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Release 4.15 kernel/debug/kdb/kdb_bt.c

Directory: kernel/debug/kdb
/*
 * Kernel Debugger Architecture Independent Stack Traceback
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * 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) { int old_lvl = console_loglevel; console_loglevel = CONSOLE_LOGLEVEL_MOTORMOUTH; kdb_trap_printk++; kdb_set_current_task(p); if (addr) { show_stack((struct task_struct *)p, addr); } else if (kdb_current_regs) { #ifdef CONFIG_X86 show_stack(p, &kdb_current_regs->sp); #else show_stack(p, NULL); #endif } else { show_stack(p, NULL); } console_loglevel = old_lvl; kdb_trap_printk--; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Wessel9798.98%266.67%
Borislav Petkov11.02%133.33%
Total98100.00%3100.00%

/* * 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 [DRSTCZEUIMA] 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 int kdb_bt1(struct task_struct *p, unsigned long mask, int argcount, int btaprompt) { char buffer[2]; if (kdb_getarea(buffer[0], (unsigned long)p) || kdb_getarea(buffer[0], (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_getstr(buffer, sizeof(buffer), "Enter <q> to end, <cr> to continue:"); if (buffer[0] == 'q') { kdb_printf("\n"); return 1; } } touch_nmi_watchdog(); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Wessel143100.00%1100.00%
Total143100.00%1100.00%


int kdb_bt(int argc, const char **argv) { int diag; int argcount = 5; 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; unsigned long mask = kdb_task_state_string(argc ? argv[1] : NULL); if (argc == 0) kdb_ps_suppressed(); /* Run the active tasks first */ for_each_online_cpu(cpu) { p = kdb_curr_task(cpu); if (kdb_bt1(p, mask, argcount, btaprompt)) return 0; } /* Now the inactive tasks */ kdb_do_each_thread(g, p) { if (KDB_FLAG(CMD_INTERRUPT)) return 0; if (task_curr(p)) continue; if (kdb_bt1(p, mask, argcount, btaprompt)) return 0; } kdb_while_each_thread(g, p); } 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) { kdb_set_current_task(p); return kdb_bt1(p, ~0UL, argcount, 0); } 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; kdb_set_current_task((struct task_struct *)addr); return kdb_bt1((struct task_struct *)addr, ~0UL, argcount, 0); } else if (strcmp(argv[0], "btc") == 0) { unsigned long cpu = ~0; struct task_struct *save_current_task = kdb_current_task; char buf[80]; if (argc > 1) return KDB_ARGCOUNT; if (argc == 1) { diag = kdbgetularg((char *)argv[1], &cpu); if (diag) return diag; } /* Recursive use of kdb_parse, do not use argv after * this point */ argv = NULL; if (cpu != ~0) { if (cpu >= num_possible_cpus() || !cpu_online(cpu)) { kdb_printf("no process for cpu %ld\n", cpu); return 0; } sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); kdb_parse(buf); return 0; } kdb_printf("btc: cpu status: "); kdb_parse("cpu\n"); for_each_online_cpu(cpu) { sprintf(buf, "btt 0x%p\n", KDB_TSK(cpu)); kdb_parse(buf); touch_nmi_watchdog(); } kdb_set_current_task(save_current_task); 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, ~0UL, argcount, 0); } } /* NOTREACHED */ return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Jason Wessel615100.00%3100.00%
Total615100.00%3100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Jason Wessel87799.43%457.14%
Ingo Molnar40.45%228.57%
Borislav Petkov10.11%114.29%
Total882100.00%7100.00%
Directory: kernel/debug/kdb
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