Major cleanup of internal mutex locking. Be more consistant in how we do

things, and avoid potential deadlocks caused when a thread holding a uClibc
internal lock get canceled and terminates without releasing the lock.  This
change also provides a single place, bits/uClibc_mutex.h, for thread libraries
to modify to change all instances of internal locking.

2 files changed, 60 insertions, 74 deletions

diff --git a/libc/pwd_grp/lckpwdf.c b/libc/pwd_grp/lckpwdf.c
index 2d38e89f9..f241cdffc 100644
--- a/libc/pwd_grp/lckpwdf.c
+++ b/libc/pwd_grp/lckpwdf.c
@@ -48,12 +48,8 @@ libc_hidden_proto(alarm)
 static int lock_fd = -1;
 
 /* Prevent problems in multithreaded program by using mutex.  */
-#ifdef __UCLIBC_HAS_THREADS__
-# include <pthread.h>
-static pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
-#endif
-#define LOCK   __pthread_mutex_lock(&mylock)
-#define UNLOCK __pthread_mutex_unlock(&mylock)
+#include <bits/uClibc_mutex.h>
+__UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
 
 
 /* Prototypes for local functions.  */
@@ -70,19 +66,19 @@ lckpwdf (void)
   struct sigaction new_act;		/* New signal action.  */
   struct flock fl;			/* Information struct for locking.  */
   int result;
+  int rv = -1;
 
   if (lock_fd != -1)
     /* Still locked by own process.  */
     return -1;
 
   /* Prevent problems caused by multiple threads.  */
-  LOCK;
+  __UCLIBC_MUTEX_LOCK(mylock);
 
   lock_fd = open (_PATH_PASSWD, O_WRONLY);
   if (lock_fd == -1) {
     /* Cannot create lock file.  */
-    UNLOCK;
-    return -1;
+	goto DONE;
   }
 
   /* Make sure file gets correctly closed when process finished.  */
@@ -91,16 +87,14 @@ lckpwdf (void)
     /* Cannot get file flags.  */
     close(lock_fd);
     lock_fd = -1;
-    UNLOCK;
-    return -1;
+	goto DONE;
   }
   flags |= FD_CLOEXEC;		/* Close on exit.  */
   if (fcntl (lock_fd, F_SETFD, flags) < 0) {
     /* Cannot set new flags.  */
     close(lock_fd);
     lock_fd = -1;
-    UNLOCK;
-    return -1;
+	goto DONE;
   }
 
   /* Now we have to get exclusive write access.  Since multiple
@@ -121,8 +115,7 @@ lckpwdf (void)
     /* Cannot install signal handler.  */
     close(lock_fd);
     lock_fd = -1;
-    UNLOCK;
-    return -1;
+	goto DONE;
   }
 
   /* Now make sure the alarm signal is not blocked.  */
@@ -132,8 +125,7 @@ lckpwdf (void)
     sigaction (SIGALRM, &saved_act, NULL);
     close(lock_fd);
     lock_fd = -1;
-    UNLOCK;
-    return -1;
+	goto DONE;
   }
 
   /* Start timer.  If we cannot get the lock in the specified time we
@@ -160,11 +152,12 @@ lckpwdf (void)
   if (result < 0) {
     close(lock_fd);
     lock_fd = -1;
-    UNLOCK;
-    return -1;
+	goto DONE;
   }
+  rv = 0;
 
-  UNLOCK;
+DONE:
+  __UCLIBC_MUTEX_UNLOCK(mylock);
   return 0;
 }
 
@@ -180,7 +173,7 @@ ulckpwdf (void)
   else
     {
       /* Prevent problems caused by multiple threads.  */
-      LOCK;
+	  __UCLIBC_MUTEX_LOCK(mylock);
 
       result = close (lock_fd);
 
@@ -188,7 +181,7 @@ ulckpwdf (void)
       lock_fd = -1;
 
       /* Clear mutex.  */
-      UNLOCK;
+	  __UCLIBC_MUTEX_UNLOCK(mylock);
     }
 
   return result;
diff --git a/libc/pwd_grp/pwd_grp.c b/libc/pwd_grp/pwd_grp.c
index 2a9d4519a..d223a9e36 100644
--- a/libc/pwd_grp/pwd_grp.c
+++ b/libc/pwd_grp/pwd_grp.c
@@ -34,9 +34,7 @@
 #ifdef __UCLIBC_HAS_SHADOW__
 #include <shadow.h>
 #endif
-#ifdef __UCLIBC_HAS_THREADS__
-#include <pthread.h>
-#endif
+#include <bits/uClibc_mutex.h>
 
 libc_hidden_proto(strchr)
 libc_hidden_proto(strcmp)
@@ -253,7 +251,7 @@ libc_hidden_def(sgetspent_r)
 
 #ifdef L_getpwnam_r
 #define GETXXKEY_R_FUNC		getpwnam_r
-#define GETXXKEY_R_PARSER   	__parsepwent
+#define GETXXKEY_R_PARSER	__parsepwent
 #define GETXXKEY_R_ENTTYPE	struct passwd
 #define GETXXKEY_R_TEST(ENT)	(!strcmp((ENT)->pw_name, key))
 #define DO_GETXXKEY_R_KEYTYPE	const char *__restrict
@@ -263,7 +261,7 @@ libc_hidden_def(sgetspent_r)
 
 #ifdef L_getgrnam_r
 #define GETXXKEY_R_FUNC		getgrnam_r
-#define GETXXKEY_R_PARSER   	__parsegrent
+#define GETXXKEY_R_PARSER	__parsegrent
 #define GETXXKEY_R_ENTTYPE	struct group
 #define GETXXKEY_R_TEST(ENT)	(!strcmp((ENT)->gr_name, key))
 #define DO_GETXXKEY_R_KEYTYPE	const char *__restrict
@@ -273,7 +271,7 @@ libc_hidden_def(sgetspent_r)
 
 #ifdef L_getspnam_r
 #define GETXXKEY_R_FUNC		getspnam_r
-#define GETXXKEY_R_PARSER   	__parsespent
+#define GETXXKEY_R_PARSER	__parsespent
 #define GETXXKEY_R_ENTTYPE	struct spwd
 #define GETXXKEY_R_TEST(ENT)	(!strcmp((ENT)->sp_namp, key))
 #define DO_GETXXKEY_R_KEYTYPE	const char *__restrict
@@ -283,7 +281,7 @@ libc_hidden_def(sgetspent_r)
 
 #ifdef L_getpwuid_r
 #define GETXXKEY_R_FUNC		getpwuid_r
-#define GETXXKEY_R_PARSER   	__parsepwent
+#define GETXXKEY_R_PARSER	__parsepwent
 #define GETXXKEY_R_ENTTYPE	struct passwd
 #define GETXXKEY_R_TEST(ENT)	((ENT)->pw_uid == key)
 #define DO_GETXXKEY_R_KEYTYPE	uid_t
@@ -293,7 +291,7 @@ libc_hidden_def(sgetspent_r)
 
 #ifdef L_getgrgid_r
 #define GETXXKEY_R_FUNC		getgrgid_r
-#define GETXXKEY_R_PARSER   	__parsegrent
+#define GETXXKEY_R_PARSER	__parsegrent
 #define GETXXKEY_R_ENTTYPE	struct group
 #define GETXXKEY_R_TEST(ENT)	((ENT)->gr_gid == key)
 #define DO_GETXXKEY_R_KEYTYPE	gid_t
@@ -458,47 +456,40 @@ int getpw(uid_t uid, char *buf)
 
 #endif
 /**********************************************************************/
-#if defined(L_getpwent_r) || defined(L_getgrent_r) || defined(L_getspent_r)
-#ifdef __UCLIBC_HAS_THREADS__
-# include <pthread.h>
-static pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
-#endif
-#define LOCK		__pthread_mutex_lock(&mylock)
-#define UNLOCK		__pthread_mutex_unlock(&mylock)
-#endif
 
 #ifdef L_getpwent_r
+__UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
 
 static FILE *pwf /*= NULL*/;
 
 void setpwent(void)
 {
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 	if (pwf) {
 		rewind(pwf);
 	}
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 }
 
 void endpwent(void)
 {
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 	if (pwf) {
 		fclose(pwf);
 		pwf = NULL;
 	}
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 }
 
 
 libc_hidden_proto(getpwent_r)
-int getpwent_r(struct passwd *__restrict resultbuf, 
+int getpwent_r(struct passwd *__restrict resultbuf,
 			   char *__restrict buffer, size_t buflen,
 			   struct passwd **__restrict result)
 {
 	int rv;
 
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 
 	*result = NULL;				/* In case of error... */
 
@@ -516,7 +507,7 @@ int getpwent_r(struct passwd *__restrict resultbuf,
 	}
 
  ERR:
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 
 	return rv;
 }
@@ -525,26 +516,27 @@ libc_hidden_def(getpwent_r)
 #endif
 /**********************************************************************/
 #ifdef L_getgrent_r
+__UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
 
 static FILE *grf /*= NULL*/;
 
 void setgrent(void)
 {
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 	if (grf) {
 		rewind(grf);
 	}
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 }
 
 void endgrent(void)
 {
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 	if (grf) {
 		fclose(grf);
 		grf = NULL;
 	}
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 }
 
 libc_hidden_proto(getgrent_r)
@@ -554,7 +546,7 @@ int getgrent_r(struct group *__restrict resultbuf,
 {
 	int rv;
 
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 
 	*result = NULL;				/* In case of error... */
 
@@ -572,7 +564,7 @@ int getgrent_r(struct group *__restrict resultbuf,
 	}
 
  ERR:
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 
 	return rv;
 }
@@ -581,35 +573,36 @@ libc_hidden_def(getgrent_r)
 #endif
 /**********************************************************************/
 #ifdef L_getspent_r
+__UCLIBC_MUTEX_STATIC(mylock, PTHREAD_MUTEX_INITIALIZER);
 
 static FILE *spf /*= NULL*/;
 
 void setspent(void)
 {
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 	if (spf) {
 		rewind(spf);
 	}
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 }
 
 void endspent(void)
 {
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 	if (spf) {
 		fclose(spf);
 		spf = NULL;
 	}
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 }
 
 libc_hidden_proto(getspent_r)
-int getspent_r(struct spwd *resultbuf, char *buffer, 
+int getspent_r(struct spwd *resultbuf, char *buffer,
 			   size_t buflen, struct spwd **result)
 {
 	int rv;
 
-	LOCK;
+	__UCLIBC_MUTEX_LOCK(mylock);
 
 	*result = NULL;				/* In case of error... */
 
@@ -627,7 +620,7 @@ int getspent_r(struct spwd *resultbuf, char *buffer,
 	}
 
  ERR:
-	UNLOCK;
+	__UCLIBC_MUTEX_UNLOCK(mylock);
 
 	return rv;
 }
@@ -842,11 +835,11 @@ int putgrent(const struct group *__restrict p, FILE *__restrict f)
 
 static const unsigned char _sp_off[] = {
 	offsetof(struct spwd, sp_lstchg),	/* 2 - not a char ptr */
-	offsetof(struct spwd, sp_min), 		/* 3 - not a char ptr */
+	offsetof(struct spwd, sp_min),		/* 3 - not a char ptr */
 	offsetof(struct spwd, sp_max),		/* 4 - not a char ptr */
-	offsetof(struct spwd, sp_warn), 	/* 5 - not a char ptr */
-	offsetof(struct spwd, sp_inact), 	/* 6 - not a char ptr */
-	offsetof(struct spwd, sp_expire), 	/* 7 - not a char ptr */
+	offsetof(struct spwd, sp_warn),		/* 5 - not a char ptr */
+	offsetof(struct spwd, sp_inact),	/* 6 - not a char ptr */
+	offsetof(struct spwd, sp_expire),	/* 7 - not a char ptr */
 };
 
 int putspent(const struct spwd *p, FILE *stream)
@@ -899,13 +892,13 @@ int putspent(const struct spwd *p, FILE *stream)
 #ifdef L___parsepwent
 
 static const unsigned char pw_off[] = {
-	offsetof(struct passwd, pw_name), 	/* 0 */
+	offsetof(struct passwd, pw_name),	/* 0 */
 	offsetof(struct passwd, pw_passwd),	/* 1 */
 	offsetof(struct passwd, pw_uid),	/* 2 - not a char ptr */
-	offsetof(struct passwd, pw_gid), 	/* 3 - not a char ptr */
+	offsetof(struct passwd, pw_gid),	/* 3 - not a char ptr */
 	offsetof(struct passwd, pw_gecos),	/* 4 */
-	offsetof(struct passwd, pw_dir), 	/* 5 */
-	offsetof(struct passwd, pw_shell) 	/* 6 */
+	offsetof(struct passwd, pw_dir),	/* 5 */
+	offsetof(struct passwd, pw_shell)	/* 6 */
 };
 
 int attribute_hidden __parsepwent(void *data, char *line)
@@ -918,7 +911,7 @@ int attribute_hidden __parsepwent(void *data, char *line)
 	do {
 		p = ((char *) ((struct passwd *) data)) + pw_off[i];
 
-		if ((i & 6) ^ 2) { 	/* i!=2 and i!=3 */
+		if ((i & 6) ^ 2) {	/* i!=2 and i!=3 */
 			*((char **) p) = line;
 			if (i==6) {
 				return 0;
@@ -958,7 +951,7 @@ int attribute_hidden __parsepwent(void *data, char *line)
 #ifdef L___parsegrent
 
 static const unsigned char gr_off[] = {
-	offsetof(struct group, gr_name), 	/* 0 */
+	offsetof(struct group, gr_name),	/* 0 */
 	offsetof(struct group, gr_passwd),	/* 1 */
 	offsetof(struct group, gr_gid)		/* 2 - not a char ptr */
 };
@@ -1040,7 +1033,7 @@ int attribute_hidden __parsegrent(void *data, char *line)
 					if (!--i) break;
 					while (*++p) {}
 				} while (1);
-			}				
+			}
 			*members = NULL;
 
 			return 0;
@@ -1059,12 +1052,12 @@ static const unsigned char sp_off[] = {
 	offsetof(struct spwd, sp_namp),		/* 0 */
 	offsetof(struct spwd, sp_pwdp),		/* 1 */
 	offsetof(struct spwd, sp_lstchg),	/* 2 - not a char ptr */
-	offsetof(struct spwd, sp_min), 		/* 3 - not a char ptr */
+	offsetof(struct spwd, sp_min),		/* 3 - not a char ptr */
 	offsetof(struct spwd, sp_max),		/* 4 - not a char ptr */
-	offsetof(struct spwd, sp_warn), 	/* 5 - not a char ptr */
-	offsetof(struct spwd, sp_inact), 	/* 6 - not a char ptr */
-	offsetof(struct spwd, sp_expire), 	/* 7 - not a char ptr */
-	offsetof(struct spwd, sp_flag) 		/* 8 - not a char ptr */
+	offsetof(struct spwd, sp_warn),		/* 5 - not a char ptr */
+	offsetof(struct spwd, sp_inact),	/* 6 - not a char ptr */
+	offsetof(struct spwd, sp_expire),	/* 7 - not a char ptr */
+	offsetof(struct spwd, sp_flag)		/* 8 - not a char ptr */
 };
 
 int attribute_hidden __parsespent(void *data, char * line)