qemu-e2k/hw/display/ati_2d.c
BALATON Zoltan ac2071c379 ati-vga: Fix checks in ati_2d_blt() to avoid crash
In some corner cases (that never happen during normal operation but a
malicious guest could program wrong values) pixman functions were
called with parameters that result in a crash. Fix this and add more
checks to disallow such cases.

Reported-by: Ziming Zhang <ezrakiez@gmail.com>
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-id: 20200406204029.19559747D5D@zero.eik.bme.hu
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2020-04-07 09:25:23 +02:00

205 lines
8.3 KiB
C

/*
* QEMU ATI SVGA emulation
* 2D engine functions
*
* Copyright (c) 2019 BALATON Zoltan
*
* This work is licensed under the GNU GPL license version 2 or later.
*/
#include "qemu/osdep.h"
#include "ati_int.h"
#include "ati_regs.h"
#include "qemu/log.h"
#include "ui/pixel_ops.h"
/*
* NOTE:
* This is 2D _acceleration_ and supposed to be fast. Therefore, don't try to
* reinvent the wheel (unlikely to get better with a naive implementation than
* existing libraries) and avoid (poorly) reimplementing gfx primitives.
* That is unnecessary and would become a performance problem. Instead, try to
* map to and reuse existing optimised facilities (e.g. pixman) wherever
* possible.
*/
static int ati_bpp_from_datatype(ATIVGAState *s)
{
switch (s->regs.dp_datatype & 0xf) {
case 2:
return 8;
case 3:
case 4:
return 16;
case 5:
return 24;
case 6:
return 32;
default:
qemu_log_mask(LOG_UNIMP, "Unknown dst datatype %d\n",
s->regs.dp_datatype & 0xf);
return 0;
}
}
#define DEFAULT_CNTL (s->regs.dp_gui_master_cntl & GMC_DST_PITCH_OFFSET_CNTL)
void ati_2d_blt(ATIVGAState *s)
{
/* FIXME it is probably more complex than this and may need to be */
/* rewritten but for now as a start just to get some output: */
DisplaySurface *ds = qemu_console_surface(s->vga.con);
DPRINTF("%p %u ds: %p %d %d rop: %x\n", s->vga.vram_ptr,
s->vga.vbe_start_addr, surface_data(ds), surface_stride(ds),
surface_bits_per_pixel(ds),
(s->regs.dp_mix & GMC_ROP3_MASK) >> 16);
unsigned dst_x = (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ?
s->regs.dst_x : s->regs.dst_x + 1 - s->regs.dst_width);
unsigned dst_y = (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ?
s->regs.dst_y : s->regs.dst_y + 1 - s->regs.dst_height);
int bpp = ati_bpp_from_datatype(s);
if (!bpp) {
qemu_log_mask(LOG_GUEST_ERROR, "Invalid bpp\n");
return;
}
int dst_stride = DEFAULT_CNTL ? s->regs.dst_pitch : s->regs.default_pitch;
if (!dst_stride) {
qemu_log_mask(LOG_GUEST_ERROR, "Zero dest pitch\n");
return;
}
uint8_t *dst_bits = s->vga.vram_ptr + (DEFAULT_CNTL ?
s->regs.dst_offset : s->regs.default_offset);
if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
dst_bits += s->regs.crtc_offset & 0x07ffffff;
dst_stride *= bpp;
}
uint8_t *end = s->vga.vram_ptr + s->vga.vram_size;
if (dst_bits >= end || dst_bits + dst_x + (dst_y + s->regs.dst_height) *
dst_stride >= end) {
qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
return;
}
DPRINTF("%d %d %d, %d %d %d, (%d,%d) -> (%d,%d) %dx%d %c %c\n",
s->regs.src_offset, s->regs.dst_offset, s->regs.default_offset,
s->regs.src_pitch, s->regs.dst_pitch, s->regs.default_pitch,
s->regs.src_x, s->regs.src_y, s->regs.dst_x, s->regs.dst_y,
s->regs.dst_width, s->regs.dst_height,
(s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? '>' : '<'),
(s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? 'v' : '^'));
switch (s->regs.dp_mix & GMC_ROP3_MASK) {
case ROP3_SRCCOPY:
{
unsigned src_x = (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ?
s->regs.src_x : s->regs.src_x + 1 - s->regs.dst_width);
unsigned src_y = (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ?
s->regs.src_y : s->regs.src_y + 1 - s->regs.dst_height);
int src_stride = DEFAULT_CNTL ?
s->regs.src_pitch : s->regs.default_pitch;
if (!src_stride) {
qemu_log_mask(LOG_GUEST_ERROR, "Zero source pitch\n");
return;
}
uint8_t *src_bits = s->vga.vram_ptr + (DEFAULT_CNTL ?
s->regs.src_offset : s->regs.default_offset);
if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
src_bits += s->regs.crtc_offset & 0x07ffffff;
src_stride *= bpp;
}
if (src_bits >= end || src_bits + src_x +
(src_y + s->regs.dst_height) * src_stride >= end) {
qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
return;
}
src_stride /= sizeof(uint32_t);
dst_stride /= sizeof(uint32_t);
DPRINTF("pixman_blt(%p, %p, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d)\n",
src_bits, dst_bits, src_stride, dst_stride, bpp, bpp,
src_x, src_y, dst_x, dst_y,
s->regs.dst_width, s->regs.dst_height);
if (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT &&
s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM) {
pixman_blt((uint32_t *)src_bits, (uint32_t *)dst_bits,
src_stride, dst_stride, bpp, bpp,
src_x, src_y, dst_x, dst_y,
s->regs.dst_width, s->regs.dst_height);
} else {
/* FIXME: We only really need a temporary if src and dst overlap */
int llb = s->regs.dst_width * (bpp / 8);
int tmp_stride = DIV_ROUND_UP(llb, sizeof(uint32_t));
uint32_t *tmp = g_malloc(tmp_stride * sizeof(uint32_t) *
s->regs.dst_height);
pixman_blt((uint32_t *)src_bits, tmp,
src_stride, tmp_stride, bpp, bpp,
src_x, src_y, 0, 0,
s->regs.dst_width, s->regs.dst_height);
pixman_blt(tmp, (uint32_t *)dst_bits,
tmp_stride, dst_stride, bpp, bpp,
0, 0, dst_x, dst_y,
s->regs.dst_width, s->regs.dst_height);
g_free(tmp);
}
if (dst_bits >= s->vga.vram_ptr + s->vga.vbe_start_addr &&
dst_bits < s->vga.vram_ptr + s->vga.vbe_start_addr +
s->vga.vbe_regs[VBE_DISPI_INDEX_YRES] * s->vga.vbe_line_offset) {
memory_region_set_dirty(&s->vga.vram, s->vga.vbe_start_addr +
s->regs.dst_offset +
dst_y * surface_stride(ds),
s->regs.dst_height * surface_stride(ds));
}
s->regs.dst_x = (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ?
dst_x + s->regs.dst_width : dst_x);
s->regs.dst_y = (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ?
dst_y + s->regs.dst_height : dst_y);
break;
}
case ROP3_PATCOPY:
case ROP3_BLACKNESS:
case ROP3_WHITENESS:
{
uint32_t filler = 0;
switch (s->regs.dp_mix & GMC_ROP3_MASK) {
case ROP3_PATCOPY:
filler = s->regs.dp_brush_frgd_clr;
break;
case ROP3_BLACKNESS:
filler = 0xffUL << 24 | rgb_to_pixel32(s->vga.palette[0],
s->vga.palette[1], s->vga.palette[2]);
break;
case ROP3_WHITENESS:
filler = 0xffUL << 24 | rgb_to_pixel32(s->vga.palette[3],
s->vga.palette[4], s->vga.palette[5]);
break;
}
dst_stride /= sizeof(uint32_t);
DPRINTF("pixman_fill(%p, %d, %d, %d, %d, %d, %d, %x)\n",
dst_bits, dst_stride, bpp,
s->regs.dst_x, s->regs.dst_y,
s->regs.dst_width, s->regs.dst_height,
filler);
pixman_fill((uint32_t *)dst_bits, dst_stride, bpp,
s->regs.dst_x, s->regs.dst_y,
s->regs.dst_width, s->regs.dst_height,
filler);
if (dst_bits >= s->vga.vram_ptr + s->vga.vbe_start_addr &&
dst_bits < s->vga.vram_ptr + s->vga.vbe_start_addr +
s->vga.vbe_regs[VBE_DISPI_INDEX_YRES] * s->vga.vbe_line_offset) {
memory_region_set_dirty(&s->vga.vram, s->vga.vbe_start_addr +
s->regs.dst_offset +
dst_y * surface_stride(ds),
s->regs.dst_height * surface_stride(ds));
}
s->regs.dst_y = (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ?
dst_y + s->regs.dst_height : dst_y);
break;
}
default:
qemu_log_mask(LOG_UNIMP, "Unimplemented ati_2d blt op %x\n",
(s->regs.dp_mix & GMC_ROP3_MASK) >> 16);
}
}