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// SPDX-License-Identifier: GPL-2.0
#include <linux/compiler.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/user.h>
#include <syscall.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ptrace.h>
#include <asm/ptrace.h>
#include <errno.h>
#include "debug.h"
#include "tests/tests.h"
#include "arch-tests.h"
static noinline int bp_1(void)
{
pr_debug("in %s\n", __func__);
return 0;
}
static noinline int bp_2(void)
{
pr_debug("in %s\n", __func__);
return 0;
}
static int spawn_child(void)
{
int child = fork();
if (child == 0) {
/*
* The child sets itself for as tracee and
* waits in signal for parent to trace it,
* then it calls bp_1 and quits.
*/
int err = ptrace(PTRACE_TRACEME, 0, NULL, NULL);
if (err) {
pr_debug("failed to PTRACE_TRACEME\n");
exit(1);
}
raise(SIGCONT);
bp_1();
exit(0);
}
return child;
}
/*
* This tests creates HW breakpoint, tries to
* change it and checks it was properly changed.
*/
static int bp_modify1(void)
{
pid_t child;
int status;
unsigned long rip = 0, dr7 = 1;
child = spawn_child();
waitpid(child, &status, 0);
if (WIFEXITED(status)) {
pr_debug("tracee exited prematurely 1\n");
return TEST_FAIL;
}
/*
* The parent does following steps:
* - creates a new breakpoint (id 0) for bp_2 function
* - changes that breakponit to bp_1 function
* - waits for the breakpoint to hit and checks
* it has proper rip of bp_1 function
* - detaches the child
*/
if (ptrace(PTRACE_POKEUSER, child,
offsetof(struct user, u_debugreg[0]), bp_2)) {
pr_debug("failed to set breakpoint, 1st time: %s\n",
strerror(errno));
goto out;
}
if (ptrace(PTRACE_POKEUSER, child,
offsetof(struct user, u_debugreg[0]), bp_1)) {
pr_debug("failed to set breakpoint, 2nd time: %s\n",
strerror(errno));
goto out;
}
if (ptrace(PTRACE_POKEUSER, child,
offsetof(struct user, u_debugreg[7]), dr7)) {
pr_debug("failed to set dr7: %s\n", strerror(errno));
goto out;
}
if (ptrace(PTRACE_CONT, child, NULL, NULL)) {
pr_debug("failed to PTRACE_CONT: %s\n", strerror(errno));
goto out;
}
waitpid(child, &status, 0);
if (WIFEXITED(status)) {
pr_debug("tracee exited prematurely 2\n");
return TEST_FAIL;
}
rip = ptrace(PTRACE_PEEKUSER, child,
offsetof(struct user_regs_struct, rip), NULL);
if (rip == (unsigned long) -1) {
pr_debug("failed to PTRACE_PEEKUSER: %s\n",
strerror(errno));
goto out;
}
pr_debug("rip %lx, bp_1 %p\n", rip, bp_1);
out:
if (ptrace(PTRACE_DETACH, child, NULL, NULL)) {
pr_debug("failed to PTRACE_DETACH: %s", strerror(errno));
return TEST_FAIL;
}
return rip == (unsigned long) bp_1 ? TEST_OK : TEST_FAIL;
}
/*
* This tests creates HW breakpoint, tries to
* change it to bogus value and checks the original
* breakpoint is hit.
*/
static int bp_modify2(void)
{
pid_t child;
int status;
unsigned long rip = 0, dr7 = 1;
child = spawn_child();
waitpid(child, &status, 0);
if (WIFEXITED(status)) {
pr_debug("tracee exited prematurely 1\n");
return TEST_FAIL;
}
/*
* The parent does following steps:
* - creates a new breakpoint (id 0) for bp_1 function
* - tries to change that breakpoint to (-1) address
* - waits for the breakpoint to hit and checks
* it has proper rip of bp_1 function
* - detaches the child
*/
if (ptrace(PTRACE_POKEUSER, child,
offsetof(struct user, u_debugreg[0]), bp_1)) {
pr_debug("failed to set breakpoint: %s\n",
strerror(errno));
goto out;
}
if (ptrace(PTRACE_POKEUSER, child,
offsetof(struct user, u_debugreg[7]), dr7)) {
pr_debug("failed to set dr7: %s\n", strerror(errno));
goto out;
}
if (!ptrace(PTRACE_POKEUSER, child,
offsetof(struct user, u_debugreg[0]), (unsigned long) (-1))) {
pr_debug("failed, breakpoint set to bogus address\n");
goto out;
}
if (ptrace(PTRACE_CONT, child, NULL, NULL)) {
pr_debug("failed to PTRACE_CONT: %s\n", strerror(errno));
goto out;
}
waitpid(child, &status, 0);
if (WIFEXITED(status)) {
pr_debug("tracee exited prematurely 2\n");
return TEST_FAIL;
}
rip = ptrace(PTRACE_PEEKUSER, child,
offsetof(struct user_regs_struct, rip), NULL);
if (rip == (unsigned long) -1) {
pr_debug("failed to PTRACE_PEEKUSER: %s\n",
strerror(errno));
goto out;
}
pr_debug("rip %lx, bp_1 %p\n", rip, bp_1);
out:
if (ptrace(PTRACE_DETACH, child, NULL, NULL)) {
pr_debug("failed to PTRACE_DETACH: %s", strerror(errno));
return TEST_FAIL;
}
return rip == (unsigned long) bp_1 ? TEST_OK : TEST_FAIL;
}
int test__bp_modify(struct test *test __maybe_unused,
int subtest __maybe_unused)
{
TEST_ASSERT_VAL("modify test 1 failed\n", !bp_modify1());
TEST_ASSERT_VAL("modify test 2 failed\n", !bp_modify2());
return 0;
}
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