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>
20 #include "../kselftest.h"
23 /* Breakpoint access modes */
30 static pid_t child_pid;
33 * Ensures the child and parent are always "talking" about
34 * the same test sequence. (ie: that we haven't forgotten
35 * to call check_trapped() somewhere).
39 static void set_breakpoint_addr(void *addr, int n)
43 ret = ptrace(PTRACE_POKEUSER, child_pid,
44 offsetof(struct user, u_debugreg[n]), addr);
46 perror("Can't set breakpoint addr\n");
51 static void toggle_breakpoint(int n, int type, int len,
52 int local, int global, int set)
57 unsigned long vdr7, dr7;
86 dr7 = ptrace(PTRACE_PEEKUSER, child_pid,
87 offsetof(struct user, u_debugreg[7]), 0);
89 vdr7 = (xlen | xtype) << 16;
106 ret = ptrace(PTRACE_POKEUSER, child_pid,
107 offsetof(struct user, u_debugreg[7]), dr7);
109 perror("Can't set dr7");
114 /* Dummy variables to test read/write accesses */
115 static unsigned long long dummy_var[4];
117 /* Dummy functions to test execution accesses */
118 static void dummy_func(void) { }
119 static void dummy_func1(void) { }
120 static void dummy_func2(void) { }
121 static void dummy_func3(void) { }
123 static void (*dummy_funcs[])(void) = {
132 static void check_trapped(void)
135 * If we haven't trapped, wake up the parent
136 * so that it notices the failure.
139 kill(getpid(), SIGUSR1);
145 static void write_var(int len)
147 char *pcval; short *psval; int *pival; long long *plval;
150 for (i = 0; i < 4; i++) {
153 pcval = (char *)&dummy_var[i];
157 psval = (short *)&dummy_var[i];
161 pival = (int *)&dummy_var[i];
165 plval = (long long *)&dummy_var[i];
166 *plval = 0xffffffffffffffffLL;
173 static void read_var(int len)
175 char cval; short sval; int ival; long long lval;
178 for (i = 0; i < 4; i++) {
181 cval = *(char *)&dummy_var[i];
184 sval = *(short *)&dummy_var[i];
187 ival = *(int *)&dummy_var[i];
190 lval = *(long long *)&dummy_var[i];
198 * Do the r/w/x accesses to trigger the breakpoints. And run
201 static void trigger_tests(void)
203 int len, local, global, i;
207 ret = ptrace(PTRACE_TRACEME, 0, NULL, 0);
209 perror("Can't be traced?\n");
213 /* Wake up father so that it sets up the first test */
214 kill(getpid(), SIGUSR1);
216 /* Test instruction breakpoints */
217 for (local = 0; local < 2; local++) {
218 for (global = 0; global < 2; global++) {
219 if (!local && !global)
222 for (i = 0; i < 4; i++) {
229 /* Test write watchpoints */
230 for (len = 1; len <= sizeof(long); len <<= 1) {
231 for (local = 0; local < 2; local++) {
232 for (global = 0; global < 2; global++) {
233 if (!local && !global)
240 /* Test read/write watchpoints (on read accesses) */
241 for (len = 1; len <= sizeof(long); len <<= 1) {
242 for (local = 0; local < 2; local++) {
243 for (global = 0; global < 2; global++) {
244 if (!local && !global)
259 kill(getpid(), SIGUSR1);
262 static void check_success(const char *msg)
268 /* Wait for the child to SIGTRAP */
273 if (WSTOPSIG(status) == SIGTRAP) {
274 child_nr_tests = ptrace(PTRACE_PEEKDATA, child_pid,
276 if (child_nr_tests == nr_tests)
278 if (ptrace(PTRACE_POKEDATA, child_pid, &trapped, 1)) {
279 perror("Can't poke\n");
286 printf("%s [%s]\n", msg, msg2);
289 static void launch_instruction_breakpoints(char *buf, int local, int global)
293 for (i = 0; i < 4; i++) {
294 set_breakpoint_addr(dummy_funcs[i], i);
295 toggle_breakpoint(i, BP_X, 1, local, global, 1);
296 ptrace(PTRACE_CONT, child_pid, NULL, 0);
297 sprintf(buf, "Test breakpoint %d with local: %d global: %d",
300 toggle_breakpoint(i, BP_X, 1, local, global, 0);
304 static void launch_watchpoints(char *buf, int mode, int len,
305 int local, int global)
307 const char *mode_str;
315 for (i = 0; i < 4; i++) {
316 set_breakpoint_addr(&dummy_var[i], i);
317 toggle_breakpoint(i, mode, len, local, global, 1);
318 ptrace(PTRACE_CONT, child_pid, NULL, 0);
319 sprintf(buf, "Test %s watchpoint %d with len: %d local: "
320 "%d global: %d", mode_str, i, len, local, global);
322 toggle_breakpoint(i, mode, len, local, global, 0);
326 /* Set the breakpoints and check the child successfully trigger them */
327 static void launch_tests(void)
330 int len, local, global, i;
332 /* Instruction breakpoints */
333 for (local = 0; local < 2; local++) {
334 for (global = 0; global < 2; global++) {
335 if (!local && !global)
337 launch_instruction_breakpoints(buf, local, global);
341 /* Write watchpoint */
342 for (len = 1; len <= sizeof(long); len <<= 1) {
343 for (local = 0; local < 2; local++) {
344 for (global = 0; global < 2; global++) {
345 if (!local && !global)
347 launch_watchpoints(buf, BP_W, len,
353 /* Read-Write watchpoint */
354 for (len = 1; len <= sizeof(long); len <<= 1) {
355 for (local = 0; local < 2; local++) {
356 for (global = 0; global < 2; global++) {
357 if (!local && !global)
359 launch_watchpoints(buf, BP_RW, len,
366 ptrace(PTRACE_CONT, child_pid, NULL, 0);
367 check_success("Test icebp");
370 ptrace(PTRACE_CONT, child_pid, NULL, 0);
371 check_success("Test int 3 trap");
373 ptrace(PTRACE_CONT, child_pid, NULL, 0);
376 int main(int argc, char **argv)
395 return ksft_exit_pass();