This is the followup work of task comm cleanups[1]. A new macro TASK_COMM_LEN_16 is introduced to replace old hard-coded 16 in various files, in order to make them grepable. The difference between TASK_COMM_LEN and TASK_COMM_LEN_16 is: - TASK_COMM_LEN The size should be same with the TASK_COMM_LEN defined in linux/sched.h. - TASK_COMM_LEN_16 The size must be a fixed-size 16 no matter what TASK_COMM_LEN is. The usage around it is exposed to userspace, so this macro is defined in the UAPI header. [1]. https://lore.kernel.org/lkml/20211120112738.45980-1-laoar.shao@xxxxxxxxx/ Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx> Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> Cc: Michal Miroslaw <mirq-linux@xxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> --- Changes since v2: - make TASK_COMM_LEN_16 a single instance (Michal) - merge all the patches into a single patch Changes since v1: - use TASK_COMM_LEN_16 instead of TASK_COMM_LEN in patch #3 (Steven) - avoid changing samples/bpf and bpf/progs (Alexei) --- include/linux/elfcore-compat.h | 8 ++------ include/linux/elfcore.h | 9 ++------- include/uapi/linux/cn_proc.h | 3 ++- include/uapi/linux/sched.h | 7 +++++++ tools/include/uapi/linux/sched.h | 7 +++++++ tools/perf/tests/evsel-tp-sched.c | 7 ++++--- 6 files changed, 24 insertions(+), 17 deletions(-) diff --git a/include/linux/elfcore-compat.h b/include/linux/elfcore-compat.h index 54feb64e9b5d..319daa69bb23 100644 --- a/include/linux/elfcore-compat.h +++ b/include/linux/elfcore-compat.h @@ -2,6 +2,7 @@ #ifndef _LINUX_ELFCORE_COMPAT_H #define _LINUX_ELFCORE_COMPAT_H +#include <uapi/linux/sched.h> #include <linux/elf.h> #include <linux/elfcore.h> #include <linux/compat.h> @@ -43,12 +44,7 @@ struct compat_elf_prpsinfo __compat_uid_t pr_uid; __compat_gid_t pr_gid; compat_pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid; - /* - * The hard-coded 16 is derived from TASK_COMM_LEN, but it can't be - * changed as it is exposed to userspace. We'd better make it hard-coded - * here. - */ - char pr_fname[16]; + char pr_fname[TASK_COMM_LEN_16]; char pr_psargs[ELF_PRARGSZ]; }; diff --git a/include/linux/elfcore.h b/include/linux/elfcore.h index 746e081879a5..d3bb4bd3c985 100644 --- a/include/linux/elfcore.h +++ b/include/linux/elfcore.h @@ -65,13 +65,8 @@ struct elf_prpsinfo __kernel_gid_t pr_gid; pid_t pr_pid, pr_ppid, pr_pgrp, pr_sid; /* Lots missing */ - /* - * The hard-coded 16 is derived from TASK_COMM_LEN, but it can't be - * changed as it is exposed to userspace. We'd better make it hard-coded - * here. - */ - char pr_fname[16]; /* filename of executable */ - char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */ + char pr_fname[TASK_COMM_LEN_16]; /* filename of executable */ + char pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */ }; static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs) diff --git a/include/uapi/linux/cn_proc.h b/include/uapi/linux/cn_proc.h index db210625cee8..88e645230ea5 100644 --- a/include/uapi/linux/cn_proc.h +++ b/include/uapi/linux/cn_proc.h @@ -20,6 +20,7 @@ #define _UAPICN_PROC_H #include <linux/types.h> +#include "sched.h" /* * Userspace sends this enum to register with the kernel that it is listening @@ -110,7 +111,7 @@ struct proc_event { struct comm_proc_event { __kernel_pid_t process_pid; __kernel_pid_t process_tgid; - char comm[16]; + char comm[TASK_COMM_LEN_16]; } comm; struct coredump_proc_event { diff --git a/include/uapi/linux/sched.h b/include/uapi/linux/sched.h index 3bac0a8ceab2..490fd5d48378 100644 --- a/include/uapi/linux/sched.h +++ b/include/uapi/linux/sched.h @@ -145,4 +145,11 @@ struct clone_args { SCHED_FLAG_KEEP_ALL | \ SCHED_FLAG_UTIL_CLAMP) +/* + * For the one which is exposed to userspace and thus can't be changed. + */ +enum { + TASK_COMM_LEN_16 = 16, +}; + #endif /* _UAPI_LINUX_SCHED_H */ diff --git a/tools/include/uapi/linux/sched.h b/tools/include/uapi/linux/sched.h index 3bac0a8ceab2..490fd5d48378 100644 --- a/tools/include/uapi/linux/sched.h +++ b/tools/include/uapi/linux/sched.h @@ -145,4 +145,11 @@ struct clone_args { SCHED_FLAG_KEEP_ALL | \ SCHED_FLAG_UTIL_CLAMP) +/* + * For the one which is exposed to userspace and thus can't be changed. + */ +enum { + TASK_COMM_LEN_16 = 16, +}; + #endif /* _UAPI_LINUX_SCHED_H */ diff --git a/tools/perf/tests/evsel-tp-sched.c b/tools/perf/tests/evsel-tp-sched.c index cf4da3d748c2..0b74bf2ca1ce 100644 --- a/tools/perf/tests/evsel-tp-sched.c +++ b/tools/perf/tests/evsel-tp-sched.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/err.h> +#include <linux/sched.h> #include <traceevent/event-parse.h> #include "evsel.h" #include "tests.h" @@ -43,7 +44,7 @@ static int test__perf_evsel__tp_sched_test(struct test_suite *test __maybe_unuse return -1; } - if (evsel__test_field(evsel, "prev_comm", 16, false)) + if (evsel__test_field(evsel, "prev_comm", TASK_COMM_LEN_16, false)) ret = -1; if (evsel__test_field(evsel, "prev_pid", 4, true)) @@ -55,7 +56,7 @@ static int test__perf_evsel__tp_sched_test(struct test_suite *test __maybe_unuse if (evsel__test_field(evsel, "prev_state", sizeof(long), true)) ret = -1; - if (evsel__test_field(evsel, "next_comm", 16, false)) + if (evsel__test_field(evsel, "next_comm", TASK_COMM_LEN_16, false)) ret = -1; if (evsel__test_field(evsel, "next_pid", 4, true)) @@ -73,7 +74,7 @@ static int test__perf_evsel__tp_sched_test(struct test_suite *test __maybe_unuse return -1; } - if (evsel__test_field(evsel, "comm", 16, false)) + if (evsel__test_field(evsel, "comm", TASK_COMM_LEN_16, false)) ret = -1; if (evsel__test_field(evsel, "pid", 4, true)) -- 2.17.1
