arm64: entry: handle debug exceptions in el*_inv
Currently we enable debug exceptions before reading ESR_EL1 in both
el0_inv and el1_inv. If a debug exception is taken before we read
ESR_EL1, the value will have been corrupted.
As el*_inv is typically fatal, an intervening debug exception results in
misleading debug information being logged to the console, but is not
otherwise harmful.
As with the other entry paths, we can use the ESR_EL1 value stashed
earlier in the exception entry (in x25 for el0_sync{,_compat}, and x1
for el1_sync), giving us better error reporting in this case.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index a7691a3..f860bfd 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -352,8 +352,8 @@
// TODO: add support for undefined instructions in kernel mode
enable_dbg
mov x0, sp
+ mov x2, x1
mov x1, #BAD_SYNC
- mrs x2, esr_el1
b bad_mode
ENDPROC(el1_sync)
@@ -553,7 +553,7 @@
ct_user_exit
mov x0, sp
mov x1, #BAD_SYNC
- mrs x2, esr_el1
+ mov x2, x25
bl bad_mode
b ret_to_user
ENDPROC(el0_sync)