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| author | Dmitry Safonov <dima@arista.com> | 2020-06-29 17:48:46 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-07-23 00:56:53 +0300 |
| commit | 44e215352cf17333992d56941b5bf4af60a67609 (patch) | |
| tree | ce11eb17de32a092e43a75d51092027f32e4bffe /arch/x86/kernel/dumpstack.c | |
| parent | fd07f802a70935fbbfb9cc2d11e1d8ac95f28e44 (diff) | |
| download | linux-44e215352cf17333992d56941b5bf4af60a67609.tar.xz | |
x86/dumpstack: Add log_lvl to __show_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_regs().
Keep the used log level intact to separate visible change.
[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/20200629144847.492794-3-dima@arista.com
Diffstat (limited to 'arch/x86/kernel/dumpstack.c')
| -rw-r--r-- | arch/x86/kernel/dumpstack.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index c36d629a25a8..4954d6678cef 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -146,7 +146,7 @@ static void show_regs_if_on_stack(struct stack_info *info, struct pt_regs *regs, * they can be printed in the right context. */ if (!partial && on_stack(info, regs, sizeof(*regs))) { - __show_regs(regs, SHOW_REGS_SHORT); + __show_regs(regs, SHOW_REGS_SHORT, KERN_DEFAULT); } else if (partial && on_stack(info, (void *)regs + IRET_FRAME_OFFSET, IRET_FRAME_SIZE)) { @@ -345,7 +345,7 @@ void oops_end(unsigned long flags, struct pt_regs *regs, int signr) oops_exit(); /* Executive summary in case the oops scrolled away */ - __show_regs(&exec_summary_regs, SHOW_REGS_ALL); + __show_regs(&exec_summary_regs, SHOW_REGS_ALL, KERN_DEFAULT); if (!signr) return; @@ -437,9 +437,12 @@ void die_addr(const char *str, struct pt_regs *regs, long err, long gp_addr) void show_regs(struct pt_regs *regs) { + enum show_regs_mode print_kernel_regs; + show_regs_print_info(KERN_DEFAULT); - __show_regs(regs, user_mode(regs) ? SHOW_REGS_USER : SHOW_REGS_ALL); + print_kernel_regs = user_mode(regs) ? SHOW_REGS_USER : SHOW_REGS_ALL; + __show_regs(regs, print_kernel_regs, KERN_DEFAULT); /* * When in-kernel, we also print out the stack at the time of the fault.. |