Which serves as a global default sys_info mask. When users want the same
system information for many error cases (panic, hung, lockup ...), they
can chose to set this global knob only once, while not setting up each
individual sys_info knobs.
This just adds a 'lazy' option, and doesn't change existing kernel
behavior as the mask is 0 by default.
Link: https://lkml.kernel.org/r/[email protected]
Suggested-by: Andrew Morton <[email protected]>
Signed-off-by: Feng Tang <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: "Paul E . McKenney" <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Compiler was not happy about dead variable in use:
lib/sys_info.c:52:19: error: variable 'sys_info_avail' is not needed and will not be emitted [-Werror,-Wunneeded-internal-declaration]
52 | static const char sys_info_avail[] = "tasks,mem,timers,locks,ftrace,all_bt,blocked_tasks";
| ^~~~~~~~~~~~~~
This was fixed by adding __maybe_unused attribute that just hides the
issue and didn't actually fix the root cause. Rewrite the fix by moving
the local variable from stack to a heap.
As a side effect this drops unneeded "synchronisation" of duplicative info
and also makes code ready for the further refactoring.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Cc: Feng Tang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
There is no need to keep a custom structure just for the need of a plain
array of strings. Replace struct sys_info_name with plain array of
strings.
With that done, simplify the code, in particular, naturally use
for_each_set_bit() when iterating over si_bits_global bitmap.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Cc: Feng Tang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Patch series "panic: sys_info: Refactor and fix a potential issue", v3.
While targeting the compilation issue due to dangling variable, I have
noticed more opportunities for refactoring that helps to avoid above
mentioned compilation issue in a cleaner way and also fixes a potential
problem with global variable access.
This patch (of 6):
The for-loop might re-read the content of the memory the si_bits_global
points to on each iteration. Instead, just capture it for the sake of
consistency and use that instead.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Andy Shevchenko <[email protected]>
Reviewed-by: Feng Tang <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
'panic_print' was introduced to help debugging kernel panic by dumping
different kinds of system information like tasks' call stack, memory,
ftrace buffer, etc. Actually this function could also be used to help
debugging other cases like task-hung, soft/hard lockup, etc. where user
may need the snapshot of system info at that time.
Extract system info dump function related code from panic.c to separate
file sys_info.[ch], for wider usage by other kernel parts for debugging.
Also modify the macro names about singulars/plurals.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Feng Tang <[email protected]>
Suggested-by: Petr Mladek <[email protected]>
Cc: John Ogness <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Lance Yang <[email protected]>
Cc: "Paul E . McKenney" <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Feng Tang