Minimal supplement to upstream Kernel Self Protection Project changes. Features already provided by SELinux + Yama and archs other than multiarch arm64 / x86_64 aren't in scope. Only tags have stable history. Shared IRC channel with KSPP: irc.libera.chat #linux-hardening
e0ec3ec698
The goal of the WARN was to catch when we are still actively using the
fence as we go into the runtime suspend. However, the reg->pin_count is
too coarse as it does not distinguish between exclusive ownership of the
fence register from activity.
I've not improved on the WARN, nor have we captured this WARN in an
exact igt, but it is showing up regularly in the wild:
[ 1915.935332] WARNING: CPU: 1 PID: 10861 at drivers/gpu/drm/i915/i915_gem.c:2022 i915_gem_runtime_suspend+0x116/0x130 [i915]
[ 1915.935383] WARN_ON(reg->pin_count)[ 1915.935399] Modules linked in:
snd_hda_intel i915 drm_kms_helper vgem netconsole scsi_transport_iscsi fuse vfat fat x86_pkg_temp_thermal coretemp intel_cstate intel_uncore snd_hda_codec_hdmi snd_hda_codec_generic snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mei_me mei serio_raw intel_rapl_perf intel_pch_thermal soundcore wmi acpi_pad i2c_algo_bit syscopyarea sysfillrect sysimgblt fb_sys_fops drm r8169 mii video [last unloaded: drm_kms_helper]
[ 1915.935785] CPU: 1 PID: 10861 Comm: kworker/1:0 Tainted: G U W 4.9.0-rc5+ #170
[ 1915.935799] Hardware name: LENOVO 80MX/Lenovo E31-80, BIOS DCCN34WW(V2.03) 12/01/2015
[ 1915.935822] Workqueue: pm pm_runtime_work
[ 1915.935845] ffffc900044fbbf0 ffffffffac3220bc ffffc900044fbc40 0000000000000000
[ 1915.935890] ffffc900044fbc30 ffffffffac059bcb 000007e6044fbc60 ffff8801626e3198
[ 1915.935937] ffff8801626e0000 0000000000000002 ffffffffc05e5d4e 0000000000000000
[ 1915.935985] Call Trace:
[ 1915.936013] [<ffffffffac3220bc>] dump_stack+0x4f/0x73
[ 1915.936038] [<ffffffffac059bcb>] __warn+0xcb/0xf0
[ 1915.936060] [<ffffffffac059c4f>] warn_slowpath_fmt+0x5f/0x80
[ 1915.936158] [<ffffffffc052d916>] i915_gem_runtime_suspend+0x116/0x130 [i915]
[ 1915.936251] [<ffffffffc04f1c74>] intel_runtime_suspend+0x64/0x280 [i915]
[ 1915.936277] [<ffffffffac0926f1>] ? dequeue_entity+0x241/0xbc0
[ 1915.936298] [<ffffffffac36bb85>] pci_pm_runtime_suspend+0x55/0x180
[ 1915.936317] [<ffffffffac36bb30>] ? pci_pm_runtime_resume+0xa0/0xa0
[ 1915.936339] [<ffffffffac4514e2>] __rpm_callback+0x32/0x70
[ 1915.936356] [<ffffffffac451544>] rpm_callback+0x24/0x80
[ 1915.936375] [<ffffffffac36bb30>] ? pci_pm_runtime_resume+0xa0/0xa0
[ 1915.936392] [<ffffffffac45222d>] rpm_suspend+0x12d/0x680
[ 1915.936415] [<ffffffffac69f6d7>] ? _raw_spin_unlock_irq+0x17/0x30
[ 1915.936435] [<ffffffffac0810b8>] ? finish_task_switch+0x88/0x220
[ 1915.936455] [<ffffffffac4534bf>] pm_runtime_work+0x6f/0xb0
[ 1915.936477] [<ffffffffac074353>] process_one_work+0x1f3/0x4d0
[ 1915.936501] [<ffffffffac074678>] worker_thread+0x48/0x4e0
[ 1915.936523] [<ffffffffac074630>] ? process_one_work+0x4d0/0x4d0
[ 1915.936542] [<ffffffffac074630>] ? process_one_work+0x4d0/0x4d0
[ 1915.936559] [<ffffffffac07a2c9>] kthread+0xd9/0xf0
[ 1915.936580] [<ffffffffac07a1f0>] ? kthread_park+0x60/0x60
[ 1915.936600] [<ffffffffac69fe62>] ret_from_fork+0x22/0x30
In the case the register is pinned, it should be present and we will
need to invalidate them to be restored upon resume as we cannot expect
the owner of the pin to call get_fence prior to use after resume.
Fixes:
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.