arm64/kernel: fix incorrect EL0 check in inv_entry macro

[ 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>

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 00f7ba3d82b8300c69d8f73f6da02f24568f29c1..2dfbb831e4af20ad8b8d3b5067e2a2e6e2f3a66e 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -234,7 +234,7 @@ 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