kernel.git/arch/s390, branch linux-5.8.y

s390/pci: Mark all VFs as not implementing PCI_COMMAND_MEMORY

2020-10-29T09:08:05Z

[ Upstream commit 08b6e22b850c28b6032da1e4d767a33116e23dfb ] For s390 we can have VFs that are passed-through without the associated PF. Firmware provides an emulation layer to allow these devices to operate independently, but is missing emulation of the Memory Space Enable bit. For these as well as linked VFs, set no_command_memory which specifies these devices do not implement PCI_COMMAND_MEMORY. Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Signed-off-by: Matthew Rosato Reviewed-by: Niklas Schnelle Reviewed-by: Pierre Morel Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin

mm/gup: fix gup_fast with dynamic page table folding

2020-10-01T15:36:34Z

commit d3f7b1bb204099f2f7306318896223e8599bb6a2 upstream. Currently to make sure that every page table entry is read just once gup_fast walks perform READ_ONCE and pass pXd value down to the next gup_pXd_range function by value e.g.: static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end, unsigned int flags, struct page **pages, int *nr) ... pudp = pud_offset(&p4d, addr); This function passes a reference on that local value copy to pXd_offset, and might get the very same pointer in return. This happens when the level is folded (on most arches), and that pointer should not be iterated. On s390 due to the fact that each task might have different 5,4 or 3-level address translation and hence different levels folded the logic is more complex and non-iteratable pointer to a local copy leads to severe problems. Here is an example of what happens with gup_fast on s390, for a task with 3-level paging, crossing a 2 GB pud boundary: // addr = 0x1007ffff000, end = 0x10080001000 static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end, unsigned int flags, struct page **pages, int *nr) { unsigned long next; pud_t *pudp; // pud_offset returns &p4d itself (a pointer to a value on stack) pudp = pud_offset(&p4d, addr); do { // on second iteratation reading "random" stack value pud_t pud = READ_ONCE(*pudp); // next = 0x10080000000, due to PUD_SIZE/MASK != PGDIR_SIZE/MASK on s390 next = pud_addr_end(addr, end); ... } while (pudp++, addr = next, addr != end); // pudp++ iterating over stack return 1; } This happens since s390 moved to common gup code with commit d1874a0c2805 ("s390/mm: make the pxd_offset functions more robust") and commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code"). s390 tried to mimic static level folding by changing pXd_offset primitives to always calculate top level page table offset in pgd_offset and just return the value passed when pXd_offset has to act as folded. What is crucial for gup_fast and what has been overlooked is that PxD_SIZE/MASK and thus pXd_addr_end should also change correspondingly. And the latter is not possible with dynamic folding. To fix the issue in addition to pXd values pass original pXdp pointers down to gup_pXd_range functions. And introduce pXd_offset_lockless helpers, which take an additional pXd entry value parameter. This has already been discussed in https://lkml.kernel.org/r/20190418100218.0a4afd51@mschwideX1 Fixes: 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code") Signed-off-by: Vasily Gorbik Signed-off-by: Andrew Morton Reviewed-by: Gerald Schaefer Reviewed-by: Alexander Gordeev Reviewed-by: Jason Gunthorpe Reviewed-by: Mike Rapoport Reviewed-by: John Hubbard Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Dave Hansen Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Jeff Dike Cc: Richard Weinberger Cc: Dave Hansen Cc: Andy Lutomirski Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Arnd Bergmann Cc: Andrey Ryabinin Cc: Heiko Carstens Cc: Christian Borntraeger Cc: Claudio Imbrenda Cc: [5.2+] Link: https://lkml.kernel.org/r/patch.git-943f1e5dcff2.your-ad-here.call-01599856292-ext-8676@work.hours Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

s390/init: add missing __init annotations

2020-10-01T15:36:24Z

[ Upstream commit fcb2b70cdb194157678fb1a75f9ff499aeba3d2a ] Add __init to reserve_memory_end, reserve_oldmem and remove_oldmem. Sometimes these functions are not inlined, and then the build complains about section mismatch. Signed-off-by: Ilya Leoshkevich Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/pci: fix leak of DMA tables on hard unplug

2020-09-23T11:00:02Z

commit afdf9550e54627fcf4dd609bdc1153059378cdf5 upstream. commit f606b3ef47c9 ("s390/pci: adapt events for zbus") removed the zpci_disable_device() call for a zPCI event with PEC 0x0304 because the device is already deconfigured by the platform. This however skips the Linux side of the disable in particular it leads to leaking the DMA tables and bitmaps because zpci_dma_exit_device() is never called on the device. If the device transitions to the Reserved state we call zpci_zdev_put() but zpci_release_device() will not call zpci_disable_device() because the state of the zPCI function is already ZPCI_FN_STATE_STANDBY. If the device is put into the Standby state, zpci_disable_device() is not called and the device is assumed to have been put in Standby through platform action. At this point the device may be removed by a subsequent event with PEC 0x0308 or 0x0306 which calls zpci_zdev_put() with the same problem as above or the device may be configured again in which case zpci_disable_device() is also not called. Fix this by calling zpci_disable_device() explicitly for PEC 0x0304 as before. To make it more clear that zpci_disable_device() may be called, even if the lower level device has already been disabled by the platform, add a comment to zpci_disable_device(). Cc: # 5.8 Fixes: f606b3ef47c9 ("s390/pci: adapt events for zbus") Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390: add 3f program exception handler

2020-09-23T11:00:02Z

commit cd4d3d5f21ddbfae3f686ac0ff405f21f7847ad3 upstream. Program exception 3f (secure storage violation) can only be detected when the CPU is running in SIE with a format 4 state description, e.g. running a protected guest. Because of this and because user space partly controls the guest memory mapping and can trigger this exception, we want to send a SIGSEGV to the process running the guest and not panic the kernel. Signed-off-by: Janosch Frank Cc: # 5.7 Fixes: 084ea4d611a3 ("s390/mm: add (non)secure page access exceptions handlers") Reviewed-by: Claudio Imbrenda Reviewed-by: Cornelia Huck Acked-by: Christian Borntraeger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390: fix GENERIC_LOCKBREAK dependency typo in Kconfig

2020-09-09T17:14:30Z

commit 114b9df419bf5db097b322ebb03fcf2f502f9380 upstream. Commit fa686453053b ("sched/rt, s390: Use CONFIG_PREEMPTION") changed a bunch of uses of CONFIG_PREEMPT to _PREEMPTION. Except in the Kconfig it used two T's. That's the only place in the system where that spelling exists, so let's fix that. Fixes: fa686453053b ("sched/rt, s390: Use CONFIG_PREEMPTION") Cc: # 5.6 Signed-off-by: Eric Farman Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman

s390: don't trace preemption in percpu macros

2020-09-09T17:14:11Z

[ Upstream commit 1196f12a2c960951d02262af25af0bb1775ebcc2 ] Since commit a21ee6055c30 ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables") the lockdep code itself uses percpu variables. This leads to recursions because the percpu macros are calling preempt_enable() which might call trace_preempt_on(). Signed-off-by: Sven Schnelle Reviewed-by: Vasily Gorbik Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/ptrace: fix storage key handling

2020-08-26T09:49:12Z

[ Upstream commit fd78c59446b8d050ecf3e0897c5a486c7de7c595 ] The key member of the runtime instrumentation control block contains only the access key, not the complete storage key. Therefore the value must be shifted by four bits. Since existing user space does not necessarily query and set the access key correctly, just ignore the user space provided key and use the correct one. Note: this is only relevant for debugging purposes in case somebody compiles a kernel with a default storage access key set to a value not equal to zero. Fixes: 262832bc5acd ("s390/ptrace: add runtime instrumention register get/set") Reported-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/runtime_instrumentation: fix storage key handling

2020-08-26T09:49:12Z

[ Upstream commit 9eaba29c7985236e16468f4e6a49cc18cf01443e ] The key member of the runtime instrumentation control block contains only the access key, not the complete storage key. Therefore the value must be shifted by four bits. Note: this is only relevant for debugging purposes in case somebody compiles a kernel with a default storage access key set to a value not equal to zero. Fixes: e4b8b3f33fca ("s390: add support for runtime instrumentation") Reported-by: Claudio Imbrenda Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/pci: ignore stale configuration request event

2020-08-26T09:49:02Z

commit b76fee1bc56c31a9d2a49592810eba30cc06d61a upstream. A configuration request event may be stale, that is the event may reference a zdev which was already configured. This can happen when a hotplug happens during boot such that the device is discovered and configured in the initial clp_list_pci(), then after initialization we enable events and process the original configuration request which additionally still contains the old disabled function handle leading to a failure during device enablement and subsequent I/O lockout. Fix this by restoring the check that the device to be configured is in standby which was removed in commit f606b3ef47c9 ("s390/pci: adapt events for zbus"). This check does not need serialization as we only enable the events after zPCI has fully initialized, which includes the initial clp_list_pci(), rescan only does updates and events are serialized with respect to each other. Fixes: f606b3ef47c9 ("s390/pci: adapt events for zbus") Cc: # 5.8 Reported-by: Shalini Chellathurai Saroja Tested-by: Shalini Chellathurai Saroja Acked-by: Pierre Morel Signed-off-by: Niklas Schnelle Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman