From d95d66d9a4bf554aec91ab70e60876ee4acd94c2 Mon Sep 17 00:00:00 2001 From: Dmitry Safonov Date: Mon, 8 Jun 2020 21:32:00 -0700 Subject: [PATCH] x86: 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 Signed-off-by: Andrew Morton Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20200418201944.482088-42-dima@arista.com Signed-off-by: Linus Torvalds --- arch/x86/kernel/dumpstack.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index b94bc31a1757b..4396f2cfad197 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -279,7 +279,8 @@ next: } } -void show_stack(struct task_struct *task, unsigned long *sp) +void show_stack_loglvl(struct task_struct *task, unsigned long *sp, + const char *loglvl) { task = task ? : current; @@ -290,7 +291,12 @@ void show_stack(struct task_struct *task, unsigned long *sp) if (!sp && task == current) sp = get_stack_pointer(current, NULL); - show_trace_log_lvl(task, NULL, sp, KERN_DEFAULT); + show_trace_log_lvl(task, NULL, sp, loglvl); +} + +void show_stack(struct task_struct *task, unsigned long *sp) +{ + show_stack_loglvl(task, sp, KERN_DEFAULT); } void show_stack_regs(struct pt_regs *regs) -- 2.39.5