diff options
| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2025-10-30 12:44:17 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-20 14:03:40 -0800 |
| commit | d79a3aeb747c17095d679cc4402d87f0e7c3405e (patch) | |
| tree | e512aa428374aaaaa91b7c70b608cd22144ae2a6 /lib/sys_info.c | |
| parent | 3e4b89e970365db7fe2c4171be06c0e88e3bcbe6 (diff) | |
panic: sys_info: capture si_bits_global before iterating over it
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/20251030132007.3742368-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20251030132007.3742368-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Feng Tang <feng.tang@linux.alibaba.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/sys_info.c')
| -rw-r--r-- | lib/sys_info.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/lib/sys_info.c b/lib/sys_info.c index 496f9151c9b6..d542a024406a 100644 --- a/lib/sys_info.c +++ b/lib/sys_info.c @@ -58,11 +58,11 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write, char names[sizeof(sys_info_avail)]; struct ctl_table table; unsigned long *si_bits_global; + unsigned long si_bits; si_bits_global = ro_table->data; if (write) { - unsigned long si_bits; int ret; table = *ro_table; @@ -81,9 +81,12 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write, char *delim = ""; int i, len = 0; + /* The access to the global value is not synchronized. */ + si_bits = READ_ONCE(*si_bits_global); + names[0] = '\0'; for (i = 0; i < ARRAY_SIZE(si_names); i++) { - if (*si_bits_global & si_names[i].bit) { + if (si_bits & si_names[i].bit) { len += scnprintf(names + len, sizeof(names) - len, "%s%s", delim, si_names[i].name); delim = ","; |