arm64/kernel: fix incorrect EL0 check in inv_entry macro

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>

diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 1f7f5a2b61bf0de999d80e6ced16bec120f716b6..12e8d2bcb3f9da4e643649442685138dea7966d1 100644 (file)
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -277,7 +277,7 @@ 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