From: Feng Tang Date: Mon, 25 Aug 2025 02:56:58 +0000 (+0800) Subject: lib/sys_info: handle sys_info_mask==0 case X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=31cf021b6161ac63c2ab8c64415cca0e3e136636;p=users%2Fhch%2Fmisc.git lib/sys_info: handle sys_info_mask==0 case Generalization of panic_print's dump function [1] has been merged, and this patchset is to address some remaining issues, like adding note of the obsoletion of 'panic_print' cmdline parameter, refining the kernel document for panic_print, and hardening some string management. This patch (of 4): It is a normal case that bitmask parameter is 0, so pre-initialize the names[] to null string to cover this case. Also remove the superfluous "+1" in names[sizeof(sys_info_avail) + 1], which is needed for 'strlen()', but not for 'sizeof()'. Link: https://lkml.kernel.org/r/20250825025701.81921-1-feng.tang@linux.alibaba.com Link: https://lkml.kernel.org/r/20250825025701.81921-2-feng.tang@linux.alibaba.com Link: Link: https://lkml.kernel.org/r/20250703021004.42328-1-feng.tang@linux.alibaba.com [1] Signed-off-by: Feng Tang Suggested-by: Petr Mladek Reviewed-by: Petr Mladek Cc: Askar Safin Cc: John Ogness Cc: Jonathan Corbet Cc: Lance Yang Cc: "Paul E . McKenney" Cc: Steven Rostedt Signed-off-by: Andrew Morton --- diff --git a/lib/sys_info.c b/lib/sys_info.c index 5bf503fd7ec1..496f9151c9b6 100644 --- a/lib/sys_info.c +++ b/lib/sys_info.c @@ -55,7 +55,7 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write, void *buffer, size_t *lenp, loff_t *ppos) { - char names[sizeof(sys_info_avail) + 1]; + char names[sizeof(sys_info_avail)]; struct ctl_table table; unsigned long *si_bits_global; @@ -81,6 +81,7 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write, char *delim = ""; int i, len = 0; + names[0] = '\0'; for (i = 0; i < ARRAY_SIZE(si_names); i++) { if (*si_bits_global & si_names[i].bit) { len += scnprintf(names + len, sizeof(names) - len,