tequilaOS/platform_system_core
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

liblog: reset pid and uid cache after a vfork()

Browse source 
Bionic getuid() and getpid() calls cache to reduce the need to
perform a syscall, and also reset their own cache after a vfork().
No more need for liblog to be performing this flawed cache operation.

Bug: 30085794
Change-Id: I70feed8bff0ddd919c2885a348ba67b14ddc0e0d
This commit is contained in:
Mark Salyzyn 2016-07-13 07:38:39 -07:00
parent 4c06cd8634
commit ec4f5c776d
3 changed files with 5 additions and 29 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
liblog/logger.h
View file

@ -146,11 +146,13 @@ struct android_log_transport_context {
/* OS specific dribs and drabs */
#if defined(_WIN32)
#include <private/android_filesystem_config.h>
typedef uint32_t uid_t;
static inline uid_t __android_log_uid() { return AID_SYSTEM; }
#else
static inline uid_t __android_log_uid() { return getuid(); }
#endif
LIBLOG_HIDDEN uid_t __android_log_uid();
LIBLOG_HIDDEN pid_t __android_log_pid();
LIBLOG_HIDDEN void __android_log_lock();
LIBLOG_HIDDEN int __android_log_trylock();
LIBLOG_HIDDEN void __android_log_unlock();

26
liblog/logger_lock.c
View file

@ -22,34 +22,8 @@
#include <pthread.h>
#endif
#include <private/android_filesystem_config.h>
#include "logger.h"
LIBLOG_HIDDEN uid_t __android_log_uid()
{
#if defined(_WIN32)
return AID_SYSTEM;
#else
static uid_t last_uid = AID_ROOT; /* logd *always* starts up as AID_ROOT */
if (last_uid == AID_ROOT) { /* have we called to get the UID yet? */
last_uid = getuid();
}
return last_uid;
#endif
}
LIBLOG_HIDDEN pid_t __android_log_pid()
{
static pid_t last_pid = (pid_t) -1;
if (last_pid == (pid_t) -1) {
last_pid = getpid();
}
return last_pid;
}
#if !defined(_WIN32)
static pthread_mutex_t log_init_lock = PTHREAD_MUTEX_INITIALIZER;
#endif

2
liblog/pmsg_writer.c
View file

@ -142,7 +142,7 @@ static int pmsgWrite(log_id_t logId, struct timespec *ts,
pmsgHeader.magic = LOGGER_MAGIC;
pmsgHeader.len = sizeof(pmsgHeader) + sizeof(header);
pmsgHeader.uid = __android_log_uid();
pmsgHeader.pid = __android_log_pid();
pmsgHeader.pid = getpid();
header.id = logId;
header.tid = gettid();