diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index 2a18bd320e92..b0132a342bb5 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "bpf_testmod.h" #include "bpf_testmod_kfunc.h" @@ -358,6 +359,119 @@ static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = { .write = bpf_testmod_test_write, }; +/* bpf_testmod_uprobe sysfs attribute is so far enabled for x86_64 only, + * please see test_uretprobe_regs_change test + */ +#ifdef __x86_64__ + +static int +uprobe_ret_handler(struct uprobe_consumer *self, unsigned long func, + struct pt_regs *regs) + +{ + regs->ax = 0x12345678deadbeef; + regs->cx = 0x87654321feebdaed; + regs->r11 = (u64) -1; + return true; +} + +struct testmod_uprobe { + struct path path; + loff_t offset; + struct uprobe_consumer consumer; +}; + +static DEFINE_MUTEX(testmod_uprobe_mutex); + +static struct testmod_uprobe uprobe = { + .consumer.ret_handler = uprobe_ret_handler, +}; + +static int testmod_register_uprobe(loff_t offset) +{ + int err = -EBUSY; + + if (uprobe.offset) + return -EBUSY; + + mutex_lock(&testmod_uprobe_mutex); + + if (uprobe.offset) + goto out; + + err = kern_path("/proc/self/exe", LOOKUP_FOLLOW, &uprobe.path); + if (err) + goto out; + + err = uprobe_register_refctr(d_real_inode(uprobe.path.dentry), + offset, 0, &uprobe.consumer); + if (err) + path_put(&uprobe.path); + else + uprobe.offset = offset; + +out: + mutex_unlock(&testmod_uprobe_mutex); + return err; +} + +static void testmod_unregister_uprobe(void) +{ + mutex_lock(&testmod_uprobe_mutex); + + if (uprobe.offset) { + uprobe_unregister(d_real_inode(uprobe.path.dentry), + uprobe.offset, &uprobe.consumer); + uprobe.offset = 0; + } + + mutex_unlock(&testmod_uprobe_mutex); +} + +static ssize_t +bpf_testmod_uprobe_write(struct file *file, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t len) +{ + unsigned long offset = 0; + int err = 0; + + if (kstrtoul(buf, 0, &offset)) + return -EINVAL; + + if (offset) + err = testmod_register_uprobe(offset); + else + testmod_unregister_uprobe(); + + return err ?: strlen(buf); +} + +static struct bin_attribute bin_attr_bpf_testmod_uprobe_file __ro_after_init = { + .attr = { .name = "bpf_testmod_uprobe", .mode = 0666, }, + .write = bpf_testmod_uprobe_write, +}; + +static int register_bpf_testmod_uprobe(void) +{ + return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_uprobe_file); +} + +static void unregister_bpf_testmod_uprobe(void) +{ + testmod_unregister_uprobe(); + sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_uprobe_file); +} + +#else +static int register_bpf_testmod_uprobe(void) +{ + return 0; +} + +static void unregister_bpf_testmod_uprobe(void) { } +#endif + BTF_KFUNCS_START(bpf_testmod_common_kfunc_ids) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_new, KF_ITER_NEW) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_next, KF_ITER_NEXT | KF_RET_NULL) @@ -912,7 +1026,13 @@ static int bpf_testmod_init(void) return -EINVAL; sock = NULL; mutex_init(&sock_lock); - return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + ret = sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + if (ret < 0) + return ret; + ret = register_bpf_testmod_uprobe(); + if (ret < 0) + return ret; + return 0; } static void bpf_testmod_exit(void) @@ -927,6 +1047,7 @@ static void bpf_testmod_exit(void) bpf_kfunc_close_sock(); sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + unregister_bpf_testmod_uprobe(); } module_init(bpf_testmod_init); diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c index 311ac19d8992..1a50cd35205d 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c @@ -149,15 +149,82 @@ static void test_uretprobe_regs_equal(void) cleanup: uprobe_syscall__destroy(skel); } + +#define BPF_TESTMOD_UPROBE_TEST_FILE "/sys/kernel/bpf_testmod_uprobe" + +static int write_bpf_testmod_uprobe(unsigned long offset) +{ + size_t n, ret; + char buf[30]; + int fd; + + n = sprintf(buf, "%lu", offset); + + fd = open(BPF_TESTMOD_UPROBE_TEST_FILE, O_WRONLY); + if (fd < 0) + return -errno; + + ret = write(fd, buf, n); + close(fd); + return ret != n ? (int) ret : 0; +} + +static void test_uretprobe_regs_change(void) +{ + struct pt_regs before = {}, after = {}; + unsigned long *pb = (unsigned long *) &before; + unsigned long *pa = (unsigned long *) &after; + unsigned long cnt = sizeof(before)/sizeof(*pb); + unsigned int i, err, offset; + + offset = get_uprobe_offset(uretprobe_regs_trigger); + + err = write_bpf_testmod_uprobe(offset); + if (!ASSERT_OK(err, "register_uprobe")) + return; + + uretprobe_regs(&before, &after); + + err = write_bpf_testmod_uprobe(0); + if (!ASSERT_OK(err, "unregister_uprobe")) + return; + + for (i = 0; i < cnt; i++) { + unsigned int offset = i * sizeof(unsigned long); + + switch (offset) { + case offsetof(struct pt_regs, rax): + ASSERT_EQ(pa[i], 0x12345678deadbeef, "rax"); + break; + case offsetof(struct pt_regs, rcx): + ASSERT_EQ(pa[i], 0x87654321feebdaed, "rcx"); + break; + case offsetof(struct pt_regs, r11): + ASSERT_EQ(pa[i], (__u64) -1, "r11"); + break; + default: + if (!ASSERT_EQ(pa[i], pb[i], "register before-after value check")) + fprintf(stdout, "failed register offset %u\n", offset); + } + } +} + #else static void test_uretprobe_regs_equal(void) { test__skip(); } + +static void test_uretprobe_regs_change(void) +{ + test__skip(); +} #endif void test_uprobe_syscall(void) { if (test__start_subtest("uretprobe_regs_equal")) test_uretprobe_regs_equal(); + if (test__start_subtest("uretprobe_regs_change")) + test_uretprobe_regs_change(); }