4.4-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit b660950c60a7278f9d8deb7c32a162031207c758 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 3028d9b028c7..586326981769 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -243,7 +243,7 @@ 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