sh: add loglvl to show_trace()

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 parameter to show_trace() as a preparation to introduce
show_stack_loglvl().

[1]: https://lore.kernel.org/lkml/[email protected]/T/#u

Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Rich Felker <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 5 insertions, 5 deletions

diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c
index 959064b90055..d488a47a1f0f 100644
--- a/arch/sh/kernel/dumpstack.c
+++ b/arch/sh/kernel/dumpstack.c
@@ -127,16 +127,16 @@ static const struct stacktrace_ops print_trace_ops = {
 };
 
 void show_trace(struct task_struct *tsk, unsigned long *sp,
-		struct pt_regs *regs)
+		struct pt_regs *regs, const char *loglvl)
 {
 	if (regs && user_mode(regs))
 		return;
 
-	printk("\nCall trace:\n");
+	printk("%s\nCall trace:\n", loglvl);
 
-	unwind_stack(tsk, regs, sp, &print_trace_ops, "");
+	unwind_stack(tsk, regs, sp, &print_trace_ops, (void *)loglvl);
 
-	printk("\n");
+	printk("%s\n", loglvl);
 
 	if (!tsk)
 		tsk = current;
@@ -158,5 +158,5 @@ void show_stack(struct task_struct *tsk, unsigned long *sp)
 	stack = (unsigned long)sp;
 	dump_mem("Stack: ", KERN_DEFAULT, stack, THREAD_SIZE +
 		 (unsigned long)task_stack_page(tsk));
-	show_trace(tsk, sp, NULL);
+	show_trace(tsk, sp, NULL, KERN_DEFAULT);
 }