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2022-03-08s390/extable: fix exception table sortingHeiko Carstens
commit c194dad21025dfd043210912653baab823bdff67 upstream. s390 has a swap_ex_entry_fixup function, however it is not being used since common code expects a swap_ex_entry_fixup define. If it is not defined the default implementation will be used. So fix this by adding a proper define. However also the implementation of the function must be fixed, since a NULL value for handler has a special meaning and must not be adjusted. Luckily all of this doesn't fix a real bug currently: the main extable is correctly sorted during build time, and for runtime sorting there is currently no case where the handler field is not NULL. Fixes: 05a68e892e89 ("s390/kernel: expand exception table logic to allow new handling options") Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-11KVM: s390: Return error on SIDA memop on normal guestJanis Schoetterl-Glausch
commit 2c212e1baedcd782b2535a3f86bc491977677c0e upstream. Refuse SIDA memops on guests which are not protected. For normal guests, the secure instruction data address designation, which determines the location we access, is not under control of KVM. Fixes: 19e122776886 (KVM: S390: protvirt: Introduce instruction data area bounce buffer) Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01s390/hypfs: include z/VM guests with access control group setVasily Gorbik
commit 663d34c8df98740f1e90241e78e456d00b3c6cad upstream. Currently if z/VM guest is allowed to retrieve hypervisor performance data globally for all guests (privilege class B) the query is formed in a way to include all guests but the group name is left empty. This leads to that z/VM guests which have access control group set not being included in the results (even local vm). Change the query group identifier from empty to "any" to retrieve information about all guests from any groups (or without a group set). Cc: stable@vger.kernel.org Fixes: 31cb4bd31a48 ("[S390] Hypervisor filesystem (s390_hypfs) for z/VM") Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01s390/module: fix loading modules with a lot of relocationsIlya Leoshkevich
commit f3b7e73b2c6619884351a3a0a7468642f852b8a2 upstream. If the size of the PLT entries generated by apply_rela() exceeds 64KiB, the first ones can no longer reach __jump_r1 with brc. Fix by using brcl. An alternative solution is to add a __jump_r1 copy after every 64KiB, however, the space savings are quite small and do not justify the additional complexity. Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Cc: stable@vger.kernel.org Reported-by: Andrea Righi <andrea.righi@canonical.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27s390/mm: fix 2KB pgtable release raceAlexander Gordeev
commit c2c224932fd0ee6854d6ebfc8d059c2bcad86606 upstream. There is a race on concurrent 2KB-pgtables release paths when both upper and lower halves of the containing parent page are freed, one via page_table_free_rcu() + __tlb_remove_table(), and the other via page_table_free(). The race might lead to a corruption as result of remove of list item in page_table_free() concurrently with __free_page() in __tlb_remove_table(). Let's assume first the lower and next the upper 2KB-pgtables are freed from a page. Since both halves of the page are allocated the tracking byte (bits 24-31 of the page _refcount) has value of 0x03 initially: CPU0 CPU1 ---- ---- page_table_free_rcu() // lower half { // _refcount[31..24] == 0x03 ... atomic_xor_bits(&page->_refcount, 0x11U << (0 + 24)); // _refcount[31..24] <= 0x12 ... table = table | (1U << 0); tlb_remove_table(tlb, table); } ... __tlb_remove_table() { // _refcount[31..24] == 0x12 mask = _table & 3; // mask <= 0x01 ... page_table_free() // upper half { // _refcount[31..24] == 0x12 ... atomic_xor_bits( &page->_refcount, 1U << (1 + 24)); // _refcount[31..24] <= 0x10 // mask <= 0x10 ... atomic_xor_bits(&page->_refcount, mask << (4 + 24)); // _refcount[31..24] <= 0x00 // mask <= 0x00 ... if (mask != 0) // == false break; fallthrough; ... if (mask & 3) // == false ... else __free_page(page); list_del(&page->lru); ^^^^^^^^^^^^^^^^^^ RACE! ^^^^^^^^^^^^^^^^^^^^^ } ... } The problem is page_table_free() releases the page as result of lower nibble unset and __tlb_remove_table() observing zero too early. With this update page_table_free() will use the similar logic as page_table_free_rcu() + __tlb_remove_table(), and mark the fragment as pending for removal in the upper nibble until after the list_del(). In other words, the parent page is considered as unreferenced and safe to release only when the lower nibble is cleared already and unsetting a bit in upper nibble results in that nibble turned zero. Cc: stable@vger.kernel.org Suggested-by: Vlastimil Babka <vbabka@suse.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-20KVM: s390: Clarify SIGP orders versus STOP/RESTARTEric Farman
commit 812de04661c4daa7ac385c0dfd62594540538034 upstream. With KVM_CAP_S390_USER_SIGP, there are only five Signal Processor orders (CONDITIONAL EMERGENCY SIGNAL, EMERGENCY SIGNAL, EXTERNAL CALL, SENSE, and SENSE RUNNING STATUS) which are intended for frequent use and thus are processed in-kernel. The remainder are sent to userspace with the KVM_CAP_S390_USER_SIGP capability. Of those, three orders (RESTART, STOP, and STOP AND STORE STATUS) have the potential to inject work back into the kernel, and thus are asynchronous. Let's look for those pending IRQs when processing one of the in-kernel SIGP orders, and return BUSY (CC2) if one is in process. This is in agreement with the Principles of Operation, which states that only one order can be "active" on a CPU at a time. Cc: stable@vger.kernel.org Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Eric Farman <farman@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20211213210550.856213-2-farman@linux.ibm.com [borntraeger@linux.ibm.com: add stable tag] Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-22s390/kexec_file: fix error handling when applying relocationsPhilipp Rudo
[ Upstream commit 41967a37b8eedfee15b81406a9f3015be90d3980 ] arch_kexec_apply_relocations_add currently ignores all errors returned by arch_kexec_do_relocs. This means that every unknown relocation is silently skipped causing unpredictable behavior while the relocated code runs. Fix this by checking for errors and fail kexec_file_load if an unknown relocation type is encountered. The problem was found after gcc changed its behavior and used R_390_PLT32DBL relocations for brasl instruction and relied on ld to resolve the relocations in the final link in case direct calls are possible. As the purgatory code is only linked partially (option -r) ld didn't resolve the relocations leaving them for arch_kexec_do_relocs. But arch_kexec_do_relocs doesn't know how to handle R_390_PLT32DBL relocations so they were silently skipped. This ultimately caused an endless loop in the purgatory as the brasl instructions kept branching to itself. Fixes: 71406883fd35 ("s390/kexec_file: Add kexec_file_load system call") Reported-by: Tao Liu <ltao@redhat.com> Signed-off-by: Philipp Rudo <prudo@redhat.com> Link: https://lore.kernel.org/r/20211208130741.5821-3-prudo@redhat.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-17s390/test_unwind: use raw opcode instead of invalid instructionIlie Halip
[ Upstream commit 53ae7230918154d1f4281d7aa3aae9650436eadf ] Building with clang & LLVM_IAS=1 leads to an error: arch/s390/lib/test_unwind.c:179:4: error: invalid register pair " mvcl %%r1,%%r1\n" ^ The test creates an invalid instruction that would trap at runtime, but the LLVM inline assembler tries to validate it at compile time too. Use the raw instruction opcode instead. Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Ilie Halip <ilie.halip@gmail.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Suggested-by: Ulrich Weigand <Ulrich.Weigand@de.ibm.com> Link: https://github.com/ClangBuiltLinux/linux/issues/1421 Link: https://lore.kernel.org/r/20211117174822.3632412-1-ilie.halip@gmail.com Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> [hca@linux.ibm.com: use illegal opcode, and update comment] Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-08s390/pci: move pseudo-MMIO to prevent MIO overlapNiklas Schnelle
commit 52d04d408185b7aa47628d2339c28ec70074e0ae upstream. When running without MIO support, with pci=nomio or for devices which are not MIO-capable the zPCI subsystem generates pseudo-MMIO addresses to allow access to PCI BARs via MMIO based Linux APIs even though the platform uses function handles and BAR numbers. This is done by stashing an index into our global IOMAP array which contains the function handle in the 16 most significant bits of the addresses returned by ioremap() always setting the most significant bit. On the other hand the MIO addresses assigned by the platform for use, while requiring special instructions, allow PCI access with virtually mapped physical addresses. Now the problem is that these MIO addresses and our own pseudo-MMIO addresses may overlap, while functionally this would not be a problem by itself this overlap is detected by common code as both address types are added as resources in the iomem_resource tree. This leads to the overlapping resource claim of either the MIO capable or non-MIO capable devices with being rejected. Since PCI is tightly coupled to the use of the iomem_resource tree, see for example the code for request_mem_region(), we can't reasonably get rid of the overlap being detected by keeping our pseudo-MMIO addresses out of the iomem_resource tree. Instead let's move the range used by our own pseudo-MMIO addresses by starting at (1UL << 62) and only using addresses below (1UL << 63) thus avoiding the range currently used for MIO addresses. Fixes: c7ff0e918a7c ("s390/pci: deal with devices that have no support for MIO instructions") Cc: stable@vger.kernel.org # 5.3+ Reviewed-by: Pierre Morel <pmorel@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-08s390/setup: avoid using memblock_enforce_memory_limitVasily Gorbik
[ Upstream commit 5dbc4cb4667457b0c53bcd7bff11500b3c362975 ] There is a difference in how architectures treat "mem=" option. For some that is an amount of online memory, for s390 and x86 this is the limiting max address. Some memblock api like memblock_enforce_memory_limit() take limit argument and explicitly treat it as the size of online memory, and use __find_max_addr to convert it to an actual max address. Current s390 usage: memblock_enforce_memory_limit(memblock_end_of_DRAM()); yields different results depending on presence of memory holes (offline memory blocks in between online memory). If there are no memory holes limit == max_addr in memblock_enforce_memory_limit() and it does trim online memory and reserved memory regions. With memory holes present it actually does nothing. Since we already use memblock_remove() explicitly to trim online memory regions to potential limit (think mem=, kdump, addressing limits, etc.) drop the usage of memblock_enforce_memory_limit() altogether. Trimming reserved regions should not be required, since we now use memblock_set_current_limit() to limit allocations and any explicit memory reservations above the limit is an actual problem we should not hide. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-12-01s390/mm: validate VMA in PGSTE manipulation functionsDavid Hildenbrand
commit fe3d10024073f06f04c74b9674bd71ccc1d787cf upstream. We should not walk/touch page tables outside of VMA boundaries when holding only the mmap sem in read mode. Evil user space can modify the VMA layout just before this function runs and e.g., trigger races with page table removal code since commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"). gfn_to_hva() will only translate using KVM memory regions, but won't validate the VMA. Further, we should not allocate page tables outside of VMA boundaries: if evil user space decides to map hugetlbfs to these ranges, bad things will happen because we suddenly have PTE or PMD page tables where we shouldn't have them. Similarly, we have to check if we suddenly find a hugetlbfs VMA, before calling get_locked_pte(). Fixes: 2d42f9477320 ("s390/kvm: Add PGSTE manipulation functions") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20210909162248.14969-4-david@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26s390/kexec: fix memory leak of ipl report bufferBaoquan He
commit 4aa9340584e37debef06fa99b56d064beb723891 upstream. unreferenced object 0x38000195000 (size 4096): comm "kexec", pid 8548, jiffies 4294953647 (age 32443.270s) hex dump (first 32 bytes): 00 00 00 c8 20 00 00 00 00 00 00 c0 02 80 00 00 .... ........... 40 40 40 40 40 40 40 40 00 00 00 00 00 00 00 00 @@@@@@@@........ backtrace: [<0000000011a2f199>] __vmalloc_node_range+0xc0/0x140 [<0000000081fa2752>] vzalloc+0x5a/0x70 [<0000000063a4c92d>] ipl_report_finish+0x2c/0x180 [<00000000553304da>] kexec_file_add_ipl_report+0xf4/0x150 [<00000000862d033f>] kexec_file_add_components+0x124/0x160 [<000000000d2717bb>] arch_kexec_kernel_image_load+0x62/0x90 [<000000002e0373b6>] kimage_file_alloc_init+0x1aa/0x2e0 [<0000000060f2d14f>] __do_sys_kexec_file_load+0x17c/0x2c0 [<000000008c86fe5a>] __s390x_sys_kexec_file_load+0x40/0x50 [<000000001fdb9dac>] __do_syscall+0x1bc/0x1f0 [<000000003ee4258d>] system_call+0x78/0xa0 Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Philipp Rudo <prudo@redhat.com> Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to next kernel") Cc: <stable@vger.kernel.org> # v5.2: 20c76e242e70: s390/kexec: fix return code handling Cc: <stable@vger.kernel.org> # v5.2 Link: https://lore.kernel.org/r/20211116033101.GD21646@MiWiFi-R3L-srv Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26s390/kexec: fix return code handlingHeiko Carstens
[ Upstream commit 20c76e242e7025bd355619ba67beb243ba1a1e95 ] kexec_file_add_ipl_report ignores that ipl_report_finish may fail and can return an error pointer instead of a valid pointer. Fix this and simplify by returning NULL in case of an error and let the only caller handle this case. Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to next kernel") Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18KVM: s390: Fix handle_sske page fault handlingJanis Schoetterl-Glausch
[ Upstream commit 85f517b29418158d3e6e90c3f0fc01b306d2f1a1 ] If handle_sske cannot set the storage key, because there is no page table entry or no present large page entry, it calls fixup_user_fault. However, currently, if the call succeeds, handle_sske returns -EAGAIN, without having set the storage key. Instead, retry by continue'ing the loop without incrementing the address. The same issue in handle_pfmf was fixed by a11bdb1a6b78 ("KVM: s390: Fix pfmf and conditional skey emulation"). Fixes: bd096f644319 ("KVM: s390: Add skey emulation fault handling") Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20211022152648.26536-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18KVM: s390: pv: avoid stalls for kvm_s390_pv_init_vmClaudio Imbrenda
[ Upstream commit 1e2aa46de526a5adafe580bca4c25856bb06f09e ] When the system is heavily overcommitted, kvm_s390_pv_init_vm might generate stall notifications. Fix this by using uv_call_sched instead of just uv_call. This is ok because we are not holding spinlocks. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: 214d9bbcd3a672 ("s390/mm: provide memory management functions for protected KVM guests") Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Message-Id: <20210920132502.36111-4-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18KVM: s390: pv: avoid double free of sida pageClaudio Imbrenda
[ Upstream commit d4074324b07a94a1fca476d452dfbb3a4e7bf656 ] If kvm_s390_pv_destroy_cpu is called more than once, we risk calling free_page on a random page, since the sidad field is aliased with the gbea, which is not guaranteed to be zero. This can happen, for example, if userspace calls the KVM_PV_DISABLE IOCTL, and it fails, and then userspace calls the same IOCTL again. This scenario is only possible if KVM has some serious bug or if the hardware is broken. The solution is to simply return successfully immediately if the vCPU was already non secure. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: 19e1227768863a1469797c13ef8fea1af7beac2c ("KVM: S390: protvirt: Introduce instruction data area bounce buffer") Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Message-Id: <20210920132502.36111-3-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18s390/gmap: don't unconditionally call pte_unmap_unlock() in __gmap_zap()David Hildenbrand
[ Upstream commit b159f94c86b43cf7e73e654bc527255b1f4eafc4 ] ... otherwise we will try unlocking a spinlock that was never locked via a garbage pointer. At the time we reach this code path, we usually successfully looked up a PGSTE already; however, evil user space could have manipulated the VMA layout in the meantime and triggered removal of the page table. Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20210909162248.14969-3-david@redhat.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02KVM: s390: preserve deliverable_mask in __airqs_kick_single_vcpuHalil Pasic
[ Upstream commit 0e9ff65f455dfd0a8aea5e7843678ab6fe097e21 ] Changing the deliverable mask in __airqs_kick_single_vcpu() is a bug. If one idle vcpu can't take the interrupts we want to deliver, we should look for another vcpu that can, instead of saying that we don't want to deliver these interrupts by clearing the bits from the deliverable_mask. Fixes: 9f30f6216378 ("KVM: s390: add gib_alert_irq_handler()") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20211019175401.3757927-3-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-02KVM: s390: clear kicked_mask before sleeping againHalil Pasic
[ Upstream commit 9b57e9d5010bbed7c0d9d445085840f7025e6f9a ] The idea behind kicked mask is that we should not re-kick a vcpu that is already in the "kick" process, i.e. that was kicked and is is about to be dispatched if certain conditions are met. The problem with the current implementation is, that it assumes the kicked vcpu is going to enter SIE shortly. But under certain circumstances, the vcpu we just kicked will be deemed non-runnable and will remain in wait state. This can happen, if the interrupt(s) this vcpu got kicked to deal with got already cleared (because the interrupts got delivered to another vcpu). In this case kvm_arch_vcpu_runnable() would return false, and the vcpu would remain in kvm_vcpu_block(), but this time with its kicked_mask bit set. So next time around we wouldn't kick the vcpu form __airqs_kick_single_vcpu(), but would assume that we just kicked it. Let us make sure the kicked_mask is cleared before we give up on re-dispatching the vcpu. Fixes: 9f30f6216378 ("KVM: s390: add gib_alert_irq_handler()") Reported-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Michael Mueller <mimu@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20211019175401.3757927-2-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-10-27s390/pci: fix zpci_zdev_put() on reserveNiklas Schnelle
commit a46044a92add6a400f4dada7b943b30221f7cc80 upstream. Since commit 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") the reference count of a zpci_dev is incremented between pcibios_add_device() and pcibios_release_device() which was supposed to prevent the zpci_dev from being freed while the common PCI code has access to it. It was missed however that the handling of zPCI availability events assumed that once zpci_zdev_put() was called no later availability event would still see the device. With the previously mentioned commit however this assumption no longer holds and we must make sure that we only drop the initial long-lived reference the zPCI subsystem holds exactly once. Do so by introducing a zpci_device_reserved() function that handles when a device is reserved. Here we make sure the zpci_dev will not be considered for further events by removing it from the zpci_list. This also means that the device actually stays in the ZPCI_FN_STATE_RESERVED state between the time we know it has been reserved and the final reference going away. We thus need to consider it a real state instead of just a conceptual state after the removal. The final cleanup of PCI resources, removal from zbus, and destruction of the IOMMU stays in zpci_release_device() to make sure holders of the reference do see valid data until the release. Fixes: 2a671f77ee49 ("s390/pci: fix use after free of zpci_dev") Cc: stable@vger.kernel.org Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-20s390: fix strrchr() implementationRoberto Sassu
commit 8e0ab8e26b72a80e991c66a8abc16e6c856abe3d upstream. Fix two problems found in the strrchr() implementation for s390 architectures: evaluate empty strings (return the string address instead of NULL, if '\0' is passed as second argument); evaluate the first character of non-empty strings (the current implementation stops at the second). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Heiko Carstens <hca@linux.ibm.com> (incorrect behavior with empty strings) Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Link: https://lore.kernel.org/r/20211005120836.60630-1-roberto.sassu@huawei.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-13bpf, s390: Fix potential memory leak about jit_dataTiezhu Yang
[ Upstream commit 686cb8b9f6b46787f035afe8fbd132a74e6b1bdd ] Make sure to free jit_data through kfree() in the error path. Fixes: 1c8f9b91c456 ("bpf: s390: add JIT support for multi-function programs") Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26s390/pci_mmio: fully validate the VMA before calling follow_pte()David Hildenbrand
commit a8b92b8c1eac8d655a97b1e90f4d83c25d9b9a18 upstream. We should not walk/touch page tables outside of VMA boundaries when holding only the mmap sem in read mode. Evil user space can modify the VMA layout just before this function runs and e.g., trigger races with page table removal code since commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"). find_vma() does not check if the address is >= the VMA start address; use vma_lookup() instead. Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22s390/bpf: Fix branch shortening during codegen passIlya Leoshkevich
commit 1511df6f5e9ef32826f20db2ee81f8527154dc14 upstream. EMIT6_PCREL() macro assumes that the previous pass generated 6 bytes of code, which is not the case if branch shortening took place. Fix by using jit->prg, like all the other EMIT6_PCREL_*() macros. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22s390/bpf: Fix 64-bit subtraction of the -0x80000000 constantIlya Leoshkevich
commit 6e61dc9da0b7a0d91d57c2e20b5ea4fd2d4e7e53 upstream. The JIT uses agfi for subtracting constants, but -(-0x80000000) cannot be represented as a 32-bit signed binary integer. Fix by using algfi in this particular case. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-22s390/bpf: Fix optimizing out zero-extensionsIlya Leoshkevich
commit db7bee653859ef7179be933e7d1384644f795f26 upstream. Currently the JIT completely removes things like `reg32 += 0`, however, the BPF_ALU semantics requires the target register to be zero-extended in such cases. Fix by optimizing out only the arithmetic operation, but not the subsequent zero-extension. Reported-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18s390/pv: fix the forcing of the swiotlbHalil Pasic
commit 93ebb6828723b8aef114415c4dc3518342f7dcad upstream. Since commit 903cd0f315fe ("swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing") if code sets swiotlb_force it needs to do so before the swiotlb is initialised. Otherwise io_tlb_default_mem->force_bounce will not get set to true, and devices that use (the default) swiotlb will not bounce despite switolb_force having the value of SWIOTLB_FORCE. Let us restore swiotlb functionality for PV by fulfilling this new requirement. This change addresses what turned out to be a fragility in commit 64e1f0c531d1 ("s390/mm: force swiotlb for protected virtualization"), which ain't exactly broken in its original context, but could give us some more headache if people backport the broken change and forget this fix. Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Fixes: 903cd0f315fe ("swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing") Fixes: 64e1f0c531d1 ("s390/mm: force swiotlb for protected virtualization") Cc: stable@vger.kernel.org #5.3+ Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-18s390: make PCI mio support a machine flagNiklas Schnelle
[ Upstream commit 3322ba0d7bea1e24ae464418626f6a15b69533ab ] Kernel support for the newer PCI mio instructions can be toggled off with the pci=nomio command line option which needs to integrate with common code PCI option parsing. However this option then toggles static branches which can't be toggled yet in an early_param() call. Thus commit 9964f396f1d0 ("s390: fix setting of mio addressing control") moved toggling the static branches to the PCI init routine. With this setup however we can't check for mio support outside the PCI code during early boot, i.e. before switching the static branches, which we need to be able to export this as an ELF HWCAP. Improve on this by turning mio availability into a machine flag that gets initially set based on CONFIG_PCI and the facility bit and gets toggled off if pci=nomio is found during PCI option parsing allowing simple access to this machine flag after early init. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-18s390/jump_label: print real address in a case of a jump label bugHeiko Carstens
[ Upstream commit 5492886c14744d239e87f1b0b774b5a341e755cc ] In case of a jump label print the real address of the piece of code where a mismatch was detected. This is right before the system panics, so there is nothing revealed. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15KVM: s390: index kvm->arch.idle_mask by vcpu_idxHalil Pasic
commit a3e03bc1368c1bc16e19b001fc96dc7430573cc8 upstream. While in practice vcpu->vcpu_idx == vcpu->vcp_id is often true, it may not always be, and we must not rely on this. Reason is that KVM decides the vcpu_idx, userspace decides the vcpu_id, thus the two might not match. Currently kvm->arch.idle_mask is indexed by vcpu_id, which implies that code like for_each_set_bit(vcpu_id, kvm->arch.idle_mask, online_vcpus) { vcpu = kvm_get_vcpu(kvm, vcpu_id); do_stuff(vcpu); } is not legit. Reason is that kvm_get_vcpu expects an vcpu_idx, not an vcpu_id. The trouble is, we do actually use kvm->arch.idle_mask like this. To fix this problem we have two options. Either use kvm_get_vcpu_by_id(vcpu_id), which would loop to find the right vcpu_id, or switch to indexing via vcpu_idx. The latter is preferable for obvious reasons. Let us make switch from indexing kvm->arch.idle_mask by vcpu_id to indexing it by vcpu_idx. To keep gisa_int.kicked_mask indexed by the same index as idle_mask lets make the same change for it as well. Fixes: 1ee0bc559dc3 ("KVM: s390: get rid of local_int array") Signed-off-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Christian Bornträger <borntraeger@de.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: <stable@vger.kernel.org> # 3.15+ Link: https://lore.kernel.org/r/20210827125429.1912577-1-pasic@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-15s390/debug: fix debug area life cyclePeter Oberparleiter
[ Upstream commit 9372a82892c2caa6bccab9a4081166fa769699f8 ] Currently allocation and registration of s390dbf debug areas are tied together. As a result, a debug area cannot be unregistered and re-registered while any process has an associated debugfs file open. Fix this by splitting alloc/release from register/unregister. Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15s390/debug: keep debug data on resizePeter Oberparleiter
[ Upstream commit 1204777867e8486a88dbb4793fe256b31ea05eeb ] Any previously recorded s390dbf debug data is reset when a debug area is resized using the 'pages' sysfs attribute. This can make live-debugging unnecessarily complex. Fix this by copying existing debug data to the newly allocated debug area when resizing. Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15s390/pci: fix misleading rc in clp_set_pci_fn()Niklas Schnelle
[ Upstream commit f7addcdd527a6dddfebe20c358b87bdb95624612 ] Currently clp_set_pci_fn() always returns 0 as long as the CLP request itself succeeds even if the operation itself returns a response code other than CLP_RC_OK or CLP_RC_SETPCIFN_ALRDY. This is highly misleading because calling code assumes that a zero rc means that the operation was successful. Fix this by returning the response code or cc on failure with the exception of the special handling for CLP_RC_SETPCIFN_ALRDY. Also let's not assume that the returned function handle for CLP_RC_SETPCIFN_ALRDY is 0, we don't need it anyway. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-15s390/kasan: fix large PMD pages address alignment checkAlexander Gordeev
[ Upstream commit ddd63c85ef67ea9ea7282ad35eafb6568047126e ] It is currently possible to initialize a large PMD page when the address is not aligned on page boundary. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-26s390/pci: fix use after free of zpci_devNiklas Schnelle
[ Upstream commit 2a671f77ee49f3e78997b77fdee139467ff6a598 ] The struct pci_dev uses reference counting but zPCI assumed erroneously that the last reference would always be the local reference after calling pci_stop_and_remove_bus_device(). This is usually the case but not how reference counting works and thus inherently fragile. In fact one case where this causes a NULL pointer dereference when on an SRIOV device the function 0 was hot unplugged before another function of the same multi-function device. In this case the second function's pdev->sriov->dev reference keeps the struct pci_dev of function 0 alive even after the unplug. This bug was previously hidden by the fact that we were leaking the struct pci_dev which in turn means that it always outlived the struct zpci_dev. This was fixed in commit 0b13525c20fe ("s390/pci: fix leak of PCI device structure") exposing the broken behavior. Fix this by accounting for the long living reference a struct pci_dev has to its underlying struct zpci_dev via the zbus->function[] array and only release that in pcibios_release_device() ensuring that the struct pci_dev is not left with a dangling reference. This is a minimal fix in the future it would probably better to use fine grained reference counting for struct zpci_dev. Fixes: 05bc1be6db4b2 ("s390/pci: create zPCI bus") Cc: stable@vger.kernel.org Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-08-04bpf: Introduce BPF nospec instruction for mitigating Spectre v4Daniel Borkmann
[ Upstream commit f5e81d1117501546b7be050c5fbafa6efd2c722c ] In case of JITs, each of the JIT backends compiles the BPF nospec instruction /either/ to a machine instruction which emits a speculation barrier /or/ to /no/ machine instruction in case the underlying architecture is not affected by Speculative Store Bypass or has different mitigations in place already. This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence' instruction for mitigation. In case of arm64, we rely on the firmware mitigation as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled, it works for all of the kernel code with no need to provide any additional instructions here (hence only comment in arm64 JIT). Other archs can follow as needed. The BPF nospec instruction is specifically targeting Spectre v4 since i) we don't use a serialization barrier for the Spectre v1 case, and ii) mitigation instructions for v1 and v4 might be different on some archs. The BPF nospec is required for a future commit, where the BPF verifier does annotate intermediate BPF programs with speculation barriers. Co-developed-by: Piotr Krysiuk <piotras@gmail.com> Co-developed-by: Benedict Schlueter <benedict.schlueter@rub.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Piotr Krysiuk <piotras@gmail.com> Signed-off-by: Benedict Schlueter <benedict.schlueter@rub.de> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28s390/boot: fix use of expolines in the DMA codeAlexander Egorenkov
commit 463f36c76fa4ec015c640ff63ccf52e7527abee0 upstream. The DMA code section of the decompressor must be compiled with expolines if Spectre V2 mitigation has been enabled for the decompressed kernel. This is required because although the decompressor's image contains the DMA code section, it is handed over to the decompressed kernel for use. Because the DMA code is already slow w/o expolines, use expolines always regardless whether the decompressed kernel is using them or not. This simplifies the DMA code by dropping the conditional compilation of expolines. Fixes: bf72630130c2 ("s390: use proper expoline sections for .dma code") Cc: <stable@vger.kernel.org> # 5.2 Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28s390/ftrace: fix ftrace_update_ftrace_func implementationVasily Gorbik
commit f8c2602733c953ed7a16e060640b8e96f9d94b9b upstream. s390 enforces DYNAMIC_FTRACE if FUNCTION_TRACER is selected. At the same time implementation of ftrace_caller is not compliant with HAVE_DYNAMIC_FTRACE since it doesn't provide implementation of ftrace_update_ftrace_func() and calls ftrace_trace_function() directly. The subtle difference is that during ftrace code patching ftrace replaces function tracer via ftrace_update_ftrace_func() and activates it back afterwards. Unexpected direct calls to ftrace_trace_function() during ftrace code patching leads to nullptr-dereferences when tracing is activated for one of functions which are used during code patching. Those function currently are: copy_from_kernel_nofault() copy_from_kernel_nofault_allowed() preempt_count_sub() [with debug_defconfig] preempt_count_add() [with debug_defconfig] Corresponding KASAN report: BUG: KASAN: nullptr-dereference in function_trace_call+0x316/0x3b0 Read of size 4 at addr 0000000000001e08 by task migration/0/15 CPU: 0 PID: 15 Comm: migration/0 Tainted: G B 5.13.0-41423-g08316af3644d Hardware name: IBM 3906 M04 704 (LPAR) Stopper: multi_cpu_stop+0x0/0x3e0 <- stop_machine_cpuslocked+0x1e4/0x218 Call Trace: [<0000000001f77caa>] show_stack+0x16a/0x1d0 [<0000000001f8de42>] dump_stack+0x15a/0x1b0 [<0000000001f81d56>] print_address_description.constprop.0+0x66/0x2e0 [<000000000082b0ca>] kasan_report+0x152/0x1c0 [<00000000004cfd8e>] function_trace_call+0x316/0x3b0 [<0000000001fb7082>] ftrace_caller+0x7a/0x7e [<00000000006bb3e6>] copy_from_kernel_nofault_allowed+0x6/0x10 [<00000000006bb42e>] copy_from_kernel_nofault+0x3e/0xd0 [<000000000014605c>] ftrace_make_call+0xb4/0x1f8 [<000000000047a1b4>] ftrace_replace_code+0x134/0x1d8 [<000000000047a6e0>] ftrace_modify_all_code+0x120/0x1d0 [<000000000047a7ec>] __ftrace_modify_code+0x5c/0x78 [<000000000042395c>] multi_cpu_stop+0x224/0x3e0 [<0000000000423212>] cpu_stopper_thread+0x33a/0x5a0 [<0000000000243ff2>] smpboot_thread_fn+0x302/0x708 [<00000000002329ea>] kthread+0x342/0x408 [<00000000001066b2>] __ret_from_fork+0x92/0xf0 [<0000000001fb57fa>] ret_from_fork+0xa/0x30 The buggy address belongs to the page: page:(____ptrval____) refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1 flags: 0x1ffff00000001000(reserved|node=0|zone=0|lastcpupid=0x1ffff) raw: 1ffff00000001000 0000040000000048 0000040000000048 0000000000000000 raw: 0000000000000000 0000000000000000 ffffffff00000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: 0000000000001d00: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 0000000000001d80: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 >0000000000001e00: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 ^ 0000000000001e80: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 0000000000001f00: f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 f7 ================================================================== To fix that introduce ftrace_func callback to be called from ftrace_caller and update it in ftrace_update_ftrace_func(). Fixes: 4cc9bed034d1 ("[S390] cleanup ftrace backend functions") Cc: stable@vger.kernel.org Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28s390/bpf: Perform r1 range checking before accessing jit->seen_reg[r1]Colin Ian King
[ Upstream commit 91091656252f5d6d8c476e0c92776ce9fae7b445 ] Currently array jit->seen_reg[r1] is being accessed before the range checking of index r1. The range changing on r1 should be performed first since it will avoid any potential out-of-range accesses on the array seen_reg[] and also it is more optimal to perform checks on r1 before fetching data from the array. Fix this by swapping the order of the checks before the array access. Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/bpf/20210715125712.24690-1-colin.king@canonical.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-25s390: introduce proper type handling call_on_stack() macroHeiko Carstens
[ Upstream commit 41d71fe59cce41237f24f3b7bdc1b414069a34ed ] The existing CALL_ON_STACK() macro allows for subtle bugs: - There is no type checking of the function that is being called. That is: missing or too many arguments do not cause any compile error or warning. The same is true if the return type of the called function changes. This can lead to quite random bugs. - Sign and zero extension of arguments is missing. Given that the s390 C ABI requires that the caller of a function performs proper sign and zero extension this can also lead to subtle bugs. - If arguments to the CALL_ON_STACK() macros contain functions calls register corruption can happen due to register asm constructs being used. Therefore introduce a new call_on_stack() macro which is supposed to fix all these problems. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-25s390/traps: do not test MONITOR CALL without CONFIG_BUGIlya Leoshkevich
[ Upstream commit b8e9cc20b808e26329090c19ff80b7f5098e98ff ] tinyconfig fails to boot, because without CONFIG_BUG report_bug() always returns BUG_TRAP_TYPE_BUG, which causes mc 0,0 in test_monitor_call() to panic. Fix by skipping the test without CONFIG_BUG. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20s390/mem_detect: fix tprot() program check new psw handlingHeiko Carstens
[ Upstream commit da9057576785aaab52e706e76c0475c85b77ec14 ] The tprot() inline asm temporarily changes the program check new psw to redirect a potential program check on the diag instruction. Restoring of the program check new psw is done in C code behind the inline asm. This can be problematic, especially if the function is inlined, since the compiler can reorder instructions in such a way that a different instruction, which may result in a program check, might be executed before the program check new psw has been restored. To avoid such a scenario move restoring into the inline asm. For consistency reasons move also saving of the original program check new psw into the inline asm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20s390/mem_detect: fix diag260() program check new psw handlingHeiko Carstens
[ Upstream commit 86807f348f418a84970eebb8f9912a7eea16b497 ] The __diag260() inline asm temporarily changes the program check new psw to redirect a potential program check on the diag instruction. Restoring of the program check new psw is done in C code behind the inline asm. This can be problematic, especially if the function is inlined, since the compiler can reorder instructions in such a way that a different instruction, which may result in a program check, might be executed before the program check new psw has been restored. To avoid such a scenario move restoring into the inline asm. For consistency reasons move also saving of the original program check new psw into the inline asm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20s390/ipl_parm: fix program check new psw handlingHeiko Carstens
[ Upstream commit 88c2510cecb7e2b518e3c4fdf3cf0e13ebe9377c ] The __diag308() inline asm temporarily changes the program check new psw to redirect a potential program check on the diag instruction. Restoring of the program check new psw is done in C code behind the inline asm. This can be problematic, especially if the function is inlined, since the compiler can reorder instructions in such a way that a different instruction, which may result in a program check, might be executed before the program check new psw has been restored. To avoid such a scenario move restoring into the inline asm. For consistency reasons move also saving of the original program check new psw into the inline asm. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20s390/processor: always inline stap() and __load_psw_mask()Heiko Carstens
[ Upstream commit 9c9a915afd90f7534c16a71d1cd44b58596fddf3 ] s390 is the only architecture which makes use of the __no_kasan_or_inline attribute for two functions. Given that both stap() and __load_psw_mask() are very small functions they can and should be always inlined anyway. Therefore get rid of __no_kasan_or_inline and always inline these functions. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20s390: disable SSP when neededFabrice Fontaine
[ Upstream commit 42e8d652438f5ddf04e5dac299cb5e623d113dc0 ] Though -nostdlib is passed in PURGATORY_LDFLAGS and -ffreestanding in KBUILD_CFLAGS_DECOMPRESSOR, -fno-stack-protector must also be passed to avoid linking errors related to undefined references to '__stack_chk_guard' and '__stack_chk_fail' if toolchain enforces -fstack-protector. Fixes - https://gitlab.com/kubu93/buildroot/-/jobs/1247043361 Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Link: https://lore.kernel.org/r/20210510053133.1220167-1-fontaine.fabrice@gmail.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20s390/sclp_vt220: fix console name to match deviceValentin Vidic
[ Upstream commit b7d91d230a119fdcc334d10c9889ce9c5e15118b ] Console name reported in /proc/consoles: ttyS1 -W- (EC p ) 4:65 does not match the char device name: crw--w---- 1 root root 4, 65 May 17 12:18 /dev/ttysclp0 so debian-installer inside a QEMU s390x instance gets confused and fails to start with the following error: steal-ctty: No such file or directory Signed-off-by: Valentin Vidic <vvidic@valentin-vidic.from.hr> Link: https://lore.kernel.org/r/20210427194010.9330-1-vvidic@valentin-vidic.from.hr Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14s390: preempt: Fix preempt_count initializationValentin Schneider
commit 6a942f5780545ebd11aca8b3ac4b163397962322 upstream. S390's init_idle_preempt_count(p, cpu) doesn't actually let us initialize the preempt_count of the requested CPU's idle task: it unconditionally writes to the current CPU's. This clearly conflicts with idle_threads_init(), which intends to initialize *all* the idle tasks, including their preempt_count (or their CPU's, if the arch uses a per-CPU preempt_count). Unfortunately, it seems the way s390 does things doesn't let us initialize every possible CPU's preempt_count early on, as the pages where this resides are only allocated when a CPU is brought up and are freed when it is brought down. Let the arch-specific code set a CPU's preempt_count when its lowcore is allocated, and turn init_idle_preempt_count() into an empty stub. Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled") Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20210707163338.1623014-1-valentin.schneider@arm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-14s390: appldata depends on PROC_SYSCTLRandy Dunlap
[ Upstream commit 5d3516b3647621d5a1180672ea9e0817fb718ada ] APPLDATA_BASE should depend on PROC_SYSCTL instead of PROC_FS. Building with PROC_FS but not PROC_SYSCTL causes a build error, since appldata_base.c uses data and APIs from fs/proc/proc_sysctl.c. arch/s390/appldata/appldata_base.o: in function `appldata_generic_handler': appldata_base.c:(.text+0x192): undefined reference to `sysctl_vals' Fixes: c185b783b099 ("[S390] Remove config options.") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: linux-s390@vger.kernel.org Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Link: https://lore.kernel.org/r/20210528002420.17634-1-rdunlap@infradead.org Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14s390: enable HAVE_IOREMAP_PROTNiklas Schnelle
[ Upstream commit d460bb6c6417588dd8b0907d34f69b237918812a ] In commit b02002cc4c0f ("s390/pci: Implement ioremap_wc/prot() with MIO") we implemented both ioremap_wc() and ioremap_prot() however until now we had not set HAVE_IOREMAP_PROT in Kconfig, do so now. This also requires implementing pte_pgprot() as this is used in the generic_access_phys() code enabled by CONFIG_HAVE_IOREMAP_PROT. As with ioremap_wc() we need to take the MMIO Write Back bit index into account. Moreover since the pgprot value returned from pte_pgprot() is to be used for mappings into kernel address space we must make sure that it uses appropriate kernel page table protection bits. In particular a pgprot value originally coming from userspace could have the _PAGE_PROTECT bit set to enable fault based dirty bit accounting which would then make the mapping inaccessible when used in kernel address space. Fixes: b02002cc4c0f ("s390/pci: Implement ioremap_wc/prot() with MIO") Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>