From 7765706c0584ed4a30e0b7a3ada742e490ef02b0 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 6 Jun 2014 15:42:42 -0400 Subject: [PATCH] add O_CLOEXEC fallback for open and related functions since there is no easy way to detect whether open honored or ignored the O_CLOEXEC flag, the optimal solution to providing a fallback is simply to make the fcntl syscall to set the close-on-exec flag immediately after open returns. --- src/fcntl/open.c | 7 ++++++- src/stdio/__fopen_rb_ca.c | 1 + src/stdio/fopen.c | 2 ++ 3 files changed, 9 insertions(+), 1 deletion(-) diff --git a/src/fcntl/open.c b/src/fcntl/open.c index 0594ed7e..088a28f7 100644 --- a/src/fcntl/open.c +++ b/src/fcntl/open.c @@ -10,7 +10,12 @@ int open(const char *filename, int flags, ...) va_start(ap, flags); mode = va_arg(ap, mode_t); va_end(ap); - return sys_open_cp(filename, flags, mode); + + int fd = __sys_open_cp(filename, flags, mode); + if (fd>=0 && (flags & O_CLOEXEC)) + __syscall(SYS_fcntl, fd, F_SETFD, FD_CLOEXEC); + + return __syscall_ret(fd); } LFS64(open); diff --git a/src/stdio/__fopen_rb_ca.c b/src/stdio/__fopen_rb_ca.c index b72c6304..183a5d55 100644 --- a/src/stdio/__fopen_rb_ca.c +++ b/src/stdio/__fopen_rb_ca.c @@ -8,6 +8,7 @@ FILE *__fopen_rb_ca(const char *filename, FILE *f, unsigned char *buf, size_t le f->fd = sys_open(filename, O_RDONLY|O_CLOEXEC); if (f->fd < 0) return 0; + __syscall(SYS_fcntl, f->fd, F_SETFD, FD_CLOEXEC); f->flags = F_NOWR | F_PERM; f->buf = buf + UNGET; diff --git a/src/stdio/fopen.c b/src/stdio/fopen.c index 3d97cfa8..07bdb6e8 100644 --- a/src/stdio/fopen.c +++ b/src/stdio/fopen.c @@ -20,6 +20,8 @@ FILE *fopen(const char *restrict filename, const char *restrict mode) fd = sys_open_cp(filename, flags, 0666); if (fd < 0) return 0; + if (flags & O_CLOEXEC) + __syscall(SYS_fcntl, fd, F_SETFD, FD_CLOEXEC); f = __fdopen(fd, mode); if (f) return f; -- 2.25.1