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alistair23-linux
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generic bug: use show_regs() instead of dump_stack() 

The current generic bug implementation has a call to dump_stack() in case a
WARN_ON(whatever) gets hit.  Since report_bug(), which calls dump_stack(),
gets called from an exception handler we can do better: just pass the
pt_regs structure to report_bug() and pass it to show_regs() in case of a
warning.  This will give more debug informations like register contents,
etc...  In addition this avoids some pointless lines that dump_stack()
emits, since it includes a stack backtrace of the exception handler which
is of no interest in case of a warning.  E.g.  on s390 the following lines
are currently always present in a stack backtrace if dump_stack() gets
called from report_bug():

 [<000000000001517a>] show_trace+0x92/0xe8)
 [<0000000000015270>] show_stack+0xa0/0xd0
 [<00000000000152ce>] dump_stack+0x2e/0x3c
 [<0000000000195450>] report_bug+0x98/0xf8
 [<0000000000016cc8>] illegal_op+0x1fc/0x21c
 [<00000000000227d6>] sysc_return+0x0/0x10

Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hifive-unleashed-5.1
Heiko Carstens 2007-07-15 23:41:39 -07:00 committed by Linus Torvalds
parent 94bed2a9c4
commit 608e261968
10 changed files with 16 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/avr32/kernel/traps.c
View File

@ -184,7 +184,7 @@ asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
enum bug_trap_type type;
type = report_bug(regs->pc);
type = report_bug(regs->pc, regs);
switch (type) {
case BUG_TRAP_TYPE_NONE:
break;

2
arch/i386/kernel/traps.c
View File

@ -390,7 +390,7 @@ void die(const char * str, struct pt_regs * regs, long err)
unsigned long esp;
unsigned short ss;
report_bug(regs->eip);
report_bug(regs->eip, regs);
printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
#ifdef CONFIG_PREEMPT

2
arch/parisc/kernel/traps.c
View File

@ -302,7 +302,7 @@ static void handle_break(struct pt_regs *regs)
if (unlikely(iir == PARISC_BUG_BREAK_INSN && !user_mode(regs))) {
/* check if a BUG() or WARN() trapped here. */
enum bug_trap_type tt;
tt = report_bug(regs->iaoq[0] & ~3);
tt = report_bug(regs->iaoq[0] & ~3, regs);
if (tt == BUG_TRAP_TYPE_WARN) {
regs->iaoq[0] += 4;
regs->iaoq[1] += 4;

2
arch/powerpc/kernel/traps.c
View File

@ -777,7 +777,7 @@ void __kprobes program_check_exception(struct pt_regs *regs)
return;
if (!(regs->msr & MSR_PR) && /* not user-mode */
report_bug(regs->nip) == BUG_TRAP_TYPE_WARN) {
report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
regs->nip += 4;
return;
}

2
arch/ppc/kernel/traps.c
View File

@ -619,7 +619,7 @@ void program_check_exception(struct pt_regs *regs)
return;
if (!(regs->msr & MSR_PR) && /* not user-mode */
report_bug(regs->nip) == BUG_TRAP_TYPE_WARN) {
report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {
regs->nip += 4;
return;
}

2
arch/s390/kernel/traps.c
View File

@ -319,7 +319,7 @@ static void __kprobes inline do_trap(long interruption_code, int signr,
else {
enum bug_trap_type btt;
btt = report_bug(regs->psw.addr & PSW_ADDR_INSN);
btt = report_bug(regs->psw.addr & PSW_ADDR_INSN, regs);
if (btt == BUG_TRAP_TYPE_WARN)
return;
die(str, regs, interruption_code);

2
arch/sh/kernel/traps.c
View File

@ -874,7 +874,7 @@ void __init trap_init(void)
void handle_BUG(struct pt_regs *regs)
{
enum bug_trap_type tt;
tt = report_bug(regs->pc);
tt = report_bug(regs->pc, regs);
if (tt == BUG_TRAP_TYPE_WARN) {
regs->pc += 2;
return;

2
arch/x86_64/kernel/traps.c
View File

@ -531,7 +531,7 @@ void die(const char * str, struct pt_regs * regs, long err)
unsigned long flags = oops_begin();
if (!user_mode(regs))
report_bug(regs->rip);
report_bug(regs->rip, regs);
__die(str, regs, err);
oops_end(flags);

7
include/linux/bug.h
View File

@ -10,6 +10,8 @@ enum bug_trap_type {
BUG_TRAP_TYPE_BUG = 2,
};
struct pt_regs;
#ifdef CONFIG_GENERIC_BUG
#include <asm-generic/bug.h>
@ -20,7 +22,7 @@ static inline int is_warning_bug(const struct bug_entry *bug)
const struct bug_entry *find_bug(unsigned long bugaddr);
enum bug_trap_type report_bug(unsigned long bug_addr);
enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);
int module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *,
struct module *);
@ -31,7 +33,8 @@ int is_valid_bugaddr(unsigned long addr);
#else /* !CONFIG_GENERIC_BUG */
static inline enum bug_trap_type report_bug(unsigned long bug_addr)
static inline enum bug_trap_type report_bug(unsigned long bug_addr,
struct pt_regs *regs)
{
return BUG_TRAP_TYPE_BUG;
}

5
lib/bug.c
View File

@ -38,6 +38,7 @@
#include <linux/list.h>
#include <linux/module.h>
#include <linux/bug.h>
#include <linux/sched.h>
extern const struct bug_entry __start___bug_table[], __stop___bug_table[];
@ -112,7 +113,7 @@ const struct bug_entry *find_bug(unsigned long bugaddr)
return module_find_bug(bugaddr);
}
enum bug_trap_type report_bug(unsigned long bugaddr)
enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs)
{
const struct bug_entry *bug;
const char *file;
@ -147,7 +148,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr)
"[verbose debug info unavailable]\n",
(void *)bugaddr);
dump_stack();
show_regs(regs);
return BUG_TRAP_TYPE_WARN;
}