platform_bionic/libc/bionic/pthread_setname_np.cpp
Elliott Hughes 5bb113cba2 Pass caller names to __pthread_internal_find for better errors.
On http://b/122082295 we had this abort:

  12-27 15:29:31.237 10222 10814 10848 F libc    : invalid pthread_t 0xb1907960 passed to libc

This wasn't super helpful. We can do better. Now you get something like
this instead:

  03-27 02:34:58.754 25329 25329 W libc    : invalid pthread_t (0) passed to pthread_join

Test: adb shell crasher
Bug: http://b/123255692
Change-Id: I1d545665a233308480cc3747ec3120e2b6de0453
2019-02-01 16:31:10 -08:00

104 lines
3.4 KiB
C++

/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <pthread.h>
#include <fcntl.h>
#include <stdio.h> // For snprintf.
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "private/ErrnoRestorer.h"
#include "pthread_internal.h"
// This value is not exported by kernel headers.
#define MAX_TASK_COMM_LEN 16
static int __open_task_comm_fd(pthread_t t, int flags, const char* caller) {
char comm_name[64];
snprintf(comm_name, sizeof(comm_name), "/proc/self/task/%d/comm",
__pthread_internal_gettid(t, caller));
return open(comm_name, O_CLOEXEC | flags);
}
int pthread_getname_np(pthread_t t, char* buf, size_t buf_size) {
ErrnoRestorer errno_restorer;
if (buf_size < MAX_TASK_COMM_LEN) return ERANGE;
// Getting our own name is an easy special case.
if (t == pthread_self()) {
return prctl(PR_GET_NAME, buf) ? errno : 0;
}
// We have to get another thread's name.
int fd = __open_task_comm_fd(t, O_RDONLY, "pthread_getname_np");
if (fd == -1) return errno;
ssize_t n = TEMP_FAILURE_RETRY(read(fd, buf, buf_size));
close(fd);
if (n == -1) return errno;
// The kernel adds a trailing '\n' to the /proc file,
// so this is actually the normal case for short names.
if (n > 0 && buf[n - 1] == '\n') {
buf[n - 1] = '\0';
return 0;
}
if (n == static_cast<ssize_t>(buf_size)) return ERANGE;
buf[n] = '\0';
return 0;
}
int pthread_setname_np(pthread_t t, const char* thread_name) {
ErrnoRestorer errno_restorer;
size_t thread_name_len = strlen(thread_name);
if (thread_name_len >= MAX_TASK_COMM_LEN) return ERANGE;
// Setting our own name is an easy special case.
if (t == pthread_self()) {
return prctl(PR_SET_NAME, thread_name) ? errno : 0;
}
// We have to set another thread's name.
int fd = __open_task_comm_fd(t, O_WRONLY, "pthread_setname_np");
if (fd == -1) return errno;
ssize_t n = TEMP_FAILURE_RETRY(write(fd, thread_name, thread_name_len));
close(fd);
if (n == -1) return errno;
if (n != static_cast<ssize_t>(thread_name_len)) return EIO;
return 0;
}