From 1b42804d27b1c2623309950e9b203b11f4c67f4f Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 7 Jul 2015 18:00:49 +0100 Subject: [PATCH] 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 Acked-by: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/kernel/entry.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index a7691a378668..f860bfda454a 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -352,8 +352,8 @@ el1_inv: // 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 @@ el0_inv: 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) -- 2.34.1