From e4efec8c28bce3be6078657f0846e59ccded593b Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 3 Oct 2017 19:14:38 +0100 Subject: [PATCH] ARM: 8702/1: head-common.S: Clear lr before jumping to start_kernel() commit 59b6359dd92d18f5dc04b14a4c926fa08ab66f7c upstream. If CONFIG_DEBUG_LOCK_ALLOC=y, the kernel log is spammed with a few hundred identical messages: unwind: Unknown symbol address c0800300 unwind: Index not found c0800300 c0800300 is the return address from the last subroutine call (to __memzero()) in __mmap_switched(). Apparently having this address in the link register confuses the unwinder. To fix this, reset the link register to zero before jumping to start_kernel(). Fixes: 9520b1a1b5f7a348 ("ARM: head-common.S: speed up startup code") Suggested-by: Ard Biesheuvel Signed-off-by: Geert Uytterhoeven Acked-by: Nicolas Pitre Signed-off-by: Russell King Signed-off-by: Greg Kroah-Hartman Signed-off-by: Nick Desaulniers --- arch/arm/kernel/head-common.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index 7e662bdd5cb3..932b2244e709 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -101,6 +101,7 @@ __mmap_switched: str r2, [r6] @ Save atags pointer cmp r7, #0 strne r0, [r7] @ Save control register values + mov lr, #0 b start_kernel ENDPROC(__mmap_switched)