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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - lib/dump_stack.c
1 // SPDX-License-Identifier: GPL-2.0
3 * Provide a default dump_stack() function for architectures
4 * which don't implement their own.
7 #include <linux/kernel.h>
8 #include <linux/export.h>
9 #include <linux/sched.h>
10 #include <linux/sched/debug.h>
11 #include <linux/smp.h>
12 #include <linux/atomic.h>
13 #include <linux/kexec.h>
14 #include <linux/utsname.h>
16 static char dump_stack_arch_desc_str
[128];
19 * dump_stack_set_arch_desc - set arch-specific str to show with task dumps
20 * @fmt: printf-style format string
21 * @...: arguments for the format string
23 * The configured string will be printed right after utsname during task
24 * dumps. Usually used to add arch-specific system identifiers. If an
25 * arch wants to make use of such an ID string, it should initialize this
26 * as soon as possible during boot.
28 void __init
dump_stack_set_arch_desc(const char *fmt
, ...)
33 vsnprintf(dump_stack_arch_desc_str
, sizeof(dump_stack_arch_desc_str
),
39 * dump_stack_print_info - print generic debug info for dump_stack()
42 * Arch-specific dump_stack() implementations can use this function to
43 * print out the same debug information as the generic dump_stack().
45 void dump_stack_print_info(const char *log_lvl
)
47 printk("%sCPU: %d PID: %d Comm: %.20s %s%s %s %.*s\n",
48 log_lvl
, raw_smp_processor_id(), current
->pid
, current
->comm
,
49 kexec_crash_loaded() ? "Kdump: loaded " : "",
51 init_utsname()->release
,
52 (int)strcspn(init_utsname()->version
, " "),
53 init_utsname()->version
);
55 if (dump_stack_arch_desc_str
[0] != '\0')
56 printk("%sHardware name: %s\n",
57 log_lvl
, dump_stack_arch_desc_str
);
59 print_worker_info(log_lvl
, current
);
63 * show_regs_print_info - print generic debug info for show_regs()
66 * show_regs() implementations can use this function to print out generic
69 void show_regs_print_info(const char *log_lvl
)
71 dump_stack_print_info(log_lvl
);
74 static void __dump_stack(void)
76 dump_stack_print_info(KERN_DEFAULT
);
77 show_stack(NULL
, NULL
, KERN_DEFAULT
);
81 * dump_stack - dump the current task information and its stack trace
83 * Architectures can override this implementation by implementing its own.
86 static atomic_t dump_lock
= ATOMIC_INIT(-1);
88 asmlinkage __visible
void dump_stack(void)
96 * Permit this cpu to perform nested stack dumps while serialising
100 local_irq_save(flags
);
101 cpu
= smp_processor_id();
102 old
= atomic_cmpxchg(&dump_lock
, -1, cpu
);
105 } else if (old
== cpu
) {
108 local_irq_restore(flags
);
110 * Wait for the lock to release before jumping to
111 * atomic_cmpxchg() in order to mitigate the thundering herd
114 do { cpu_relax(); } while (atomic_read(&dump_lock
) != -1);
121 atomic_set(&dump_lock
, -1);
123 local_irq_restore(flags
);
126 asmlinkage __visible
void dump_stack(void)
131 EXPORT_SYMBOL(dump_stack
);