From: David van Moolenbroek <david@minix3.org>
Date: Wed, 20 Jul 2016 13:03:03 +0000 (+0000)
Subject: VFS: support close-on-exec flag for copyfd(2)
X-Git-Url: http://zhaoyanbai.com/repos//%22http:/www.isc.org/%22?a=commitdiff_plain;h=45443f35b5fbb37ddb8b53f6a25e7f19a75f49ea;p=minix.git

VFS: support close-on-exec flag for copyfd(2)

The flag is supported only when copying out file descriptors (i.e.
COPYFD_TO).  It will be used by UDS to support MSG_CMSG_CLOEXEC.

Change-Id: I46bfd04b5f28e22ec48938e43e42f78d3931220d
---

diff --git a/minix/include/minix/syslib.h b/minix/include/minix/syslib.h
index b5f573863..1d0611f70 100644
--- a/minix/include/minix/syslib.h
+++ b/minix/include/minix/syslib.h
@@ -274,6 +274,8 @@ int copyfd(endpoint_t endpt, int fd, int what);
 #define COPYFD_FROM	0	/* copy file descriptor from remote process */
 #define COPYFD_TO	1	/* copy file descriptor to remote process */
 #define COPYFD_CLOSE	2	/* close file descriptor in remote process */
+#define COPYFD_CLOEXEC	0x8000	/* with COPYFD_TO: set close-on-exec flag */
+#define COPYFD_FLAGS	0xF000	/* flags mask */
 int closenb(int fd);
 
 /*
diff --git a/minix/servers/vfs/filedes.c b/minix/servers/vfs/filedes.c
index ea7ee4a4e..7ddb51b42 100644
--- a/minix/servers/vfs/filedes.c
+++ b/minix/servers/vfs/filedes.c
@@ -532,7 +532,7 @@ int do_copyfd(void)
   struct vnode *vp;
   struct smap *sp;
   endpoint_t endpt;
-  int r, fd, what, slot;
+  int r, fd, what, flags, slot;
 
   /* This should be replaced with an ACL check. */
   if (!super_user) return(EPERM);
@@ -541,6 +541,9 @@ int do_copyfd(void)
   fd = job_m_in.m_lsys_vfs_copyfd.fd;
   what = job_m_in.m_lsys_vfs_copyfd.what;
 
+  flags = what & COPYFD_FLAGS;
+  what &= ~COPYFD_FLAGS;
+
   if (isokendpt(endpt, &slot) != OK) return(EINVAL);
   rfp = &fproc[slot];
 
@@ -608,6 +611,7 @@ int do_copyfd(void)
 	}
 
 	rfp = fp;
+	flags &= ~COPYFD_CLOEXEC;
 
 	/* FALLTHROUGH */
   case COPYFD_TO:
@@ -619,6 +623,8 @@ int do_copyfd(void)
 	/* If found, fill the slot and return the slot number. */
 	if (fd < OPEN_MAX) {
 		rfp->fp_filp[fd] = rfilp;
+		if (flags & COPYFD_CLOEXEC)
+			FD_SET(fd, &rfp->fp_cloexec_set);
 		rfilp->filp_count++;
 		r = fd;
 	} else