Both dump_stack() and show_stack() are currently implemented by each
architecture. show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack(). On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.
The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().
There's no reason to require archs to implement two separate but mostly
identical functions. It leads to unnecessary subtle information.
This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin. Blackfin's
dump_stack() does something wonky that I don't understand.
Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information. This is used
in blackfin.
This patch brings the following behavior changes.
* On some archs, an extra level in backtrace for show_stack() could be
printed. This is because the top frame was determined in
dump_stack() on those archs while generic dump_stack() can't do that
reliably. It can be compensated by inlining dump_stack() but not
sure whether that'd be necessary.
* Most archs didn't use to print debug info on dump_stack(). They do
now.
An example WARN dump follows.
WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
Hardware name: empty
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
Call Trace:
[<
ffffffff81c614dc>] dump_stack+0x19/0x1b
[<
ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
[<
ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
[<
ffffffff8234a071>] init_workqueues+0x35/0x505
...
v2: CPU number added to the generic debug info as requested by s390
folks and dropped the s390 specific dump_stack(). This loses %ksp
from the debug message which the maintainers think isn't important
enough to keep the s390-specific dump_stack() implementation.
dump_stack_print_info() is moved to kernel/printk.c from
lib/dump_stack.c. Because linkage is per objecct file,
dump_stack_print_info() living in the same lib file as generic
dump_stack() means that archs which implement custom dump_stack()
- at this point, only blackfin - can't use dump_stack_print_info()
as that will bring in the generic version of dump_stack() too. v1
The v1 patch broke build on blackfin due to this issue. The build
breakage was reported by Fengguang Wu.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dik_show_trace(sp);
}
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void
die_if_kernel(char * str, struct pt_regs *regs, long err, unsigned long *r9_15)
{
show_stacktrace(tsk, NULL);
}
-/* Expected by Rest of kernel code */
-void dump_stack(void)
-{
- show_stacktrace(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
/* Another API expected by schedular, shows up in "ps" as Wait Channel
* Ofcourse just returning schedule( ) would be pointless so unwind until
* the function is not in schedular code
}
#endif
-void dump_stack(void)
-{
- dump_backtrace(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
}
}
-void dump_stack(void)
-{
- dump_backtrace(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
show_stack_log_lvl(tsk, (unsigned long)stack, NULL, "");
}
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace_log_lvl(current, &stack, NULL, "");
-}
-EXPORT_SYMBOL(dump_stack);
-
static const char *cpu_modes[] = {
"Application", "Supervisor", "Interrupt level 0", "Interrupt level 1",
"Interrupt level 2", "Interrupt level 3", "Exception", "NMI"
#endif
trace_buffer_save(tflags);
dump_bfin_trace_buffer();
+ dump_stack_print_info(KERN_DEFAULT);
show_stack(current, &stack);
trace_buffer_restore(tflags);
}
pr_err("A31: %08lx B31: %08lx\n", regs->a31, regs->b31);
}
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_stack(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
-
void die(char *str, struct pt_regs *fp, int nr)
{
console_verbose();
#endif
void
-dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
-void
set_nmi_handler(void (*handler)(struct pt_regs *))
{
nmi_handler = handler;
BUG();
} /* end compound_exception() */
-/*****************************************************************************/
-/*
- * The architecture-independent backtrace generator
- */
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *task, unsigned long *sp)
{
}
{
show_stack(tsk,(unsigned long *)tsk->thread.esp0);
}
-
-void dump_stack(void)
-{
- show_stack(NULL,NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
do_show_stack(task, fp, 0);
}
-void dump_stack(void)
-{
- unsigned long *fp;
- asm("%0 = r30" : "=r" (fp));
- show_stack(current, fp);
-}
-EXPORT_SYMBOL(dump_stack);
-
int die(const char *str, struct pt_regs *regs, long err)
{
static struct {
}
void
-dump_stack (void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
-void
show_regs (struct pt_regs *regs)
{
unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
show_trace(task, sp);
}
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace(current, &stack);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static void show_registers(struct pt_regs *regs)
{
int i = 0;
}
/*
- * The architecture-independent backtrace generator
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace(&stack);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
-/*
* The vector number returned in the frame pointer may also contain
* the "fs" (Fault Status) bits on ColdFire. These are in the bottom
* 2 bits, and upper 2 bits. So we need to mask out the real vector
show_trace(tsk, sp, NULL);
}
-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
debug_show_held_locks(task);
}
-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
show_stacktrace(task, ®s);
}
-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- struct pt_regs regs;
-
- prepare_frametrace(®s);
- show_backtrace(current, ®s);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static void show_code(unsigned int __user *pc)
{
long i;
}
/*
- * the architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_stack(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
-/*
* dump the register file in the specified exception frame
*/
void show_registers_only(struct pt_regs *regs)
*/
}
-/*
- * The architecture-independent backtrace generator
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_stack(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
void show_registers(struct pt_regs *regs)
{
int i;
}
}
-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static void do_show_stack(struct unwind_frame_info *info)
{
int i = 1;
} while (count++ < kstack_depth_to_print);
}
-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
#ifdef CONFIG_PPC64
/* Called with hard IRQs off */
void __ppc64_runlatch_on(void)
#endif
}
-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- printk("CPU: %d %s %s %.*s\n",
- task_thread_info(current)->cpu, print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
- printk("Process %s (pid: %d, task: %p, ksp: %p)\n",
- current->comm, current->pid, current,
- (void *) current->thread.ksp);
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
{
return (regs->psw.mask & bits) / ((~bits + 1) & bits);
printk(KERN_NOTICE "\n");
}
-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- show_stack(current_thread_info()->task,
- (long *) get_irq_regs()->regs[0]);
-}
-EXPORT_SYMBOL(dump_stack);
-
void __die(const char *str, struct pt_regs *regs, const char *file,
const char *func, unsigned long line)
{
(unsigned long)task_stack_page(tsk));
show_trace(tsk, sp, NULL);
}
-
-void dump_stack(void)
-{
- show_stack(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
printk("\n");
}
-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
/*
* Note: sparc64 has a pretty intricated thread_saved_pc, check it out.
*/
} while (++count < 16);
}
-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
static inline struct reg_window *kernel_stack_up(struct reg_window *rw)
{
unsigned long fp = rw->ins[6];
}
#endif
-/*
- * stack dumps generator - this is used by arch-independent code.
- * And this is identical to i386 currently.
- */
-void dump_stack(void)
-{
- unsigned long stack;
-
- show_trace(current, &stack);
-}
-EXPORT_SYMBOL(dump_stack);
-
/*Stolen from arch/i386/kernel/traps.c */
static const int kstack_depth_to_print = 24;
c_backtrace(fp, mode);
}
-void dump_stack(void)
-{
- dump_backtrace(NULL, NULL);
-}
-EXPORT_SYMBOL(dump_stack);
-
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
dump_backtrace(NULL, tsk);
show_stack_log_lvl(task, NULL, sp, bp, "");
}
-/*
- * The architecture-independent dump_stack generator
- */
-void dump_stack(void)
-{
- unsigned long bp;
- unsigned long stack;
-
- bp = stack_frame(current, NULL);
- printk("Pid: %d, comm: %.20s %s %s %.*s\n",
- current->pid, current->comm, print_tainted(),
- init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
- show_trace(NULL, NULL, &stack, bp);
-}
-EXPORT_SYMBOL(dump_stack);
-
static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;
show_trace(task, stack);
}
-void dump_stack(void)
-{
- show_stack(current, NULL);
-}
-
-EXPORT_SYMBOL(dump_stack);
-
-
void show_code(unsigned int *pc)
{
long i;
void log_buf_kexec_setup(void);
void __init setup_log_buf(int early);
+void dump_stack_print_info(const char *log_lvl);
#else
static inline __printf(1, 0)
int vprintk(const char *s, va_list args)
static inline void setup_log_buf(int early)
{
}
+
+static inline void dump_stack_print_info(const char *log_lvl)
+{
+}
#endif
extern void dump_stack(void) __cold;
#include <linux/rculist.h>
#include <linux/poll.h>
#include <linux/irq_work.h>
+#include <linux/utsname.h>
#include <asm/uaccess.h>
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
}
EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
+
+/**
+ * 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\n",
+ log_lvl, raw_smp_processor_id(), current->pid, current->comm,
+ print_tainted(), init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+}
+
#endif
#include <linux/kernel.h>
#include <linux/export.h>
+#include <linux/sched.h>
+/**
+ * dump_stack - dump the current task information and its stack trace
+ *
+ * Architectures can override this implementation by implementing its own.
+ */
void dump_stack(void)
{
- printk(KERN_NOTICE
- "This architecture does not implement dump_stack()\n");
+ dump_stack_print_info(KERN_DEFAULT);
+ show_stack(NULL, NULL);
}
-
EXPORT_SYMBOL(dump_stack);
projects / platform / upstream / kernel-adaptation-pc.git / commitdiff