#define LOCK(x) (libc.threads_minus_1 ? (__lock(x),1) : ((void)(x),1))
#define UNLOCK(x) (*(volatile int *)(x)=0)
-int __rsyscall(int, long, long, long, long, long, long);
+void __synccall(void (*)(void *), void *);
+int __setxid(int, int, int, int);
extern char **__environ;
#define environ __environ
#define SIGTIMER 32
#define SIGCANCEL 33
-#define SIGSYSCALL 34
+#define SIGSYNCCALL 34
#define SIGPT_SET ((sigset_t *)(unsigned long [1+(sizeof(long)==4)]){ \
[sizeof(long)==4] = 3UL<<(32*(sizeof(long)>4)) })
void __wait(volatile int *, volatile int *, int, int);
void __wake(volatile int *, int, int);
-void __rsyscall_lock();
-void __rsyscall_unlock();
+void __synccall_lock();
+void __synccall_unlock();
#define DEFAULT_STACK_SIZE (16384-PAGE_SIZE)
#define DEFAULT_GUARD_SIZE PAGE_SIZE
+++ /dev/null
-#include "pthread_impl.h"
-
-/* "rsyscall" is a mechanism by which a thread can synchronously force all
- * other threads to perform an arbitrary syscall. It is necessary to work
- * around the non-conformant implementation of setuid() et al on Linux,
- * which affect only the calling thread and not the whole process. This
- * implementation performs some tricks with signal delivery to work around
- * the fact that it does not keep any list of threads in userspace. */
-
-static struct {
- volatile int lock, hold, blocks, cnt;
- unsigned long arg[6];
- int nr;
- int err;
- int init;
-} rs;
-
-static void rsyscall_handler(int sig, siginfo_t *si, void *ctx)
-{
- struct pthread *self = __pthread_self();
- long r;
-
- if (!rs.hold || rs.cnt == libc.threads_minus_1) return;
-
- /* Threads which have already decremented themselves from the
- * thread count must not increment rs.cnt or otherwise act. */
- if (self->dead) {
- sigfillset(&((ucontext_t *)ctx)->uc_sigmask);
- return;
- }
-
- r = __syscall(rs.nr, rs.arg[0], rs.arg[1],
- rs.arg[2], rs.arg[3], rs.arg[4], rs.arg[5]);
- if (r < 0) rs.err=-r;
-
- a_inc(&rs.cnt);
- __wake(&rs.cnt, 1, 1);
- while(rs.hold)
- __wait(&rs.hold, 0, 1, 1);
- a_dec(&rs.cnt);
- if (!rs.cnt) __wake(&rs.cnt, 1, 1);
-}
-
-int __rsyscall(int nr, long a, long b, long c, long d, long e, long f)
-{
- int i, ret;
- sigset_t set = { 0 };
- struct pthread *self;
-
- if (!libc.threads_minus_1)
- return syscall(nr, a, b, c, d, e, f);
-
- self = __pthread_self();
-
- LOCK(&rs.lock);
- while ((i=rs.blocks))
- __wait(&rs.blocks, 0, i, 1);
-
- __syscall(SYS_rt_sigprocmask, SIG_BLOCK, (uint64_t[]){-1}, &set, 8);
-
- if (!rs.init) {
- struct sigaction sa = {
- .sa_flags = SA_SIGINFO | SA_RESTART,
- .sa_sigaction = rsyscall_handler,
- .sa_mask = set
- };
- sigfillset(&sa.sa_mask);
- sa.sa_sigaction = rsyscall_handler;
- __libc_sigaction(SIGSYSCALL, &sa, 0);
- rs.init = 1;
- }
-
- rs.nr = nr;
- rs.arg[0] = a; rs.arg[1] = b;
- rs.arg[2] = c; rs.arg[3] = d;
- rs.arg[4] = d; rs.arg[5] = f;
- rs.err = 0;
- rs.cnt = 0;
- rs.hold = 1;
-
- /* Dispatch signals until all threads respond */
- for (i=libc.threads_minus_1; i; i--)
- sigqueue(self->pid, SIGSYSCALL, (union sigval){0});
- while ((i=rs.cnt) < libc.threads_minus_1) {
- sigqueue(self->pid, SIGSYSCALL, (union sigval){0});
- __wait(&rs.cnt, 0, i, 1);
- }
-
- /* Handle any lingering signals with no-op */
- __syscall(SYS_rt_sigprocmask, SIG_SETMASK, &set, &set, 8);
-
- /* Resume other threads' signal handlers and wait for them */
- rs.hold = 0;
- __wake(&rs.hold, -1, 0);
- while((i=rs.cnt)) __wait(&rs.cnt, 0, i, 1);
-
- if (rs.err) errno = rs.err, ret = -1;
- else ret = syscall(nr, a, b, c, d, e, f);
-
- UNLOCK(&rs.lock);
- return ret;
-}
-
-void __rsyscall_lock()
-{
- a_inc(&rs.blocks);
- while (rs.lock) __wait(&rs.lock, 0, 1, 1);
-}
-
-void __rsyscall_unlock()
-{
- a_dec(&rs.blocks);
- if (rs.lock) __wake(&rs.blocks, 1, 1);
-}
static void dummy_0()
{
}
-weak_alias(dummy_0, __rsyscall_lock);
-weak_alias(dummy_0, __rsyscall_unlock);
+weak_alias(dummy_0, __synccall_lock);
+weak_alias(dummy_0, __synccall_unlock);
weak_alias(dummy_0, __pthread_tsd_run_dtors);
#ifdef __pthread_unwind_next
new->tlsdesc[1] = (uintptr_t)new;
stack = (void *)((uintptr_t)new-1 & ~(uintptr_t)15);
- __rsyscall_lock();
+ __synccall_lock();
a_inc(&libc.threads_minus_1);
ret = __uniclone(stack, start, new);
- __rsyscall_unlock();
+ __synccall_unlock();
if (ret < 0) {
a_dec(&libc.threads_minus_1);
--- /dev/null
+#include "pthread_impl.h"
+#include <semaphore.h>
+
+static struct chain {
+ struct chain *next;
+ sem_t sem, sem2;
+} *head;
+
+static void (*callback)(void *), *context;
+static int chainlen;
+static sem_t chainlock, chaindone;
+static pthread_rwlock_t lock = PTHREAD_RWLOCK_INITIALIZER;
+
+static void handler(int sig, siginfo_t *si, void *ctx)
+{
+ struct chain ch;
+ pthread_t self = __pthread_self();
+ int old_errno = errno;
+
+ if (chainlen == libc.threads_minus_1) return;
+
+ sigqueue(self->pid, SIGSYNCCALL, (union sigval){0});
+
+ /* Threads which have already decremented themselves from the
+ * thread count must not act. Block further receipt of signals
+ * and return. */
+ if (self->dead) {
+ memset(&((ucontext_t *)ctx)->uc_sigmask, -1, 8);
+ errno = old_errno;
+ return;
+ }
+
+ sem_init(&ch.sem, 0, 0);
+ sem_init(&ch.sem2, 0, 0);
+
+ while (sem_wait(&chainlock));
+ ch.next = head;
+ head = &ch;
+ if (++chainlen == libc.threads_minus_1) sem_post(&chaindone);
+ sem_post(&chainlock);
+
+ while (sem_wait(&ch.sem));
+ callback(context);
+ sem_post(&ch.sem2);
+ while (sem_wait(&ch.sem));
+
+ errno = old_errno;
+}
+
+void __synccall(void (*func)(void *), void *ctx)
+{
+ pthread_t self;
+ struct sigaction sa;
+ struct chain *cur, *next;
+ uint64_t oldmask;
+
+ pthread_rwlock_wrlock(&lock);
+
+ __syscall(SYS_rt_sigprocmask, SIG_BLOCK, (uint64_t[]){-1}, &oldmask, 8);
+
+ if (!libc.threads_minus_1) {
+ func(ctx);
+ return;
+ }
+
+ sem_init(&chaindone, 0, 0);
+ sem_init(&chainlock, 0, 1);
+ chainlen = 0;
+ callback = func;
+ context = ctx;
+
+ sa.sa_flags = SA_SIGINFO | SA_RESTART;
+ sa.sa_sigaction = handler;
+ sigfillset(&sa.sa_mask);
+ __libc_sigaction(SIGSYNCCALL, &sa, 0);
+
+ self = __pthread_self();
+ sigqueue(self->pid, SIGSYNCCALL, (union sigval){0});
+ while (sem_wait(&chaindone));
+
+ for (cur=head; cur; cur=cur->next) {
+ sem_post(&cur->sem);
+ while (sem_wait(&cur->sem2));
+ }
+ func(ctx);
+
+ for (cur=head; cur; cur=next) {
+ next = cur->next;
+ sem_post(&cur->sem);
+ }
+
+ sa.sa_flags = 0;
+ sa.sa_handler = SIG_IGN;
+ __libc_sigaction(SIGSYNCCALL, &sa, 0);
+
+ __syscall(SYS_rt_sigprocmask, SIG_SETMASK, &oldmask, 0, 8);
+
+ pthread_rwlock_unlock(&lock);
+}
+
+void __synccall_lock()
+{
+ pthread_rwlock_rdlock(&lock);
+}
+
+void __synccall_unlock()
+{
+ pthread_rwlock_unlock(&lock);
+}
#include <unistd.h>
+#include "libc.h"
+#include "syscall.h"
int setegid(gid_t egid)
{
- return setregid(-1, egid);
+ return __setxid(SYS_setresgid, -1, egid, -1);
}
#include <unistd.h>
+#include "syscall.h"
+#include "libc.h"
int seteuid(uid_t euid)
{
- return setreuid(-1, euid);
+ return __setxid(SYS_setresuid, -1, euid, -1);
}
int setgid(gid_t gid)
{
- return __rsyscall(SYS_setgid, gid, 0, 0, 0, 0, 0);
+ return __setxid(SYS_setgid, gid, 0, 0);
}
int setregid(gid_t rgid, gid_t egid)
{
- return __rsyscall(SYS_setregid, rgid, egid, 0, 0, 0, 0);
+ return __setxid(SYS_setregid, rgid, egid, 0);
}
int setresgid(gid_t rgid, gid_t egid, gid_t sgid)
{
- return __rsyscall(SYS_setresgid, rgid, egid, sgid, 0, 0, 0);
+ return __setxid(SYS_setresgid, rgid, egid, sgid);
}
int setresuid(uid_t ruid, uid_t euid, uid_t suid)
{
- return __rsyscall(SYS_setresuid, ruid, euid, suid, 0, 0, 0);
+ return __setxid(SYS_setresuid, ruid, euid, suid);
}
int setreuid(uid_t ruid, uid_t euid)
{
- return __rsyscall(SYS_setreuid, ruid, euid, 0, 0, 0, 0);
+ return __setxid(SYS_setreuid, ruid, euid, 0);
}
int setuid(uid_t uid)
{
- return __rsyscall(SYS_setuid, uid, 0, 0, 0, 0, 0);
+ return __setxid(SYS_setuid, uid, 0, 0);
}
projects / oweals / musl.git / commitdiff