/* * Kernel module for testing static keys. * * Copyright 2015 Akamai Technologies Inc. All Rights Reserved * * Authors: * Jason Baron * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include /* old keys */ struct static_key old_true_key = STATIC_KEY_INIT_TRUE; struct static_key old_false_key = STATIC_KEY_INIT_FALSE; /* new api */ DEFINE_STATIC_KEY_TRUE(true_key); DEFINE_STATIC_KEY_FALSE(false_key); /* external */ extern struct static_key base_old_true_key; extern struct static_key base_inv_old_true_key; extern struct static_key base_old_false_key; extern struct static_key base_inv_old_false_key; /* new api */ extern struct static_key_true base_true_key; extern struct static_key_true base_inv_true_key; extern struct static_key_false base_false_key; extern struct static_key_false base_inv_false_key; struct test_key { bool init_state; struct static_key *key; bool (*test_key)(void); }; #define test_key_func(key, branch) \ static bool key ## _ ## branch(void) \ { \ return branch(&key); \ } static void invert_key(struct static_key *key) { if (static_key_enabled(key)) static_key_disable(key); else static_key_enable(key); } static void invert_keys(struct test_key *keys, int size) { struct static_key *previous = NULL; int i; for (i = 0; i < size; i++) { if (previous != keys[i].key) { invert_key(keys[i].key); previous = keys[i].key; } } } static int verify_keys(struct test_key *keys, int size, bool invert) { int i; bool ret, init; for (i = 0; i < size; i++) { ret = static_key_enabled(keys[i].key); init = keys[i].init_state; if (ret != (invert ? !init : init)) return -EINVAL; ret = keys[i].test_key(); if (static_key_enabled(keys[i].key)) { if (!ret) return -EINVAL; } else { if (ret) return -EINVAL; } } return 0; } test_key_func(old_true_key, static_key_true) test_key_func(old_false_key, static_key_false) test_key_func(true_key, static_branch_likely) test_key_func(true_key, static_branch_unlikely) test_key_func(false_key, static_branch_likely) test_key_func(false_key, static_branch_unlikely) test_key_func(base_old_true_key, static_key_true) test_key_func(base_inv_old_true_key, static_key_true) test_key_func(base_old_false_key, static_key_false) test_key_func(base_inv_old_false_key, static_key_false) test_key_func(base_true_key, static_branch_likely) test_key_func(base_true_key, static_branch_unlikely) test_key_func(base_inv_true_key, static_branch_likely) test_key_func(base_inv_true_key, static_branch_unlikely) test_key_func(base_false_key, static_branch_likely) test_key_func(base_false_key, static_branch_unlikely) test_key_func(base_inv_false_key, static_branch_likely) test_key_func(base_inv_false_key, static_branch_unlikely) static int __init test_static_key_init(void) { int ret; int size; struct test_key static_key_tests[] = { /* internal keys - old keys */ { .init_state = true, .key = &old_true_key, .test_key = &old_true_key_static_key_true, }, { .init_state = false, .key = &old_false_key, .test_key = &old_false_key_static_key_false, }, /* internal keys - new keys */ { .init_state = true, .key = &true_key.key, .test_key = &true_key_static_branch_likely, }, { .init_state = true, .key = &true_key.key, .test_key = &true_key_static_branch_unlikely, }, { .init_state = false, .key = &false_key.key, .test_key = &false_key_static_branch_likely, }, { .init_state = false, .key = &false_key.key, .test_key = &false_key_static_branch_unlikely, }, /* external keys - old keys */ { .init_state = true, .key = &base_old_true_key, .test_key = &base_old_true_key_static_key_true, }, { .init_state = false, .key = &base_inv_old_true_key, .test_key = &base_inv_old_true_key_static_key_true, }, { .init_state = false, .key = &base_old_false_key, .test_key = &base_old_false_key_static_key_false, }, { .init_state = true, .key = &base_inv_old_false_key, .test_key = &base_inv_old_false_key_static_key_false, }, /* external keys - new keys */ { .init_state = true, .key = &base_true_key.key, .test_key = &base_true_key_static_branch_likely, }, { .init_state = true, .key = &base_true_key.key, .test_key = &base_true_key_static_branch_unlikely, }, { .init_state = false, .key = &base_inv_true_key.key, .test_key = &base_inv_true_key_static_branch_likely, }, { .init_state = false, .key = &base_inv_true_key.key, .test_key = &base_inv_true_key_static_branch_unlikely, }, { .init_state = false, .key = &base_false_key.key, .test_key = &base_false_key_static_branch_likely, }, { .init_state = false, .key = &base_false_key.key, .test_key = &base_false_key_static_branch_unlikely, }, { .init_state = true, .key = &base_inv_false_key.key, .test_key = &base_inv_false_key_static_branch_likely, }, { .init_state = true, .key = &base_inv_false_key.key, .test_key = &base_inv_false_key_static_branch_unlikely, }, }; size = ARRAY_SIZE(static_key_tests); ret = verify_keys(static_key_tests, size, false); if (ret) goto out; invert_keys(static_key_tests, size); ret = verify_keys(static_key_tests, size, true); if (ret) goto out; invert_keys(static_key_tests, size); ret = verify_keys(static_key_tests, size, false); if (ret) goto out; return 0; out: return ret; } static void __exit test_static_key_exit(void) { } module_init(test_static_key_init); module_exit(test_static_key_exit); MODULE_AUTHOR("Jason Baron "); MODULE_LICENSE("GPL"); tel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/math-emu/soft-fp.h')