[PATCH v3 1/4] sys_info: add helper for callers that print some sys_info on their own
From: Bradley Morgan <hidden>
Date: 2026-06-25 15:26:16
Also in:
lkml, stable
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
Some callers print some sys_info on their own before calling sys_info().
Add a helper which would allow to prevent a duplicated output.
It is a bit tricky because kernel_si_mask should be used only
when the call-specific si_mask is empty. But the duplicated
output must be prevented there as well.
Fixes: a9af76a78760 ("watchdog: add sys_info sysctls to dump sys info on system lockup")
Cc: stable@vger.kernel.org
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Bradley Morgan <redacted>
---
include/linux/sys_info.h | 1 +
lib/sys_info.c | 20 ++++++++++++++++++--
2 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/include/linux/sys_info.h b/include/linux/sys_info.h
index a5bc3ea3d44b..f1c2552ca3d1 100644
--- a/include/linux/sys_info.h
+++ b/include/linux/sys_info.h@@ -18,6 +18,7 @@ #define SYS_INFO_BLOCKED_TASKS 0x00000080 void sys_info(unsigned long si_mask); +void sys_info_with_filter(unsigned long si_mask, unsigned long si_ignore_mask); unsigned long sys_info_parse_param(char *str); #ifdef CONFIG_SYSCTL
diff --git a/lib/sys_info.c b/lib/sys_info.c
index f32a06ec9ed4..d411fee10415 100644
--- a/lib/sys_info.c
+++ b/lib/sys_info.c@@ -136,8 +136,10 @@ static int __init sys_info_sysctl_init(void) subsys_initcall(sys_info_sysctl_init); #endif -static void __sys_info(unsigned long si_mask) +static void __sys_info(unsigned long si_mask, unsigned long si_ignore_mask) { + si_mask &= ~si_ignore_mask; + if (si_mask & SYS_INFO_TASKS) show_state();
@@ -160,7 +162,21 @@ static void __sys_info(unsigned long si_mask) show_state_filter(TASK_UNINTERRUPTIBLE); } +void sys_info_with_filter(unsigned long si_mask, unsigned long si_ignore_mask) +{ + unsigned long dump_mask = si_mask & ~si_ignore_mask; + + /* + * Do not fall back to kernel_si_mask when the caller context + * required only the ignored information. + */ + if (si_mask && !dump_mask) + return; + + __sys_info(dump_mask ? : kernel_si_mask, si_ignore_mask); +} + void sys_info(unsigned long si_mask) { - __sys_info(si_mask ? : kernel_si_mask); + sys_info_with_filter(si_mask, 0); }
--
2.53.0