
valid_stack_ptr() is buggy: it assumes that all stacks are of size THREAD_SIZE, which is not true for exception stacks. So the walk_stack() callbacks will need to know the location of the beginning of the stack as well as the end. Another issue is that in general the various features of a stack (type, size, next stack pointer, description string) are scattered around in various places throughout the stack dump code. Encapsulate all that information in a single place with a new stack_info struct and a get_stack_info() interface. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8164dd0db96b7e6a279fa17ae5e6dc375eecb4a9.1473905218.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
215 lines
4.5 KiB
C
215 lines
4.5 KiB
C
/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
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*/
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#include <linux/kallsyms.h>
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#include <linux/kprobes.h>
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <linux/kdebug.h>
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#include <linux/export.h>
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#include <linux/ptrace.h>
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#include <linux/kexec.h>
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#include <linux/sysfs.h>
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#include <linux/bug.h>
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#include <linux/nmi.h>
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#include <asm/stacktrace.h>
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void stack_type_str(enum stack_type type, const char **begin, const char **end)
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{
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switch (type) {
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case STACK_TYPE_IRQ:
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case STACK_TYPE_SOFTIRQ:
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*begin = "IRQ";
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*end = "EOI";
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break;
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default:
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*begin = NULL;
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*end = NULL;
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}
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}
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static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
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{
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unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack);
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unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
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if (stack < begin || stack >= end)
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return false;
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info->type = STACK_TYPE_IRQ;
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info->begin = begin;
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info->end = end;
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/*
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* See irq_32.c -- the next stack pointer is stored at the beginning of
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* the stack.
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*/
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info->next_sp = (unsigned long *)*begin;
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return true;
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}
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static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
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{
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unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack);
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unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
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if (stack < begin || stack >= end)
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return false;
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info->type = STACK_TYPE_SOFTIRQ;
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info->begin = begin;
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info->end = end;
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/*
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* The next stack pointer is stored at the beginning of the stack.
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* See irq_32.c.
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*/
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info->next_sp = (unsigned long *)*begin;
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return true;
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}
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int get_stack_info(unsigned long *stack, struct task_struct *task,
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struct stack_info *info, unsigned long *visit_mask)
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{
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if (!stack)
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goto unknown;
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task = task ? : current;
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if (in_task_stack(stack, task, info))
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return 0;
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if (task != current)
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goto unknown;
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if (in_hardirq_stack(stack, info))
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return 0;
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if (in_softirq_stack(stack, info))
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return 0;
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unknown:
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info->type = STACK_TYPE_UNKNOWN;
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return -EINVAL;
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}
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void dump_trace(struct task_struct *task, struct pt_regs *regs,
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unsigned long *stack, unsigned long bp,
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const struct stacktrace_ops *ops, void *data)
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{
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unsigned long visit_mask = 0;
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int graph = 0;
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task = task ? : current;
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stack = stack ? : get_stack_pointer(task, regs);
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bp = bp ? : (unsigned long)get_frame_pointer(task, regs);
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for (;;) {
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const char *begin_str, *end_str;
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struct stack_info info;
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if (get_stack_info(stack, task, &info, &visit_mask))
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break;
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stack_type_str(info.type, &begin_str, &end_str);
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if (begin_str && ops->stack(data, begin_str) < 0)
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break;
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bp = ops->walk_stack(task, stack, bp, ops, data, &info, &graph);
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if (end_str && ops->stack(data, end_str) < 0)
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break;
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stack = info.next_sp;
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touch_nmi_watchdog();
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}
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}
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EXPORT_SYMBOL(dump_trace);
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void
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show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
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unsigned long *sp, unsigned long bp, char *log_lvl)
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{
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unsigned long *stack;
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int i;
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sp = sp ? : get_stack_pointer(task, regs);
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stack = sp;
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for (i = 0; i < kstack_depth_to_print; i++) {
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if (kstack_end(stack))
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break;
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if ((i % STACKSLOTS_PER_LINE) == 0) {
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if (i != 0)
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pr_cont("\n");
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printk("%s %08lx", log_lvl, *stack++);
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} else
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pr_cont(" %08lx", *stack++);
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touch_nmi_watchdog();
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}
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pr_cont("\n");
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show_trace_log_lvl(task, regs, sp, bp, log_lvl);
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}
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void show_regs(struct pt_regs *regs)
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{
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int i;
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show_regs_print_info(KERN_EMERG);
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__show_regs(regs, !user_mode(regs));
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/*
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* When in-kernel, we also print out the stack and code at the
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* time of the fault..
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*/
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if (!user_mode(regs)) {
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unsigned int code_prologue = code_bytes * 43 / 64;
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unsigned int code_len = code_bytes;
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unsigned char c;
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u8 *ip;
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pr_emerg("Stack:\n");
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show_stack_log_lvl(NULL, regs, NULL, 0, KERN_EMERG);
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pr_emerg("Code:");
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ip = (u8 *)regs->ip - code_prologue;
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if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
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/* try starting at IP */
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ip = (u8 *)regs->ip;
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code_len = code_len - code_prologue + 1;
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}
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for (i = 0; i < code_len; i++, ip++) {
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if (ip < (u8 *)PAGE_OFFSET ||
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probe_kernel_address(ip, c)) {
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pr_cont(" Bad EIP value.");
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break;
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}
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if (ip == (u8 *)regs->ip)
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pr_cont(" <%02x>", c);
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else
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pr_cont(" %02x", c);
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}
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}
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pr_cont("\n");
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}
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int is_valid_bugaddr(unsigned long ip)
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{
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unsigned short ud2;
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if (ip < PAGE_OFFSET)
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return 0;
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if (probe_kernel_address((unsigned short *)ip, ud2))
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return 0;
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return ud2 == 0x0b0f;
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}
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