On Tue, Jun 23, 2020 at 11:04:30PM -0400, Andrey Grodzovsky wrote: > > On 6/23/20 2:05 AM, Greg KH wrote: > > On Tue, Jun 23, 2020 at 12:51:00AM -0400, Andrey Grodzovsky wrote: > > > On 6/22/20 12:45 PM, Greg KH wrote: > > > > On Mon, Jun 22, 2020 at 12:07:25PM -0400, Andrey Grodzovsky wrote: > > > > > On 6/22/20 7:21 AM, Greg KH wrote: > > > > > > On Mon, Jun 22, 2020 at 11:51:24AM +0200, Daniel Vetter wrote: > > > > > > > On Sun, Jun 21, 2020 at 02:03:05AM -0400, Andrey Grodzovsky wrote: > > > > > > > > Track sysfs files in a list so they all can be removed during pci remove > > > > > > > > since otherwise their removal after that causes crash because parent > > > > > > > > folder was already removed during pci remove. > > > > > > Huh? That should not happen, do you have a backtrace of that crash? > > > > > 2 examples in the attached trace. > > > > Odd, how did you trigger these? > > > > > > By manually triggering PCI remove from sysfs > > > > > > cd /sys/bus/pci/devices/0000\:05\:00.0 && echo 1 > remove > > For some reason, I didn't think that video/drm devices could handle > > hot-remove like this. The "old" PCI hotplug specification explicitly > > said that video devices were not supported, has that changed? > > > > And this whole issue is probably tied to the larger issue that Daniel > > was asking me about, when it came to device lifetimes and the drm layer, > > so odds are we need to fix that up first before worrying about trying to > > support this crazy request, right? :) > > > > > > > [ 925.738225 < 0.188086>] BUG: kernel NULL pointer dereference, address: 0000000000000090 > > > > > [ 925.738232 < 0.000007>] #PF: supervisor read access in kernel mode > > > > > [ 925.738236 < 0.000004>] #PF: error_code(0x0000) - not-present page > > > > > [ 925.738240 < 0.000004>] PGD 0 P4D 0 > > > > > [ 925.738245 < 0.000005>] Oops: 0000 [#1] SMP PTI > > > > > [ 925.738249 < 0.000004>] CPU: 7 PID: 2547 Comm: amdgpu_test Tainted: G W OE 5.5.0-rc7-dev-kfd+ #50 > > > > > [ 925.738256 < 0.000007>] Hardware name: System manufacturer System Product Name/RAMPAGE IV FORMULA, BIOS 4804 12/30/2013 > > > > > [ 925.738266 < 0.000010>] RIP: 0010:kernfs_find_ns+0x18/0x110 > > > > > [ 925.738270 < 0.000004>] Code: a6 cf ff 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 41 57 41 56 49 89 f6 41 55 41 54 49 89 fd 55 53 49 89 d4 <0f> b7 af 90 00 00 00 8b 05 8f ee 6b 01 48 8b 5f 68 66 83 e5 20 41 > > > > > [ 925.738282 < 0.000012>] RSP: 0018:ffffad6d0118fb00 EFLAGS: 00010246 > > > > > [ 925.738287 < 0.000005>] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 2098a12076864b7e > > > > > [ 925.738292 < 0.000005>] RDX: 0000000000000000 RSI: ffffffffb6606b31 RDI: 0000000000000000 > > > > > [ 925.738297 < 0.000005>] RBP: ffffffffb6606b31 R08: ffffffffb5379d10 R09: 0000000000000000 > > > > > [ 925.738302 < 0.000005>] R10: ffffad6d0118fb38 R11: ffff9a75f64820a8 R12: 0000000000000000 > > > > > [ 925.738307 < 0.000005>] R13: 0000000000000000 R14: ffffffffb6606b31 R15: ffff9a7612b06130 > > > > > [ 925.738313 < 0.000006>] FS: 00007f3eca4e8700(0000) GS:ffff9a763dbc0000(0000) knlGS:0000000000000000 > > > > > [ 925.738319 < 0.000006>] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > > > [ 925.738323 < 0.000004>] CR2: 0000000000000090 CR3: 0000000035e5a005 CR4: 00000000000606e0 > > > > > [ 925.738329 < 0.000006>] Call Trace: > > > > > [ 925.738334 < 0.000005>] kernfs_find_and_get_ns+0x2e/0x50 > > > > > [ 925.738339 < 0.000005>] sysfs_remove_group+0x25/0x80 > > > > > [ 925.738344 < 0.000005>] sysfs_remove_groups+0x29/0x40 > > > > > [ 925.738350 < 0.000006>] free_msi_irqs+0xf5/0x190 > > > > > [ 925.738354 < 0.000004>] pci_disable_msi+0xe9/0x120 > > > > So the PCI core is trying to clean up attributes that it had registered, > > > > which is fine. But we can't seem to find the attributes? Were they > > > > already removed somewhere else? > > > > > > > > that's odd. > > > > > > Yes, as i pointed above i am emulating device remove from sysfs and this > > > triggers pci device remove sequence and as part of that my specific device > > > folder (05:00.0) is removed from the sysfs tree. > > But why are things being removed twice? > > > Not sure I understand what removed twice ? I remove only once per sysfs attribute. This code path shows that the kernel is trying to remove a file that is not present, so someone removed it already... thanks, gre k-h _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
