From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- .../testing/selftests/seccomp/seccomp_benchmark.c | 248 +++++++++++++++++++++ 1 file changed, 248 insertions(+) create mode 100644 tools/testing/selftests/seccomp/seccomp_benchmark.c (limited to 'tools/testing/selftests/seccomp/seccomp_benchmark.c') diff --git a/tools/testing/selftests/seccomp/seccomp_benchmark.c b/tools/testing/selftests/seccomp/seccomp_benchmark.c new file mode 100644 index 000000000..5b5c9d558 --- /dev/null +++ b/tools/testing/selftests/seccomp/seccomp_benchmark.c @@ -0,0 +1,248 @@ +/* + * Strictly speaking, this is not a test. But it can report during test + * runs so relative performace can be measured. + */ +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../kselftest.h" + +unsigned long long timing(clockid_t clk_id, unsigned long long samples) +{ + struct timespec start, finish; + unsigned long long i; + pid_t pid, ret; + + pid = getpid(); + assert(clock_gettime(clk_id, &start) == 0); + for (i = 0; i < samples; i++) { + ret = syscall(__NR_getpid); + assert(pid == ret); + } + assert(clock_gettime(clk_id, &finish) == 0); + + i = finish.tv_sec - start.tv_sec; + i *= 1000000000ULL; + i += finish.tv_nsec - start.tv_nsec; + + printf("%lu.%09lu - %lu.%09lu = %llu (%.1fs)\n", + finish.tv_sec, finish.tv_nsec, + start.tv_sec, start.tv_nsec, + i, (double)i / 1000000000.0); + + return i; +} + +unsigned long long calibrate(void) +{ + struct timespec start, finish; + unsigned long long i, samples, step = 9973; + pid_t pid, ret; + int seconds = 15; + + printf("Calibrating sample size for %d seconds worth of syscalls ...\n", seconds); + + samples = 0; + pid = getpid(); + assert(clock_gettime(CLOCK_MONOTONIC, &start) == 0); + do { + for (i = 0; i < step; i++) { + ret = syscall(__NR_getpid); + assert(pid == ret); + } + assert(clock_gettime(CLOCK_MONOTONIC, &finish) == 0); + + samples += step; + i = finish.tv_sec - start.tv_sec; + i *= 1000000000ULL; + i += finish.tv_nsec - start.tv_nsec; + } while (i < 1000000000ULL); + + return samples * seconds; +} + +bool approx(int i_one, int i_two) +{ + double one = i_one, one_bump = one * 0.01; + double two = i_two, two_bump = two * 0.01; + + one_bump = one + MAX(one_bump, 2.0); + two_bump = two + MAX(two_bump, 2.0); + + /* Equal to, or within 1% or 2 digits */ + if (one == two || + (one > two && one <= two_bump) || + (two > one && two <= one_bump)) + return true; + return false; +} + +bool le(int i_one, int i_two) +{ + if (i_one <= i_two) + return true; + return false; +} + +long compare(const char *name_one, const char *name_eval, const char *name_two, + unsigned long long one, bool (*eval)(int, int), unsigned long long two) +{ + bool good; + + printf("\t%s %s %s (%lld %s %lld): ", name_one, name_eval, name_two, + (long long)one, name_eval, (long long)two); + if (one > INT_MAX) { + printf("Miscalculation! Measurement went negative: %lld\n", (long long)one); + return 1; + } + if (two > INT_MAX) { + printf("Miscalculation! Measurement went negative: %lld\n", (long long)two); + return 1; + } + + good = eval(one, two); + printf("%s\n", good ? "✔️" : "❌"); + + return good ? 0 : 1; +} + +int main(int argc, char *argv[]) +{ + struct sock_filter bitmap_filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, offsetof(struct seccomp_data, nr)), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog bitmap_prog = { + .len = (unsigned short)ARRAY_SIZE(bitmap_filter), + .filter = bitmap_filter, + }; + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, offsetof(struct seccomp_data, args[0])), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + long ret, bits; + unsigned long long samples, calc; + unsigned long long native, filter1, filter2, bitmap1, bitmap2; + unsigned long long entry, per_filter1, per_filter2; + + setbuf(stdout, NULL); + + printf("Running on:\n"); + system("uname -a"); + + printf("Current BPF sysctl settings:\n"); + /* Avoid using "sysctl" which may not be installed. */ + system("grep -H . /proc/sys/net/core/bpf_jit_enable"); + system("grep -H . /proc/sys/net/core/bpf_jit_harden"); + + if (argc > 1) + samples = strtoull(argv[1], NULL, 0); + else + samples = calibrate(); + + printf("Benchmarking %llu syscalls...\n", samples); + + /* Native call */ + native = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid native: %llu ns\n", native); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + assert(ret == 0); + + /* One filter resulting in a bitmap */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &bitmap_prog); + assert(ret == 0); + + bitmap1 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 1 filter (bitmap): %llu ns\n", bitmap1); + + /* Second filter resulting in a bitmap */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &bitmap_prog); + assert(ret == 0); + + bitmap2 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 2 filters (bitmap): %llu ns\n", bitmap2); + + /* Third filter, can no longer be converted to bitmap */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + assert(ret == 0); + + filter1 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 3 filters (full): %llu ns\n", filter1); + + /* Fourth filter, can not be converted to bitmap because of filter 3 */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &bitmap_prog); + assert(ret == 0); + + filter2 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 4 filters (full): %llu ns\n", filter2); + + /* Estimations */ +#define ESTIMATE(fmt, var, what) do { \ + var = (what); \ + printf("Estimated " fmt ": %llu ns\n", var); \ + if (var > INT_MAX) \ + goto more_samples; \ + } while (0) + + ESTIMATE("total seccomp overhead for 1 bitmapped filter", calc, + bitmap1 - native); + ESTIMATE("total seccomp overhead for 2 bitmapped filters", calc, + bitmap2 - native); + ESTIMATE("total seccomp overhead for 3 full filters", calc, + filter1 - native); + ESTIMATE("total seccomp overhead for 4 full filters", calc, + filter2 - native); + ESTIMATE("seccomp entry overhead", entry, + bitmap1 - native - (bitmap2 - bitmap1)); + ESTIMATE("seccomp per-filter overhead (last 2 diff)", per_filter1, + filter2 - filter1); + ESTIMATE("seccomp per-filter overhead (filters / 4)", per_filter2, + (filter2 - native - entry) / 4); + + printf("Expectations:\n"); + ret |= compare("native", "≤", "1 bitmap", native, le, bitmap1); + bits = compare("native", "≤", "1 filter", native, le, filter1); + if (bits) + goto more_samples; + + ret |= compare("per-filter (last 2 diff)", "≈", "per-filter (filters / 4)", + per_filter1, approx, per_filter2); + + bits = compare("1 bitmapped", "≈", "2 bitmapped", + bitmap1 - native, approx, bitmap2 - native); + if (bits) { + printf("Skipping constant action bitmap expectations: they appear unsupported.\n"); + goto out; + } + + ret |= compare("entry", "≈", "1 bitmapped", entry, approx, bitmap1 - native); + ret |= compare("entry", "≈", "2 bitmapped", entry, approx, bitmap2 - native); + ret |= compare("native + entry + (per filter * 4)", "≈", "4 filters total", + entry + (per_filter1 * 4) + native, approx, filter2); + if (ret == 0) + goto out; + +more_samples: + printf("Saw unexpected benchmark result. Try running again with more samples?\n"); +out: + return 0; +} -- cgit v1.2.3