Subject: valgrind: does not notice Intel DRI mapping in client process Package: valgrind Version: 1:3.14.0-3 Severity: normal Tags: upstream
Hi, I'm trying to debug a program that renders using OpenGL, so for direct rendering, a portion of video ram is directly mapped into client address space for the command queue. Valgrind doesn't notice this mapping being made, so all commands are treated as invalid accesses: ==7997== Invalid write of size 4 ==7997== at 0x4EDAFBD2: ??? (in /usr/lib/x86_64-linux-gnu/dri/i965_dri.so) ==7997== by 0x285B0242: ??? (in /usr/lib/x86_64-linux-gnu/libGLX_mesa.so.0.0.0) ==7997== by 0x4891C5A: wxGLCanvasX11::SwapBuffers() (glx11.cpp:604) [...] ==7997== Address 0x7fea79042944 is not stack'd, malloc'd or (recently) free'd The mapping can be found in /proc/7997/maps: [...] 7fea76937000-7fea77037000 rw-s 00000000 00:18 7365028 /i915 (deleted) 7fea77037000-7fea79037000 rw-s 00000000 00:18 7366173 /i915 (deleted) 7fea79037000-7fea7903b000 rw-s 00000000 00:18 7369037 /i915 (deleted) 7fea7903b000-7fea7903f000 rw-s 00000000 00:18 7369035 /i915 (deleted) 7fea7903f000-7fea79044000 rw-s 00000000 00:18 7369034 /i915 (deleted) This generates a few thousand error messages for each drawing operation, and valgrind soon stops reporting errors. It appears as if the memory is mapped through the DRM_IOCTL_I915_GEM_MMAP ioctl on the DRM device. Simon - -- System Information: Debian Release: 10.1 APT prefers stable APT policy: (990, 'stable'), (500, 'stable-updates'), (500, 'stable-debug') Architecture: amd64 (x86_64) Foreign Architectures: i386, armhf Kernel: Linux 4.19.0-5-amd64 (SMP w/8 CPU cores) Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C), LANGUAGE=de_DE.UTF-8 (charmap=ANSI_X3.4-1968) (ignored: LC_ALL set to C) Shell: /bin/sh linked to /bin/dash Init: sysvinit (via /sbin/init) LSM: AppArmor: enabled Versions of packages valgrind depends on: ii libc6 2.28-10 ii libc6-dbg 2.28-10 Versions of packages valgrind recommends: ii gdb 8.2.1-2+b1 ii valgrind-dbg 1:3.14.0-3 Versions of packages valgrind suggests: pn alleyoop <none> pn kcachegrind <none> pn valgrind-mpi <none> pn valkyrie <none> - -- no debconf information -----BEGIN PGP SIGNATURE----- iQEyBAEBCgAdFiEEtjuqOJSXmNjSiX3Tfr04e7CZCBEFAl2o5V8ACgkQfr04e7CZ CBFAsQf40e/X0514ViMhCmL39Cy0cotKtjSKcbCEoVGHprTYU0MASitWIGqE1JGs 54pVZC/FCWV7N7EnElU2hHOaN5kbQOfWfvri+5XURupn9YiVd7Rj+THI2exGXFw2 aQEWIGhowjRh7s84CI8bkb3FgOqX5MxE8Mncypxi5O9bCmDzujwuMcm9if5zLFdh Mk4b1CYtTffx9Ua5Qo7z/yXa/4QnkAOTn6iA9g3FJhAJzC59bPUmCJI2nG4YGBjz HCPRGS10AFEyUbQfYrDWxsIUG32suulqMbjo41yVLTXr4GNqdBAHhnanQBQShcNB O+tNmrrmIPt2DpFXN7ZyH5fkQduE =LWj0 -----END PGP SIGNATURE-----
