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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219// SPDX-License-Identifier: GPL-2.0/* * Kernel Debugger Architecture Independent Stack Traceback * * Copyright (c) 1999-2004 Silicon Graphics, Inc. All Rights Reserved. * Copyright (c) 2009 Wind River Systems, Inc. All Rights Reserved. */
#include <linux/ctype.h>#include <linux/string.h>#include <linux/kernel.h>#include <linux/sched/signal.h>#include <linux/sched/debug.h>#include <linux/kdb.h>#include <linux/nmi.h>#include "kdb_private.h"
static void kdb_show_stack(struct task_struct *p, void *addr){ kdb_trap_printk++;
if (!addr && kdb_task_has_cpu(p)) { int old_lvl = console_loglevel;
console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH; kdb_dump_stack_on_cpu(kdb_process_cpu(p)); console_loglevel = old_lvl; } else { show_stack(p, addr, KERN_EMERG); }
kdb_trap_printk--;}
/* * kdb_bt * * This function implements the 'bt' command. Print a stack * traceback. * * bt [<address-expression>] (addr-exp is for alternate stacks) * btp <pid> Kernel stack for <pid> * btt <address-expression> Kernel stack for task structure at * <address-expression> * bta [state_chars>|A] All useful processes, optionally * filtered by state * btc [<cpu>] The current process on one cpu, * default is all cpus * * bt <address-expression> refers to a address on the stack, that location * is assumed to contain a return address. * * btt <address-expression> refers to the address of a struct task. * * Inputs: * argc argument count * argv argument vector * Outputs: * None. * Returns: * zero for success, a kdb diagnostic if error * Locking: * none. * Remarks: * Backtrack works best when the code uses frame pointers. But even * without frame pointers we should get a reasonable trace. * * mds comes in handy when examining the stack to do a manual traceback or * to get a starting point for bt <address-expression>. */
static intkdb_bt1(struct task_struct *p, const char *mask, bool btaprompt){ char ch;
if (kdb_getarea(ch, (unsigned long)p) || kdb_getarea(ch, (unsigned long)(p+1)-1)) return KDB_BADADDR; if (!kdb_task_state(p, mask)) return 0; kdb_printf("Stack traceback for pid %d\n", p->pid); kdb_ps1(p); kdb_show_stack(p, NULL); if (btaprompt) { kdb_printf("Enter <q> to end, <cr> or <space> to continue:"); do { ch = kdb_getchar(); } while (!strchr("\r\n q", ch)); kdb_printf("\n");
/* reset the pager */ kdb_nextline = 1;
if (ch == 'q') return 1; } touch_nmi_watchdog(); return 0;}
static voidkdb_bt_cpu(unsigned long cpu){ struct task_struct *kdb_tsk;
if (cpu >= num_possible_cpus() || !cpu_online(cpu)) { kdb_printf("WARNING: no process for cpu %ld\n", cpu); return; }
/* If a CPU failed to round up we could be here */ kdb_tsk = KDB_TSK(cpu); if (!kdb_tsk) { kdb_printf("WARNING: no task for cpu %ld\n", cpu); return; }
kdb_bt1(kdb_tsk, "A", false);}
intkdb_bt(int argc, const char **argv){ int diag; int btaprompt = 1; int nextarg; unsigned long addr; long offset;
/* Prompt after each proc in bta */ kdbgetintenv("BTAPROMPT", &btaprompt);
if (strcmp(argv[0], "bta") == 0) { struct task_struct *g, *p; unsigned long cpu; const char *mask = argc ? argv[1] : kdbgetenv("PS");
if (argc == 0) kdb_ps_suppressed(); /* Run the active tasks first */ for_each_online_cpu(cpu) { p = curr_task(cpu); if (kdb_bt1(p, mask, btaprompt)) return 0; } /* Now the inactive tasks */ for_each_process_thread(g, p) { if (KDB_FLAG(CMD_INTERRUPT)) return 0; if (task_curr(p)) continue; if (kdb_bt1(p, mask, btaprompt)) return 0; } } else if (strcmp(argv[0], "btp") == 0) { struct task_struct *p; unsigned long pid; if (argc != 1) return KDB_ARGCOUNT; diag = kdbgetularg((char *)argv[1], &pid); if (diag) return diag; p = find_task_by_pid_ns(pid, &init_pid_ns); if (p) return kdb_bt1(p, "A", false); kdb_printf("No process with pid == %ld found\n", pid); return 0; } else if (strcmp(argv[0], "btt") == 0) { if (argc != 1) return KDB_ARGCOUNT; diag = kdbgetularg((char *)argv[1], &addr); if (diag) return diag; return kdb_bt1((struct task_struct *)addr, "A", false); } else if (strcmp(argv[0], "btc") == 0) { unsigned long cpu = ~0; if (argc > 1) return KDB_ARGCOUNT; if (argc == 1) { diag = kdbgetularg((char *)argv[1], &cpu); if (diag) return diag; } if (cpu != ~0) { kdb_bt_cpu(cpu); } else { /* * Recursive use of kdb_parse, do not use argv after * this point. */ argv = NULL; kdb_printf("btc: cpu status: "); kdb_parse("cpu\n"); for_each_online_cpu(cpu) { kdb_bt_cpu(cpu); touch_nmi_watchdog(); } } return 0; } else { if (argc) { nextarg = 1; diag = kdbgetaddrarg(argc, argv, &nextarg, &addr, &offset, NULL); if (diag) return diag; kdb_show_stack(kdb_current_task, (void *)addr); return 0; } else { return kdb_bt1(kdb_current_task, "A", false); } }
/* NOTREACHED */ return 0;}