text: // SPDX-License-Identifier: GPL-2.0
  /*
   * User Events FTrace Test Program
   *
   * Copyright (c) 2021 Beau Belgrave <beaub@linux.microsoft.com>
   */
  
  #include <errno.h>
  #include <linux/user_events.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <fcntl.h>
  #include <sys/ioctl.h>
  #include <sys/stat.h>
  #include <unistd.h>
  
  #include "../kselftest_harness.h"
  
  const char *data_file = "/sys/kernel/debug/tracing/user_events_data";
  const char *status_file = "/sys/kernel/debug/tracing/user_events_status";
  const char *enable_file = "/sys/kernel/debug/tracing/events/user_events/__test_event/enable";
  const char *trace_file = "/sys/kernel/debug/tracing/trace";
  const char *fmt_file = "/sys/kernel/debug/tracing/events/user_events/__test_event/format";
  
  static int trace_bytes(void)
  {
  	int fd = open(trace_file, O_RDONLY);
  	char buf[256];
  	int bytes = 0, got;
  
  	if (fd == -1)
  		return -1;
  
  	while (true) {
  		got = read(fd, buf, sizeof(buf));
  
  		if (got == -1)
  			return -1;
  
  		if (got == 0)
  			break;
  
  		bytes += got;
  	}
  
  	close(fd);
  
  	return bytes;
  }
  
  static int skip_until_empty_line(FILE *fp)
  {
  	int c, last = 0;
  
  	while (true) {
  		c = getc(fp);
  
  		if (c == EOF)
  			break;
  
  		if (last == '\n' && c == '\n')
  			return 0;
  
  		last = c;
  	}
  
  	return -1;
  }
  
  static int get_print_fmt(char *buffer, int len)
  {
  	FILE *fp = fopen(fmt_file, "r");
  	char *newline;
  
  	if (!fp)
  		return -1;
  
  	/* Read until empty line (Skip Common) */
  	if (skip_until_empty_line(fp) < 0)
  		goto err;
  
  	/* Read until empty line (Skip Properties) */
  	if (skip_until_empty_line(fp) < 0)
  		goto err;
  
  	/* Read in print_fmt: */
  	if (fgets(buffer, len, fp) == NULL)
  		goto err;
  
  	newline = strchr(buffer, '\n');
  
  	if (newline)
  		*newline = '\0';
  
  	fclose(fp);
  
  	return 0;
  err:
  	fclose(fp);
  
  	return -1;
  }
  
  static int clear(void)
  {
  	int fd = open(data_file, O_RDWR);
  
  	if (fd == -1)
  		return -1;
  
  	if (ioctl(fd, DIAG_IOCSDEL, "__test_event") == -1)
  		if (errno != ENOENT)
  			return -1;
  
  	close(fd);
  
  	return 0;
  }
  
  static int check_print_fmt(const char *event, const char *expected)
  {
  	struct user_reg reg = {0};
  	char print_fmt[256];
  	int ret;
  	int fd;
  
  	/* Ensure cleared */
  	ret = clear();
  
  	if (ret != 0)
  		return ret;
  
  	fd = open(data_file, O_RDWR);
  
  	if (fd == -1)
  		return fd;
  
  	reg.size = sizeof(reg);
  	reg.name_args = (__u64)event;
  
  	/* Register should work */
  	ret = ioctl(fd, DIAG_IOCSREG, &reg);
  
  	close(fd);
  
  	if (ret != 0)
  		return ret;
  
  	/* Ensure correct print_fmt */
  	ret = get_print_fmt(print_fmt, sizeof(print_fmt));
  
  	if (ret != 0)
  		return ret;
  
  	return strcmp(print_fmt, expected);
  }
  
  FIXTURE(user) {
  	int status_fd;
  	int data_fd;
  	int enable_fd;
  };
  
  FIXTURE_SETUP(user) {
  	self->status_fd = open(status_file, O_RDONLY);
  	ASSERT_NE(-1, self->status_fd);
  
  	self->data_fd = open(data_file, O_RDWR);
  	ASSERT_NE(-1, self->data_fd);
  
  	self->enable_fd = -1;
  }
  
  FIXTURE_TEARDOWN(user) {
  	close(self->status_fd);
  	close(self->data_fd);
  
  	if (self->enable_fd != -1) {
  		write(self->enable_fd, "0", sizeof("0"));
  		close(self->enable_fd);
  	}
  
  	ASSERT_EQ(0, clear());
  }
  
  TEST_F(user, register_events) {
  	struct user_reg reg = {0};
  	int page_size = sysconf(_SC_PAGESIZE);
  	char *status_page;
  
  	reg.size = sizeof(reg);
  	reg.name_args = (__u64)"__test_event u32 field1; u32 field2";
  
  	status_page = mmap(NULL, page_size, PROT_READ, MAP_SHARED,
  			   self->status_fd, 0);
  
  	/* Register should work */
  	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
  	ASSERT_EQ(0, reg.write_index);
  	ASSERT_NE(0, reg.status_index);
  
  	/* Multiple registers should result in same index */
  	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
  	ASSERT_EQ(0, reg.write_index);
  	ASSERT_NE(0, reg.status_index);
  
  	/* Ensure disabled */
  	self->enable_fd = open(enable_file, O_RDWR);
  	ASSERT_NE(-1, self->enable_fd);
  	ASSERT_NE(-1, write(self->enable_fd, "0", sizeof("0")))
  
  	/* MMAP should work and be zero'd */
  	ASSERT_NE(MAP_FAILED, status_page);
  	ASSERT_NE(NULL, status_page);
  	ASSERT_EQ(0, status_page[reg.status_index]);
  
  	/* Enable event and ensure bits updated in status */
  	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
  	ASSERT_EQ(EVENT_STATUS_FTRACE, status_page[reg.status_index]);
  
  	/* Disable event and ensure bits updated in status */
  	ASSERT_NE(-1, write(self->enable_fd, "0", sizeof("0")))
  	ASSERT_EQ(0, status_page[reg.status_index]);
  
  	/* File still open should return -EBUSY for delete */
  	ASSERT_EQ(-1, ioctl(self->data_fd, DIAG_IOCSDEL, "__test_event"));
  	ASSERT_EQ(EBUSY, errno);
  
  	/* Delete should work only after close */
  	close(self->data_fd);
  	self->data_fd = open(data_file, O_RDWR);
  	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSDEL, "__test_event"));
  
  	/* Unmap should work */
  	ASSERT_EQ(0, munmap(status_page, page_size));
  }
  
  TEST_F(user, write_events) {
  	struct user_reg reg = {0};
  	struct iovec io[3];
  	__u32 field1, field2;
  	int before = 0, after = 0;
  
  	reg.size = sizeof(reg);
  	reg.name_args = (__u64)"__test_event u32 field1; u32 field2";
  
  	field1 = 1;
  	field2 = 2;
  
  	io[0].iov_base = &reg.write_index;
  	io[0].iov_len = sizeof(reg.write_index);
  	io[1].iov_base = &field1;
  	io[1].iov_len = sizeof(field1);
  	io[2].iov_base = &field2;
  	io[2].iov_len = sizeof(field2);
  
  	/* Register should work */
  	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
  	ASSERT_EQ(0, reg.write_index);
  	ASSERT_NE(0, reg.status_index);
  
  	/* Write should fail on invalid slot with ENOENT */
  	io[0].iov_base = &field2;
  	io[0].iov_len = sizeof(field2);
  	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	ASSERT_EQ(ENOENT, errno);
  	io[0].iov_base = &reg.write_index;
  	io[0].iov_len = sizeof(reg.write_index);
  
  	/* Enable event */
  	self->enable_fd = open(enable_file, O_RDWR);
  	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
  
  	/* Write should make it out to ftrace buffers */
  	before = trace_bytes();
  	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	after = trace_bytes();
  	ASSERT_GT(after, before);
  }
  
  TEST_F(user, write_fault) {
  	struct user_reg reg = {0};
  	struct iovec io[2];
  	int l = sizeof(__u64);
  	void *anon;
  
  	reg.size = sizeof(reg);
  	reg.name_args = (__u64)"__test_event u64 anon";
  
  	anon = mmap(NULL, l, PROT_READ, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
  	ASSERT_NE(MAP_FAILED, anon);
  
  	io[0].iov_base = &reg.write_index;
  	io[0].iov_len = sizeof(reg.write_index);
  	io[1].iov_base = anon;
  	io[1].iov_len = l;
  
  	/* Register should work */
  	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
  	ASSERT_EQ(0, reg.write_index);
  	ASSERT_NE(0, reg.status_index);
  
  	/* Write should work normally */
  	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 2));
  
  	/* Faulted data should zero fill and work */
  	ASSERT_EQ(0, madvise(anon, l, MADV_DONTNEED));
  	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 2));
  	ASSERT_EQ(0, munmap(anon, l));
  }
  
  TEST_F(user, write_validator) {
  	struct user_reg reg = {0};
  	struct iovec io[3];
  	int loc, bytes;
  	char data[8];
  	int before = 0, after = 0;
  
  	reg.size = sizeof(reg);
  	reg.name_args = (__u64)"__test_event __rel_loc char[] data";
  
  	/* Register should work */
  	ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, &reg));
  	ASSERT_EQ(0, reg.write_index);
  	ASSERT_NE(0, reg.status_index);
  
  	io[0].iov_base = &reg.write_index;
  	io[0].iov_len = sizeof(reg.write_index);
  	io[1].iov_base = &loc;
  	io[1].iov_len = sizeof(loc);
  	io[2].iov_base = data;
  	bytes = snprintf(data, sizeof(data), "Test") + 1;
  	io[2].iov_len = bytes;
  
  	/* Undersized write should fail */
  	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 1));
  	ASSERT_EQ(EINVAL, errno);
  
  	/* Enable event */
  	self->enable_fd = open(enable_file, O_RDWR);
  	ASSERT_NE(-1, write(self->enable_fd, "1", sizeof("1")))
  
  	/* Full in-bounds write should work */
  	before = trace_bytes();
  	loc = DYN_LOC(0, bytes);
  	ASSERT_NE(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	after = trace_bytes();
  	ASSERT_GT(after, before);
  
  	/* Out of bounds write should fault (offset way out) */
  	loc = DYN_LOC(1024, bytes);
  	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	ASSERT_EQ(EFAULT, errno);
  
  	/* Out of bounds write should fault (offset 1 byte out) */
  	loc = DYN_LOC(1, bytes);
  	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	ASSERT_EQ(EFAULT, errno);
  
  	/* Out of bounds write should fault (size way out) */
  	loc = DYN_LOC(0, bytes + 1024);
  	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	ASSERT_EQ(EFAULT, errno);
  
  	/* Out of bounds write should fault (size 1 byte out) */
  	loc = DYN_LOC(0, bytes + 1);
  	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	ASSERT_EQ(EFAULT, errno);
  
  	/* Non-Null should fault */
  	memset(data, 'A', sizeof(data));
  	loc = DYN_LOC(0, bytes);
  	ASSERT_EQ(-1, writev(self->data_fd, (const struct iovec *)io, 3));
  	ASSERT_EQ(EFAULT, errno);
  }
  
  TEST_F(user, print_fmt) {
  	int ret;
  
  	ret = check_print_fmt("__test_event __rel_loc char[] data",
  			      "print fmt: \"data=%s\", __get_rel_str(data)");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event __data_loc char[] data",
  			      "print fmt: \"data=%s\", __get_str(data)");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event s64 data",
  			      "print fmt: \"data=%lld\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event u64 data",
  			      "print fmt: \"data=%llu\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event s32 data",
  			      "print fmt: \"data=%d\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event u32 data",
  			      "print fmt: \"data=%u\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event int data",
  			      "print fmt: \"data=%d\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event unsigned int data",
  			      "print fmt: \"data=%u\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event s16 data",
  			      "print fmt: \"data=%d\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event u16 data",
  			      "print fmt: \"data=%u\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event short data",
  			      "print fmt: \"data=%d\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event unsigned short data",
  			      "print fmt: \"data=%u\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event s8 data",
  			      "print fmt: \"data=%d\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event u8 data",
  			      "print fmt: \"data=%u\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event char data",
  			      "print fmt: \"data=%d\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event unsigned char data",
  			      "print fmt: \"data=%u\", REC->data");
  	ASSERT_EQ(0, ret);
  
  	ret = check_print_fmt("__test_event char[4] data",
  			      "print fmt: \"data=%s\", REC->data");
  	ASSERT_EQ(0, ret);
  }
  
  int main(int argc, char **argv)
  {
  	return test_harness_run(argc, argv);
  }
  