fix rsyscall handler: must not clobber errno from signal context

diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c
index 52487001484ce8c1edfc08cd7b7027055c4a130d..410eefc2a7f3c1601e7ab17f96c71963d3745bf3 100644 (file)
--- a/src/thread/pthread_create.c
+++ b/src/thread/pthread_create.c
@@ -89,6 +89,7 @@ static struct {
 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;
 
@@ -99,8 +100,9 @@ static void rsyscall_handler(int sig, siginfo_t *si, void *ctx)
                return;
        }
 
-       if (syscall(rs.nr, rs.arg[0], rs.arg[1], rs.arg[2],
-               rs.arg[3], rs.arg[4], rs.arg[5]) < 0 && !rs.err) rs.err=errno;
+       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);