From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966209AbcIHJu2 (ORCPT ); Thu, 8 Sep 2016 05:50:28 -0400 Received: from terminus.zytor.com ([198.137.202.10]:39920 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965174AbcIHJuZ (ORCPT ); Thu, 8 Sep 2016 05:50:25 -0400 Date: Thu, 8 Sep 2016 02:49:37 -0700 From: tip-bot for Josh Poimboeuf Message-ID: Cc: brgerst@gmail.com, keescook@chromium.org, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, nilayvaish@gmail.com, luto@amacapital.net, hpa@zytor.com, mingo@kernel.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, byungchul.park@lge.com, fweisbec@gmail.com, torvalds@linux-foundation.org, jpoimboe@redhat.com Reply-To: keescook@chromium.org, brgerst@gmail.com, tglx@linutronix.de, peterz@infradead.org, luto@kernel.org, nilayvaish@gmail.com, jpoimboe@redhat.com, torvalds@linux-foundation.org, byungchul.park@lge.com, fweisbec@gmail.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, luto@amacapital.net, mingo@kernel.org, hpa@zytor.com In-Reply-To: References: To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] x86/dumpstack: Add get_stack_pointer() and get_frame_pointer() Git-Commit-ID: 4b8afafbe743be1a81c96ddcd75b19c534d5e262 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 4b8afafbe743be1a81c96ddcd75b19c534d5e262 Gitweb: http://git.kernel.org/tip/4b8afafbe743be1a81c96ddcd75b19c534d5e262 Author: Josh Poimboeuf AuthorDate: Wed, 24 Aug 2016 11:50:17 -0500 Committer: Ingo Molnar CommitDate: Thu, 8 Sep 2016 08:58:40 +0200 x86/dumpstack: Add get_stack_pointer() and get_frame_pointer() The various functions involved in dumping the stack all do similar things with regard to getting the stack pointer and the frame pointer based on the regs and task arguments. Create helper functions to do that instead. Signed-off-by: Josh Poimboeuf Reviewed-by: Andy Lutomirski Cc: Andy Lutomirski Cc: Brian Gerst Cc: Byungchul Park Cc: Frederic Weisbecker Cc: Kees Cook Cc: Linus Torvalds Cc: Nilay Vaish Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/f448914885a35f333fe04da1b97a6c2cc1f80974.1472057064.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/stacktrace.h | 41 ++++++++++++++++++++++----------------- arch/x86/kernel/dumpstack.c | 5 ++--- arch/x86/kernel/dumpstack_32.c | 25 ++++-------------------- arch/x86/kernel/dumpstack_64.c | 30 ++++------------------------ 4 files changed, 33 insertions(+), 68 deletions(-) diff --git a/arch/x86/include/asm/stacktrace.h b/arch/x86/include/asm/stacktrace.h index 7646fb2..3552f5e 100644 --- a/arch/x86/include/asm/stacktrace.h +++ b/arch/x86/include/asm/stacktrace.h @@ -50,36 +50,41 @@ void dump_trace(struct task_struct *tsk, struct pt_regs *regs, #ifdef CONFIG_X86_32 #define STACKSLOTS_PER_LINE 8 -#define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :) #else #define STACKSLOTS_PER_LINE 4 -#define get_bp(bp) asm("movq %%rbp, %0" : "=r" (bp) :) #endif #ifdef CONFIG_FRAME_POINTER -static inline unsigned long -stack_frame(struct task_struct *task, struct pt_regs *regs) +static inline unsigned long * +get_frame_pointer(struct task_struct *task, struct pt_regs *regs) { - unsigned long bp; - if (regs) - return regs->bp; + return (unsigned long *)regs->bp; - if (task == current) { - /* Grab bp right from our regs */ - get_bp(bp); - return bp; - } + if (!task || task == current) + return __builtin_frame_address(0); - return ((struct inactive_task_frame *)task->thread.sp)->bp; + return (unsigned long *)((struct inactive_task_frame *)task->thread.sp)->bp; } #else -static inline unsigned long -stack_frame(struct task_struct *task, struct pt_regs *regs) +static inline unsigned long * +get_frame_pointer(struct task_struct *task, struct pt_regs *regs) { - return 0; + return NULL; +} +#endif /* CONFIG_FRAME_POINTER */ + +static inline unsigned long * +get_stack_pointer(struct task_struct *task, struct pt_regs *regs) +{ + if (regs) + return (unsigned long *)kernel_stack_pointer(regs); + + if (!task || task == current) + return __builtin_frame_address(0); + + return (unsigned long *)task->thread.sp; } -#endif extern void show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, @@ -106,7 +111,7 @@ static inline unsigned long caller_frame_pointer(void) { struct stack_frame *frame; - get_bp(frame); + frame = __builtin_frame_address(0); #ifdef CONFIG_FRAME_POINTER frame = frame->next_frame; diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index f0ddf85..6d6f468 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -170,15 +170,14 @@ show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs, void show_stack(struct task_struct *task, unsigned long *sp) { unsigned long bp = 0; - unsigned long stack; /* * Stack frames below this one aren't interesting. Don't show them * if we're printing for %current. */ if (!sp && (!task || task == current)) { - sp = &stack; - bp = stack_frame(current, NULL); + sp = get_stack_pointer(current, NULL); + bp = (unsigned long)get_frame_pointer(current, NULL); } show_stack_log_lvl(task, NULL, sp, bp, ""); diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c index 0967571..358fe1c 100644 --- a/arch/x86/kernel/dumpstack_32.c +++ b/arch/x86/kernel/dumpstack_32.c @@ -46,19 +46,9 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, int graph = 0; u32 *prev_esp; - if (!task) - task = current; - - if (!stack) { - unsigned long dummy; - - stack = &dummy; - if (task != current) - stack = (unsigned long *)task->thread.sp; - } - - if (!bp) - bp = stack_frame(task, regs); + task = task ? : current; + stack = stack ? : get_stack_pointer(task, regs); + bp = bp ? : (unsigned long)get_frame_pointer(task, regs); for (;;) { void *end_stack; @@ -95,14 +85,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, unsigned long *stack; int i; - if (sp == NULL) { - if (regs) - sp = (unsigned long *)regs->sp; - else if (task) - sp = (unsigned long *)task->thread.sp; - else - sp = (unsigned long *)&sp; - } + sp = sp ? : get_stack_pointer(task, regs); stack = sp; for (i = 0; i < kstack_depth_to_print; i++) { diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 066eb5c7..7f3b806 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -151,25 +151,14 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs, { const unsigned cpu = get_cpu(); unsigned long *irq_stack = (unsigned long *)per_cpu(irq_stack_ptr, cpu); - unsigned long dummy; unsigned used = 0; int graph = 0; int done = 0; - if (!task) - task = current; + task = task ? : current; + stack = stack ? : get_stack_pointer(task, regs); + bp = bp ? : (unsigned long)get_frame_pointer(task, regs); - if (!stack) { - if (regs) - stack = (unsigned long *)regs->sp; - else if (task != current) - stack = (unsigned long *)task->thread.sp; - else - stack = &dummy; - } - - 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 @@ -256,18 +245,7 @@ show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs, irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu)); irq_stack = irq_stack_end - (IRQ_STACK_SIZE / sizeof(long)); - /* - * Debugging aid: "show_stack(NULL, NULL);" prints the - * back trace for this cpu: - */ - if (sp == NULL) { - if (regs) - sp = (unsigned long *)regs->sp; - else if (task) - sp = (unsigned long *)task->thread.sp; - else - sp = (unsigned long *)&sp; - } + sp = sp ? : get_stack_pointer(task, regs); stack = sp; for (i = 0; i < kstack_depth_to_print; i++) {