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[Qemu-devel] [PULL 2/3] hw/display/ramfb: lock guest resolution after it
From: |
Gerd Hoffmann |
Subject: |
[Qemu-devel] [PULL 2/3] hw/display/ramfb: lock guest resolution after it's set |
Date: |
Fri, 24 May 2019 10:57:16 +0200 |
From: Hou Qiming <address@hidden>
Only allow one resolution change per guest boot, which prevents a
crash when the guest writes garbage to the configuration space (e.g.
when rebooting).
Signed-off-by: HOU Qiming <address@hidden>
Signed-off-by: Marcel Apfelbaum <address@hidden>
Message-id: address@hidden
[fixed malformed patch]
Signed-off-by: Marcel Apfelbaum <address@hidden>
Signed-off-by: Gerd Hoffmann <address@hidden>
---
hw/display/ramfb.c | 26 ++++++++++++++++++++++----
1 file changed, 22 insertions(+), 4 deletions(-)
diff --git a/hw/display/ramfb.c b/hw/display/ramfb.c
index 1955b048dd24..0fe79aa8565f 100644
--- a/hw/display/ramfb.c
+++ b/hw/display/ramfb.c
@@ -30,6 +30,7 @@ struct RAMFBState {
DisplaySurface *ds;
uint32_t width, height;
struct RAMFBCfg cfg;
+ bool locked;
};
static void ramfb_unmap_display_surface(pixman_image_t *image, void *unused)
@@ -70,18 +71,25 @@ static DisplaySurface *ramfb_create_display_surface(int
width, int height,
static void ramfb_fw_cfg_write(void *dev, off_t offset, size_t len)
{
RAMFBState *s = dev;
- uint32_t fourcc, format;
+ uint32_t fourcc, format, width, height;
hwaddr stride, addr;
- s->width = be32_to_cpu(s->cfg.width);
- s->height = be32_to_cpu(s->cfg.height);
+ width = be32_to_cpu(s->cfg.width);
+ height = be32_to_cpu(s->cfg.height);
stride = be32_to_cpu(s->cfg.stride);
fourcc = be32_to_cpu(s->cfg.fourcc);
addr = be64_to_cpu(s->cfg.addr);
format = qemu_drm_format_to_pixman(fourcc);
fprintf(stderr, "%s: %dx%d @ 0x%" PRIx64 "\n", __func__,
- s->width, s->height, addr);
+ width, height, addr);
+ if (s->locked) {
+ fprintf(stderr, "%s: resolution locked, change rejected\n", __func__);
+ return;
+ }
+ s->locked = true;
+ s->width = width;
+ s->height = height;
s->ds = ramfb_create_display_surface(s->width, s->height,
format, stride, addr);
}
@@ -101,6 +109,13 @@ void ramfb_display_update(QemuConsole *con, RAMFBState *s)
dpy_gfx_update_full(con);
}
+static void ramfb_reset(void *opaque)
+{
+ RAMFBState *s = (RAMFBState *)opaque;
+ s->locked = false;
+ memset(&s->cfg, 0, sizeof(s->cfg));
+}
+
RAMFBState *ramfb_setup(Error **errp)
{
FWCfgState *fw_cfg = fw_cfg_find();
@@ -113,9 +128,12 @@ RAMFBState *ramfb_setup(Error **errp)
s = g_new0(RAMFBState, 1);
+ s->locked = false;
+
rom_add_vga("vgabios-ramfb.bin");
fw_cfg_add_file_callback(fw_cfg, "etc/ramfb",
NULL, ramfb_fw_cfg_write, s,
&s->cfg, sizeof(s->cfg), false);
+ qemu_register_reset(ramfb_reset, s);
return s;
}
--
2.18.1