@Bjorn, @Krzysztof On Mon, 2024-07-08 at 21:46 +0000, Ashish Kalra wrote: > With this patch applied, we are observing unloading and then > reloading issues with the AMD Crypto (CCP) driver: Thank you very much for digging into this, Ashish Could you give me some pointers how one could test CCP by himself? > > with DEVRES logging enabled, we observe the following logs: > > [ 218.093588] ccp 0000:a2:00.1: DEVRES REL 00000000c18c52fb > 0xffff8d09dc1972c0 devm_kzalloc_release (152 bytes) > [ 218.105527] ccp 0000:a2:00.1: DEVRES REL 000000003091fb95 > 0xffff8d09d3aad000 devm_kzalloc_release (3072 bytes) > [ 218.117500] ccp 0000:a2:00.1: DEVRES REL 0000000049e4adfe > 0xffff8d09d588f000 pcim_intx_restore (4 bytes) > [ 218.129519] ccp 0000:a2:00.1: DEVRES ADD 000000001a2ac6ad > 0xffff8cfa867b7cc0 pcim_intx_restore (4 bytes) > [ 218.140434] ccp 0000:a2:00.1: DEVRES REL 00000000627ecaf7 > 0xffff8d09d588f680 pcim_msi_release (16 bytes) > [ 218.151665] ccp 0000:a2:00.1: DEVRES REL 0000000058b2252a > 0xffff8d09dc199680 msi_device_data_release (80 bytes) > [ 218.163625] ccp 0000:a2:00.1: DEVRES REL 00000000435cc85e > 0xffff8d09d588ff80 devm_attr_group_remove (8 bytes) > [ 218.175224] ccp 0000:a2:00.1: DEVRES REL 00000000cb6fcd9b > 0xffff8d09eb583660 pcim_addr_resource_release (40 bytes) > [ 218.187319] ccp 0000:a2:00.1: DEVRES REL 00000000d64a8b84 > 0xffff8d09eb583180 pcim_iomap_release (48 bytes) > [ 218.198615] ccp 0000:a2:00.1: DEVRES REL 0000000099ac6b28 > 0xffff8d09eb5830c0 pcim_addr_resource_release (40 bytes) > [ 218.210730] ccp 0000:a2:00.1: DEVRES REL 00000000bdd27f88 > 0xffff8d09d3ac2700 pcim_release (0 bytes) > [ 218.221489] ccp 0000:a2:00.1: DEVRES REL 00000000e763315c > 0xffff8d09d3ac2240 devm_kzalloc_release (20 bytes) > [ 218.233008] ccp 0000:a2:00.1: DEVRES REL 00000000ae90f983 > 0xffff8d09dc25a800 devm_kzalloc_release (184 bytes) > [ 218.245251] ccp 0000:23:00.1: DEVRES REL 00000000a2ec0085 > 0xffff8cfa86bee700 fw_name_devm_release (16 bytes) > [ 218.256748] ccp 0000:23:00.1: DEVRES REL 0000000021bccd98 > 0xffff8cfaa528d5c0 devm_pages_release (16 bytes) > [ 218.268044] ccp 0000:23:00.1: DEVRES REL 000000003ef7cbc7 > 0xffff8cfaa1b5ec00 devm_kzalloc_release (104 bytes) > [ 218.279631] ccp 0000:23:00.1: DEVRES REL 00000000619322e1 > 0xffff8cfaa1b5e480 devm_kzalloc_release (152 bytes) > [ 218.300438] ccp 0000:23:00.1: DEVRES REL 00000000c261523b > 0xffff8cfaad88b000 devm_kzalloc_release (3072 bytes) > [ 218.331000] ccp 0000:23:00.1: DEVRES REL 00000000fbd19618 > 0xffff8cfaa528d140 pcim_intx_restore (4 bytes) > [ 218.361330] ccp 0000:23:00.1: DEVRES ADD 0000000057f8e767 > 0xffff8cfa867b7740 pcim_intx_restore (4 bytes) > [ 218.391226] ccp 0000:23:00.1: DEVRES REL 0000000058c9dce1 > 0xffff8cfaa528d880 pcim_msi_release (16 bytes) > [ 218.421340] ccp 0000:23:00.1: DEVRES REL 00000000c8ab08a7 > 0xffff8cfa9e617300 msi_device_data_release (80 bytes) > [ 218.452357] ccp 0000:23:00.1: DEVRES REL 00000000cf5baccb > 0xffff8cfaa528d8c0 devm_attr_group_remove (8 bytes) > [ 218.483011] ccp 0000:23:00.1: DEVRES REL 00000000b8cbbadd > 0xffff8cfa9c596060 pcim_addr_resource_release (40 bytes) > [ 218.514343] ccp 0000:23:00.1: DEVRES REL 00000000920f9607 > 0xffff8cfa9c596c60 pcim_iomap_release (48 bytes) > [ 218.544659] ccp 0000:23:00.1: DEVRES REL 00000000d401a708 > 0xffff8cfa9c596840 pcim_addr_resource_release (40 bytes) > [ 218.575774] ccp 0000:23:00.1: DEVRES REL 00000000865d2fa2 > 0xffff8cfaa528d940 pcim_release (0 bytes) > [ 218.605758] ccp 0000:23:00.1: DEVRES REL 00000000f5b79222 > 0xffff8cfaa528d080 devm_kzalloc_release (20 bytes) > [ 218.636260] ccp 0000:23:00.1: DEVRES REL 0000000037ef240a > 0xffff8cfa9eeb3f00 devm_kzalloc_release (184 bytes) > > and the CCP driver reload issue during driver probe: > > [ 226.552684] pci 0000:23:00.1: Resources present before probing > [ 226.568846] pci 0000:a2:00.1: Resources present before probing > > From the above DEVRES logging, it looks like pcim_intx_restore > associated resource is being released but then > being re-added during detach/unload, which causes really_probe() to > fail at probe time, as dev->devres_head is > not empty due to this added resource: > ... > [ 218.331000] ccp 0000:23:00.1: DEVRES REL 00000000fbd19618 > 0xffff8cfaa528d140 pcim_intx_restore (4 bytes) > [ 218.361330] ccp 0000:23:00.1: DEVRES ADD 0000000057f8e767 > 0xffff8cfa867b7740 pcim_intx_restore (4 bytes) > ... > > Going more deep into this: > > This is the initial pcim_intx_resoure associated resource being added > during first (CCP) driver load: > > [ 40.418933] pcim_intx+0x3a/0x120 > [ 40.418936] pci_intx+0x8b/0xa0 > [ 40.418939] __pci_enable_msix_range+0x369/0x530 > [ 40.418943] pci_enable_msix_range+0x18/0x20 > [ 40.418946] sp_pci_probe+0x106/0x310 [ccp] > [ 40.418965] ipmi device interface > [ 40.418960] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 40.418969] local_pci_probe+0x4f/0xb0 > [ 40.418973] work_for_cpu_fn+0x1e/0x30 > [ 40.418976] process_one_work+0x183/0x350 > [ 40.418980] worker_thread+0x2df/0x3f0 > [ 40.418982] ? __pfx_worker_thread+0x10/0x10 > [ 40.418985] kthread+0xd0/0x100 > [ 40.418987] ? __pfx_kthread+0x10/0x10 > [ 40.418990] ret_from_fork+0x40/0x60 > [ 40.418993] ? __pfx_kthread+0x10/0x10 > [ 40.418996] ret_from_fork_asm+0x1a/0x30 > [ 40.419001] </TASK> > .. > .. > [ 40.419012] ccp 0000:23:00.1: DEVRES ADD 00000000fbd19618 > 0xffff8cfaa528d140 pcim_intx_restore (4 bytes) > > Now, at driver unload: > devres_release_all() -> remove_nodes() -> release_nodes() ... > > remove_nodes() moves normal devres entries to the todo list, as can > be seen with the following log: > ... > [ 218.245241] moving node 00000000fbd19618 0xffff8cfaa528d140 from > devres to todo list > ... > > So, now this pcim_intx_resource associated resource is no longer part > of dev->devres_head list and has been > moved to the todo list. > > Later, when release_nodes() is invoked, it calls the associated > release() callback associated with this devres: > ... > [ 218.331000] ccp 0000:23:00.1: DEVRES REL 00000000fbd19618 > 0xffff8cfaa528d140 pcim_intx_restore (4 bytes) > ... > > The call flow for that is: > pcim_intx_restore() -> pci_intx() -> pcim_intx() ... > > Now, pcim_intx() calls get_or_create_intx_devres() which tries to > find it's associated devres using devres_find(), but > that fails to find the devres, as the devres is no longer on dev- > >devres_head and has been moved to todo list. > > Therefore, get_or_create_intx_devres() adds a new devres at driver > unload/detach time: > ... > [ 218.361330] ccp 0000:23:00.1: DEVRES ADD 0000000057f8e767 > 0xffff8cfa867b7740 pcim_intx_restore (4 bytes) > ... You're absolutely right, that seems to be the issue precisely. In fact, this problem of PCI hybrid functions calling themselves again even forced me to implement a "pure unmanaged" version of __pci_request_region(). So it's a pity that I didn't think of that problem for pci_intx(). > > But, then this is an issue as pcim_intx() is supposed to restore the > original PCI INTx state on driver detach, but it now > operating on a newly added devres and not the original devres (added > at driver probe) which contains the original PCI INTx > state, so it will be restoring an incorrect PCI INTx state ? I think this is just UB and we don't have to think about whether it's the correct state or not – it must only be restored once, so it's broken in any case. > > Additionally, this newly added devres causes driver reload/probe > failure as really_probe() now finds resources present > before probing. Yes, that has to be separated. @Bjorn: So I think the solution will be not to call into pci_intx() from pcim_intx_restore() at all anymore. Similar as we do with __pci_request_region() <-> __pcim_request_region(). Let me dig into that.. I guess you'll prefer me to send a fixup commit to squash into the pcim_intx() commit? I'm quite busy today, but will definitely deliver that quite soon. > > Not sure, if this issue has been observed with other PCI device > drivers. Everyone using pci_intx() AND pcim_enable_device() will have this issue. The only thing I'm wondering about is where your code in drivers/crypto/ccp/ calls into pci_intx()? Regards, P. > > Thanks, > Ashish >
