1 // SPDX-License-Identifier: GPL-2.0-only
37  * requires some per-architecture support (i.e. knowledge about the
39  * a small trampoline is open-coded for x86_64.  Other architectures
65 int factor;  variable
77 	return (t2.tv_sec - t1.tv_sec) + 1.0e-9 * (t2.tv_nsec - t1.tv_nsec);  in one_sysinfo_step()
84 	printf("Calibrating test set to last ~%d seconds...\n", CALIBRATE_TO_SECS);  in calibrate_set()
88 		factor += CALIBRATE_TO_SECS;  in calibrate_set()
91 	printf("test iterations = %d\n", CALIBRATION_STEP * factor);  in calibrate_set()
99 	for (i = 0; i < factor; ++i)  in perf_syscall()
100 		partial += one_sysinfo_step()/(CALIBRATION_STEP*factor);  in perf_syscall()
111 	/* printf and friends are not signal-safe. */  in handle_sigsys()
112 	len = snprintf(buf, 1024, "Caught sys_%x\n", info->si_syscall);  in handle_sigsys()
115 	if (info->si_syscall == MAGIC_SYSCALL_1)  in handle_sigsys()
153 	printf("Avg syscall time %.0lfns.\n", time1 * 1.0e9);  in main()
158 		exit(-1);  in main()
161 	fprintf(stderr, "Enabling syscall trapping.\n");  in main()
165 		  (syscall_dispatcher_end - syscall_dispatcher_start + 1),  in main()
167 		perror("prctl failed\n");  in main()
168 		exit(-1);  in main()
176 		fprintf(stderr, "Failed to return with selector blocked.\n");  in main()
177 		exit(-1);  in main()
184 		fprintf(stderr, "syscall trapping does not work.\n");  in main()
185 		exit(-1);  in main()
191 		perror("syscall trapping intercepted more syscalls than expected\n");  in main()
192 		exit(-1);  in main()
195 	printf("trapped_call_count %lu, native_call_count %lu.\n",  in main()
197 	printf("Avg syscall time %.0lfns.\n", time2 * 1.0e9);  in main()
198 	printf("Interception overhead: %.1lf%% (+%.0lfns).\n",  in main()
199 	       100.0 * (time2 / time1 - 1.0), 1.0e9 * (time2 - time1));  in main()