[PATCH] arm64: entry: add missing noinstr

[Mark Rutland]

We intend that all the early exception handling code is marked as
`noinstr`, but we forgot this for __el0_error_handler_common(), which is
called before we have completed entry from user mode. If it were
instrumented, we could run into problems with RCU, lockdep, etc.

Mark it as `noinstr` to prevent this.

The few other functions in entry-common.c which do not have `noinstr` are
called once we've completed entry, and are safe to instrument.

Fixes: bb8e93a287a5f5f1 ("arm64: entry: convert SError handlers to C")
Signed-off-by: Mark Rutland <mark.rutland at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Joey Gouly <joey.gouly at arm.com>
Cc: James Morse <james.morse at arm.com>
Cc: Will Deacon <will at kernel.org>
---
 arch/arm64/kernel/entry-common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Hi Catalin, Will,

This is an oversight with my recent entry rework. Could you please take this
for rc2?

Thanks,
Mark.

diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 12ce14a98b7c..db8b2e2d02c2 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -604,7 +604,7 @@ asmlinkage void noinstr el0t_64_fiq_handler(struct pt_regs *regs)
 	__el0_fiq_handler_common(regs);
 }
 
-static void __el0_error_handler_common(struct pt_regs *regs)
+static void noinstr __el0_error_handler_common(struct pt_regs *regs)
 {
 	unsigned long esr = read_sysreg(esr_el1);
 
-- 
2.11.0