From: olof@lixom•net (Olof Johansson)
To: paulus@samba•org
Cc: linuxppc-dev@ozlabs•org, anton@samba•org
Subject: [PATCH] powerpc: save trap number in bad_stack
Date: Mon, 16 Apr 2007 01:23:47 -0500 [thread overview]
Message-ID: <20070416062347.GA20196@lixom.net> (raw)
Save the trap number in the case of getting a bad stack in an exception
handler. It is sometimes useful to know what exception it was that caused
this to happen. Without this, no trap is reported.
Signed-off-by: Olof Johansson <olof@lixom•net>
Index: linux-2.6/arch/powerpc/kernel/asm-offsets.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/asm-offsets.c
+++ linux-2.6/arch/powerpc/kernel/asm-offsets.c
@@ -139,6 +139,7 @@ int main(void)
DEFINE(PACA_SYSTEM_TIME, offsetof(struct paca_struct, system_time));
DEFINE(PACA_SLBSHADOWPTR, offsetof(struct paca_struct, slb_shadow_ptr));
DEFINE(PACA_DATA_OFFSET, offsetof(struct paca_struct, data_offset));
+ DEFINE(PACA_TRAP_SAVE, offsetof(struct paca_struct, trap_save));
DEFINE(SLBSHADOW_STACKVSID,
offsetof(struct slb_shadow, save_area[SLB_NUM_BOLTED - 1].vsid));
Index: linux-2.6/include/asm-powerpc/paca.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/paca.h
+++ linux-2.6/include/asm-powerpc/paca.h
@@ -81,6 +81,8 @@ struct paca_struct {
u64 exslb[10]; /* used for SLB/segment table misses
* on the linear mapping */
+ u64 trap_save; /* Used when bad stack is encountered */
+
mm_context_t context;
u16 vmalloc_sllp;
u16 slb_cache[SLB_CACHE_ENTRIES];
Index: linux-2.6/arch/powerpc/kernel/head_64.S
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/head_64.S
+++ linux-2.6/arch/powerpc/kernel/head_64.S
@@ -278,8 +278,12 @@ exception_marker:
beq- 1f; \
ld r1,PACAKSAVE(r13); /* kernel stack to use */ \
1: cmpdi cr1,r1,0; /* check if r1 is in userspace */ \
- bge- cr1,bad_stack; /* abort if it is */ \
- std r9,_CCR(r1); /* save CR in stackframe */ \
+ bge- cr1,2f; /* abort if it is */ \
+ b 3f; \
+2: li r1,(n); /* will be reloaded later */ \
+ std r1,PACA_TRAP_SAVE(r13); \
+ b bad_stack; \
+3: std r9,_CCR(r1); /* save CR in stackframe */ \
std r11,_NIP(r1); /* save SRR0 in stackframe */ \
std r12,_MSR(r1); /* save SRR1 in stackframe */ \
std r10,0(r1); /* make stack chain pointer */ \
@@ -940,6 +944,8 @@ bad_stack:
SAVE_2GPRS(7,r1)
SAVE_10GPRS(12,r1)
SAVE_10GPRS(22,r1)
+ ld r12,PACA_TRAP_SAVE(r13)
+ std r12,_TRAP(r1)
addi r11,r1,INT_FRAME_SIZE
std r11,0(r1)
li r12,0
next reply other threads:[~2007-04-16 6:05 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-16 6:23 Olof Johansson [this message]
2007-04-19 23:17 ` [PATCH] powerpc: save trap number in bad_stack Benjamin Herrenschmidt
2007-04-20 2:18 ` Michael Ellerman
2007-04-20 8:51 ` Segher Boessenkool
2007-04-22 23:34 ` Olof Johansson
2007-04-22 23:38 ` [PATCH] [v2] " Olof Johansson
2007-04-23 9:29 ` Gabriel Paubert
2007-04-23 11:49 ` Olof Johansson
2007-04-23 12:19 ` [PATCH] [v3] " Olof Johansson
2007-04-23 15:11 ` [PATCH] [v4] " Olof Johansson
2007-04-23 15:34 ` Stephen Rothwell
2007-04-23 13:22 ` [PATCH] [v2] " Stephen Rothwell
2007-04-23 13:33 ` Michael Ellerman
2007-04-23 13:39 ` David Gibson
2007-04-23 13:54 ` Olof Johansson
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