From 608e2619682e951f525b08e7a48669a3c0263b41 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Sun, 15 Jul 2007 23:41:39 -0700 Subject: [PATCH] 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 Acked-by: Haavard Skinnemoen Cc: Andi Kleen Cc: Kyle McMartin Cc: Paul Mackerras Cc: Paul Mundt Cc: Martin Schwidefsky Signed-off-by: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/avr32/kernel/traps.c | 2 +- arch/i386/kernel/traps.c | 2 +- arch/parisc/kernel/traps.c | 2 +- arch/powerpc/kernel/traps.c | 2 +- arch/ppc/kernel/traps.c | 2 +- arch/s390/kernel/traps.c | 2 +- arch/sh/kernel/traps.c | 2 +- arch/x86_64/kernel/traps.c | 2 +- include/linux/bug.h | 7 +++++-- lib/bug.c | 5 +++-- 10 files changed, 16 insertions(+), 12 deletions(-) diff --git a/arch/avr32/kernel/traps.c b/arch/avr32/kernel/traps.c index 86d107511d..aaa792815c 100644 --- a/arch/avr32/kernel/traps.c +++ b/arch/avr32/kernel/traps.c @@ -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; diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 90da0575fc..28bd1c5163 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -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 diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index c3ec9f1ec0..f9bca2d74b 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -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; diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index bf6445ac9f..3b8427e628 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -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; } diff --git a/arch/ppc/kernel/traps.c b/arch/ppc/kernel/traps.c index aea100be52..0eaef7c837 100644 --- a/arch/ppc/kernel/traps.c +++ b/arch/ppc/kernel/traps.c @@ -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; } diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index ee9186f8fb..81e03b9c38 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -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); diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c index 8f18930d5b..0948088707 100644 --- a/arch/sh/kernel/traps.c +++ b/arch/sh/kernel/traps.c @@ -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; diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c index aac1c0be54..7fa155c394 100644 --- a/arch/x86_64/kernel/traps.c +++ b/arch/x86_64/kernel/traps.c @@ -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); diff --git a/include/linux/bug.h b/include/linux/bug.h index 42aa0a54b6..54398d2c6d 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -10,6 +10,8 @@ enum bug_trap_type { BUG_TRAP_TYPE_BUG = 2, }; +struct pt_regs; + #ifdef CONFIG_GENERIC_BUG #include @@ -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; } diff --git a/lib/bug.c b/lib/bug.c index 014b582c5c..530f38f557 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -38,6 +38,7 @@ #include #include #include +#include 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; } -- 2.39.5