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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-25 15:55:03 -0700
commit75467f60a3d14f08f86f2b353298d2826382ff23 (patch)
treeacd8a7d5b5a675042449386efa5b42ec44d8bf81 /tools/perf/bench/syscall.c
downloadlinux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.tar.gz
linux-stable-75467f60a3d14f08f86f2b353298d2826382ff23.zip
Merge tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipegrafted
Pull IPE fixes from Fan Wu: "Two fixes for use-after-free issues found by recent LLM-assisted code analysis. - move successful policy load auditing under the new policy directory's inode lock, preventing a concurrent policy deletion from freeing the policy while it is still being audited - protect the dm-verity root hash with RCU, preventing policy evaluation from racing with root hash replacement during preresume" * tag 'ipe-pr-20260925' of git://git.kernel.org/pub/scm/linux/kernel/git/wufan/ipe: ipe: protect the dm-verity root hash with RCU ipe: fix use-after-free when auditing a newly loaded policy
Diffstat (limited to 'tools/perf/bench/syscall.c')
-rw-r--r--tools/perf/bench/syscall.c188
1 files changed, 188 insertions, 0 deletions
diff --git a/tools/perf/bench/syscall.c b/tools/perf/bench/syscall.c
new file mode 100644
index 000000000..e7dc216f7
--- /dev/null
+++ b/tools/perf/bench/syscall.c
@@ -0,0 +1,188 @@
+/*
+ *
+ * syscall.c
+ *
+ * syscall: Benchmark for system call performance
+ */
+#include "../perf.h"
+#include "../util/util.h"
+#include <subcmd/parse-options.h>
+#include "../builtin.h"
+#include "bench.h"
+
+#include <stdio.h>
+#include <sys/time.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#ifndef __NR_fork
+#define __NR_fork -1
+#endif
+
+static int loops;
+
+static const struct option options[] = {
+ OPT_INTEGER('l', "loop", &loops, "Specify number of loops"),
+ OPT_END()
+};
+
+static const char * const bench_syscall_usage[] = {
+ "perf bench syscall <options>",
+ NULL
+};
+
+static void test_fork(void)
+{
+ pid_t pid = fork();
+
+ if (pid < 0) {
+ fprintf(stderr, "fork failed\n");
+ exit(1);
+ } else if (pid == 0) {
+ exit(0);
+ } else {
+ if (waitpid(pid, NULL, 0) < 0) {
+ fprintf(stderr, "waitpid failed\n");
+ exit(1);
+ }
+ }
+}
+
+static void test_execve(void)
+{
+ const char *pathname = "/bin/true";
+ char *const argv[] = { (char *)pathname, NULL };
+ pid_t pid = fork();
+
+ if (pid < 0) {
+ fprintf(stderr, "fork failed\n");
+ exit(1);
+ } else if (pid == 0) {
+ execve(pathname, argv, NULL);
+ fprintf(stderr, "execve /bin/true failed\n");
+ exit(1);
+ } else {
+ if (waitpid(pid, NULL, 0) < 0) {
+ fprintf(stderr, "waitpid failed\n");
+ exit(1);
+ }
+ }
+}
+
+static int bench_syscall_common(int argc, const char **argv, int syscall)
+{
+ struct timeval start, stop, diff;
+ unsigned long long result_usec = 0;
+ const char *name = NULL;
+ int i;
+
+ switch (syscall) {
+ case __NR_fork:
+ case __NR_execve:
+ /* Limit default loop to 10000 times to save time */
+ loops = 10000;
+ break;
+ default:
+ loops = 10000000;
+ break;
+ }
+
+ /* Options -l and --loops override default above */
+ argc = parse_options(argc, argv, options, bench_syscall_usage, 0);
+
+ gettimeofday(&start, NULL);
+
+ for (i = 0; i < loops; i++) {
+ switch (syscall) {
+ case __NR_getppid:
+ getppid();
+ break;
+ case __NR_getpgid:
+ getpgid(0);
+ break;
+ case __NR_fork:
+ test_fork();
+ break;
+ case __NR_execve:
+ test_execve();
+ default:
+ break;
+ }
+ }
+
+ gettimeofday(&stop, NULL);
+ timersub(&stop, &start, &diff);
+
+ switch (syscall) {
+ case __NR_getppid:
+ name = "getppid()";
+ break;
+ case __NR_getpgid:
+ name = "getpgid()";
+ break;
+ case __NR_fork:
+ name = "fork()";
+ break;
+ case __NR_execve:
+ name = "execve()";
+ break;
+ default:
+ break;
+ }
+
+ switch (bench_format) {
+ case BENCH_FORMAT_DEFAULT:
+ printf("# Executed %'d %s calls\n", loops, name);
+
+ result_usec = diff.tv_sec * 1000000;
+ result_usec += diff.tv_usec;
+
+ printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
+ (unsigned long) diff.tv_sec,
+ (unsigned long) (diff.tv_usec/1000));
+
+ printf(" %14lf usecs/op\n",
+ (double)result_usec / (double)loops);
+ printf(" %'14d ops/sec\n",
+ (int)((double)loops /
+ ((double)result_usec / (double)1000000)));
+ break;
+
+ case BENCH_FORMAT_SIMPLE:
+ printf("%lu.%03lu\n",
+ (unsigned long) diff.tv_sec,
+ (unsigned long) (diff.tv_usec / 1000));
+ break;
+
+ default:
+ /* reaching here is something disaster */
+ fprintf(stderr, "Unknown format:%d\n", bench_format);
+ exit(1);
+ break;
+ }
+
+ return 0;
+}
+
+int bench_syscall_basic(int argc, const char **argv)
+{
+ return bench_syscall_common(argc, argv, __NR_getppid);
+}
+
+int bench_syscall_getpgid(int argc, const char **argv)
+{
+ return bench_syscall_common(argc, argv, __NR_getpgid);
+}
+
+int bench_syscall_fork(int argc, const char **argv)
+{
+ return bench_syscall_common(argc, argv, __NR_fork);
+}
+
+int bench_syscall_execve(int argc, const char **argv)
+{
+ return bench_syscall_common(argc, argv, __NR_execve);
+}