/cc Matthew, Andrew (please see below)
On pondělí 2. října 2023 12:42:42 CEST Bagas Sanjaya wrote:
On Mon, Oct 02, 2023 at 08:20:15AM +0200, Oleksandr Natalenko wrote:
Hello.
On pondělí 2. října 2023 1:45:44 CEST Bagas Sanjaya wrote:
On Sun, Oct 01, 2023 at 06:32:34PM +0200, Oleksandr Natalenko wrote:
Hello.
I've got a VM from a cloud provider, and since v6.5 I observe the following kfence splat in dmesg during boot:
BUG: KFENCE: memory corruption in drm_gem_put_pages+0x186/0x250 Corrupted memory at 0x00000000e173a294 [ ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ] (in kfence-#108): drm_gem_put_pages+0x186/0x250 drm_gem_shmem_put_pages_locked+0x43/0xc0 drm_gem_shmem_object_vunmap+0x83/0xe0 drm_gem_vunmap_unlocked+0x46/0xb0 drm_fbdev_generic_helper_fb_dirty+0x1dc/0x310 drm_fb_helper_damage_work+0x96/0x170 process_one_work+0x254/0x470 worker_thread+0x55/0x4f0 kthread+0xe8/0x120 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1b/0x30 kfence-#108: 0x00000000cda343af-0x00000000aec2c095, size=3072, cache=kmalloc-4k allocated by task 51 on cpu 0 at 14.668667s: drm_gem_get_pages+0x94/0x2b0 drm_gem_shmem_get_pages+0x5d/0x110 drm_gem_shmem_object_vmap+0xc4/0x1e0 drm_gem_vmap_unlocked+0x3c/0x70 drm_client_buffer_vmap+0x23/0x50 drm_fbdev_generic_helper_fb_dirty+0xae/0x310 drm_fb_helper_damage_work+0x96/0x170 process_one_work+0x254/0x470 worker_thread+0x55/0x4f0 kthread+0xe8/0x120 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1b/0x30 freed by task 51 on cpu 0 at 14.668697s: drm_gem_put_pages+0x186/0x250 drm_gem_shmem_put_pages_locked+0x43/0xc0 drm_gem_shmem_object_vunmap+0x83/0xe0 drm_gem_vunmap_unlocked+0x46/0xb0 drm_fbdev_generic_helper_fb_dirty+0x1dc/0x310 drm_fb_helper_damage_work+0x96/0x170 process_one_work+0x254/0x470 worker_thread+0x55/0x4f0 kthread+0xe8/0x120 ret_from_fork+0x34/0x50 ret_from_fork_asm+0x1b/0x30 CPU: 0 PID: 51 Comm: kworker/0:2 Not tainted 6.5.0-pf4 #1 8b557a4173114d86eef7240f7a080080cfc4617e Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014 Workqueue: events drm_fb_helper_damage_workThis repeats a couple of times and then stops.
Currently, I'm running v6.5.5. So far, there's no impact on how VM functions for me.
The VGA adapter is as follows: 00:02.0 VGA compatible controller: Cirrus Logic GD 5446
Do you have this issue on v6.4?
No, I did not have this issue with v6.4.
Then proceed with kernel bisection. You can refer to Documentation/admin-guide/bug-bisect.rst in the kernel sources for the process.
Matthew, before I start dancing around, do you think ^^ could have the same cause as 0b62af28f249b9c4036a05acfb053058dc02e2e2 which got fixed by 863a8eb3f27098b42772f668e3977ff4cae10b04?
In the git log between v6.4 and v6.5 I see this:
``` commit 3291e09a463870610b8227f32b16b19a587edf33 Author: Matthew Wilcox (Oracle) willy@infradead.org Date: Wed Jun 21 17:45:49 2023 +0100
drm: convert drm_gem_put_pages() to use a folio_batch
Remove a few hidden compound_head() calls by converting the returned page to a folio once and using the folio APIs. ```
Thanks.