From 70f77c510a6fe9ad06ee8d95280aabdc6a09659f Mon Sep 17 00:00:00 2001 From: "Enrico Weigelt, metux IT consult" Date: Wed, 24 Jul 2024 15:38:15 +0200 Subject: [PATCH] (submit/cleanup-vidmode-dispatch) Xext: vidmode: untwist ProcVidModeGetAllModeLines() and use stack buffer The ProcVidModeGetAllModeLines() is a bit complicated, because reply structs differ depending the active protocol version. In order to make it easier to understand and allow further simplification of the request/reply marshalling (see ticket #1701), splitting the two protocol versions into separate functions. Also collecting the whole payload in a stack buffer (size is already known anyways), in order to save arbirary number of individual WriteToClient() calls, but send out the whole reply in one pass, which in turn allows further simplifications in the sending path. Signed-off-by: Enrico Weigelt, metux IT consult --- Xext/vidmode.c | 121 +++++++++++++++++++++++++++++-------------------- 1 file changed, 73 insertions(+), 48 deletions(-) diff --git a/Xext/vidmode.c b/Xext/vidmode.c index 76e6e2974..1a4e02c9a 100644 --- a/Xext/vidmode.c +++ b/Xext/vidmode.c @@ -310,6 +310,72 @@ ProcVidModeGetModeLine(ClientPtr client) return Success; } +static char *fillModeInfoV1(ClientPtr client, char *buf, int dotClock, DisplayModePtr mode) +{ + xXF86OldVidModeModeInfo info = { + .dotclock = dotClock, + .hdisplay = VidModeGetModeValue(mode, VIDMODE_H_DISPLAY), + .hsyncstart = VidModeGetModeValue(mode, VIDMODE_H_SYNCSTART), + .hsyncend = VidModeGetModeValue(mode, VIDMODE_H_SYNCEND), + .htotal = VidModeGetModeValue(mode, VIDMODE_H_TOTAL), + .vdisplay = VidModeGetModeValue(mode, VIDMODE_V_DISPLAY), + .vsyncstart = VidModeGetModeValue(mode, VIDMODE_V_SYNCSTART), + .vsyncend = VidModeGetModeValue(mode, VIDMODE_V_SYNCEND), + .vtotal = VidModeGetModeValue(mode, VIDMODE_V_TOTAL), + .flags = VidModeGetModeValue(mode, VIDMODE_FLAGS), + }; + + if (client->swapped) { + swapl(&info.dotclock); + swaps(&info.hdisplay); + swaps(&info.hsyncstart); + swaps(&info.hsyncend); + swaps(&info.htotal); + swaps(&info.vdisplay); + swaps(&info.vsyncstart); + swaps(&info.vsyncend); + swaps(&info.vtotal); + swapl(&info.flags); + } + + memcpy(buf, &info, sizeof(info)); + return buf + sizeof(info); +} + +static char *fillModeInfoV2(ClientPtr client, char *buf, int dotClock, DisplayModePtr mode) +{ + xXF86VidModeModeInfo info = { + .dotclock = dotClock, + .hdisplay = VidModeGetModeValue(mode, VIDMODE_H_DISPLAY), + .hsyncstart = VidModeGetModeValue(mode, VIDMODE_H_SYNCSTART), + .hsyncend = VidModeGetModeValue(mode, VIDMODE_H_SYNCEND), + .htotal = VidModeGetModeValue(mode, VIDMODE_H_TOTAL), + .hskew = VidModeGetModeValue(mode, VIDMODE_H_SKEW), + .vdisplay = VidModeGetModeValue(mode, VIDMODE_V_DISPLAY), + .vsyncstart = VidModeGetModeValue(mode, VIDMODE_V_SYNCSTART), + .vsyncend = VidModeGetModeValue(mode, VIDMODE_V_SYNCEND), + .vtotal = VidModeGetModeValue(mode, VIDMODE_V_TOTAL), + .flags = VidModeGetModeValue(mode, VIDMODE_FLAGS), + }; + + if (client->swapped) { + swapl(&info.dotclock); + swaps(&info.hdisplay); + swaps(&info.hsyncstart); + swaps(&info.hsyncend); + swaps(&info.htotal); + swapl(&info.hskew); + swaps(&info.vdisplay); + swaps(&info.vsyncstart); + swaps(&info.vsyncend); + swaps(&info.vtotal); + swapl(&info.flags); + } + + memcpy(buf, &info, sizeof(info)); + return buf + sizeof(info); +} + static int ProcVidModeGetAllModeLines(ClientPtr client) { @@ -357,57 +423,16 @@ ProcVidModeGetAllModeLines(ClientPtr client) } WriteToClient(client, sizeof(xXF86VidModeGetAllModeLinesReply), &rep); - do { - xXF86VidModeModeInfo mdinf = { - .dotclock = dotClock, - .hdisplay = VidModeGetModeValue(mode, VIDMODE_H_DISPLAY), - .hsyncstart = VidModeGetModeValue(mode, VIDMODE_H_SYNCSTART), - .hsyncend = VidModeGetModeValue(mode, VIDMODE_H_SYNCEND), - .htotal = VidModeGetModeValue(mode, VIDMODE_H_TOTAL), - .hskew = VidModeGetModeValue(mode, VIDMODE_H_SKEW), - .vdisplay = VidModeGetModeValue(mode, VIDMODE_V_DISPLAY), - .vsyncstart = VidModeGetModeValue(mode, VIDMODE_V_SYNCSTART), - .vsyncend = VidModeGetModeValue(mode, VIDMODE_V_SYNCEND), - .vtotal = VidModeGetModeValue(mode, VIDMODE_V_TOTAL), - .flags = VidModeGetModeValue(mode, VIDMODE_FLAGS), - .privsize = 0 - }; - if (client->swapped) { - swapl(&mdinf.dotclock); - swaps(&mdinf.hdisplay); - swaps(&mdinf.hsyncstart); - swaps(&mdinf.hsyncend); - swaps(&mdinf.htotal); - swapl(&mdinf.hskew); - swaps(&mdinf.vdisplay); - swaps(&mdinf.vsyncstart); - swaps(&mdinf.vsyncend); - swaps(&mdinf.vtotal); - swapl(&mdinf.flags); - swapl(&mdinf.privsize); - } - if (ver < 2) { - xXF86OldVidModeModeInfo oldmdinf = { - .dotclock = mdinf.dotclock, - .hdisplay = mdinf.hdisplay, - .hsyncstart = mdinf.hsyncstart, - .hsyncend = mdinf.hsyncend, - .htotal = mdinf.htotal, - .vdisplay = mdinf.vdisplay, - .vsyncstart = mdinf.vsyncstart, - .vsyncend = mdinf.vsyncend, - .vtotal = mdinf.vtotal, - .flags = mdinf.flags, - .privsize = mdinf.privsize - }; - WriteToClient(client, sizeof(xXF86OldVidModeModeInfo), &oldmdinf); - } - else { - WriteToClient(client, sizeof(xXF86VidModeModeInfo), &mdinf); - } + char payload[payload_len]; + char *walk = payload; + do { + walk = (ver < 2) ? fillModeInfoV1(client, walk, dotClock, mode) + : fillModeInfoV2(client, walk, dotClock, mode); } while (pVidMode->GetNextModeline(pScreen, &mode, &dotClock)); + WriteToClient(client, sizeof(payload), payload); + return Success; }