--- /dev/null
+/*
+ * Copyright (C) 2011 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com>
+ *
+ * Licensed under the terms of the GNU GPL License version 2
+ *
+ * Selftests for breakpoints (and more generally the do_debug() path) in x86.
+ */
+
+
+#include <sys/ptrace.h>
+#include <unistd.h>
+#include <stddef.h>
+#include <sys/user.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "../kselftest.h"
+
+
+/* Breakpoint access modes */
+enum {
+ BP_X = 1,
+ BP_RW = 2,
+ BP_W = 4,
+};
+
+static pid_t child_pid;
+
+/*
+ * Ensures the child and parent are always "talking" about
+ * the same test sequence. (ie: that we haven't forgotten
+ * to call check_trapped() somewhere).
+ */
+static int nr_tests;
+
+static void set_breakpoint_addr(void *addr, int n)
+{
+ int ret;
+
+ ret = ptrace(PTRACE_POKEUSER, child_pid,
+ offsetof(struct user, u_debugreg[n]), addr);
+ if (ret) {
+ perror("Can't set breakpoint addr\n");
+ ksft_exit_fail();
+ }
+}
+
+static void toggle_breakpoint(int n, int type, int len,
+ int local, int global, int set)
+{
+ int ret;
+
+ int xtype, xlen;
+ unsigned long vdr7, dr7;
+
+ switch (type) {
+ case BP_X:
+ xtype = 0;
+ break;
+ case BP_W:
+ xtype = 1;
+ break;
+ case BP_RW:
+ xtype = 3;
+ break;
+ }
+
+ switch (len) {
+ case 1:
+ xlen = 0;
+ break;
+ case 2:
+ xlen = 4;
+ break;
+ case 4:
+ xlen = 0xc;
+ break;
+ case 8:
+ xlen = 8;
+ break;
+ }
+
+ dr7 = ptrace(PTRACE_PEEKUSER, child_pid,
+ offsetof(struct user, u_debugreg[7]), 0);
+
+ vdr7 = (xlen | xtype) << 16;
+ vdr7 <<= 4 * n;
+
+ if (local) {
+ vdr7 |= 1 << (2 * n);
+ vdr7 |= 1 << 8;
+ }
+ if (global) {
+ vdr7 |= 2 << (2 * n);
+ vdr7 |= 1 << 9;
+ }
+
+ if (set)
+ dr7 |= vdr7;
+ else
+ dr7 &= ~vdr7;
+
+ ret = ptrace(PTRACE_POKEUSER, child_pid,
+ offsetof(struct user, u_debugreg[7]), dr7);
+ if (ret) {
+ perror("Can't set dr7");
+ ksft_exit_fail();
+ }
+}
+
+/* Dummy variables to test read/write accesses */
+static unsigned long long dummy_var[4];
+
+/* Dummy functions to test execution accesses */
+static void dummy_func(void) { }
+static void dummy_func1(void) { }
+static void dummy_func2(void) { }
+static void dummy_func3(void) { }
+
+static void (*dummy_funcs[])(void) = {
+ dummy_func,
+ dummy_func1,
+ dummy_func2,
+ dummy_func3,
+};
+
+static int trapped;
+
+static void check_trapped(void)
+{
+ /*
+ * If we haven't trapped, wake up the parent
+ * so that it notices the failure.
+ */
+ if (!trapped)
+ kill(getpid(), SIGUSR1);
+ trapped = 0;
+
+ nr_tests++;
+}
+
+static void write_var(int len)
+{
+ char *pcval; short *psval; int *pival; long long *plval;
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ switch (len) {
+ case 1:
+ pcval = (char *)&dummy_var[i];
+ *pcval = 0xff;
+ break;
+ case 2:
+ psval = (short *)&dummy_var[i];
+ *psval = 0xffff;
+ break;
+ case 4:
+ pival = (int *)&dummy_var[i];
+ *pival = 0xffffffff;
+ break;
+ case 8:
+ plval = (long long *)&dummy_var[i];
+ *plval = 0xffffffffffffffffLL;
+ break;
+ }
+ check_trapped();
+ }
+}
+
+static void read_var(int len)
+{
+ char cval; short sval; int ival; long long lval;
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ switch (len) {
+ case 1:
+ cval = *(char *)&dummy_var[i];
+ break;
+ case 2:
+ sval = *(short *)&dummy_var[i];
+ break;
+ case 4:
+ ival = *(int *)&dummy_var[i];
+ break;
+ case 8:
+ lval = *(long long *)&dummy_var[i];
+ break;
+ }
+ check_trapped();
+ }
+}
+
+/*
+ * Do the r/w/x accesses to trigger the breakpoints. And run
+ * the usual traps.
+ */
+static void trigger_tests(void)
+{
+ int len, local, global, i;
+ char val;
+ int ret;
+
+ ret = ptrace(PTRACE_TRACEME, 0, NULL, 0);
+ if (ret) {
+ perror("Can't be traced?\n");
+ return;
+ }
+
+ /* Wake up father so that it sets up the first test */
+ kill(getpid(), SIGUSR1);
+
+ /* Test instruction breakpoints */
+ for (local = 0; local < 2; local++) {
+ for (global = 0; global < 2; global++) {
+ if (!local && !global)
+ continue;
+
+ for (i = 0; i < 4; i++) {
+ dummy_funcs[i]();
+ check_trapped();
+ }
+ }
+ }
+
+ /* Test write watchpoints */
+ for (len = 1; len <= sizeof(long); len <<= 1) {
+ for (local = 0; local < 2; local++) {
+ for (global = 0; global < 2; global++) {
+ if (!local && !global)
+ continue;
+ write_var(len);
+ }
+ }
+ }
+
+ /* Test read/write watchpoints (on read accesses) */
+ for (len = 1; len <= sizeof(long); len <<= 1) {
+ for (local = 0; local < 2; local++) {
+ for (global = 0; global < 2; global++) {
+ if (!local && !global)
+ continue;
+ read_var(len);
+ }
+ }
+ }
+
+ /* Icebp trap */
+ asm(".byte 0xf1\n");
+ check_trapped();
+
+ /* Int 3 trap */
+ asm("int $3\n");
+ check_trapped();
+
+ kill(getpid(), SIGUSR1);
+}
+
+static void check_success(const char *msg)
+{
+ const char *msg2;
+ int child_nr_tests;
+ int status;
+
+ /* Wait for the child to SIGTRAP */
+ wait(&status);
+
+ msg2 = "Failed";
+
+ if (WSTOPSIG(status) == SIGTRAP) {
+ child_nr_tests = ptrace(PTRACE_PEEKDATA, child_pid,
+ &nr_tests, 0);
+ if (child_nr_tests == nr_tests)
+ msg2 = "Ok";
+ if (ptrace(PTRACE_POKEDATA, child_pid, &trapped, 1)) {
+ perror("Can't poke\n");
+ ksft_exit_fail();
+ }
+ }
+
+ nr_tests++;
+
+ printf("%s [%s]\n", msg, msg2);
+}
+
+static void launch_instruction_breakpoints(char *buf, int local, int global)
+{
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ set_breakpoint_addr(dummy_funcs[i], i);
+ toggle_breakpoint(i, BP_X, 1, local, global, 1);
+ ptrace(PTRACE_CONT, child_pid, NULL, 0);
+ sprintf(buf, "Test breakpoint %d with local: %d global: %d",
+ i, local, global);
+ check_success(buf);
+ toggle_breakpoint(i, BP_X, 1, local, global, 0);
+ }
+}
+
+static void launch_watchpoints(char *buf, int mode, int len,
+ int local, int global)
+{
+ const char *mode_str;
+ int i;
+
+ if (mode == BP_W)
+ mode_str = "write";
+ else
+ mode_str = "read";
+
+ for (i = 0; i < 4; i++) {
+ set_breakpoint_addr(&dummy_var[i], i);
+ toggle_breakpoint(i, mode, len, local, global, 1);
+ ptrace(PTRACE_CONT, child_pid, NULL, 0);
+ sprintf(buf, "Test %s watchpoint %d with len: %d local: "
+ "%d global: %d", mode_str, i, len, local, global);
+ check_success(buf);
+ toggle_breakpoint(i, mode, len, local, global, 0);
+ }
+}
+
+/* Set the breakpoints and check the child successfully trigger them */
+static void launch_tests(void)
+{
+ char buf[1024];
+ int len, local, global, i;
+
+ /* Instruction breakpoints */
+ for (local = 0; local < 2; local++) {
+ for (global = 0; global < 2; global++) {
+ if (!local && !global)
+ continue;
+ launch_instruction_breakpoints(buf, local, global);
+ }
+ }
+
+ /* Write watchpoint */
+ for (len = 1; len <= sizeof(long); len <<= 1) {
+ for (local = 0; local < 2; local++) {
+ for (global = 0; global < 2; global++) {
+ if (!local && !global)
+ continue;
+ launch_watchpoints(buf, BP_W, len,
+ local, global);
+ }
+ }
+ }
+
+ /* Read-Write watchpoint */
+ for (len = 1; len <= sizeof(long); len <<= 1) {
+ for (local = 0; local < 2; local++) {
+ for (global = 0; global < 2; global++) {
+ if (!local && !global)
+ continue;
+ launch_watchpoints(buf, BP_RW, len,
+ local, global);
+ }
+ }
+ }
+
+ /* Icebp traps */
+ ptrace(PTRACE_CONT, child_pid, NULL, 0);
+ check_success("Test icebp");
+
+ /* Int 3 traps */
+ ptrace(PTRACE_CONT, child_pid, NULL, 0);
+ check_success("Test int 3 trap");
+
+ ptrace(PTRACE_CONT, child_pid, NULL, 0);
+}
+
+int main(int argc, char **argv)
+{
+ pid_t pid;
+ int ret;
+
+ pid = fork();
+ if (!pid) {
+ trigger_tests();
+ return 0;
+ }
+
+ child_pid = pid;
+
+ wait(NULL);
+
+ launch_tests();
+
+ wait(NULL);
+
+ return ksft_exit_pass();
+}
Code Review / kvmfornfv.git / blobdiff