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-rw-r--r--tools/perf/arch/x86/tests/bp-modify.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/tools/perf/arch/x86/tests/bp-modify.c b/tools/perf/arch/x86/tests/bp-modify.c
new file mode 100644
index 000000000000..f53e4406709f
--- /dev/null
+++ b/tools/perf/arch/x86/tests/bp-modify.c
@@ -0,0 +1,213 @@
+// 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;
+}