nds32: add show_stack_loglvl()

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.

Introduce show_stack_loglvl(), that eventually will substitute
show_stack().

[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: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Link: http://lkml.kernel.org/r/20200418201944.482088-23-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dmitry Safonov 2020-06-08 21:31:02 -07:00 committed by Linus Torvalds
parent 96f0458a96
commit 18a4753f90

View File

@ -97,18 +97,19 @@ static void dump_instr(struct pt_regs *regs)
}
#define LOOP_TIMES (100)
static void __dump(struct task_struct *tsk, unsigned long *base_reg)
static void __dump(struct task_struct *tsk, unsigned long *base_reg,
const char *loglvl)
{
unsigned long ret_addr;
int cnt = LOOP_TIMES, graph = 0;
pr_emerg("Call Trace:\n");
printk("%sCall Trace:\n", loglvl);
if (!IS_ENABLED(CONFIG_FRAME_POINTER)) {
while (!kstack_end(base_reg)) {
ret_addr = *base_reg++;
if (__kernel_text_address(ret_addr)) {
ret_addr = ftrace_graph_ret_addr(
tsk, &graph, ret_addr, NULL);
print_ip_sym(KERN_EMERG, ret_addr);
print_ip_sym(loglvl, ret_addr);
}
if (--cnt < 0)
break;
@ -124,17 +125,18 @@ static void __dump(struct task_struct *tsk, unsigned long *base_reg)
ret_addr = ftrace_graph_ret_addr(
tsk, &graph, ret_addr, NULL);
print_ip_sym(KERN_EMERG, ret_addr);
print_ip_sym(loglvl, ret_addr);
}
if (--cnt < 0)
break;
base_reg = (unsigned long *)next_fp;
}
}
pr_emerg("\n");
printk("%s\n", loglvl);
}
void show_stack(struct task_struct *tsk, unsigned long *sp)
void show_stack_loglvl(struct task_struct *tsk, unsigned long *sp,
const char *loglvl)
{
unsigned long *base_reg;
@ -151,10 +153,15 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
else
__asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(base_reg));
}
__dump(tsk, base_reg);
__dump(tsk, base_reg, loglvl);
barrier();
}
void show_stack(struct task_struct *tsk, unsigned long *sp)
{
show_stack_loglvl(tsk, sp, KERN_EMERG);
}
DEFINE_SPINLOCK(die_lock);
/*