[PATCH 08/11] powerpc/40x: add exception frame marker
From: Christophe Leroy
Date: Mon Jan 28 2019 - 06:11:37 EST
This patch adds STACK_FRAME_REGS_MARKER in the stack at exception entry
in order to see interrupts in call traces as below:
[ 0.013964] Call Trace:
[ 0.014014] [c0745db0] [c007a9d4] tick_periodic.constprop.5+0xd8/0x104 (unreliable)
[ 0.014086] [c0745dc0] [c007aa20] tick_handle_periodic+0x20/0x9c
[ 0.014181] [c0745de0] [c0009cd0] timer_interrupt+0xa0/0x264
[ 0.014258] [c0745e10] [c000e484] ret_from_except+0x0/0x14
[ 0.014390] --- interrupt: 901 at console_unlock.part.7+0x3f4/0x528
[ 0.014390] LR = console_unlock.part.7+0x3f0/0x528
[ 0.014455] [c0745ee0] [c0050334] console_unlock.part.7+0x114/0x528 (unreliable)
[ 0.014542] [c0745f30] [c00524e0] register_console+0x3d8/0x44c
[ 0.014625] [c0745f60] [c0675aac] cpm_uart_console_init+0x18/0x2c
[ 0.014709] [c0745f70] [c06614f4] console_init+0x114/0x1cc
[ 0.014795] [c0745fb0] [c0658b68] start_kernel+0x300/0x3d8
[ 0.014864] [c0745ff0] [c00022cc] start_here+0x44/0x98
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
arch/powerpc/kernel/head_40x.S | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 59f6f53f1ac2..f3bfb695f952 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -132,6 +132,9 @@ _ENTRY(saved_ksp_limit)
tovirt(r1,r11); /* set new kernel sp */ \
rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
stw r0,GPR0(r11); \
+ lis r10, STACK_FRAME_REGS_MARKER@ha; /* exception frame marker */\
+ addi r10, r10, STACK_FRAME_REGS_MARKER@l; \
+ stw r10, 8(r11); \
SAVE_4GPRS(3, r11); \
SAVE_2GPRS(7, r11)
@@ -174,6 +177,9 @@ _ENTRY(saved_ksp_limit)
tovirt(r1,r11); \
rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
stw r0,GPR0(r11); \
+ lis r10, STACK_FRAME_REGS_MARKER@ha; /* exception frame marker */\
+ addi r10, r10, STACK_FRAME_REGS_MARKER@l; \
+ stw r10, 8(r11); \
SAVE_4GPRS(3, r11); \
SAVE_2GPRS(7, r11)
--
2.13.3