Re: [Qemu-devel] [PATCH v2] vga: stop passing pointers to vga_draw_line* functions

[David Buchanan <d@vidbuchanan.co.uk>]

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On 09/10/17 13:56, Gerd Hoffmann wrote:
> How do you start
> qemu?  Which user interface?

Like this:
qemu-system-x86_64 -vga cirrus [disk image]

(which I assume is using the GTK interface)

I have attached the reproducer NASM source and disk image.
Note that the reproducer is using VBE.

> Have you seen a stacktrace with pixman in there?  Care to share it?

#0  0x00007fffe1c2bf61 in  () at /usr/lib/libpixman-1.so.0
#1  0x00007fffe1c385db in  () at /usr/lib/libpixman-1.so.0
#2  0x00007fffe1c38991 in  () at /usr/lib/libpixman-1.so.0
#3  0x00007fffe1c6eb7c in  () at /usr/lib/libpixman-1.so.0
#4  0x00007fffe1c2aca1 in pixman_image_composite32 () at
/usr/lib/libpixman-1.so.0
#5  0x0000555555be5630 in gd_switch (dcl=0x555557e088b0,
surface=0x555556d76ac0) at /tmp/qemu/ui/gtk.c:628
#6  0x0000555555bb216a in dpy_gfx_replace_surface (con=0x5555569718d0,
surface=0x555556d76ac0)
    at /tmp/qemu/ui/console.c:1552
#7  0x000055555580aab6 in vga_draw_graphic (s=0x5555576de2c0,
full_update=0x1) at /tmp/qemu/hw/display/vga.c:1561
#8  0x000055555580b388 in vga_update_display (opaque=0x5555576de2c0) at
/tmp/qemu/hw/display/vga.c:1756
#9  0x0000555555bae64d in graphic_hw_update (con=0x5555569718d0) at
/tmp/qemu/ui/console.c:263
#10 0x0000555555be50f8 in gd_refresh (dcl=0x555557e088b0) at
/tmp/qemu/ui/gtk.c:493
#11 0x0000555555bb22a8 in dpy_refresh (s=0x5555577b05c0) at
/tmp/qemu/ui/console.c:1589
#12 0x0000555555bae362 in gui_update (opaque=0x5555577b05c0) at
/tmp/qemu/ui/console.c:201
#13 0x0000555555d20445 in timerlist_run_timers
(timer_list=0x555556928210) at /tmp/qemu/util/qemu-timer.c:536
#14 0x0000555555d204a2 in qemu_clock_run_timers
(type=QEMU_CLOCK_REALTIME) at /tmp/qemu/util/qemu-timer.c:547
#15 0x0000555555d208fe in qemu_clock_run_all_timers () at
/tmp/qemu/util/qemu-timer.c:662
#16 0x0000555555d21125 in main_loop_wait (nonblocking=0x0) at
/tmp/qemu/util/main-loop.c:521
#17 0x0000555555926553 in main_loop () at /tmp/qemu/vl.c:1995
#18 0x000055555592e793 in main (argc=0x4, argv=0x7fffffffe218,
envp=0x7fffffffe240) at /tmp/qemu/vl.c:4902
#19 0x00007fffdc663f6a in __libc_start_main () at /usr/lib/libc.so.6
#20 0x000055555577394a in _start ()

Thanks.

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: poc.asm --]
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	BITS	16

	ORG	0x7C00

	mov	ax, 0x4F02
	mov	bx, 0x4118 ; 1024x768x24, LFB enabled
	int	0x10 ; init VESA graphics via BIOS
	
	
	mov	dx, 0x3d4
	mov	al, 0x1d
	out	dx, al
	
	mov	dx, 0x3d5
	in	al, dx
	or	al, 0x80
	out	dx, al

	jmp	$

	TIMES	510-($-$$) DB 0
	DW	0xAA55		; boot signature

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