From 934d51cad60c9bcdaf6a4b2f31a0fb3d15a07a62 Mon Sep 17 00:00:00 2001 From: "Guilherme G. Piccoli" Date: Thu, 30 Dec 2021 20:29:14 +1100 Subject: [PATCH] docs: sysctl/kernel: add missing bit to panic_print Patch series "Some improvements on panic_print". This is a mix of a documentation fix with some additions to the "panic_print" syscall / parameter. The goal here is being able to collect all CPUs backtraces during a panic event and also to enable "panic_print" in a kdump event - details of the reasoning and design choices in the patches. This patch (of 3): Commit de6da1e8bcf0 ("panic: add an option to replay all the printk message in buffer") added a new bit to the sysctl/kernel parameter "panic_print", but the documentation was added only in kernel-parameters.txt, not in the sysctl guide. Fix it here by adding bit 5 to sysctl admin-guide documentation. Link: https://lkml.kernel.org/r/20211109202848.610874-1-gpiccoli@igalia.com Link: https://lkml.kernel.org/r/20211109202848.610874-2-gpiccoli@igalia.com Fixes: de6da1e8bcf0 ("panic: add an option to replay all the printk message in buffer") Signed-off-by: Guilherme G. Piccoli Reviewed-by: Feng Tang Cc: Luis Chamberlain Cc: Kees Cook Cc: Iurii Zaikin Cc: Samuel Iglesias Gonsalvez Signed-off-by: Andrew Morton Signed-off-by: Stephen Rothwell --- Documentation/admin-guide/sysctl/kernel.rst | 1 + 1 file changed, 1 insertion(+) diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst index 0e486f41185ef..b92ed8bd5a67e 100644 --- a/Documentation/admin-guide/sysctl/kernel.rst +++ b/Documentation/admin-guide/sysctl/kernel.rst @@ -795,6 +795,7 @@ bit 1 print system memory info bit 2 print timer info bit 3 print locks info if ``CONFIG_LOCKDEP`` is on bit 4 print ftrace buffer +bit 5: print all printk messages in buffer ===== ============================================ So for example to print tasks and memory info on panic, user can::