Currently, the log-level of show_stack() depends on a platform
realization. It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).
Furthermore, it forces the logic decision from user to an architecture
side. In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages. And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.
Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers. Also, it will consolidate
printings with headers.
Add log level argument to dump_backtrace() as a preparation for
introducing show_stack_loglvl().
[1]: https://lore.kernel.org/lkml/
20190528002412.1625-1-dima@arista.com/T/#u
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/20200418201944.482088-10-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data);
extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame);
extern void walk_stackframe(struct task_struct *tsk, struct stackframe *frame,
int (*fn)(struct stackframe *, void *), void *data);
-extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk);
+extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
+ const char *loglvl);
DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
void show_regs(struct pt_regs * regs)
{
__show_regs(regs);
void show_regs(struct pt_regs * regs)
{
__show_regs(regs);
- dump_backtrace(regs, NULL);
+ dump_backtrace(regs, NULL, KERN_DEFAULT);
}
static void tls_thread_flush(void)
}
static void tls_thread_flush(void)
int show_unhandled_signals = 0;
int show_unhandled_signals = 0;
-static void dump_backtrace_entry(unsigned long where)
+static void dump_backtrace_entry(unsigned long where, const char *loglvl)
- printk(" %pS\n", (void *)where);
+ printk("%s %pS\n", loglvl, (void *)where);
}
static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
}
static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
printk("%sCode: %s\n", lvl, str);
}
printk("%sCode: %s\n", lvl, str);
}
-void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
+void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
+ const char *loglvl)
{
struct stackframe frame;
int skip = 0;
{
struct stackframe frame;
int skip = 0;
- printk("Call trace:\n");
+ printk("%sCall trace:\n", loglvl);
do {
/* skip until specified stack frame */
if (!skip) {
do {
/* skip until specified stack frame */
if (!skip) {
- dump_backtrace_entry(frame.pc);
+ dump_backtrace_entry(frame.pc, loglvl);
} else if (frame.fp == regs->regs[29]) {
skip = 0;
/*
} else if (frame.fp == regs->regs[29]) {
skip = 0;
/*
* at which an exception has taken place, use regs->pc
* instead.
*/
* at which an exception has taken place, use regs->pc
* instead.
*/
- dump_backtrace_entry(regs->pc);
+ dump_backtrace_entry(regs->pc, loglvl);
}
} while (!unwind_frame(tsk, &frame));
}
} while (!unwind_frame(tsk, &frame));
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
- dump_backtrace(NULL, tsk);
+ dump_backtrace(NULL, tsk, KERN_DEFAULT);