2 * Copyright (C) 2011 Red Hat, Inc., Frederic Weisbecker <fweisbec@redhat.com>
4 * Licensed under the terms of the GNU GPL License version 2
6 * Selftests for breakpoints (and more generally the do_debug() path) in x86.
10 #include <sys/ptrace.h>
17 #include <sys/types.h>
22 #include "../kselftest.h"
25 /* Breakpoint access modes */
32 static pid_t child_pid;
35 * Ensures the child and parent are always "talking" about
36 * the same test sequence. (ie: that we haven't forgotten
37 * to call check_trapped() somewhere).
41 static void set_breakpoint_addr(void *addr, int n)
45 ret = ptrace(PTRACE_POKEUSER, child_pid,
46 offsetof(struct user, u_debugreg[n]), addr);
48 ksft_exit_fail_msg("Can't set breakpoint addr: %s\n",
52 static void toggle_breakpoint(int n, int type, int len,
53 int local, int global, int set)
58 unsigned long vdr7, dr7;
87 dr7 = ptrace(PTRACE_PEEKUSER, child_pid,
88 offsetof(struct user, u_debugreg[7]), 0);
90 vdr7 = (xlen | xtype) << 16;
107 ret = ptrace(PTRACE_POKEUSER, child_pid,
108 offsetof(struct user, u_debugreg[7]), dr7);
110 ksft_print_msg("Can't set dr7: %s\n", strerror(errno));
115 /* Dummy variables to test read/write accesses */
116 static unsigned long long dummy_var[4];
118 /* Dummy functions to test execution accesses */
119 static void dummy_func(void) { }
120 static void dummy_func1(void) { }
121 static void dummy_func2(void) { }
122 static void dummy_func3(void) { }
124 static void (*dummy_funcs[])(void) = {
133 static void check_trapped(void)
136 * If we haven't trapped, wake up the parent
137 * so that it notices the failure.
140 kill(getpid(), SIGUSR1);
146 static void write_var(int len)
148 char *pcval; short *psval; int *pival; long long *plval;
151 for (i = 0; i < 4; i++) {
154 pcval = (char *)&dummy_var[i];
158 psval = (short *)&dummy_var[i];
162 pival = (int *)&dummy_var[i];
166 plval = (long long *)&dummy_var[i];
167 *plval = 0xffffffffffffffffLL;
174 static void read_var(int len)
176 char cval; short sval; int ival; long long lval;
179 for (i = 0; i < 4; i++) {
182 cval = *(char *)&dummy_var[i];
185 sval = *(short *)&dummy_var[i];
188 ival = *(int *)&dummy_var[i];
191 lval = *(long long *)&dummy_var[i];
199 * Do the r/w/x accesses to trigger the breakpoints. And run
202 static void trigger_tests(void)
204 int len, local, global, i;
208 ret = ptrace(PTRACE_TRACEME, 0, NULL, 0);
210 ksft_print_msg("Can't be traced? %s\n", strerror(errno));
214 /* Wake up father so that it sets up the first test */
215 kill(getpid(), SIGUSR1);
217 /* Test instruction breakpoints */
218 for (local = 0; local < 2; local++) {
219 for (global = 0; global < 2; global++) {
220 if (!local && !global)
223 for (i = 0; i < 4; i++) {
230 /* Test write watchpoints */
231 for (len = 1; len <= sizeof(long); len <<= 1) {
232 for (local = 0; local < 2; local++) {
233 for (global = 0; global < 2; global++) {
234 if (!local && !global)
241 /* Test read/write watchpoints (on read accesses) */
242 for (len = 1; len <= sizeof(long); len <<= 1) {
243 for (local = 0; local < 2; local++) {
244 for (global = 0; global < 2; global++) {
245 if (!local && !global)
260 kill(getpid(), SIGUSR1);
263 static void check_success(const char *msg)
269 /* Wait for the child to SIGTRAP */
274 if (WSTOPSIG(status) == SIGTRAP) {
275 child_nr_tests = ptrace(PTRACE_PEEKDATA, child_pid,
277 if (child_nr_tests == nr_tests)
279 if (ptrace(PTRACE_POKEDATA, child_pid, &trapped, 1))
280 ksft_exit_fail_msg("Can't poke: %s\n", strerror(errno));
286 ksft_test_result_pass(msg);
288 ksft_test_result_fail(msg);
291 static void launch_instruction_breakpoints(char *buf, int local, int global)
295 for (i = 0; i < 4; i++) {
296 set_breakpoint_addr(dummy_funcs[i], i);
297 toggle_breakpoint(i, BP_X, 1, local, global, 1);
298 ptrace(PTRACE_CONT, child_pid, NULL, 0);
299 sprintf(buf, "Test breakpoint %d with local: %d global: %d\n",
302 toggle_breakpoint(i, BP_X, 1, local, global, 0);
306 static void launch_watchpoints(char *buf, int mode, int len,
307 int local, int global)
309 const char *mode_str;
317 for (i = 0; i < 4; i++) {
318 set_breakpoint_addr(&dummy_var[i], i);
319 toggle_breakpoint(i, mode, len, local, global, 1);
320 ptrace(PTRACE_CONT, child_pid, NULL, 0);
322 "Test %s watchpoint %d with len: %d local: %d global: %d\n",
323 mode_str, i, len, local, global);
325 toggle_breakpoint(i, mode, len, local, global, 0);
329 /* Set the breakpoints and check the child successfully trigger them */
330 static void launch_tests(void)
333 int len, local, global, i;
335 /* Instruction breakpoints */
336 for (local = 0; local < 2; local++) {
337 for (global = 0; global < 2; global++) {
338 if (!local && !global)
340 launch_instruction_breakpoints(buf, local, global);
344 /* Write watchpoint */
345 for (len = 1; len <= sizeof(long); len <<= 1) {
346 for (local = 0; local < 2; local++) {
347 for (global = 0; global < 2; global++) {
348 if (!local && !global)
350 launch_watchpoints(buf, BP_W, len,
356 /* Read-Write watchpoint */
357 for (len = 1; len <= sizeof(long); len <<= 1) {
358 for (local = 0; local < 2; local++) {
359 for (global = 0; global < 2; global++) {
360 if (!local && !global)
362 launch_watchpoints(buf, BP_RW, len,
369 ptrace(PTRACE_CONT, child_pid, NULL, 0);
370 check_success("Test icebp\n");
373 ptrace(PTRACE_CONT, child_pid, NULL, 0);
374 check_success("Test int 3 trap\n");
376 ptrace(PTRACE_CONT, child_pid, NULL, 0);
379 int main(int argc, char **argv)