Xext: Use SHMDIR and O_TMPFILE when creating mapping files

ShmCreateSegment asks for a file descriptor for a memory mapped file
created by the X server. This patch uses O_TMPFILE where available,
and also uses the SHMDIR directory to store the files, both for the
O_TMPFILE and mkstemp cases.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Julien Cristau <jcristau@debian.org>
This commit is contained in:
Keith Packard 2013-11-13 14:16:33 +09:00
parent 5a969f0928
commit cc63204926

View File

@ -37,6 +37,7 @@ in this Software without prior written authorization from The Open Group.
#include <sys/shm.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <X11/X.h>
#include <X11/Xproto.h>
#include "misc.h"
@ -1176,6 +1177,35 @@ ProcShmAttachFd(ClientPtr client)
return Success;
}
static int
shm_tmpfile(void)
{
#ifdef SHMDIR
int fd;
int flags;
char template[] = SHMDIR "/shmfd-XXXXXX";
#ifdef O_TMPFILE
fd = open(SHMDIR, O_TMPFILE|O_RDWR|O_CLOEXEC|O_EXCL, 0666);
if (fd >= 0) {
ErrorF ("Using O_TMPFILE\n");
return fd;
}
ErrorF ("Not using O_TMPFILE\n");
#endif
fd = mkstemp(template);
if (fd < 0)
return -1;
unlink(template);
if (fcntl(fd, F_GETFD, &flags) >= 0) {
flags |= FD_CLOEXEC;
(void) fcntl(fd, F_SETFD, &flags);
}
return fd;
#else
return -1;
#endif
}
static int
ProcShmCreateSegment(ClientPtr client)
{
@ -1188,17 +1218,15 @@ ProcShmCreateSegment(ClientPtr client)
.sequenceNumber = client->sequence,
.length = 0,
};
char template[] = "/tmp/shm-XXXXXX";
REQUEST_SIZE_MATCH(xShmCreateSegmentReq);
if ((stuff->readOnly != xTrue) && (stuff->readOnly != xFalse)) {
client->errorValue = stuff->readOnly;
return BadValue;
}
fd = mkstemp(template);
fd = shm_tmpfile();
if (fd < 0)
return BadAlloc;
unlink(template);
if (ftruncate(fd, stuff->size) < 0) {
close(fd);
return BadAlloc;