Move back to using per-thread credentials on Linux. Fixes the glibc native AIO lost wakeup problem.

See this post:

https://lists.samba.org/archive/samba-technical/2012-June/085101.html

for details.

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Fri Jun 29 03:57:45 CEST 2012 on sn-devel-104

1 files changed, 41 insertions, 9 deletions

diff --git a/lib/util/setid.c b/lib/util/setid.c
index 8b2efc076f..66c06397ee 100644
--- a/lib/util/setid.c
+++ b/lib/util/setid.c
@@ -70,10 +70,22 @@ int samba_setgroups(size_t setlen, const gid_t *gidset);
 
 #include "../lib/util/setid.h"
 
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+#if defined(HAVE_SYSCALL_H)
+#include <syscall.h>
+#endif
+
+#if defined(HAVE_SYS_SYSCALL_H)
+#include <sys/syscall.h>
+#endif
+#endif
+
 /* All the setXX[ug]id functions and setgroups Samba uses. */
 int samba_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 {
-#if defined(HAVE_SETRESUID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	return syscall(SYS_setresuid, ruid, euid, suid);
+#elif defined(HAVE_SETRESUID)
 	return setresuid(ruid, euid, suid);
 #else
 	errno = ENOSYS;
@@ -83,7 +95,9 @@ int samba_setresuid(uid_t ruid, uid_t euid, uid_t suid)
 
 int samba_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 {
-#if defined(HAVE_SETRESGID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	return syscall(SYS_setresgid, rgid, egid, sgid);
+#elif defined(HAVE_SETRESGID)
 	return setresgid(rgid, egid, sgid);
 #else
 	errno = ENOSYS;
@@ -93,7 +107,9 @@ int samba_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 
 int samba_setreuid(uid_t ruid, uid_t euid)
 {
-#if defined(HAVE_SETREUID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	return syscall(SYS_setreuid, ruid, euid);
+#elif defined(HAVE_SETREUID)
 	return setreuid(ruid, euid);
 #else
 	errno = ENOSYS;
@@ -103,7 +119,9 @@ int samba_setreuid(uid_t ruid, uid_t euid)
 
 int samba_setregid(gid_t rgid, gid_t egid)
 {
-#if defined(HAVE_SETREGID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	return syscall(SYS_setregid, rgid, egid);
+#elif defined(HAVE_SETREGID)
 	return setregid(rgid, egid);
 #else
 	errno = ENOSYS;
@@ -113,7 +131,10 @@ int samba_setregid(gid_t rgid, gid_t egid)
 
 int samba_seteuid(uid_t euid)
 {
-#if defined(HAVE_SETEUID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	/* seteuid is not a separate system call. */
+	return syscall(SYS_setresuid, -1, euid, -1);
+#elif defined(HAVE_SETEUID)
 	return seteuid(euid);
 #else
 	errno = ENOSYS;
@@ -123,7 +144,10 @@ int samba_seteuid(uid_t euid)
 
 int samba_setegid(gid_t egid)
 {
-#if defined(HAVE_SETEGID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	/* setegid is not a separate system call. */
+	return syscall(SYS_setresgid, -1, egid, -1);
+#elif defined(HAVE_SETEGID)
 	return setegid(egid);
 #else
 	errno = ENOSYS;
@@ -133,7 +157,9 @@ int samba_setegid(gid_t egid)
 
 int samba_setuid(uid_t uid)
 {
-#if defined(HAVE_SETUID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	return syscall(SYS_setuid, uid);
+#elif defined(HAVE_SETUID)
 	return setuid(uid);
 #else
 	errno = ENOSYS;
@@ -143,7 +169,9 @@ int samba_setuid(uid_t uid)
 
 int samba_setgid(gid_t gid)
 {
-#if defined(HAVE_SETGID)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	return syscall(SYS_setgid, gid);
+#elif defined(HAVE_SETGID)
 	return setgid(gid);
 #else
 	errno = ENOSYS;
@@ -156,6 +184,7 @@ int samba_setuidx(int flags, uid_t uid)
 #if defined(HAVE_SETUIDX)
 	return setuidx(flags, uid);
 #else
+	/* USE_LINUX_THREAD_CREDENTIALS doesn't have this. */
 	errno = ENOSYS;
 	return -1;
 #endif
@@ -166,6 +195,7 @@ int samba_setgidx(int flags, gid_t gid)
 #if defined(HAVE_SETGIDX)
 	return setgidx(flags, gid);
 #else
+	/* USE_LINUX_THREAD_CREDENTIALS doesn't have this. */
 	errno = ENOSYS;
 	return -1;
 #endif
@@ -173,7 +203,9 @@ int samba_setgidx(int flags, gid_t gid)
 
 int samba_setgroups(size_t setlen, const gid_t *gidset)
 {
-#if defined(HAVE_SETGROUPS)
+#if defined(USE_LINUX_THREAD_CREDENTIALS)
+	return syscall(SYS_setgroups, setlen, gidset);
+#elif defined(HAVE_SETGROUPS)
 	return setgroups(setlen, gidset);
 #else
 	errno = ENOSYS;