ce079f6d87
Add mmap_read_lock/unlock around vma_lookup(). The core code requires this for lookups. Since we only check if the return value is NULL, we can immediately unlock. This fixes the following splat in the selftes: i915: Running i915_gem_mman_live_selftests/igt_mmap ------------[ cut here ]------------ WARNING: CPU: 3 PID: 5654 at include/linux/mmap_lock.h:164 find_vma+0x4e/0xb0 Modules linked in: i915(+) vgem fuse snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic ledtrig_audio mei_hdcp x86_pkg_temp_thermal coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_intel_dspcfg snd_hda_codec snd_hwdep e1000e snd_hda_core ptp snd_pcm ttm mei_me pps_core i2c_i801 prime_numbers i2c_smbus mei [last unloaded: i915] CPU: 3 PID: 5654 Comm: i915_selftest Tainted: G U 5.15.0-rc1-CI-Trybot_7984+ #1 Hardware name: Micro-Star International Co., Ltd. MS-7B54/Z370M MORTAR (MS-7B54), BIOS 1.00 10/31/2017 RIP: 0010:find_vma+0x4e/0xb0 Code: de 48 89 ef e8 d3 94 fe ff 48 85 c0 74 34 48 83 c4 08 5b 5d c3 48 8d bf 28 01 00 00 be ff ff ff ff e8 d6 46 8b 00 85 c0 75 c8 <0f> 0b 48 8b 85 b8 00 00 00 48 85 c0 75 c6 48 89 ef e8 12 26 87 00 RSP: 0018:ffffc900013df980 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00007f9df2b80000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffff822e314c RDI: ffffffff8233c83f RBP: ffff88811bafc840 R08: ffff888107d0ddb8 R09: 00000000fffffffe R10: 0000000000000001 R11: 00000000ffbae7ba R12: 0000000000000000 R13: 0000000000000000 R14: ffff88812a710000 R15: ffff888114fa42c0 FS: 00007f9def9d4c00(0000) GS:ffff888266580000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f799627fe50 CR3: 000000011bbc2006 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __igt_mmap+0xe0/0x490 [i915] igt_mmap+0xd2/0x160 [i915] ? __trace_bprintk+0x6e/0x80 __i915_subtests.cold.7+0x42/0x92 [i915] ? i915_perf_selftests+0x20/0x20 [i915] ? __i915_nop_setup+0x10/0x10 [i915] __run_selftests.part.3+0x10d/0x172 [i915] i915_live_selftests.cold.5+0x1f/0x47 [i915] i915_pci_probe+0x93/0x1d0 [i915] Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Closes: https://gitlab.freedesktop.org/drm/intel/issues/4129 Link: https://patchwork.freedesktop.org/patch/msgid/20210915105946.394412-1-maarten.lankhorst@linux.intel.com Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.