/* * linux/fs/hpfs/buffer.c * * Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999 * * general buffer i/o */ #include #include #include #include "hpfs_fn.h" secno hpfs_search_hotfix_map(struct super_block *s, secno sec) { unsigned i; struct hpfs_sb_info *sbi = hpfs_sb(s); for (i = 0; unlikely(i < sbi->n_hotfixes); i++) { if (sbi->hotfix_from[i] == sec) { return sbi->hotfix_to[i]; } } return sec; } unsigned hpfs_search_hotfix_map_for_range(struct super_block *s, secno sec, unsigned n) { unsigned i; struct hpfs_sb_info *sbi = hpfs_sb(s); for (i = 0; unlikely(i < sbi->n_hotfixes); i++) { if (sbi->hotfix_from[i] >= sec && sbi->hotfix_from[i] < sec + n) { n = sbi->hotfix_from[i] - sec; } } return n; } void hpfs_prefetch_sectors(struct super_block *s, unsigned secno, int n) { struct buffer_head *bh; struct blk_plug plug; if (n <= 0 || unlikely(secno >= hpfs_sb(s)->sb_fs_size)) return; if (unlikely(hpfs_search_hotfix_map_for_range(s, secno, n) != n)) return; bh = sb_find_get_block(s, secno); if (bh) { if (buffer_uptodate(bh)) { brelse(bh); return; } brelse(bh); }; blk_start_plug(&plug); while (n > 0) { if (unlikely(secno >= hpfs_sb(s)->sb_fs_size)) break; sb_breadahead(s, secno); secno++; n--; } blk_finish_plug(&plug); } /* Map a sector into a buffer and return pointers to it and to the buffer. */ void *hpfs_map_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp, int ahead) { struct buffer_head *bh; hpfs_lock_assert(s); hpfs_prefetch_sectors(s, secno, ahead); cond_resched(); *bhp = bh = sb_bread(s, hpfs_search_hotfix_map(s, secno)); if (bh != NULL) return bh->b_data; else { pr_err("%s(): read error\n", __func__); return NULL; } } /* Like hpfs_map_sector but don't read anything */ void *hpfs_get_sector(struct super_block *s, unsigned secno, struct buffer_head **bhp) { struct buffer_head *bh; /*return hpfs_map_sector(s, secno, bhp, 0);*/ hpfs_lock_assert(s); cond_resched(); if ((*bhp = bh = sb_getblk(s, hpfs_search_hotfix_map(s, secno))) != NULL) { if (!buffer_uptodate(bh)) wait_on_buffer(bh); set_buffer_uptodate(bh); return bh->b_data; } else { pr_err("%s(): getblk failed\n", __func__); return NULL; } } /* Map 4 sectors into a 4buffer and return pointers to it and to the buffer. */ void *hpfs_map_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh, int ahead) { char *data; hpfs_lock_assert(s); cond_resched(); if (secno & 3) { pr_err("%s(): unaligned read\n", __func__); return NULL; } hpfs_prefetch_sectors(s, secno, 4 + ahead); if (!hpfs_map_sector(s, secno + 0, &qbh->bh[0], 0)) goto bail0; if (!hpfs_map_sector(s, secno + 1, &qbh->bh[1], 0)) goto bail1; if (!hpfs_map_sector(s, secno + 2, &qbh->bh[2], 0)) goto bail2; if (!hpfs_map_sector(s, secno + 3, &qbh->bh[3], 0)) goto bail3; if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) && likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) && likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) { return qbh->data = qbh->bh[0]->b_data; } qbh->data = data = kmalloc(2048, GFP_NOFS); if (!data) { pr_err("%s(): out of memory\n", __func__); goto bail4; } memcpy(data + 0 * 512, qbh->bh[0]->b_data, 512); memcpy(data + 1 * 512, qbh->bh[1]->b_data, 512); memcpy(data + 2 * 512, qbh->bh[2]->b_data, 512); memcpy(data + 3 * 512, qbh->bh[3]->b_data, 512); return data; bail4: brelse(qbh->bh[3]); bail3: brelse(qbh->bh[2]); bail2: brelse(qbh->bh[1]); bail1: brelse(qbh->bh[0]); bail0: return NULL; } /* Don't read sectors */ void *hpfs_get_4sectors(struct super_block *s, unsigned secno, struct quad_buffer_head *qbh) { cond_resched(); hpfs_lock_assert(s); if (secno & 3) { pr_err("%s(): unaligned read\n", __func__); return NULL; } if (!hpfs_get_sector(s, secno + 0, &qbh->bh[0])) goto bail0; if (!hpfs_get_sector(s, secno + 1, &qbh->bh[1])) goto bail1; if (!hpfs_get_sector(s, secno + 2, &qbh->bh[2])) goto bail2; if (!hpfs_get_sector(s, secno + 3, &qbh->bh[3])) goto bail3; if (likely(qbh->bh[1]->b_data == qbh->bh[0]->b_data + 1 * 512) && likely(qbh->bh[2]->b_data == qbh->bh[0]->b_data + 2 * 512) && likely(qbh->bh[3]->b_data == qbh->bh[0]->b_data + 3 * 512)) { return qbh->data = qbh->bh[0]->b_data; } if (!(qbh->data = kmalloc(2048, GFP_NOFS))) { pr_err("%s(): out of memory\n", __func__); goto bail4; } return qbh->data; bail4: brelse(qbh->bh[3]); bail3: brelse(qbh->bh[2]); bail2: brelse(qbh->bh[1]); bail1: brelse(qbh->bh[0]); bail0: return NULL; } void hpfs_brelse4(struct quad_buffer_head *qbh) { if (unlikely(qbh->data != qbh->bh[0]->b_data)) kfree(qbh->data); brelse(qbh->bh[0]); brelse(qbh->bh[1]); brelse(qbh->bh[2]); brelse(qbh->bh[3]); } void hpfs_mark_4buffers_dirty(struct quad_buffer_head *qbh) { if (unlikely(qbh->data != qbh->bh[0]->b_data)) { memcpy(qbh->bh[0]->b_data, qbh->data + 0 * 512, 512); memcpy(qbh->bh[1]->b_data, qbh->data + 1 * 512, 512); memcpy(qbh->bh[2]->b_data, qbh->data + 2 * 512, 512); memcpy(qbh->bh[3]->b_data, qbh->data + 3 * 512, 512); } mark_buffer_dirty(qbh->bh[0]); mark_buffer_dirty(qbh->bh[1]); mark_buffer_dirty(qbh->bh[2]); mark_buffer_dirty(qbh->bh[3]); } lt;torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800 committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800 commit39cb2c9a316e77f6dfba96c543e55b6672d5a37e (patch) tree98fe974ee4e20121253de7f61fc8d01bdb3821c1 /tools/perf/pmu-events/arch/x86/haswell/floating-point.json parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_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 'tools/perf/pmu-events/arch/x86/haswell/floating-point.json')