Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753666Ab1CJWZU (ORCPT ); Thu, 10 Mar 2011 17:25:20 -0500 Received: from hera.kernel.org ([140.211.167.34]:60960 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751137Ab1CJWZT (ORCPT ); Thu, 10 Mar 2011 17:25:19 -0500 Date: Thu, 10 Mar 2011 22:24:53 GMT From: tip-bot for Namhyung Kim Cc: linux-kernel@vger.kernel.org, acme@redhat.com, paulus@samba.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, namhyung@gmail.com, ssp@redhat.com, fweisbec@gmail.com, tglx@linutronix.de Reply-To: mingo@redhat.com, hpa@zytor.com, paulus@samba.org, acme@redhat.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, namhyung@gmail.com, ssp@redhat.com In-Reply-To: <1299584662-24421-1-git-send-email-namhyung@gmail.com> References: <1299584662-24421-1-git-send-email-namhyung@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/cleanups] x86, dumpstack: Correct stack dump info when frame pointer is available Message-ID: Git-Commit-ID: 074206a787e4dfdc4c290789ab6604c7f9e691ca X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 10 Mar 2011 22:24:55 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 12235 Lines: 337 Commit-ID: 074206a787e4dfdc4c290789ab6604c7f9e691ca Gitweb: http://git.kernel.org/tip/074206a787e4dfdc4c290789ab6604c7f9e691ca Author: Namhyung Kim AuthorDate: Tue, 8 Mar 2011 20:44:19 +0900 Committer: Thomas Gleixner CommitDate: Thu, 10 Mar 2011 23:20:30 +0100 x86, dumpstack: Correct stack dump info when frame pointer is available Current stack dump code scans entire stack and checks each entry for a pointer to kernel code. If CONFIG_FRAME_POINTER=y it could mark whether the pointer is valid or not based on value of the frame pointer. Invalid entries could be preceded by '?' sign. However this was not going to happen because scan start point was always higher than the frame pointer so that they could not meet. Commit 9c0729dc8062 ("x86: Eliminate bp argument from the stack tracing routines") delayed bp acquisition point, so the bp was read in lower frame, thus all of the entries were marked invalid. This patch fixes this by reverting above commit while retaining stack_frame() helper as suggested by Frederic Weisbecker. End result looks like below: before: [ 3.508329] Call Trace: [ 3.508551] [] ? panic+0x91/0x199 [ 3.508662] [] ? printk+0x68/0x6a [ 3.508770] [] ? mount_block_root+0x257/0x26e [ 3.508876] [] ? mount_root+0x56/0x5a [ 3.508975] [] ? prepare_namespace+0x170/0x1a9 [ 3.509216] [] ? kernel_init+0x1d2/0x1e2 [ 3.509335] [] ? kernel_thread_helper+0x4/0x10 [ 3.509442] [] ? restore_args+0x0/0x30 [ 3.509542] [] ? kernel_init+0x0/0x1e2 [ 3.509641] [] ? kernel_thread_helper+0x0/0x10 after: [ 3.522991] Call Trace: [ 3.523351] [] panic+0x91/0x199 [ 3.523468] [] ? printk+0x68/0x6a [ 3.523576] [] mount_block_root+0x257/0x26e [ 3.523681] [] mount_root+0x56/0x5a [ 3.523780] [] prepare_namespace+0x170/0x1a9 [ 3.523885] [] kernel_init+0x1d2/0x1e2 [ 3.523987] [] kernel_thread_helper+0x4/0x10 [ 3.524228] [] ? restore_args+0x0/0x30 [ 3.524345] [] ? kernel_init+0x0/0x1e2 [ 3.524445] [] ? kernel_thread_helper+0x0/0x10 Signed-off-by: Namhyung Kim Cc: Soren Sandmann Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker LKML-Reference: <1299584662-24421-1-git-send-email-namhyung@gmail.com> Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/kdebug.h | 2 +- arch/x86/include/asm/stacktrace.h | 6 +++--- arch/x86/kernel/cpu/perf_event.c | 2 +- arch/x86/kernel/dumpstack.c | 14 ++++++++------ arch/x86/kernel/dumpstack_32.c | 15 ++++++++------- arch/x86/kernel/dumpstack_64.c | 14 +++++++------- arch/x86/kernel/process.c | 2 +- arch/x86/kernel/stacktrace.c | 6 +++--- 8 files changed, 32 insertions(+), 29 deletions(-) diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h index ca242d3..e28ec43 100644 --- a/arch/x86/include/asm/kdebug.h +++ b/arch/x86/include/asm/kdebug.h @@ -27,7 +27,7 @@ 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_trace(struct task_struct *t, struct pt_regs *regs, - unsigned long *sp); + unsigned long *sp, unsigned long bp); extern void __show_regs(struct pt_regs *regs, int all); extern void show_regs(struct pt_regs *regs); extern unsigned long oops_begin(void); diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index 52b5c7e..d7e89c8 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -47,7 +47,7 @@ struct stacktrace_ops { }; 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); #ifdef CONFIG_X86_32 @@ -86,11 +86,11 @@ stack_frame(struct task_struct *task, struct pt_regs *regs) extern void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *stack, char *log_lvl); + unsigned long *stack, unsigned long bp, char *log_lvl); extern void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *sp, char *log_lvl); + unsigned long *sp, unsigned long bp, char *log_lvl); extern unsigned int code_bytes; diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 9d977a2..d19cdc2 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1710,7 +1710,7 @@ perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) perf_callchain_store(entry, regs->ip); - dump_trace(NULL, regs, NULL, &backtrace_ops, entry); + dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry); } #ifdef CONFIG_COMPAT diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index df20723..c330160 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -175,21 +175,21 @@ static const struct stacktrace_ops print_trace_ops = { void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *stack, char *log_lvl) + unsigned long *stack, unsigned long bp, char *log_lvl) { printk("%sCall Trace:\n", log_lvl); - dump_trace(task, regs, stack, &print_trace_ops, log_lvl); + dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl); } void show_trace(struct task_struct *task, struct pt_regs *regs, - unsigned long *stack) + unsigned long *stack, unsigned long bp) { - show_trace_log_lvl(task, regs, stack, ""); + show_trace_log_lvl(task, regs, stack, bp, ""); } void show_stack(struct task_struct *task, unsigned long *sp) { - show_stack_log_lvl(task, NULL, sp, ""); + show_stack_log_lvl(task, NULL, sp, 0, ""); } /* @@ -197,14 +197,16 @@ void show_stack(struct task_struct *task, unsigned long *sp) */ void dump_stack(void) { + unsigned long bp; unsigned long stack; + bp = stack_frame(current, NULL); 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, &stack); + show_trace(NULL, NULL, &stack, bp); } EXPORT_SYMBOL(dump_stack); diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index 74cc1ed..3b97a80 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -17,12 +17,11 @@ #include -void dump_trace(struct task_struct *task, - struct pt_regs *regs, unsigned long *stack, +void dump_trace(struct task_struct *task, struct pt_regs *regs, + unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data) { int graph = 0; - unsigned long bp; if (!task) task = current; @@ -35,7 +34,9 @@ void dump_trace(struct task_struct *task, stack = (unsigned long *)task->thread.sp; } - bp = stack_frame(task, regs); + if (!bp) + bp = stack_frame(task, regs); + for (;;) { struct thread_info *context; @@ -55,7 +56,7 @@ EXPORT_SYMBOL(dump_trace); void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *sp, char *log_lvl) + unsigned long *sp, unsigned long bp, char *log_lvl) { unsigned long *stack; int i; @@ -77,7 +78,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, touch_nmi_watchdog(); } printk(KERN_CONT "\n"); - show_trace_log_lvl(task, regs, sp, log_lvl); + show_trace_log_lvl(task, regs, sp, bp, log_lvl); } @@ -102,7 +103,7 @@ void show_registers(struct pt_regs *regs) u8 *ip; printk(KERN_EMERG "Stack:\n"); - show_stack_log_lvl(NULL, regs, ®s->sp, KERN_EMERG); + show_stack_log_lvl(NULL, regs, ®s->sp, 0, KERN_EMERG); printk(KERN_EMERG "Code: "); diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index a6b6fcf..e71c98d 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -139,8 +139,8 @@ fixup_bp_irq_link(unsigned long bp, unsigned long *stack, * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack */ -void dump_trace(struct task_struct *task, - struct pt_regs *regs, unsigned long *stack, +void dump_trace(struct task_struct *task, struct pt_regs *regs, + unsigned long *stack, unsigned long bp, const struct stacktrace_ops *ops, void *data) { const unsigned cpu = get_cpu(); @@ -150,7 +150,6 @@ void dump_trace(struct task_struct *task, struct thread_info *tinfo; int graph = 0; unsigned long dummy; - unsigned long bp; if (!task) task = current; @@ -161,7 +160,8 @@ void dump_trace(struct task_struct *task, stack = (unsigned long *)task->thread.sp; } - bp = stack_frame(task, regs); + if (!bp) + bp = stack_frame(task, regs); /* * Print function call entries in all stacks, starting at the * current stack address. If the stacks consist of nested @@ -225,7 +225,7 @@ EXPORT_SYMBOL(dump_trace); void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, - unsigned long *sp, char *log_lvl) + unsigned long *sp, unsigned long bp, char *log_lvl) { unsigned long *irq_stack_end; unsigned long *irq_stack; @@ -269,7 +269,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, preempt_enable(); printk(KERN_CONT "\n"); - show_trace_log_lvl(task, regs, sp, log_lvl); + show_trace_log_lvl(task, regs, sp, bp, log_lvl); } void show_registers(struct pt_regs *regs) @@ -298,7 +298,7 @@ void show_registers(struct pt_regs *regs) printk(KERN_EMERG "Stack:\n"); show_stack_log_lvl(NULL, regs, (unsigned long *)sp, - KERN_EMERG); + 0, KERN_EMERG); printk(KERN_EMERG "Code: "); diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ff45541..f4c6cc4 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -87,7 +87,7 @@ void exit_thread(void) void show_regs(struct pt_regs *regs) { show_registers(regs); - show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs)); + show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs), 0); } void show_regs_common(void) diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c index 938c8e1..6515733 100644 --- a/arch/x86/kernel/stacktrace.c +++ b/arch/x86/kernel/stacktrace.c @@ -73,7 +73,7 @@ static const struct stacktrace_ops save_stack_ops_nosched = { */ void save_stack_trace(struct stack_trace *trace) { - dump_trace(current, NULL, NULL, &save_stack_ops, trace); + dump_trace(current, NULL, NULL, 0, &save_stack_ops, trace); if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } @@ -81,14 +81,14 @@ EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_regs(struct stack_trace *trace, struct pt_regs *regs) { - dump_trace(current, regs, NULL, &save_stack_ops, trace); + dump_trace(current, regs, NULL, 0, &save_stack_ops, trace); if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) { - dump_trace(tsk, NULL, NULL, &save_stack_ops_nosched, trace); + dump_trace(tsk, NULL, NULL, 0, &save_stack_ops_nosched, trace); if (trace->nr_entries < trace->max_entries) trace->entries[trace->nr_entries++] = ULONG_MAX; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/