# Re: \[PATCH\] tracing: Replace strncpy() with strscpy() when copying comm - From: Steven Rostedt \ - Date: 2024-10-30 23:40:09 - List: linux-trace-kernel - Page: https://ratatoskr.run/linux-trace-kernel/2024/10/2806754 - Thread: https://ratatoskr.run/linux-trace-kernel/2024/07/2690619/t.md ```text On Wed, 31 Jul 2024 15:50:58 +0800 Jinjie Ruan [ref] wrote: > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index 6ece1308d36a..4ee0e64719fa 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -1599,7 +1599,7 @@ static inline void save_comm(char *comm, struct task_struct *task) > return; > } > > - strncpy(comm, task->comm, TASK_COMM_LEN); > + strscpy(comm, task->comm); > } > Was this even compiled? In file included from /work/git/test-linux.git/include/linux/container_of.h:5, from /work/git/test-linux.git/include/linux/list.h:5, from /work/git/test-linux.git/include/linux/module.h:12, from /work/git/test-linux.git/kernel/trace/trace_events_hist.c:8: /work/git/test-linux.git/kernel/trace/trace_events_hist.c: In function ‘save_comm’: /work/git/test-linux.git/include/linux/build_bug.h:16:51: error: negative width in bit-field ‘’ 16 | #define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) | ^ /work/git/test-linux.git/include/linux/compiler.h:243:33: note: in expansion of macro ‘BUILD_BUG_ON_ZERO’ 243 | #define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0])) | ^~~~~~~~~~~~~~~~~ /work/git/test-linux.git/include/linux/string.h:79:47: note: in expansion of macro ‘__must_be_array’ 79 | sized_strscpy(dst, src, sizeof(dst) + __must_be_array(dst) + \ | ^~~~~~~~~~~~~~~ /work/git/test-linux.git/include/linux/args.h:25:24: note: in expansion of macro ‘__strscpy0’ 25 | #define __CONCAT(a, b) a ## b | ^ /work/git/test-linux.git/include/linux/args.h:26:27: note: in expansion of macro ‘__CONCAT’ 26 | #define CONCATENATE(a, b) __CONCAT(a, b) | ^~~~~~~~ /work/git/test-linux.git/include/linux/string.h:113:9: note: in expansion of macro ‘CONCATENATE’ 113 | CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__) | ^~~~~~~~~~~ /work/git/test-linux.git/kernel/trace/trace_events_hist.c:1602:9: note: in expansion of macro ‘strscpy’ 1602 | strscpy(comm, task->comm); | ^~~~~~~ Bah! -- Steve ```