Created attachment 116015 [details] Xorg log after segfault Summary: on x86_64 linuxfromscratch, with current released versions of everything, if I use the default sna acceleration with a 4.0 kernel (tested with 4.0.3 and 4.0.4) Xorg segfaults while trying to start. Oddly, if I build a 3.19.0 kernel (still using gcc-5) on the same sytem, it is fine. With 4.0 kernels, if I enable uxa and force that in a conf file Xorg works fine. This is a SandyBridge running as x86_64 : processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz stepping : 7 lspci says: 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller]) Subsystem: Gigabyte Technology Co., Ltd 2nd Generation Core Processor Family Integrated Graphics Controller Flags: bus master, fast devsel, latency 0, IRQ 24 Memory at f7800000 (64-bit, non-prefetchable) [size=4M] Memory at e0000000 (64-bit, prefetchable) [size=256M] I/O ports at f000 [size=64] Expansion ROM at <unassigned> [disabled] Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit- Capabilities: [d0] Power Management version 2 Capabilities: [a4] PCI Advanced Features Kernel driver in use: i915 Main package versions xf86-video-intel-2.99.917 xorg-server-1.17.1 mesa-10.5.5 libdrm-2.4.61 This is using the VGA connector Steps to reproduce: run 'startx'
Created attachment 116016 [details] full backtrace from gdb
Created attachment 116017 [details] dmesg with drm.debug=0x06, from boot until the segfault
It's libdrm fallout, already fixed though I want to look at that bt more.
To get past the mmap failure, needs a libdrm fix or the ddx w/a. However, that crash should not happen, so: commit 8b7bdff750a98fc7644fc9ab17bedc79b03198b4 Author: Chris Wilson <chris@chris-wilson.co.uk> Date: Mon May 25 08:02:46 2015 +0100 sna: Initialise no-op callbacks early In case of error, we try to free up memory before trying again. This involves callbacks into higher level code - but if we fail early, we will not have those hooks installed. Set no-ops stubs early to prevent untimely crashes. References: https://bugs.freedesktop.org/show_bug.cgi?id=90622#c1 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
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