Commit 90996f59 authored by Alexander Volkov's avatar Alexander Volkov Committed by Adam Jackson

Xephyr: Prefer using MIT-SHM FD-passing when possible

This makes the shared memory visible only for the Xephyr
and the X server to which it is connected.
Signed-off-by: Alexander Volkov's avatarAlexander Volkov <a.volkov@rusbitech.ru>
Reviewed-by: Keith Packard's avatarKeith Packard <keithp@keithp.com>
parent 8a220bd8
......@@ -2305,7 +2305,7 @@ XEPHYR_INCS=
AM_CONDITIONAL(KDRIVE, [test x$KDRIVE = xyes])
if test "$KDRIVE" = yes; then
XEPHYR_REQUIRED_LIBS="xau xdmcp xcb xcb-shape xcb-render xcb-renderutil xcb-aux xcb-image xcb-icccm xcb-shm xcb-keysyms xcb-randr xcb-xkb"
XEPHYR_REQUIRED_LIBS="xau xdmcp xcb xcb-shape xcb-render xcb-renderutil xcb-aux xcb-image xcb-icccm xcb-shm >= 1.9 xcb-keysyms xcb-randr xcb-xkb"
if test "x$XV" = xyes; then
XEPHYR_REQUIRED_LIBS="$XEPHYR_REQUIRED_LIBS xcb-xv"
fi
......
......@@ -79,6 +79,7 @@ typedef struct _ephyrScrPriv {
const char *output; /* Set via -output option */
unsigned char *fb_data; /* only used when host bpp != server bpp */
xcb_shm_segment_info_t shminfo;
size_t shmsize;
KdScreenInfo *screen;
int mynum; /* Screen number */
......
......@@ -41,6 +41,7 @@
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <X11/keysym.h>
#include <xcb/xcb.h>
......@@ -75,6 +76,7 @@ struct EphyrHostXVars {
Bool use_sw_cursor;
Bool use_fullscreen;
Bool have_shm;
Bool have_shm_fd_passing;
int n_screens;
KdScreenInfo **screens;
......@@ -417,29 +419,77 @@ hostx_set_title(char *title)
#pragma does_not_return(exit)
#endif
static void
hostx_init_shm(void)
{
/* Try to get share memory ximages for a little bit more speed */
if (!hostx_has_extension(&xcb_shm_id) || getenv("XEPHYR_NO_SHM")) {
HostX.have_shm = FALSE;
} else {
xcb_generic_error_t *error = NULL;
xcb_shm_query_version_cookie_t cookie;
xcb_shm_query_version_reply_t *reply;
HostX.have_shm = TRUE;
HostX.have_shm_fd_passing = FALSE;
cookie = xcb_shm_query_version(HostX.conn);
reply = xcb_shm_query_version_reply(HostX.conn, cookie, &error);
if (reply) {
HostX.have_shm_fd_passing =
(reply->major_version == 1 && reply->minor_version >= 2) ||
reply->major_version > 1;
free(reply);
}
free(error);
}
}
static Bool
hostx_create_shm_segment(xcb_shm_segment_info_t *shminfo, size_t size)
{
shminfo->shmaddr = NULL;
shminfo->shmid = shmget(IPC_PRIVATE, size, IPC_CREAT|0666);
if (shminfo->shmid != -1) {
shminfo->shmaddr = shmat(shminfo->shmid, 0, 0);
if (shminfo->shmaddr == (void *)-1) {
shminfo->shmaddr = NULL;
} else {
xcb_generic_error_t *error = NULL;
xcb_void_cookie_t cookie;
shmctl(shminfo->shmid, IPC_RMID, 0);
if (HostX.have_shm_fd_passing) {
xcb_generic_error_t *error = NULL;
xcb_shm_create_segment_cookie_t cookie;
xcb_shm_create_segment_reply_t *reply;
shminfo->shmseg = xcb_generate_id(HostX.conn);
cookie = xcb_shm_create_segment(HostX.conn, shminfo->shmseg, size, TRUE);
reply = xcb_shm_create_segment_reply(HostX.conn, cookie, &error);
if (!error && reply && reply->nfd == 1) {
int *fds = xcb_shm_create_segment_reply_fds(HostX.conn, reply);
if (fds) {
shminfo->shmaddr =
(uint8_t *)mmap(0, size, PROT_READ|PROT_WRITE, MAP_SHARED, fds[0], 0);
close(fds[0]);
if (shminfo->shmaddr == MAP_FAILED)
shminfo->shmaddr = NULL;
}
}
free(error);
free(reply);
} else {
shminfo->shmid = shmget(IPC_PRIVATE, size, IPC_CREAT|0666);
if (shminfo->shmid != -1) {
shminfo->shmaddr = shmat(shminfo->shmid, 0, 0);
if (shminfo->shmaddr == (void *)-1) {
shminfo->shmaddr = NULL;
} else {
xcb_generic_error_t *error = NULL;
xcb_void_cookie_t cookie;
shmctl(shminfo->shmid, IPC_RMID, 0);
shminfo->shmseg = xcb_generate_id(HostX.conn);
cookie = xcb_shm_attach_checked(HostX.conn, shminfo->shmseg, shminfo->shmid, TRUE);
error = xcb_request_check(HostX.conn, cookie);
shminfo->shmseg = xcb_generate_id(HostX.conn);
cookie = xcb_shm_attach_checked(HostX.conn, shminfo->shmseg, shminfo->shmid, TRUE);
error = xcb_request_check(HostX.conn, cookie);
if (error) {
free(error);
shmdt(shminfo->shmaddr);
shminfo->shmaddr = NULL;
if (error) {
free(error);
shmdt(shminfo->shmaddr);
shminfo->shmaddr = NULL;
}
}
}
}
......@@ -448,10 +498,15 @@ hostx_create_shm_segment(xcb_shm_segment_info_t *shminfo, size_t size)
}
static void
hostx_destroy_shm_segment(xcb_shm_segment_info_t *shminfo)
hostx_destroy_shm_segment(xcb_shm_segment_info_t *shminfo, size_t size)
{
xcb_shm_detach(HostX.conn, shminfo->shmseg);
shmdt(shminfo->shmaddr);
if (HostX.have_shm_fd_passing)
munmap(shminfo->shmaddr, size);
else
shmdt(shminfo->shmaddr);
shminfo->shmaddr = NULL;
}
......@@ -676,21 +731,18 @@ hostx_init(void)
}
}
/* Try to get share memory ximages for a little bit more speed */
if (!hostx_has_extension(&xcb_shm_id) || getenv("XEPHYR_NO_SHM")) {
fprintf(stderr, "\nXephyr unable to use SHM XImages\n");
HostX.have_shm = FALSE;
}
else {
hostx_init_shm();
if (HostX.have_shm) {
/* Really really check we have shm - better way ?*/
xcb_shm_segment_info_t shminfo;
HostX.have_shm = TRUE;
if (!hostx_create_shm_segment(&shminfo, 1)) {
fprintf(stderr, "\nXephyr unable to use SHM XImages\n");
HostX.have_shm = FALSE;
} else {
hostx_destroy_shm_segment(&shminfo);
hostx_destroy_shm_segment(&shminfo, 1);
}
} else {
fprintf(stderr, "\nXephyr unable to use SHM XImages\n");
}
xcb_flush(HostX.conn);
......@@ -837,7 +889,7 @@ hostx_screen_init(KdScreenInfo *screen,
if (HostX.have_shm) {
xcb_shm_detach(HostX.conn, scrpriv->shminfo.shmseg);
xcb_image_destroy(scrpriv->ximg);
hostx_destroy_shm_segment(&scrpriv->shminfo);
hostx_destroy_shm_segment(&scrpriv->shminfo, scrpriv->shmsize);
}
else {
free(scrpriv->ximg->data);
......@@ -857,8 +909,9 @@ hostx_screen_init(KdScreenInfo *screen,
~0,
NULL);
scrpriv->shmsize = scrpriv->ximg->stride * buffer_height;
if (!hostx_create_shm_segment(&scrpriv->shminfo,
scrpriv->ximg->stride * buffer_height)) {
scrpriv->shmsize)) {
EPHYR_DBG
("Can't create SHM Segment, falling back to plain XImages");
HostX.have_shm = FALSE;
......
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