Bug 111376

hi, confirming the crash. In my case I cut installation script (check below).
I believe that simply iris enabled would be enough.

meson setup . mbuild_dbg_x64 \
-Dplatforms=surfaceless,x11,wayland,drm \
-Dprefix=/home/den/mesa64/mesa-commit_test/ \
-Dlmsensors=true \
-Dlibunwind=false \
-Dgallium-nine=false \
-Dgallium-xa=false \
-Dgallium-xvmc=false \
-Dgallium-opencl=disabled \
-Dglx-read-only-text=false \
-Dosmesa=none \
-Dbuild-tests=false \
-Dglx=dri \
-Dshared-glapi=true \
-Ddri3=true \
-Degl=true \
-Dgbm=true \
-Dgles1=false \
-Dgles2=true \
-Dglvnd=false \
-Dselinux=false \
-Dvalgrind=false \
-Ddri-drivers= \
-Dgallium-drivers=iris \
-Dvulkan-drivers= \
-Dvulkan-overlay-layer=true \
-Db_ndebug=true \
-Dbuildtype=debug

Mike,

Your last comment does not configure LTO/O3.  Does this reproduce for you on debug builds?

What is your hardware and kernel?

thanks!

I suspect it's something crashing in iris_monitor_init_metrics.  The only thing in that commit of real relevance is the new driver hooks, and...

[Sunday, August 11, 2019] [4:13:07 PM PDT] <Kayden> does it help if you drop the iris_screen.c changes?  + pscreen->get_driver_query_group_info = iris_get_monitor_group_info;    and   +   pscreen->get_driver_query_info = iris_get_monitor_info;
[Sunday, August 11, 2019] [4:29:12 PM PDT] <FireBurn>   Yip that worked

I have no idea why LTO would matter.

If I enable debugging and still pass LTO flags in I don't see the issue

I'll see if I can get anything more useful out

Here's a slightly different back trace:

Thread 1 "steam" received signal SIGSEGV, Segmentation fault.
0xf6411277 in ir_function::clone(void*, hash_table*) const () from /usr/lib/dri/iris_dri.so
(gdb) bt
#0  0xf6411277 in ir_function::clone(void*, hash_table*) const () from /usr/lib/dri/iris_dri.so
#1  0xf641ce8c in clone_ir_list(void*, exec_list*, exec_list const*) () from /usr/lib/dri/iris_dri.so
#2  0xf5e0c875 in link_intrastage_shaders(void*, gl_context*, gl_shader_program*, gl_shader**, unsigned int, bool) [clone .constprop.0] () from /usr/lib/dri/iris_dri.so
#3  0xf640c187 in link_shaders(gl_context*, gl_shader_program*) [clone .part.0] () from /usr/lib/dri/iris_dri.so
#4  0xf64c70f3 in _mesa_glsl_link_shader () from /usr/lib/dri/iris_dri.so
#5  0xf66787a2 in _mesa_get_fixed_func_fragment_program () from /usr/lib/dri/iris_dri.so
#6  0xf675c63b in update_program () from /usr/lib/dri/iris_dri.so
#7  0xf6772b0f in _mesa_update_state_locked () from /usr/lib/dri/iris_dri.so
#8  0xf6773217 in _mesa_update_state () from /usr/lib/dri/iris_dri.so
#9  0xf64974a7 in _mesa_Clear () from /usr/lib/dri/iris_dri.so
#10 0xed1a3806 in ?? () from /home/fireburn/.local/share/Steam/ubuntu12_32/vgui2_s.so
#11 0xed1b24ed in ?? () from /home/fireburn/.local/share/Steam/ubuntu12_32/vgui2_s.so
#12 0xf054bc6d in ?? () from /home/fireburn/.local/share/Steam/ubuntu12_32/steamui.so
#13 0xf054bef5 in ?? () from /home/fireburn/.local/share/Steam/ubuntu12_32/steamui.so
#14 0xf053e28f in ?? () from /home/fireburn/.local/share/Steam/ubuntu12_32/steamui.so
#15 0xf0491eaa in ?? () from /home/fireburn/.local/share/Steam/ubuntu12_32/steamui.so
#16 0xf0493c2e in ?? () from /home/fireburn/.local/share/Steam/ubuntu12_32/steamui.so
#17 0x5658e1b0 in RunSteam(int, char**, bool) ()
#18 0x5658f0ab in ?? ()
#19 0x5657a06c in ?? ()
#20 0xf78a5021 in __libc_start_main () from /lib/libc.so.6
#21 0x5657dd29 in _start ()

As a workaround, this disables LTO on GCC just for iris:
---8<---
diff --git a/src/gallium/drivers/iris/meson.build b/src/gallium/drivers/iris/meson.build
index 3f611c2b5698be71ba08..c9f62a877c0df6889411 100644
--- a/src/gallium/drivers/iris/meson.build
+++ b/src/gallium/drivers/iris/meson.build
@@ -85,8 +85,8 @@ libiris = static_library(
     # these should not be necessary, but main/macros.h...
     inc_mesa, inc_mapi
   ],
-  c_args : [c_vis_args, c_sse2_args],
-  cpp_args : [cpp_vis_args, c_sse2_args],
+  c_args : [c_vis_args, c_sse2_args, gcc_lto_quirk],
+  cpp_args : [cpp_vis_args, c_sse2_args, gcc_lto_quirk],
   dependencies : [dep_libdrm, dep_valgrind, idep_genxml, idep_libintel_common],
   link_with : [
     iris_gen_libs, libintel_compiler, libintel_dev, libisl,
--->8---

Does this help?

Have you checked if LTO causes any issues on Clang for instance?

Thanks, I'm currently working around it with:

diff --git a/src/gallium/drivers/iris/iris_screen.c b/src/gallium/drivers/iris/iris_screen.c
index e92685d4ae6..97eaeb15d4d 100644
--- a/src/gallium/drivers/iris/iris_screen.c
+++ b/src/gallium/drivers/iris/iris_screen.c
@@ -684,8 +684,6 @@ iris_screen_create(int fd, const struct pipe_screen_config *config)
    pscreen->flush_frontbuffer = iris_flush_frontbuffer;
    pscreen->get_timestamp = iris_get_timestamp;
    pscreen->query_memory_info = iris_query_memory_info;
-   pscreen->get_driver_query_group_info = iris_get_monitor_group_info;
-   pscreen->get_driver_query_info = iris_get_monitor_info;
 
    return pscreen;
 }

Using clang-10 from git also works around the issue

I think this could be related to glibc 2.30

I've see another issue in libacl with systemd-tmpfiles that looks similar

Hi Mike,

Did you get any more information about glibc 2.30 / 32bit LTO issues?  I'm stumped as to how the bisected commit could trigger a segfault in a completely different code path.

I might be able to change the initialization to defer querying the performance counters until first use.  However, it seems to me that we shouldn't complicate mesa to work around a bug in glibc.

Since this issue can't yet be confirmed as a mesa bug (vs glibc), I'm removing it from the 19.2 release tracker.

No probs, this is Iris only anyway so shouldn't be a blocker at all

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