| Message ID | 1459347521-31558-1-git-send-email-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Mar 30, 2016 at 03:18:40PM +0100, Chris Wilson wrote: > Since describe_obj() looks at state guarded by the struct_mutex, we need > to be holding it. > > [ 580.201054] drv_suspend: starting subtest debugfs-reader > [ 580.239652] ------------[ cut here ]------------ > [ 580.239696] WARNING: CPU: 0 PID: 920 at include/linux/list_check.h:25 describe_obj+0x419/0x440() > [ 580.239725] CPU: 0 PID: 920 Comm: cat Not tainted 4.5.0-rc6+ #835 > [ 580.239745] Hardware name: /NUC5CPYB, BIOS PYBSWCEL.86A.0027.2015.0507.1758 05/07/2015 > [ 580.239767] 0000000000000000 ffff88027554fcf8 ffffffff812c1135 0000000000000000 > [ 580.239815] ffffffff8193dc42 ffff88027554fd30 ffffffff8107419d ffff880071727c00 > [ 580.239858] ffff8802757d8000 ffffffff818f693c ffffffff818f693c ffff8802757b9048 > [ 580.239896] Call Trace: > [ 580.239917] [<ffffffff812c1135>] dump_stack+0x67/0x92 > [ 580.239939] [<ffffffff8107419d>] warn_slowpath_common+0x7d/0xb0 > [ 580.239959] [<ffffffff810742ba>] warn_slowpath_null+0x1a/0x20 > [ 580.239981] [<ffffffff813ce579>] describe_obj+0x419/0x440 > [ 580.240006] [<ffffffff813ced22>] i915_gem_framebuffer_info+0xa2/0x100 > [ 580.240033] [<ffffffff811a9286>] seq_read+0xe6/0x3b0 > [ 580.240059] [<ffffffff81182288>] __vfs_read+0x28/0xd0 > [ 580.240085] [<ffffffff81173378>] ? SyS_fadvise64+0x228/0x2c0 > [ 580.240112] [<ffffffff811823b2>] vfs_read+0x82/0x110 > [ 580.240137] [<ffffffff811827d9>] SyS_read+0x49/0xa0 > [ 580.240162] [<ffffffff815bac57>] entry_SYSCALL_64_fastpath+0x12/0x6b > [ 580.240187] ---[ end trace 3e2cbf34576c9878 ]--- > [ 580.281900] ------------[ cut here ]------------ Missing sob-line here. With that fixed: Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > drivers/gpu/drm/i915/i915_debugfs.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > index d02f8ce0b1c8..adabbb47a8aa 100644 > --- a/drivers/gpu/drm/i915/i915_debugfs.c > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > @@ -134,6 +134,8 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) > int pin_count = 0; > enum intel_engine_id id; > > + lockdep_assert_held(&obj->base.dev->struct_mutex); > + > seq_printf(m, "%pK: %s%s%s%s %8zdKiB %02x %02x [ ", > &obj->base, > obj->active ? "*" : " ", > @@ -1895,6 +1897,11 @@ static int i915_gem_framebuffer_info(struct seq_file *m, void *data) > struct drm_device *dev = node->minor->dev; > struct intel_framebuffer *fbdev_fb = NULL; > struct drm_framebuffer *drm_fb; > + int ret; > + > + ret = mutex_lock_interruptible(&dev->struct_mutex); > + if (ret) > + return ret; > > #ifdef CONFIG_DRM_FBDEV_EMULATION > if (to_i915(dev)->fbdev) { > @@ -1929,6 +1936,7 @@ static int i915_gem_framebuffer_info(struct seq_file *m, void *data) > seq_putc(m, '\n'); > } > mutex_unlock(&dev->mode_config.fb_lock); > + mutex_unlock(&dev->struct_mutex); > > return 0; > } > -- > 2.8.0.rc3 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index d02f8ce0b1c8..adabbb47a8aa 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -134,6 +134,8 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj) int pin_count = 0; enum intel_engine_id id; + lockdep_assert_held(&obj->base.dev->struct_mutex); + seq_printf(m, "%pK: %s%s%s%s %8zdKiB %02x %02x [ ", &obj->base, obj->active ? "*" : " ", @@ -1895,6 +1897,11 @@ static int i915_gem_framebuffer_info(struct seq_file *m, void *data) struct drm_device *dev = node->minor->dev; struct intel_framebuffer *fbdev_fb = NULL; struct drm_framebuffer *drm_fb; + int ret; + + ret = mutex_lock_interruptible(&dev->struct_mutex); + if (ret) + return ret; #ifdef CONFIG_DRM_FBDEV_EMULATION if (to_i915(dev)->fbdev) { @@ -1929,6 +1936,7 @@ static int i915_gem_framebuffer_info(struct seq_file *m, void *data) seq_putc(m, '\n'); } mutex_unlock(&dev->mode_config.fb_lock); + mutex_unlock(&dev->struct_mutex); return 0; }