From bc850d6b374fffd08336996f4b4d3bbd6bf427f6 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 30 Jan 2008 13:33:07 +0100 Subject: [PATCH] x86: add the capability to print fuzzy backtraces For enhancing the 32 bit EBP based backtracer, I need the capability for the backtracer to tell it's customer that an entry is either reliable or unreliable, and the backtrace printing code then needs to print the unreliable ones slightly different. This patch adds the basic capability, the next patch will add a user of this capability. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/pci-gart_64.c | 2 +- arch/x86/kernel/process_64.c | 4 ++-- arch/x86/kernel/stacktrace.c | 2 +- arch/x86/kernel/traps_32.c | 8 +++++--- arch/x86/kernel/traps_64.c | 39 +++++++++++++++++++++++---------------- arch/x86/mm/fault_64.c | 2 +- arch/x86/oprofile/backtrace.c | 2 +- include/asm-x86/kdebug.h | 5 +++-- include/asm-x86/stacktrace.h | 5 +++-- 9 files changed, 40 insertions(+), 29 deletions(-) diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c index d2b46b4..04ca5c5 100644 --- a/arch/x86/kernel/pci-gart_64.c +++ b/arch/x86/kernel/pci-gart_64.c @@ -167,7 +167,7 @@ static void dump_leak(void) iommu_leak_pages); for (i = 0; i < iommu_leak_pages; i += 2) { printk(KERN_DEBUG "%lu: ", iommu_pages-i); - printk_address((unsigned long) iommu_leak_tab[iommu_pages-i]); + printk_address((unsigned long) iommu_leak_tab[iommu_pages-i], 0); printk(KERN_CONT "%c", (i+1)%2 == 0 ? '\n' : ' '); } printk(KERN_DEBUG "\n"); diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index a0130eb..383760b 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -329,7 +329,7 @@ void __show_regs(struct pt_regs * regs) (int)strcspn(init_utsname()->version, " "), init_utsname()->version); printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip); - printk_address(regs->ip); + printk_address(regs->ip, regs->bp); printk("RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->sp, regs->flags); printk("RAX: %016lx RBX: %016lx RCX: %016lx\n", @@ -377,7 +377,7 @@ void show_regs(struct pt_regs *regs) { printk("CPU %d:", smp_processor_id()); __show_regs(regs); - show_trace(NULL, regs, (void *)(regs + 1)); + show_trace(NULL, regs, (void *)(regs + 1), regs->bp); } /* diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index c571edd..8c4e4f5 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -22,7 +22,7 @@ static int save_stack_stack(void *data, char *name) return -1; } -static void save_stack_address(void *data, unsigned long addr) +static void save_stack_address(void *data, unsigned long addr, int reliable) { struct stack_trace *trace = (struct stack_trace *)data; if (trace->skip > 0) { diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c index acc9af2..8ef8a9d 100644 --- a/arch/x86/kernel/traps_32.c +++ b/arch/x86/kernel/traps_32.c @@ -126,7 +126,7 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo, addr = frame->return_address; if (__kernel_text_address(addr)) - ops->address(data, addr); + ops->address(data, addr, 1); /* * break out of recursive entries (such as * end_of_stack_stop_unwind_function). Also, @@ -145,7 +145,7 @@ static inline unsigned long print_context_stack(struct thread_info *tinfo, addr = *stack++; if (__kernel_text_address(addr)) - ops->address(data, addr); + ops->address(data, addr, 1); } #endif return bp; @@ -220,9 +220,11 @@ static int print_trace_stack(void *data, char *name) /* * Print one address/symbol entries per line. */ -static void print_trace_address(void *data, unsigned long addr) +static void print_trace_address(void *data, unsigned long addr, int reliable) { printk("%s [<%08lx>] ", (char *)data, addr); + if (!reliable) + printk("? "); print_symbol("%s\n", addr); touch_nmi_watchdog(); } diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index 37b07d08..62c4d8f 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -99,13 +99,14 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) int kstack_depth_to_print = 12; #ifdef CONFIG_KALLSYMS -void printk_address(unsigned long address) +void printk_address(unsigned long address, int reliable) { unsigned long offset = 0, symsize; const char *symname; char *modname; char *delim = ":"; char namebuf[128]; + char reliab[4] = "";; symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf); @@ -113,13 +114,16 @@ void printk_address(unsigned long address) printk(" [<%016lx>]\n", address); return; } + if (!reliable) + strcpy(reliab, "? "); + if (!modname) modname = delim = ""; - printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n", - address, delim, modname, delim, symname, offset, symsize); + printk(" [<%016lx>] %s%s%s%s%s+0x%lx/0x%lx\n", + address, reliab, delim, modname, delim, symname, offset, symsize); } #else -void printk_address(unsigned long address) +void printk_address(unsigned long address, int reliable) { printk(" [<%016lx>]\n", address); } @@ -215,7 +219,7 @@ static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) } void dump_trace(struct task_struct *tsk, struct pt_regs *regs, - unsigned long *stack, + unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data) { const unsigned cpu = get_cpu(); @@ -252,7 +256,7 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, * down the cause of the crash will be able to figure \ * out the call path that was taken. \ */ \ - ops->address(data, addr); \ + ops->address(data, addr, 1); \ } \ } while (0) @@ -331,10 +335,10 @@ static int print_trace_stack(void *data, char *name) return 0; } -static void print_trace_address(void *data, unsigned long addr) +static void print_trace_address(void *data, unsigned long addr, int reliable) { touch_nmi_watchdog(); - printk_address(addr); + printk_address(addr, reliable); } static const struct stacktrace_ops print_trace_ops = { @@ -345,15 +349,17 @@ static const struct stacktrace_ops print_trace_ops = { }; void -show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack) +show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack, + unsigned long bp) { printk("\nCall Trace:\n"); - dump_trace(tsk, regs, stack, &print_trace_ops, NULL); + dump_trace(tsk, regs, stack, bp, &print_trace_ops, NULL); printk("\n"); } static void -_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp) +_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp, + unsigned long bp) { unsigned long *stack; int i; @@ -387,12 +393,12 @@ _show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *sp) printk(" %016lx", *stack++); touch_nmi_watchdog(); } - show_trace(tsk, regs, sp); + show_trace(tsk, regs, sp, bp); } void show_stack(struct task_struct *tsk, unsigned long * sp) { - _show_stack(tsk, NULL, sp); + _show_stack(tsk, NULL, sp, 0); } /* @@ -401,13 +407,14 @@ void show_stack(struct task_struct *tsk, unsigned long * sp) void dump_stack(void) { unsigned long dummy; + unsigned long bp = 0; printk("Pid: %d, comm: %.20s %s %s %.*s\n", current->pid, current->comm, print_tainted(), init_utsname()->release, (int)strcspn(init_utsname()->version, " "), init_utsname()->version); - show_trace(NULL, NULL, &dummy); + show_trace(NULL, NULL, &dummy, bp); } EXPORT_SYMBOL(dump_stack); @@ -432,7 +439,7 @@ void show_registers(struct pt_regs *regs) */ if (in_kernel) { printk("Stack: "); - _show_stack(NULL, regs, (unsigned long*)sp); + _show_stack(NULL, regs, (unsigned long *)sp, regs->bp); printk("\nCode: "); if (regs->ip < PAGE_OFFSET) @@ -527,7 +534,7 @@ int __kprobes __die(const char * str, struct pt_regs * regs, long err) add_taint(TAINT_DIE); /* Executive summary in case the oops scrolled away */ printk(KERN_ALERT "RIP "); - printk_address(regs->ip); + printk_address(regs->ip, regs->bp); printk(" RSP <%016lx>\n", regs->sp); if (kexec_should_crash(current)) crash_kexec(regs); diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c index e828329..cf7e998 100644 --- a/arch/x86/mm/fault_64.c +++ b/arch/x86/mm/fault_64.c @@ -578,7 +578,7 @@ no_context: else printk(KERN_ALERT "Unable to handle kernel paging request"); printk(" at %016lx RIP: \n" KERN_ALERT, address); - printk_address(regs->ip); + printk_address(regs->ip, regs->bp); dump_pagetable(address); tsk->thread.cr2 = address; tsk->thread.trap_no = 14; diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index cc353a0..671a7ec 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -32,7 +32,7 @@ static int backtrace_stack(void *data, char *name) return 0; } -static void backtrace_address(void *data, unsigned long addr) +static void backtrace_address(void *data, unsigned long addr, int reliable) { unsigned int *depth = data; diff --git a/include/asm-x86/kdebug.h b/include/asm-x86/kdebug.h index e9f42d1..dd442a1 100644 --- a/include/asm-x86/kdebug.h +++ b/include/asm-x86/kdebug.h @@ -22,12 +22,13 @@ enum die_val { DIE_PAGE_FAULT, }; -extern void printk_address(unsigned long address); +extern void printk_address(unsigned long address, int reliable); extern void die(const char *,struct pt_regs *,long); extern int __must_check __die(const char *, struct pt_regs *, long); extern void show_registers(struct pt_regs *regs); extern void __show_registers(struct pt_regs *, int all); -extern void show_trace(struct task_struct *, struct pt_regs *, unsigned long *); +extern void show_trace(struct task_struct *t, struct pt_regs *regs, + unsigned long *sp, unsigned long bp); extern void __show_regs(struct pt_regs *regs); extern void show_regs(struct pt_regs *regs); extern void dump_pagetable(unsigned long); diff --git a/include/asm-x86/stacktrace.h b/include/asm-x86/stacktrace.h index 70dd5ba..30f8252 100644 --- a/include/asm-x86/stacktrace.h +++ b/include/asm-x86/stacktrace.h @@ -9,12 +9,13 @@ struct stacktrace_ops { void (*warning)(void *data, char *msg); /* msg must contain %s for the symbol */ void (*warning_symbol)(void *data, char *msg, unsigned long symbol); - void (*address)(void *data, unsigned long address); + void (*address)(void *data, unsigned long address, int reliable); /* On negative return stop dumping */ int (*stack)(void *data, char *name); }; -void dump_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack, +void dump_trace(struct task_struct *tsk, struct pt_regs *regs, + unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data); #endif -- 2.7.4