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| author | Tomas Mudrunka <tomas.mudrunka@gmail.com> | 2023-11-20 14:14:51 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-25 10:23:16 +0300 |
| commit | 39ff20f5fd4481c9acf3b75c7b705b1ec6604588 (patch) | |
| tree | 8fcc7cd52cf910207c6544da66cc7a66803da8a4 /Documentation/admin-guide | |
| parent | 01c33b813864ca15a9dec22045ce1a5bb09d5e74 (diff) | |
| download | linux-39ff20f5fd4481c9acf3b75c7b705b1ec6604588.tar.xz | |
/proc/sysrq-trigger: accept multiple keys at once
This way we can do:
`echo _reisub > /proc/sysrq-trigger`
Instead of:
`for i in r e i s u b; do echo "$i" > /proc/sysrq-trigger; done;`
This can be very useful when trying to execute sysrq combo remotely
or from userspace. When sending keys in multiple separate writes,
userspace (eg. bash or ssh) can be killed before whole combo is completed.
Therefore putting all keys in single write is more robust approach.
Signed-off-by: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20231120111451.527952-1-tomas.mudrunka@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/sysrq.rst | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/Documentation/admin-guide/sysrq.rst b/Documentation/admin-guide/sysrq.rst index 51906e47327b..2f2e5bd440f9 100644 --- a/Documentation/admin-guide/sysrq.rst +++ b/Documentation/admin-guide/sysrq.rst @@ -75,10 +75,19 @@ On other submit a patch to be included in this section. On all - Write a character to /proc/sysrq-trigger. e.g.:: + Write a single character to /proc/sysrq-trigger. + Only the first character is processed, the rest of the string is + ignored. However, it is not recommended to write any extra characters + as the behavior is undefined and might change in the future versions. + E.g.:: echo t > /proc/sysrq-trigger + Alternatively, write multiple characters prepended by underscore. + This way, all characters will be processed. E.g.:: + + echo _reisub > /proc/sysrq-trigger + The :kbd:`<command key>` is case sensitive. What are the 'command' keys? |