https://bugzilla.kernel.org/show_bug.cgi?id=52231
Summary: possible circular locking dependency detected in radeon driver Product: Drivers Version: 2.5 Kernel Version: 3.8-rc2 Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) AssignedTo: drivers_video-dri@kernel-bugs.osdl.org ReportedBy: casteyde.christian@free.fr Regression: Yes
Kernel 3.8-rc2 Slackware64 14 Core i7, 6 GB RAM, 64 bit mode
Since kernel 3.8-rc2 with kmemcheck and lockdep hacking options turned on, I get the following lockdep warning:
EXT4-fs (sda3): re-mounted. Opts: discard,commit=0
====================================================== [ INFO: possible circular locking dependency detected ] 3.8.0-rc2 #21 Not tainted ------------------------------------------------------- 99video/2835 is trying to acquire lock: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8109f2f4>] __blocking_notifier_call_chain+0x54/0xd0
but task is already holding lock: (console_lock){+.+.+.}, at: [<ffffffff81344a65>] store_fbstate+0x55/0x80
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (console_lock){+.+.+.}: [<ffffffff810c9eaa>] lock_acquire+0x5a/0x70 [<ffffffff810756e7>] console_lock+0x57/0x60 [<ffffffff813a1874>] register_con_driver+0x34/0x140 [<ffffffff813a2fe9>] take_over_console+0x29/0x60 [<ffffffff8134a90b>] fbcon_takeover+0x5b/0xb0 [<ffffffff8134f7ad>] fbcon_event_notify+0x72d/0x830 [<ffffffff8109f00e>] notifier_call_chain+0x5e/0x150 [<ffffffff8109f30d>] __blocking_notifier_call_chain+0x6d/0xd0 [<ffffffff8109f381>] blocking_notifier_call_chain+0x11/0x20 [<ffffffff81340df6>] fb_notifier_call_chain+0x16/0x20 [<ffffffff8134301d>] register_framebuffer+0x1bd/0x2f0 [<ffffffff813adf43>] drm_fb_helper_single_fb_probe+0x1d3/0x2f0 [<ffffffff813ae231>] drm_fb_helper_initial_config+0x1d1/0x240 [<ffffffff81417b1a>] radeon_fbdev_init+0xba/0x110 [<ffffffff81412a01>] radeon_modeset_init+0x501/0xb60 [<ffffffff813f00d0>] radeon_driver_load_kms+0xe0/0x150 [<ffffffff813bb5ce>] drm_get_pci_dev+0x17e/0x2b0 [<ffffffff813d643a>] radeon_pci_probe+0xaa/0xe0 [<ffffffff8132f196>] local_pci_probe+0x46/0x80 [<ffffffff8132f7c1>] pci_device_probe+0x101/0x110 [<ffffffff8146cb86>] driver_probe_device+0x76/0x220 [<ffffffff8146cdd3>] __driver_attach+0xa3/0xb0 [<ffffffff8146ae4d>] bus_for_each_dev+0x4d/0x90 [<ffffffff8146c6d9>] driver_attach+0x19/0x20 [<ffffffff8146c2a0>] bus_add_driver+0x1a0/0x270 [<ffffffff8146d442>] driver_register+0x72/0x170 [<ffffffff8132f89f>] __pci_register_driver+0x5f/0x70 [<ffffffff813bb815>] drm_pci_init+0x115/0x130 [<ffffffff820a7460>] radeon_init+0xe7/0xe9 [<ffffffff810002da>] do_one_initcall+0x11a/0x170 [<ffffffff81811aec>] kernel_init+0x11c/0x290 [<ffffffff8182ffec>] ret_from_fork+0x7c/0xb0
-> #0 ((fb_notifier_list).rwsem){.+.+.+}: [<ffffffff810c96f0>] __lock_acquire+0x1a20/0x1ca0 [<ffffffff810c9eaa>] lock_acquire+0x5a/0x70 [<ffffffff8182ca39>] down_read+0x39/0x8c [<ffffffff8109f2f4>] __blocking_notifier_call_chain+0x54/0xd0 [<ffffffff8109f381>] blocking_notifier_call_chain+0x11/0x20 [<ffffffff81340df6>] fb_notifier_call_chain+0x16/0x20 [<ffffffff81341516>] fb_set_suspend+0x46/0x60 [<ffffffff81344a70>] store_fbstate+0x60/0x80 [<ffffffff81468493>] dev_attr_store+0x13/0x20 [<ffffffff811b813b>] sysfs_write_file+0xdb/0x150 [<ffffffff81148b86>] vfs_write+0xa6/0x160 [<ffffffff81148e90>] sys_write+0x50/0xa0 [<ffffffff81830092>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1 ---- ---- lock(console_lock); lock((fb_notifier_list).rwsem); lock(console_lock); lock((fb_notifier_list).rwsem);
*** DEADLOCK ***
4 locks held by 99video/2835: #0: (&buffer->mutex){+.+.+.}, at: [<ffffffff811b80a3>] sysfs_write_file+0x43/0x150 #1: (s_active#124){.+.+.+}, at: [<ffffffff811b8123>] sysfs_write_file+0xc3/0x150 #2: (&fb_info->lock){+.+.+.}, at: [<ffffffff813412c1>] lock_fb_info+0x21/0x60 #3: (console_lock){+.+.+.}, at: [<ffffffff81344a65>] store_fbstate+0x55/0x80
stack backtrace: Pid: 2835, comm: 99video Not tainted 3.8.0-rc2 #21 Call Trace: [<ffffffff81823b11>] print_circular_bug+0x28e/0x29f [<ffffffff810c96f0>] __lock_acquire+0x1a20/0x1ca0 [<ffffffff810c9eaa>] lock_acquire+0x5a/0x70 [<ffffffff8109f2f4>] ? __blocking_notifier_call_chain+0x54/0xd0 [<ffffffff810c4e0f>] ? __lock_is_held+0x5f/0x90 [<ffffffff8182ca39>] down_read+0x39/0x8c [<ffffffff8109f2f4>] ? __blocking_notifier_call_chain+0x54/0xd0 [<ffffffff8109f2f4>] __blocking_notifier_call_chain+0x54/0xd0 [<ffffffff8109f2f4>] __blocking_notifier_call_chain+0x54/0xd0 [<ffffffff8109f381>] blocking_notifier_call_chain+0x11/0x20 [<ffffffff81340df6>] fb_notifier_call_chain+0x16/0x20 [<ffffffff81341516>] fb_set_suspend+0x46/0x60 [<ffffffff810756e7>] ? console_lock+0x57/0x60 [<ffffffff81344a65>] ? store_fbstate+0x55/0x80 [<ffffffff81344a70>] store_fbstate+0x60/0x80 [<ffffffff81468493>] dev_attr_store+0x13/0x20 [<ffffffff811b813b>] sysfs_write_file+0xdb/0x150 [<ffffffff81148b86>] vfs_write+0xa6/0x160 [<ffffffff81148e90>] sys_write+0x50/0xa0 [<ffffffff81830092>] system_call_fastpath+0x16/0x1b PM: Syncing filesystems ... done. WARNING: kmemcheck: Caught 16-bit read from uninitialized memory (ffff8801c52bbc20) 010000000000000001000000000000000000000000000000b0bb2bc50188ffff u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u ^ Pid: 2256, comm: X Not tainted 3.8.0-rc2 #21 Acer Aspire 7750G/JE70_HR RIP: 0010:[<ffffffff813ac091>] [<ffffffff813ac091>] drm_fb_helper_setcmap+0x111/0x400 RSP: 0018:ffff8801c0c35978 EFLAGS: 00010206 RAX: ffff8801c52bbc00 RBX: ffff8801c476e800 RCX: 0000000000000000 RDX: 000000000000000f RSI: ffff8801c52bb850 RDI: 00000000000000ff RBP: ffff8801c0c35a48 R08: 00000000001d5300 R09: 0000000000ffffff R10: 0000000000000000 R11: 000000000000ffff R12: 0000000000000000 R13: 0000000000000010 R14: 0000000000000010 R15: ffff8801c52bb800 FS: 00007f34900ed8c0(0000) GS:ffff8801c7e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8801c644bf10 CR3: 00000001c30d3000 CR4: 00000000000407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 [<ffffffff81344375>] fb_set_cmap+0x65/0x140 [<ffffffff81341dff>] fb_set_var+0x1cf/0x480 [<ffffffff8134be21>] fbcon_blank+0x1e1/0x2e0 [<ffffffff813a3f79>] do_unblank_screen+0xa9/0x1d0 [<ffffffff81399744>] complete_change_console+0x64/0xf0 [<ffffffff8139aa32>] vt_ioctl+0x1262/0x1350 [<ffffffff8138fd98>] tty_ioctl+0x2c8/0xd10 [<ffffffff8115aae7>] do_vfs_ioctl+0x97/0x5a0 [<ffffffff8115b03b>] sys_ioctl+0x4b/0x90 [<ffffffff81830092>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff WARNING: kmemcheck: Caught 16-bit read from uninitialized memory (ffff8801c52bbe20) ea00000077000000260000000b00000002000000040000000100000001000000 u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u ^ Pid: 2256, comm: X Not tainted 3.8.0-rc2 #21 Acer Aspire 7750G/JE70_HR RIP: 0010:[<ffffffff813ac0af>] [<ffffffff813ac0af>] drm_fb_helper_setcmap+0x12f/0x400 RSP: 0018:ffff8801c0c35978 EFLAGS: 00010246 RAX: ffff8801c52bbe00 RBX: ffff8801c476e800 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffff8801c52bb850 RDI: 00000000000000ff RBP: ffff8801c0c35a48 R08: 00000000001d5300 R09: 0000000000ffffff R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000010 R13: 0000000000000010 R14: 0000000000000010 R15: ffff8801c52bb800 FS: 00007f34900ed8c0(0000) GS:ffff8801c7e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8801c644bf10 CR3: 00000001c30d3000 CR4: 00000000000407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 [<ffffffff81344375>] fb_set_cmap+0x65/0x140 [<ffffffff81341dff>] fb_set_var+0x1cf/0x480 [<ffffffff8134be21>] fbcon_blank+0x1e1/0x2e0 [<ffffffff813a3f79>] do_unblank_screen+0xa9/0x1d0 [<ffffffff81399744>] complete_change_console+0x64/0xf0 [<ffffffff8139aa32>] vt_ioctl+0x1262/0x1350 [<ffffffff8138fd98>] tty_ioctl+0x2c8/0xd10 [<ffffffff8115aae7>] do_vfs_ioctl+0x97/0x5a0 [<ffffffff8115b03b>] sys_ioctl+0x4b/0x90 [<ffffffff81830092>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff WARNING: kmemcheck: Caught 16-bit read from uninitialized memory (ffff8801c4778020) 000000000000000010fa0881ffffffff00000000000000000000000000000000 u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u ^ Pid: 2256, comm: X Not tainted 3.8.0-rc2 #21 Acer Aspire 7750G/JE70_HR RIP: 0010:[<ffffffff813ac0b8>] [<ffffffff813ac0b8>] drm_fb_helper_setcmap+0x138/0x400 RSP: 0018:ffff8801c0c35978 EFLAGS: 00010246 RAX: ffff8801c4778000 RBX: ffff8801c476e800 RCX: 0000000000000000 RDX: 0000000000000010 RSI: ffff8801c52bb850 RDI: 00000000000000ff RBP: ffff8801c0c35a48 R08: 00000000001d5300 R09: 00000000000000ea R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000010 R13: 0000000000000010 R14: 0000000000000010 R15: ffff8801c52bb800 FS: 00007f34900ed8c0(0000) GS:ffff8801c7e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8801c644bf10 CR3: 00000001c30d3000 CR4: 00000000000407f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400 [<ffffffff81344375>] fb_set_cmap+0x65/0x140 [<ffffffff81341dff>] fb_set_var+0x1cf/0x480 [<ffffffff8134be21>] fbcon_blank+0x1e1/0x2e0 [<ffffffff813a3f79>] do_unblank_screen+0xa9/0x1d0 [<ffffffff81399744>] complete_change_console+0x64/0xf0 [<ffffffff8139aa32>] vt_ioctl+0x1262/0x1350 [<ffffffff8138fd98>] tty_ioctl+0x2c8/0xd10 [<ffffffff8115aae7>] do_vfs_ioctl+0x97/0x5a0 [<ffffffff8115b03b>] sys_ioctl+0x4b/0x90 [<ffffffff81830092>] system_call_fastpath+0x16/0x1b
etc. (uninitialized read is already reported in another bugzilla entry).