From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- lib/dump_stack.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 lib/dump_stack.c (limited to 'lib/dump_stack.c') diff --git a/lib/dump_stack.c b/lib/dump_stack.c new file mode 100644 index 000000000..a00ee6eed --- /dev/null +++ b/lib/dump_stack.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Provide a default dump_stack() function for architectures + * which don't implement their own. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +static char dump_stack_arch_desc_str[128]; + +/** + * dump_stack_set_arch_desc - set arch-specific str to show with task dumps + * @fmt: printf-style format string + * @...: arguments for the format string + * + * The configured string will be printed right after utsname during task + * dumps. Usually used to add arch-specific system identifiers. If an + * arch wants to make use of such an ID string, it should initialize this + * as soon as possible during boot. + */ +void __init dump_stack_set_arch_desc(const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str), + fmt, args); + va_end(args); +} + +/** + * dump_stack_print_info - print generic debug info for dump_stack() + * @log_lvl: log level + * + * Arch-specific dump_stack() implementations can use this function to + * print out the same debug information as the generic dump_stack(). + */ +void dump_stack_print_info(const char *log_lvl) +{ + printk("%sCPU: %d PID: %d Comm: %.20s %s%s %s %.*s\n", + log_lvl, raw_smp_processor_id(), current->pid, current->comm, + kexec_crash_loaded() ? "Kdump: loaded " : "", + print_tainted(), + init_utsname()->release, + (int)strcspn(init_utsname()->version, " "), + init_utsname()->version); + + if (dump_stack_arch_desc_str[0] != '\0') + printk("%sHardware name: %s\n", + log_lvl, dump_stack_arch_desc_str); + + print_worker_info(log_lvl, current); +} + +/** + * show_regs_print_info - print generic debug info for show_regs() + * @log_lvl: log level + * + * show_regs() implementations can use this function to print out generic + * debug information. + */ +void show_regs_print_info(const char *log_lvl) +{ + dump_stack_print_info(log_lvl); +} + +static void __dump_stack(void) +{ + dump_stack_print_info(KERN_DEFAULT); + show_stack(NULL, NULL, KERN_DEFAULT); +} + +/** + * dump_stack - dump the current task information and its stack trace + * + * Architectures can override this implementation by implementing its own. + */ +#ifdef CONFIG_SMP +static atomic_t dump_lock = ATOMIC_INIT(-1); + +asmlinkage __visible void dump_stack(void) +{ + unsigned long flags; + int was_locked; + int old; + int cpu; + + /* + * Permit this cpu to perform nested stack dumps while serialising + * against other CPUs + */ +retry: + local_irq_save(flags); + cpu = smp_processor_id(); + old = atomic_cmpxchg(&dump_lock, -1, cpu); + if (old == -1) { + was_locked = 0; + } else if (old == cpu) { + was_locked = 1; + } else { + local_irq_restore(flags); + /* + * Wait for the lock to release before jumping to + * atomic_cmpxchg() in order to mitigate the thundering herd + * problem. + */ + do { cpu_relax(); } while (atomic_read(&dump_lock) != -1); + goto retry; + } + + __dump_stack(); + + if (!was_locked) + atomic_set(&dump_lock, -1); + + local_irq_restore(flags); +} +#else +asmlinkage __visible void dump_stack(void) +{ + __dump_stack(); +} +#endif +EXPORT_SYMBOL(dump_stack); -- cgit v1.2.3