When starting an xorg-server 1.17.4 session that runs within a virtual machine (virtualbox 5.0.12) I get the following reproducible crash: (EE) Backtrace: (EE) 0: /usr/bin/X (xorg_backtrace+0x56) [0x5da016] (EE) 1: /usr/bin/X (0x400000+0x1df1b9) [0x5df1b9] (EE) 2: /lib64/libc.so.6 (0x7f027ff72000+0x333f0) [0x7f027ffa53f0] (EE) 3: /usr/bin/X (xf86SlowBcopy+0xc9) [0x4baa19] (EE) 4: /usr/lib64/xorg/modules/libvgahw.so (vgaHWSaveFonts+0x16b) [0x7f027b457adb] (EE) 5: /usr/lib64/xorg/modules/drivers/vboxvideo_drv.so (0x7f027ba85000+0x5682) [0x7f027ba8a682] (EE) 6: /usr/bin/X (AddScreen+0x1c5) [0x43b285] (EE) 7: /usr/bin/X (InitOutput+0x497) [0x490007] (EE) 8: /usr/bin/X (0x400000+0x3f724) [0x43f724] (EE) 9: /lib64/libc.so.6 (__libc_start_main+0xf0) [0x7f027ff927b0] (EE) 10: /usr/bin/X (_start+0x29) [0x426f29] (EE) (EE) Illegal instruction at address 0x4baa19 (EE) Fatal server error: (EE) Caught signal 4 (Illegal instruction). Server aborting The culprit are SSE instructions in xf86SlowBcopy (point 3 of the above backtrace). More information is here: http://docs.freebsd.org/cgi/getmsg.cgi?fetch=3723422+0+/usr/local/www/mailindex/archive/2015/svn-ports-all/20150906.svn-ports-all I adapted the patch in the above FreeBSD commit and it solves the problem for me: --- hw/xfree86/os-support/misc/Makefile.in.orig 2016-01-03 16:06:39.058077040 +1100 +++ hw/xfree86/os-support/misc/Makefile.in 2016-01-03 16:10:46.004479596 +1100 @@ -530,7 +530,8 @@ #AM_LDFLAGS = -r AM_CPPFLAGS = $(XORG_INCS) -AM_CFLAGS = $(XORG_CFLAGS) $(DIX_CFLAGS) +@I386_VIDEO_TRUE@I386_VIDEO_CFLAGS = -mno-sse +AM_CFLAGS = $(I386_VIDEO_CFLAGS) $(XORG_CFLAGS) $(DIX_CFLAGS) EXTRA_DIST = $(I386_SRCS) $(PORTIO_SRCS) all: all-am Reproducible: Always Steps to Reproduce: 1. boot up your gentoo Linux virtualbox 2. start an Xsession 3. Actual Results: xorg-server crashes Expected Results: don't crash ;-)
Are you applying CFLAGS that imply sse? Does vbox not pass through sse instructions?
