move rsyscall out of pthread_create module

this is something of a tradeoff, as now set*id() functions, rather
than pthread_create, are what pull in the code overhead for dealing
with linux's refusal to implement proper POSIX thread-vs-process
semantics. my motivations are:

1. it's cleaner this way, especially cleaner to optimize out the
rsyscall locking overhead from pthread_create when it's not needed.
2. it's expected that only a tiny number of core system programs will
ever use set*id() functions, whereas many programs may want to use
threads, and making thread overhead tiny is an incentive for "light"
programs to try threads.

6 files changed, 6 insertions, 12 deletions

diff --git a/src/unistd/setgid.c b/src/unistd/setgid.c
index e98a2982..b54d2b22 100644
--- a/src/unistd/setgid.c
+++ b/src/unistd/setgid.c
@@ -4,6 +4,5 @@
 
 int setgid(gid_t gid)
 {
-	if (libc.rsyscall) return libc.rsyscall(__NR_setgid, gid, 0, 0, 0, 0, 0);
-	return syscall(SYS_setgid, gid);
+	return __rsyscall(__NR_setgid, gid, 0, 0, 0, 0, 0);
 }
diff --git a/src/unistd/setregid.c b/src/unistd/setregid.c
index ff2607dc..49c59858 100644
--- a/src/unistd/setregid.c
+++ b/src/unistd/setregid.c
@@ -4,6 +4,5 @@
 
 int setregid(gid_t rgid, gid_t egid)
 {
-	if (libc.rsyscall) return libc.rsyscall(__NR_setregid, rgid, egid, 0, 0, 0, 0);
-	return syscall(SYS_setregid, rgid, egid);
+	return __rsyscall(__NR_setregid, rgid, egid, 0, 0, 0, 0);
 }
diff --git a/src/unistd/setresgid.c b/src/unistd/setresgid.c
index 3c85a828..2b0c96d8 100644
--- a/src/unistd/setresgid.c
+++ b/src/unistd/setresgid.c
@@ -5,6 +5,5 @@
 
 int setresgid(gid_t rgid, gid_t egid, gid_t sgid)
 {
-	if (libc.rsyscall) return libc.rsyscall(__NR_setresgid, rgid, egid, sgid, 0, 0, 0);
-	return syscall(SYS_setresgid, rgid, egid, sgid);
+	return __rsyscall(__NR_setresgid, rgid, egid, sgid, 0, 0, 0);
 }
diff --git a/src/unistd/setresuid.c b/src/unistd/setresuid.c
index 376ce406..7fa6bc38 100644
--- a/src/unistd/setresuid.c
+++ b/src/unistd/setresuid.c
@@ -5,6 +5,5 @@
 
 int setresuid(uid_t ruid, uid_t euid, uid_t suid)
 {
-	if (libc.rsyscall) return libc.rsyscall(__NR_setresuid, ruid, euid, suid, 0, 0, 0);
-	return syscall(SYS_setresuid, ruid, euid, suid);
+	return __rsyscall(__NR_setresuid, ruid, euid, suid, 0, 0, 0);
 }
diff --git a/src/unistd/setreuid.c b/src/unistd/setreuid.c
index 505e8bc1..d926454a 100644
--- a/src/unistd/setreuid.c
+++ b/src/unistd/setreuid.c
@@ -4,6 +4,5 @@
 
 int setreuid(uid_t ruid, uid_t euid)
 {
-	if (libc.rsyscall) return libc.rsyscall(__NR_setreuid, ruid, euid, 0, 0, 0, 0);
-	return syscall(SYS_setreuid, ruid, euid);
+	return __rsyscall(__NR_setreuid, ruid, euid, 0, 0, 0, 0);
 }
diff --git a/src/unistd/setuid.c b/src/unistd/setuid.c
index 61e8be55..da6816de 100644
--- a/src/unistd/setuid.c
+++ b/src/unistd/setuid.c
@@ -4,6 +4,5 @@
 
 int setuid(uid_t uid)
 {
-	if (libc.rsyscall) return libc.rsyscall(__NR_setuid, uid, 0, 0, 0, 0, 0);
-	return syscall(SYS_setuid, uid);
+	return __rsyscall(__NR_setuid, uid, 0, 0, 0, 0, 0);
 }