception level as intended.

This undefined symbol strangely enough does not result in build failures,
although it is visible in vmlinux:

$ nm -n vmlinux |head
U el
0000000000000000 A _kernel_flags_le_hi32
0000000000000000 A _kernel_offset_le_hi32
0000000000000000 A _kernel_size_le_hi32
000000000000000a A _kernel_flags_le_lo32
.....

However, it does result in incorrect code being generated for invalid
exceptions taken from EL0, since the argument check in kernel_entry
assumes EL1 if its argument does not equal '0'.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/arm64/kernel/entry.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -187,7 +187,7 @@ END(vectors)
* Invalid mode handlers
*/
.macro inv_entry, el, reason, regsize = 64
- kernel_entry el, \regsize
+ kernel_entry \el, \regsize
mov x0, sp
mov x1, #\reason
mrs x2, esr_el1
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