summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/dumpstack.c
diff options
context:
space:
mode:
authorDmitry Safonov <dima@arista.com>2020-06-29 17:48:45 +0300
committerThomas Gleixner <tglx@linutronix.de>2020-07-23 00:56:53 +0300
commitfd07f802a70935fbbfb9cc2d11e1d8ac95f28e44 (patch)
treeb80bc617474e8a625cc4bd461c6740a63ac67646 /arch/x86/kernel/dumpstack.c
parentba47d845d715a010f7b51f6f89bae32845e6acb7 (diff)
downloadlinux-fd07f802a70935fbbfb9cc2d11e1d8ac95f28e44.tar.xz
x86/dumpstack: Add log_lvl to show_iret_regs()
show_trace_log_lvl() provides x86 platform-specific way to unwind backtrace with a given log level. Unfortunately, registers dump(s) are not printed with the same log level - instead, KERN_DEFAULT is always used. Arista's switches uses quite common setup with rsyslog, where only urgent messages goes to console (console_log_level=KERN_ERR), everything else goes into /var/log/ as the console baud-rate often is indecently slow (9600 bps). Backtrace dumps without registers printed have proven to be as useful as morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED (which I believe is still the most elegant way to fix raciness of sysrq[1]) the log level should be passed down the stack to register dumping functions. Besides, there is a potential use-case for printing traces with KERN_DEBUG level [2] (where registers dump shouldn't appear with higher log level). Add log_lvl parameter to show_iret_regs() as a preparation to add it to __show_regs() and show_regs_if_on_stack(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/ [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/ Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lkml.kernel.org/r/20200629144847.492794-2-dima@arista.com
Diffstat (limited to 'arch/x86/kernel/dumpstack.c')
-rw-r--r--arch/x86/kernel/dumpstack.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index b037cfa7c0c5..c36d629a25a8 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -126,10 +126,10 @@ void show_ip(struct pt_regs *regs, const char *loglvl)
show_opcodes(regs, loglvl);
}
-void show_iret_regs(struct pt_regs *regs)
+void show_iret_regs(struct pt_regs *regs, const char *log_lvl)
{
- show_ip(regs, KERN_DEFAULT);
- printk(KERN_DEFAULT "RSP: %04x:%016lx EFLAGS: %08lx", (int)regs->ss,
+ show_ip(regs, log_lvl);
+ printk("%sRSP: %04x:%016lx EFLAGS: %08lx", log_lvl, (int)regs->ss,
regs->sp, regs->flags);
}
@@ -155,7 +155,7 @@ static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs,
* full pt_regs might not have been saved yet. In that case
* just print the iret frame.
*/
- show_iret_regs(regs);
+ show_iret_regs(regs, KERN_DEFAULT);
}
}