/*
* Copyright (C) 2010 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 "../private/libc_logging.h" // Relative path so we can #include this .cpp file for testing.
#include "../private/ScopedPthreadMutexLocker.h"
#include <android/set_abort_message.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <time.h>
#include <unistd.h>
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h>
static pthread_mutex_t g_abort_msg_lock = PTHREAD_MUTEX_INITIALIZER;
__LIBC_HIDDEN__ abort_msg_t** __abort_message_ptr; // Accessible to __libc_init_common.
// Must be kept in sync with frameworks/base/core/java/android/util/EventLog.java.
enum AndroidEventLogType {
EVENT_TYPE_INT = 0,
EVENT_TYPE_LONG = 1,
EVENT_TYPE_STRING = 2,
EVENT_TYPE_LIST = 3,
EVENT_TYPE_FLOAT = 4,
};
struct BufferOutputStream {
public:
BufferOutputStream(char* buffer, size_t size) : total(0) {
buffer_ = buffer;
end_ = buffer + size - 1;
pos_ = buffer_;
pos_[0] = '\0';
}
~BufferOutputStream() {
}
void Send(const char* data, int len) {
if (len < 0) {
len = strlen(data);
}
total += len;
while (len > 0) {
int avail = end_ - pos_;
if (avail == 0) {
return;
}
if (avail > len) {
avail = len;
}
memcpy(pos_, data, avail);
pos_ += avail;
pos_[0] = '\0';
len -= avail;
}
}
size_t total;
private:
char* buffer_;
char* pos_;
char* end_;
};
struct FdOutputStream {
public:
FdOutputStream(int fd) : total(0), fd_(fd) {
}
void Send(const char* data, int len) {
if (len < 0) {
len = strlen(data);
}
total += len;
while (len > 0) {
int rc = TEMP_FAILURE_RETRY(write(fd_, data, len));
if (rc == -1) {
return;
}
data += rc;
len -= rc;
}
}
size_t total;
private:
int fd_;
};
/*** formatted output implementation
***/
/* Parse a decimal string from 'format + *ppos',
* return the value, and writes the new position past
* the decimal string in '*ppos' on exit.
*
* NOTE: Does *not* handle a sign prefix.
*/
static unsigned parse_decimal(const char *format, int *ppos) {
const char* p = format + *ppos;
unsigned result = 0;
for (;;) {
int ch = *p;
unsigned d = static_cast<unsigned>(ch - '0');
if (d >= 10U) {
break;
}
result = result*10 + d;
p++;
}
*ppos = p - format;
return result;
}
// Writes number 'value' in base 'base' into buffer 'buf' of size 'buf_size' bytes.
// Assumes that buf_size > 0.
static void format_unsigned(char* buf, size_t buf_size, uint64_t value, int base, bool caps) {
char* p = buf;
char* end = buf + buf_size - 1;
// Generate digit string in reverse order.
while (value) {
unsigned d = value % base;
value /= base;
if (p != end) {
char ch;
if (d < 10) {
ch = '0' + d;
} else {
ch = (caps ? 'A' : 'a') + (d - 10);
}
*p++ = ch;
}
}
// Special case for 0.
if (p == buf) {
if (p != end) {
*p++ = '0';
}
}
*p = '\0';
// Reverse digit string in-place.
size_t length = p - buf;
for (size_t i = 0, j = length - 1; i < j; ++i, --j) {
char ch = buf[i];
buf[i] = buf[j];
buf[j] = ch;
}
}
static void format_integer(char* buf, size_t buf_size, uint64_t value, char conversion) {
// Decode the conversion specifier.
int is_signed = (conversion == 'd' || conversion == 'i' || conversion == 'o');
int base = 10;
if (conversion == 'x' || conversion == 'X') {
base = 16;
} else if (conversion == 'o') {
base = 8;
}
bool caps = (conversion == 'X');
if (is_signed && static_cast<int64_t>(value) < 0) {
buf[0] = '-';
buf += 1;
buf_size -= 1;
value = static_cast<uint64_t>(-static_cast<int64_t>(value));
}
format_unsigned(buf, buf_size, value, base, caps);
}
template <typename Out>
static void SendRepeat(Out& o, char ch, int count) {
char pad[8];
memset(pad, ch, sizeof(pad));
const int pad_size = static_cast<int>(sizeof(pad));
while (count > 0) {
int avail = count;
if (avail > pad_size) {
avail = pad_size;
}
o.Send(pad, avail);
count -= avail;
}
}
/* Perform formatted output to an output target 'o' */
template <typename Out>
static void out_vformat(Out& o, const char* format, va_list args) {
int nn = 0;
for (;;) {
int mm;
int padZero = 0;
int padLeft = 0;
char sign = '\0';
int width = -1;
int prec = -1;
size_t bytelen = sizeof(int);
int slen;
char buffer[32]; /* temporary buffer used to format numbers */
char c;
/* first, find all characters that are not 0 or '%' */
/* then send them to the output directly */
mm = nn;
do {
c = format[mm];
if (c == '\0' || c == '%')
break;
mm++;
} while (1);
if (mm > nn) {
o.Send(format+nn, mm-nn);
nn = mm;
}
/* is this it ? then exit */
if (c == '\0')
break;
/* nope, we are at a '%' modifier */
nn++; // skip it
/* parse flags */
for (;;) {
c = format[nn++];
if (c == '\0') { /* single trailing '%' ? */
c = '%';
o.Send(&c, 1);
return;
}
else if (c == '0') {
padZero = 1;
continue;
}
else if (c == '-') {
padLeft = 1;
continue;
}
else if (c == ' ' || c == '+') {
sign = c;
continue;
}
break;
}
/* parse field width */
if ((c >= '0' && c <= '9')) {
nn --;
width = static_cast<int>(parse_decimal(format, &nn));
c = format[nn++];
}
/* parse precision */
if (c == '.') {
prec = static_cast<int>(parse_decimal(format, &nn));
c = format[nn++];
}
/* length modifier */
switch (c) {
case 'h':
bytelen = sizeof(short);
if (format[nn] == 'h') {
bytelen = sizeof(char);
nn += 1;
}
c = format[nn++];
break;
case 'l':
bytelen = sizeof(long);
if (format[nn] == 'l') {
bytelen = sizeof(long long);
nn += 1;
}
c = format[nn++];
break;
case 'z':
bytelen = sizeof(size_t);
c = format[nn++];
break;
case 't':
bytelen = sizeof(ptrdiff_t);
c = format[nn++];
break;
default:
;
}
/* conversion specifier */
const char* str = buffer;
if (c == 's') {
/* string */
str = va_arg(args, const char*);
if (str == NULL) {
str = "(null)";
}
} else if (c == 'c') {
/* character */
/* NOTE: char is promoted to int when passed through the stack */
buffer[0] = static_cast<char>(va_arg(args, int));
buffer[1] = '\0';
} else if (c == 'p') {
uint64_t value = reinterpret_cast<uintptr_t>(va_arg(args, void*));
buffer[0] = '0';
buffer[1] = 'x';
format_integer(buffer + 2, sizeof(buffer) - 2, value, 'x');
} else if (c == 'd' || c == 'i' || c == 'o' || c == 'u' || c == 'x' || c == 'X') {
/* integers - first read value from stack */
uint64_t value;
int is_signed = (c == 'd' || c == 'i' || c == 'o');
/* NOTE: int8_t and int16_t are promoted to int when passed
* through the stack
*/
switch (bytelen) {
case 1: value = static_cast<uint8_t>(va_arg(args, int)); break;
case 2: value = static_cast<uint16_t>(va_arg(args, int)); break;
case 4: value = va_arg(args, uint32_t); break;
case 8: value = va_arg(args, uint64_t); break;
default: return; /* should not happen */
}
/* sign extension, if needed */
if (is_signed) {
int shift = 64 - 8*bytelen;
value = static_cast<uint64_t>((static_cast<int64_t>(value << shift)) >> shift);
}
/* format the number properly into our buffer */
format_integer(buffer, sizeof(buffer), value, c);
} else if (c == '%') {
buffer[0] = '%';
buffer[1] = '\0';
} else {
__assert(__FILE__, __LINE__, "conversion specifier unsupported");
}
/* if we are here, 'str' points to the content that must be
* outputted. handle padding and alignment now */
slen = strlen(str);
if (sign != '\0' || prec != -1) {
__assert(__FILE__, __LINE__, "sign/precision unsupported");
}
if (slen < width && !padLeft) {
char padChar = padZero ? '0' : ' ';
SendRepeat(o, padChar, width - slen);
}
o.Send(str, slen);
if (slen < width && padLeft) {
char padChar = padZero ? '0' : ' ';
SendRepeat(o, padChar, width - slen);
}
}
}
int __libc_format_buffer(char* buffer, size_t buffer_size, const char* format, ...) {
BufferOutputStream os(buffer, buffer_size);
va_list args;
va_start(args, format);
out_vformat(os, format, args);
va_end(args);
return os.total;
}
int __libc_format_fd(int fd, const char* format, ...) {
FdOutputStream os(fd);
va_list args;
va_start(args, format);
out_vformat(os, format, args);
va_end(args);
return os.total;
}
static int __libc_write_stderr(const char* tag, const char* msg) {
int fd = TEMP_FAILURE_RETRY(open("/dev/stderr", O_CLOEXEC | O_WRONLY | O_APPEND));
if (fd == -1) {
return -1;
}
iovec vec[4];
vec[0].iov_base = const_cast<char*>(tag);
vec[0].iov_len = strlen(tag);
vec[1].iov_base = const_cast<char*>(": ");
vec[1].iov_len = 2;
vec[2].iov_base = const_cast<char*>(msg);
vec[2].iov_len = strlen(msg);
vec[3].iov_base = const_cast<char*>("\n");
vec[3].iov_len = 1;
int result = TEMP_FAILURE_RETRY(writev(fd, vec, 4));
close(fd);
return result;
}
static int __libc_open_log_socket() {
// ToDo: Ideally we want this to fail if the gid of the current
// process is AID_LOGD, but will have to wait until we have
// registered this in private/android_filesystem_config.h. We have
// found that all logd crashes thus far have had no problem stuffing
// the UNIX domain socket and moving on so not critical *today*.
int log_fd = TEMP_FAILURE_RETRY(socket(PF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC, 0));
if (log_fd < 0) {
return -1;
}
if (fcntl(log_fd, F_SETFL, O_NONBLOCK) == -1) {
close(log_fd);
return -1;
}
union {
struct sockaddr addr;
struct sockaddr_un addrUn;
} u;
memset(&u, 0, sizeof(u));
u.addrUn.sun_family = AF_UNIX;
strlcpy(u.addrUn.sun_path, "/dev/socket/logdw", sizeof(u.addrUn.sun_path));
if (TEMP_FAILURE_RETRY(connect(log_fd, &u.addr, sizeof(u.addrUn))) != 0) {
close(log_fd);
return -1;
}
return log_fd;
}
struct cache {
const prop_info* pinfo;
uint32_t serial;
char c;
};
static void refresh_cache(struct cache *cache, const char *key)
{
if (!cache->pinfo) {
cache->pinfo = __system_property_find(key);
if (!cache->pinfo) {
return;
}
}
uint32_t serial = __system_property_serial(cache->pinfo);
if (serial == cache->serial) {
return;
}
cache->serial = serial;
char buf[PROP_VALUE_MAX];
__system_property_read(cache->pinfo, 0, buf);
cache->c = buf[0];
}
// Timestamp state generally remains constant, since a change is
// rare, we can accept a trylock failure gracefully.
static pthread_mutex_t lock_clockid = PTHREAD_MUTEX_INITIALIZER;
static clockid_t __android_log_clockid()
{
static struct cache r_time_cache = { NULL, static_cast<uint32_t>(-1), 0 };
static struct cache p_time_cache = { NULL, static_cast<uint32_t>(-1), 0 };
char c;
if (pthread_mutex_trylock(&lock_clockid)) {
// We are willing to accept some race in this context
if (!(c = p_time_cache.c)) {
c = r_time_cache.c;
}
} else {
static uint32_t serial;
uint32_t current_serial = __system_property_area_serial();
if (current_serial != serial) {
refresh_cache(&r_time_cache, "ro.logd.timestamp");
refresh_cache(&p_time_cache, "persist.logd.timestamp");
serial = current_serial;
}
if (!(c = p_time_cache.c)) {
c = r_time_cache.c;
}
pthread_mutex_unlock(&lock_clockid);
}
return (tolower(c) == 'm') ? CLOCK_MONOTONIC : CLOCK_REALTIME;
}
struct log_time { // Wire format
uint32_t tv_sec;
uint32_t tv_nsec;
};
int __libc_write_log(int priority, const char* tag, const char* msg) {
int main_log_fd = __libc_open_log_socket();
if (main_log_fd == -1) {
// Try stderr instead.
return __libc_write_stderr(tag, msg);
}
iovec vec[6];
char log_id = (priority == ANDROID_LOG_FATAL) ? LOG_ID_CRASH : LOG_ID_MAIN;
vec[0].iov_base = &log_id;
vec[0].iov_len = sizeof(log_id);
uint16_t tid = gettid();
vec[1].iov_base = &tid;
vec[1].iov_len = sizeof(tid);
timespec ts;
clock_gettime(__android_log_clockid(), &ts);
log_time realtime_ts;
realtime_ts.tv_sec = ts.tv_sec;
realtime_ts.tv_nsec = ts.tv_nsec;
vec[2].iov_base = &realtime_ts;
vec[2].iov_len = sizeof(realtime_ts);
vec[3].iov_base = &priority;
vec[3].iov_len = 1;
vec[4].iov_base = const_cast<char*>(tag);
vec[4].iov_len = strlen(tag) + 1;
vec[5].iov_base = const_cast<char*>(msg);
vec[5].iov_len = strlen(msg) + 1;
int result = TEMP_FAILURE_RETRY(writev(main_log_fd, vec, sizeof(vec) / sizeof(vec[0])));
close(main_log_fd);
return result;
}
int __libc_format_log_va_list(int priority, const char* tag, const char* format, va_list args) {
char buffer[1024];
BufferOutputStream os(buffer, sizeof(buffer));
out_vformat(os, format, args);
return __libc_write_log(priority, tag, buffer);
}
int __libc_format_log(int priority, const char* tag, const char* format, ...) {
va_list args;
va_start(args, format);
int result = __libc_format_log_va_list(priority, tag, format, args);
va_end(args);
return result;
}
static int __libc_android_log_event(int32_t tag, char type, const void* payload, size_t len) {
iovec vec[6];
char log_id = LOG_ID_EVENTS;
vec[0].iov_base = &log_id;
vec[0].iov_len = sizeof(log_id);
uint16_t tid = gettid();
vec[1].iov_base = &tid;
vec[1].iov_len = sizeof(tid);
timespec ts;
clock_gettime(__android_log_clockid(), &ts);
log_time realtime_ts;
realtime_ts.tv_sec = ts.tv_sec;
realtime_ts.tv_nsec = ts.tv_nsec;
vec[2].iov_base = &realtime_ts;
vec[2].iov_len = sizeof(realtime_ts);
vec[3].iov_base = &tag;
vec[3].iov_len = sizeof(tag);
vec[4].iov_base = &type;
vec[4].iov_len = sizeof(type);
vec[5].iov_base = const_cast<void*>(payload);
vec[5].iov_len = len;
int event_log_fd = __libc_open_log_socket();
if (event_log_fd == -1) {
return -1;
}
int result = TEMP_FAILURE_RETRY(writev(event_log_fd, vec, sizeof(vec) / sizeof(vec[0])));
close(event_log_fd);
return result;
}
void __libc_android_log_event_int(int32_t tag, int value) {
__libc_android_log_event(tag, EVENT_TYPE_INT, &value, sizeof(value));
}
void __libc_android_log_event_uid(int32_t tag) {
__libc_android_log_event_int(tag, getuid());
}
void __fortify_chk_fail(const char* msg, uint32_t tag) {
if (tag != 0) {
__libc_android_log_event_uid(tag);
}
__libc_fatal("FORTIFY: %s", msg);
}
static void __libc_fatal(const char* format, va_list args) {
char msg[1024];
BufferOutputStream os(msg, sizeof(msg));
out_vformat(os, format, args);
// Log to stderr for the benefit of "adb shell" users.
struct iovec iov[2] = {
{ msg, os.total },
{ const_cast<char*>("\n"), 1 },
};
TEMP_FAILURE_RETRY(writev(2, iov, 2));
// Log to the log for the benefit of regular app developers (whose stdout and stderr are closed).
__libc_write_log(ANDROID_LOG_FATAL, "libc", msg);
android_set_abort_message(msg);
}
void __libc_fatal_no_abort(const char* format, ...) {
va_list args;
va_start(args, format);
__libc_fatal(format, args);
va_end(args);
}
void __libc_fatal(const char* format, ...) {
va_list args;
va_start(args, format);
__libc_fatal(format, args);
va_end(args);
abort();
}
void android_set_abort_message(const char* msg) {
ScopedPthreadMutexLocker locker(&g_abort_msg_lock);
if (__abort_message_ptr == NULL) {
// We must have crashed _very_ early.
return;
}
if (*__abort_message_ptr != NULL) {
// We already have an abort message.
// Assume that the first crash is the one most worth reporting.
return;
}
size_t size = sizeof(abort_msg_t) + strlen(msg) + 1;
void* map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
if (map == MAP_FAILED) {
return;
}
// TODO: if we stick to the current "one-shot" scheme, we can remove this code and
// stop storing the size.
if (*__abort_message_ptr != NULL) {
munmap(*__abort_message_ptr, (*__abort_message_ptr)->size);
}
abort_msg_t* new_abort_message = reinterpret_cast<abort_msg_t*>(map);
new_abort_message->size = size;
strcpy(new_abort_message->msg, msg);
*__abort_message_ptr = new_abort_message;
}