--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2018, Breno Leitao, IBM Corp.
+ * Licensed under GPLv2.
+ *
+ * Sigfuz(tm): A PowerPC TM-aware signal fuzzer.
+ *
+ * This is a new selftest that raises SIGUSR1 signals and handles it in a set
+ * of different ways, trying to create different scenario for testing
+ * purpose.
+ *
+ * This test works raising a signal and calling sigreturn interleaved with
+ * TM operations, as starting, suspending and terminating a transaction. The
+ * test depends on random numbers, and, based on them, it sets different TM
+ * states.
+ *
+ * Other than that, the test fills out the user context struct that is passed
+ * to the sigreturn system call with random data, in order to make sure that
+ * the signal handler syscall can handle different and invalid states
+ * properly.
+ *
+ * This selftest has command line parameters to control what kind of tests the
+ * user wants to run, as for example, if a transaction should be started prior
+ * to signal being raised, or, after the signal being raised and before the
+ * sigreturn. If no parameter is given, the default is enabling all options.
+ *
+ * This test does not check if the user context is being read and set
+ * properly by the kernel. Its purpose, at this time, is basically
+ * guaranteeing that the kernel does not crash on invalid scenarios.
+ */
+
+#include <stdio.h>
+#include <limits.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <ucontext.h>
+#include <sys/mman.h>
+#include <pthread.h>
+#include "utils.h"
+
+/* Selftest defaults */
+#define COUNT_MAX 4000 /* Number of interactions */
+#define THREADS 16 /* Number of threads */
+
+/* Arguments options */
+#define ARG_MESS_WITH_TM_AT 0x1
+#define ARG_MESS_WITH_TM_BEFORE 0x2
+#define ARG_MESS_WITH_MSR_AT 0x4
+#define ARG_FOREVER 0x10
+#define ARG_COMPLETE (ARG_MESS_WITH_TM_AT | \
+ ARG_MESS_WITH_TM_BEFORE | \
+ ARG_MESS_WITH_MSR_AT)
+
+static int args;
+static int nthread = THREADS;
+static int count_max = COUNT_MAX;
+
+/* checkpoint context */
+static ucontext_t *tmp_uc;
+
+/* Return true with 1/x probability */
+static int one_in_chance(int x)
+{
+ return rand() % x == 0;
+}
+
+/* Change TM states */
+static void mess_with_tm(void)
+{
+ /* Starts a transaction 33% of the time */
+ if (one_in_chance(3)) {
+ asm ("tbegin. ;"
+ "beq 8 ;");
+
+ /* And suspended half of them */
+ if (one_in_chance(2))
+ asm("tsuspend. ;");
+ }
+
+ /* Call 'tend' in 5% of the runs */
+ if (one_in_chance(20))
+ asm("tend. ;");
+}
+
+/* Signal handler that will be invoked with raise() */
+static void trap_signal_handler(int signo, siginfo_t *si, void *uc)
+{
+ ucontext_t *ucp = uc;
+
+ ucp->uc_link = tmp_uc;
+
+ /*
+ * Set uc_link in three possible ways:
+ * - Setting a single 'int' in the whole chunk
+ * - Cloning ucp into uc_link
+ * - Allocating a new memory chunk
+ */
+ if (one_in_chance(3)) {
+ memset(ucp->uc_link, rand(), sizeof(ucontext_t));
+ } else if (one_in_chance(2)) {
+ memcpy(ucp->uc_link, uc, sizeof(ucontext_t));
+ } else if (one_in_chance(2)) {
+ if (tmp_uc) {
+ free(tmp_uc);
+ tmp_uc = NULL;
+ }
+ tmp_uc = malloc(sizeof(ucontext_t));
+ ucp->uc_link = tmp_uc;
+ /* Trying to cause a major page fault at Kernel level */
+ madvise(ucp->uc_link, sizeof(ucontext_t), MADV_DONTNEED);
+ }
+
+ if (args & ARG_MESS_WITH_MSR_AT) {
+ /* Changing the checkpointed registers */
+ if (one_in_chance(4)) {
+ ucp->uc_link->uc_mcontext.gp_regs[PT_MSR] |= MSR_TS_S;
+ } else {
+ if (one_in_chance(2)) {
+ ucp->uc_link->uc_mcontext.gp_regs[PT_MSR] |=
+ MSR_TS_T;
+ } else if (one_in_chance(2)) {
+ ucp->uc_link->uc_mcontext.gp_regs[PT_MSR] |=
+ MSR_TS_T | MSR_TS_S;
+ }
+ }
+
+ /* Checking the current register context */
+ if (one_in_chance(2)) {
+ ucp->uc_mcontext.gp_regs[PT_MSR] |= MSR_TS_S;
+ } else if (one_in_chance(2)) {
+ if (one_in_chance(2))
+ ucp->uc_mcontext.gp_regs[PT_MSR] |=
+ MSR_TS_T;
+ else if (one_in_chance(2))
+ ucp->uc_mcontext.gp_regs[PT_MSR] |=
+ MSR_TS_T | MSR_TS_S;
+ }
+ }
+
+ if (one_in_chance(20)) {
+ /* Nested transaction start */
+ if (one_in_chance(5))
+ mess_with_tm();
+
+ /* Return without changing any other context info */
+ return;
+ }
+
+ if (one_in_chance(10))
+ ucp->uc_mcontext.gp_regs[PT_MSR] = random();
+ if (one_in_chance(10))
+ ucp->uc_mcontext.gp_regs[PT_NIP] = random();
+ if (one_in_chance(10))
+ ucp->uc_link->uc_mcontext.gp_regs[PT_MSR] = random();
+ if (one_in_chance(10))
+ ucp->uc_link->uc_mcontext.gp_regs[PT_NIP] = random();
+
+ ucp->uc_mcontext.gp_regs[PT_TRAP] = random();
+ ucp->uc_mcontext.gp_regs[PT_DSISR] = random();
+ ucp->uc_mcontext.gp_regs[PT_DAR] = random();
+ ucp->uc_mcontext.gp_regs[PT_ORIG_R3] = random();
+ ucp->uc_mcontext.gp_regs[PT_XER] = random();
+ ucp->uc_mcontext.gp_regs[PT_RESULT] = random();
+ ucp->uc_mcontext.gp_regs[PT_SOFTE] = random();
+ ucp->uc_mcontext.gp_regs[PT_DSCR] = random();
+ ucp->uc_mcontext.gp_regs[PT_CTR] = random();
+ ucp->uc_mcontext.gp_regs[PT_LNK] = random();
+ ucp->uc_mcontext.gp_regs[PT_CCR] = random();
+ ucp->uc_mcontext.gp_regs[PT_REGS_COUNT] = random();
+
+ ucp->uc_link->uc_mcontext.gp_regs[PT_TRAP] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_DSISR] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_DAR] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_ORIG_R3] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_XER] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_RESULT] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_SOFTE] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_DSCR] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_CTR] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_LNK] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_CCR] = random();
+ ucp->uc_link->uc_mcontext.gp_regs[PT_REGS_COUNT] = random();
+
+ if (args & ARG_MESS_WITH_TM_BEFORE) {
+ if (one_in_chance(2))
+ mess_with_tm();
+ }
+}
+
+static void seg_signal_handler(int signo, siginfo_t *si, void *uc)
+{
+ /* Clear exit for process that segfaults */
+ exit(0);
+}
+
+static void *sigfuz_test(void *thrid)
+{
+ struct sigaction trap_sa, seg_sa;
+ int ret, i = 0;
+ pid_t t;
+
+ tmp_uc = malloc(sizeof(ucontext_t));
+
+ /* Main signal handler */
+ trap_sa.sa_flags = SA_SIGINFO;
+ trap_sa.sa_sigaction = trap_signal_handler;
+
+ /* SIGSEGV signal handler */
+ seg_sa.sa_flags = SA_SIGINFO;
+ seg_sa.sa_sigaction = seg_signal_handler;
+
+ /* The signal handler will enable MSR_TS */
+ sigaction(SIGUSR1, &trap_sa, NULL);
+
+ /* If it does not crash, it will segfault, avoid it to retest */
+ sigaction(SIGSEGV, &seg_sa, NULL);
+
+ while (i < count_max) {
+ t = fork();
+
+ if (t == 0) {
+ /* Once seed per process */
+ srand(time(NULL) + getpid());
+ if (args & ARG_MESS_WITH_TM_AT) {
+ if (one_in_chance(2))
+ mess_with_tm();
+ }
+ raise(SIGUSR1);
+ exit(0);
+ } else {
+ waitpid(t, &ret, 0);
+ }
+ if (!(args & ARG_FOREVER))
+ i++;
+ }
+
+ /* If not freed already, free now */
+ if (tmp_uc) {
+ free(tmp_uc);
+ tmp_uc = NULL;
+ }
+
+ return NULL;
+}
+
+static int signal_fuzzer(void)
+{
+ int t, rc;
+ pthread_t *threads;
+
+ threads = malloc(nthread * sizeof(pthread_t));
+
+ for (t = 0; t < nthread; t++) {
+ rc = pthread_create(&threads[t], NULL, sigfuz_test,
+ (void *)&t);
+ if (rc)
+ perror("Thread creation error\n");
+ }
+
+ for (t = 0; t < nthread; t++) {
+ rc = pthread_join(threads[t], NULL);
+ if (rc)
+ perror("Thread join error\n");
+ }
+
+ free(threads);
+
+ return EXIT_SUCCESS;
+}
+
+static void show_help(char *name)
+{
+ printf("%s: Sigfuzzer for powerpc\n", name);
+ printf("Usage:\n");
+ printf("\t-b\t Mess with TM before raising a SIGUSR1 signal\n");
+ printf("\t-a\t Mess with TM after raising a SIGUSR1 signal\n");
+ printf("\t-m\t Mess with MSR[TS] bits at mcontext\n");
+ printf("\t-x\t Mess with everything above\n");
+ printf("\t-f\t Run forever (Press ^C to Quit)\n");
+ printf("\t-i\t Amount of interactions. (Default = %d)\n", COUNT_MAX);
+ printf("\t-t\t Amount of threads. (Default = %d)\n", THREADS);
+ exit(-1);
+}
+
+int main(int argc, char **argv)
+{
+ int opt;
+
+ while ((opt = getopt(argc, argv, "bamxt:fi:h")) != -1) {
+ if (opt == 'b') {
+ printf("Mess with TM before signal\n");
+ args |= ARG_MESS_WITH_TM_BEFORE;
+ } else if (opt == 'a') {
+ printf("Mess with TM at signal handler\n");
+ args |= ARG_MESS_WITH_TM_AT;
+ } else if (opt == 'm') {
+ printf("Mess with MSR[TS] bits in mcontext\n");
+ args |= ARG_MESS_WITH_MSR_AT;
+ } else if (opt == 'x') {
+ printf("Running with all options enabled\n");
+ args |= ARG_COMPLETE;
+ } else if (opt == 't') {
+ nthread = atoi(optarg);
+ printf("Threads = %d\n", nthread);
+ } else if (opt == 'f') {
+ args |= ARG_FOREVER;
+ printf("Press ^C to stop\n");
+ test_harness_set_timeout(-1);
+ } else if (opt == 'i') {
+ count_max = atoi(optarg);
+ printf("Running for %d interactions\n", count_max);
+ } else if (opt == 'h') {
+ show_help(argv[0]);
+ }
+ }
+
+ /* Default test suite */
+ if (!args)
+ args = ARG_COMPLETE;
+
+ test_harness(signal_fuzzer, "signal_fuzzer");
+}
projects / platform / kernel / linux-starfive.git / commitdiff