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* s390/syscalls: Avoid creation of arch/arch/ directoryMasahiro Yamada2024-12-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 0708967e2d56e370231fd07defa0d69f9ad125e8 ] Building the kernel with ARCH=s390 creates a weird arch/arch/ directory. $ find arch/arch arch/arch arch/arch/s390 arch/arch/s390/include arch/arch/s390/include/generated arch/arch/s390/include/generated/asm arch/arch/s390/include/generated/uapi arch/arch/s390/include/generated/uapi/asm The root cause is 'targets' in arch/s390/kernel/syscalls/Makefile, where the relative path is incorrect. Strictly speaking, 'targets' was not necessary in the first place because this Makefile uses 'filechk' instead of 'if_changed'. However, this commit keeps it, as it will be useful when converting 'filechk' to 'if_changed' later. Fixes: 5c75824d915e ("s390/syscalls: add Makefile to generate system call header files") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20241111134603.2063226-1-masahiroy@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: gaccess: Check if guest address is in memslotNico Boehr2024-11-082-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e8061f06185be0a06a73760d6526b8b0feadfe52 ] Previously, access_guest_page() did not check whether the given guest address is inside of a memslot. This is not a problem, since kvm_write_guest_page/kvm_read_guest_page return -EFAULT in this case. However, -EFAULT is also returned when copy_to/from_user fails. When emulating a guest instruction, the address being outside a memslot usually means that an addressing exception should be injected into the guest. Failure in copy_to/from_user however indicates that something is wrong in userspace and hence should be handled there. To be able to distinguish these two cases, return PGM_ADDRESSING in access_guest_page() when the guest address is outside guest memory. In access_guest_real(), populate vcpu->arch.pgm.code such that kvm_s390_inject_prog_cond() can be used in the caller for injecting into the guest (if applicable). Since this adds a new return value to access_guest_page(), we need to make sure that other callers are not confused by the new positive return value. There are the following users of access_guest_page(): - access_guest_with_key() does the checking itself (in guest_range_to_gpas()), so this case should never happen. Even if, the handling is set up properly. - access_guest_real() just passes the return code to its callers, which are: - read_guest_real() - see below - write_guest_real() - see below There are the following users of read_guest_real(): - ar_translation() in gaccess.c which already returns PGM_* - setup_apcb10(), setup_apcb00(), setup_apcb11() in vsie.c which always return -EFAULT on read_guest_read() nonzero return - no change - shadow_crycb(), handle_stfle() always present this as validity, this could be handled better but doesn't change current behaviour - no change There are the following users of write_guest_real(): - kvm_s390_store_status_unloaded() always returns -EFAULT on write_guest_real() failure. Fixes: 2293897805c2 ("KVM: s390: add architecture compliant guest access functions") Cc: stable@vger.kernel.org Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20240917151904.74314-2-nrb@linux.ibm.com Acked-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: gaccess: Cleanup access to guest pagesJanis Schoetterl-Glausch2024-11-081-8/+16
| | | | | | | | | | | | | | | [ Upstream commit bad13799e0305deb258372b7298a86be4c78aaba ] Introduce a helper function for guest frame access. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-Id: <20211126164549.7046-4-scgl@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Stable-dep-of: e8061f06185b ("KVM: s390: gaccess: Check if guest address is in memslot") Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: gaccess: Refactor access address range checkJanis Schoetterl-Glausch2024-11-081-53/+69
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 7faa543df19bf62d4583a64d3902705747f2ad29 ] Do not round down the first address to the page boundary, just translate it normally, which gives the value we care about in the first place. Given this, translating a single address is just the special case of translating a range spanning a single page. Make the output optional, so the function can be used to just check a range. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-Id: <20211126164549.7046-3-scgl@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Stable-dep-of: e8061f06185b ("KVM: s390: gaccess: Check if guest address is in memslot") Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: gaccess: Refactor gpa and length calculationJanis Schoetterl-Glausch2024-11-081-15/+17
| | | | | | | | | | | | | | | | [ Upstream commit 416e7f0c9d613bf84e182eba9547ae8f9f5bfa4c ] Improve readability by renaming the length variable and not calculating the offset manually. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-Id: <20211126164549.7046-2-scgl@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Stable-dep-of: e8061f06185b ("KVM: s390: gaccess: Check if guest address is in memslot") Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: Change virtual to physical address access in diag 0x258 handlerMichael Mueller2024-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | commit cad4b3d4ab1f062708fff33f44d246853f51e966 upstream. The parameters for the diag 0x258 are real addresses, not virtual, but KVM was using them as virtual addresses. This only happened to work, since the Linux kernel as a guest used to have a 1:1 mapping for physical vs virtual addresses. Fix KVM so that it correctly uses the addresses as real addresses. Cc: stable@vger.kernel.org Fixes: 8ae04b8f500b ("KVM: s390: Guest's memory access functions get access registers") Suggested-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Michael Mueller <mimu@linux.ibm.com> Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20240917151904.74314-3-nrb@linux.ibm.com Acked-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/cpum_sf: Remove WARN_ON_ONCE statementsThomas Richter2024-11-081-8/+4
| | | | | | | | | | | | | | | [ Upstream commit b495e710157606889f2d8bdc62aebf2aa02f67a7 ] Remove WARN_ON_ONCE statements. These have not triggered in the past. Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/mm: Add cond_resched() to cmm_alloc/free_pages()Gerald Schaefer2024-11-081-1/+17
| | | | | | | | | | | | | | | | | | [ Upstream commit 131b8db78558120f58c5dc745ea9655f6b854162 ] Adding/removing large amount of pages at once to/from the CMM balloon can result in rcu_sched stalls or workqueue lockups, because of busy looping w/o cond_resched(). Prevent this by adding a cond_resched(). cmm_free_pages() holds a spin_lock while looping, so it cannot be added directly to the existing loop. Instead, introduce a wrapper function that operates on maximum 256 pages at once, and add it there. Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/facility: Disable compile time optimization for decompressor codeHeiko Carstens2024-11-081-2/+4
| | | | | | | | | | | | | | | | [ Upstream commit 0147addc4fb72a39448b8873d8acdf3a0f29aa65 ] Disable compile time optimizations of test_facility() for the decompressor. The decompressor should not contain any optimized code depending on the architecture level set the kernel image is compiled for to avoid unexpected operation exceptions. Add a __DECOMPRESSOR check to test_facility() to enforce that facilities are always checked during runtime for the decompressor. Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* asm-generic: Move common compat types to asm-generic/compat.hArnd Bergmann2024-07-181-16/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fb3739759474d150a9927b920a80ea2afb4c2a51 upstream. While converting compat system call handlers to work on 32-bit architectures, I found a number of types used in those handlers that are identical between all architectures. Let's move all the identical ones into asm-generic/compat.h to avoid having to add even more identical definitions of those types. For unknown reasons, mips defines __compat_gid32_t, __compat_uid32_t and compat_caddr_t as signed, while all others have them unsigned. This seems to be a mistake, but I'm leaving it alone here. The other types all differ by size or alignment on at least on architecture. compat_aio_context_t is currently defined in linux/compat.h but also needed for compat_sys_io_getevents(), so let's move it into the same place. While we still have not decided whether the 32-bit time handling will always use the compat syscalls, or in which form, I think this is a useful cleanup that we can merge regardless. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Frank Scheiner <frank.scheiner@web.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/mm: Fix clearing storage keys for huge pagesClaudio Imbrenda2024-05-171-1/+1
| | | | | | | | | | | | | | | | | | [ Upstream commit 412050af2ea39407fe43324b0be4ab641530ce88 ] The function __storage_key_init_range() expects the end address to be the first byte outside the range to be initialized. I.e. end - start should be the size of the area to be initialized. The current code works because __storage_key_init_range() will still loop over every page in the range, but it is slower than using sske_frame(). Fixes: 3afdfca69870 ("s390/mm: Clear skeys for newly mapped huge guest pmds") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20240416114220.28489-3-imbrenda@linux.ibm.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/mm: Fix storage key clearing for guest huge pagesClaudio Imbrenda2024-05-171-1/+1
| | | | | | | | | | | | | | | | | | [ Upstream commit 843c3280686fc1a83d89ee1e0b5599c9f6b09d0c ] The function __storage_key_init_range() expects the end address to be the first byte outside the range to be initialized. I.e. end - start should be the size of the area to be initialized. The current code works because __storage_key_init_range() will still loop over every page in the range, but it is slower than using sske_frame(). Fixes: 964c2c05c9f3 ("s390/mm: Clear huge page storage keys on enable_skey") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20240416114220.28489-2-imbrenda@linux.ibm.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390: use the correct count for __iowrite64_copy()Jason Gunthorpe2024-03-011-1/+1
| | | | | | | | | | | | | | | [ Upstream commit 723a2cc8d69d4342b47dfddbfe6c19f1b135f09b ] The signature for __iowrite64_copy() requires the number of 64 bit quantities, not bytes. Multiple by 8 to get to a byte length before invoking zpci_memcpy_toio() Fixes: 87bc359b9822 ("s390/pci: speed up __iowrite64_copy by using pci store block insn") Acked-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/0-v1-9223d11a7662+1d7785-s390_iowrite64_jgg@nvidia.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: fix setting of fpc registerHeiko Carstens2024-02-231-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit b988b1bb0053c0dcd26187d29ef07566a565cf55 ] kvm_arch_vcpu_ioctl_set_fpu() allows to set the floating point control (fpc) register of a guest cpu. The new value is tested for validity by temporarily loading it into the fpc register. This may lead to corruption of the fpc register of the host process: if an interrupt happens while the value is temporarily loaded into the fpc register, and within interrupt context floating point or vector registers are used, the current fp/vx registers are saved with save_fpu_regs() assuming they belong to user space and will be loaded into fp/vx registers when returning to user space. test_fp_ctl() restores the original user space / host process fpc register value, however it will be discarded, when returning to user space. In result the host process will incorrectly continue to run with the value that was supposed to be used for a guest cpu. Fix this by simply removing the test. There is another test right before the SIE context is entered which will handles invalid values. This results in a change of behaviour: invalid values will now be accepted instead of that the ioctl fails with -EINVAL. This seems to be acceptable, given that this interface is most likely not used anymore, and this is in addition the same behaviour implemented with the memory mapped interface (replace invalid values with zero) - see sync_regs() in kvm-s390.c. Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/ptrace: handle setting of fpc register correctlyHeiko Carstens2024-02-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 8b13601d19c541158a6e18b278c00ba69ae37829 ] If the content of the floating point control (fpc) register of a traced process is modified with the ptrace interface the new value is tested for validity by temporarily loading it into the fpc register. This may lead to corruption of the fpc register of the tracing process: if an interrupt happens while the value is temporarily loaded into the fpc register, and within interrupt context floating point or vector registers are used, the current fp/vx registers are saved with save_fpu_regs() assuming they belong to user space and will be loaded into fp/vx registers when returning to user space. test_fp_ctl() restores the original user space fpc register value, however it will be discarded, when returning to user space. In result the tracer will incorrectly continue to run with the value that was supposed to be used for the traced process. Fix this by saving fpu register contents with save_fpu_regs() before using test_fp_ctl(). Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/vx: fix save/restore of fpu kernel contextHeiko Carstens2024-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit e6b2dab41888332bf83f592131e7ea07756770a4 ] The KERNEL_FPR mask only contains a flag for the first eight vector registers. However floating point registers overlay parts of the first sixteen vector registers. This could lead to vector register corruption if a kernel fpu context uses any of the vector registers 8 to 15 and is interrupted or calls a KERNEL_FPR context. If that context uses also vector registers 8 to 15, their contents will be corrupted on return. Luckily this is currently not a real bug, since the kernel has only one KERNEL_FPR user with s390_adjust_jiffies() and it is only using floating point registers 0 to 2. Fix this by using the correct bits for KERNEL_FPR. Fixes: 7f79695cc1b6 ("s390/fpu: improve kernel_fpu_[begin|end]") Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390/mm: Properly reset no-datClaudio Imbrenda2023-12-131-1/+1
| | | | | | | | | | | | | | commit 27072b8e18a73ffeffb1c140939023915a35134b upstream. When the CMMA state needs to be reset, the no-dat bit also needs to be reset. Failure to do so could cause issues in the guest, since the guest expects the bit to be cleared after a reset. Cc: <stable@vger.kernel.org> Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Message-ID: <20231109123624.37314-1-imbrenda@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/cmma: fix detection of DAT pagesHeiko Carstens2023-12-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 44d93045247661acbd50b1629e62f415f2747577 ] If the cmma no-dat feature is available the kernel page tables are walked to identify and mark all pages which are used for address translation (all region, segment, and page tables). In a subsequent loop all other pages are marked as "no-dat" pages with the ESSA instruction. This information is visible to the hypervisor, so that the hypervisor can optimize purging of guest TLB entries. The initial loop however is incorrect: only the first three of the four pages which belong to segment and region tables will be marked as being used for DAT. The last page is incorrectly marked as no-dat. This can result in incorrect guest TLB flushes. Fix this by simply marking all four pages. Cc: <stable@vger.kernel.org> Reviewed-by: Claudio Imbrenda <imbrenda@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>
* s390/mm: fix phys vs virt confusion in mark_kernel_pXd() functions familyAlexander Gordeev2023-12-081-4/+4
| | | | | | | | | | | | | [ Upstream commit 3784231b1e091857bd129fd9658a8b3cedbdcd58 ] Due to historical reasons mark_kernel_pXd() functions misuse the notion of physical vs virtual addresses difference. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Stable-dep-of: 44d930452476 ("s390/cmma: fix detection of DAT pages") Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/pci: fix iommu bitmap allocationNiklas Schnelle2023-10-251-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c1ae1c59c8c6e0b66a718308c623e0cb394dab6b upstream. Since the fixed commits both zdev->iommu_bitmap and zdev->lazy_bitmap are allocated as vzalloc(zdev->iommu_pages / 8). The problem is that zdev->iommu_bitmap is a pointer to unsigned long but the above only yields an allocation that is a multiple of sizeof(unsigned long) which is 8 on s390x if the number of IOMMU pages is a multiple of 64. This in turn is the case only if the effective IOMMU aperture is a multiple of 64 * 4K = 256K. This is usually the case and so didn't cause visible issues since both the virt_to_phys(high_memory) reduced limit and hardware limits use nice numbers. Under KVM, and in particular with QEMU limiting the IOMMU aperture to the vfio DMA limit (default 65535), it is possible for the reported aperture not to be a multiple of 256K however. In this case we end up with an iommu_bitmap whose allocation is not a multiple of 8 causing bitmap operations to access it out of bounds. Sadly we can't just fix this in the obvious way and use bitmap_zalloc() because for large RAM systems (tested on 8 TiB) the zdev->iommu_bitmap grows too large for kmalloc(). So add our own bitmap_vzalloc() wrapper. This might be a candidate for common code, but this area of code will be replaced by the upcoming conversion to use the common code DMA API on s390 so just add a local routine. Fixes: 224593215525 ("s390/pci: use virtual memory for iommu bitmap") Fixes: 13954fd6913a ("s390/pci_dma: improve lazy flush for unmap") 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* KVM: s390: fix sthyi error handlingHeiko Carstens2023-08-112-6/+9
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 0c02cc576eac161601927b41634f80bfd55bfa9e ] Commit 9fb6c9b3fea1 ("s390/sthyi: add cache to store hypervisor info") added cache handling for store hypervisor info. This also changed the possible return code for sthyi_fill(). Instead of only returning a condition code like the sthyi instruction would do, it can now also return a negative error value (-ENOMEM). handle_styhi() was not changed accordingly. In case of an error, the negative error value would incorrectly injected into the guest PSW. Add proper error handling to prevent this, and update the comment which describes the possible return values of sthyi_fill(). Fixes: 9fb6c9b3fea1 ("s390/sthyi: add cache to store hypervisor info") Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20230727182939.2050744-1-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* KVM: s390: fix KVM_S390_GET_CMMA_BITS for GFNs in memslot holesNico Boehr2023-08-111-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 285cff4c0454340a4dc53f46e67f2cb1c293bd74 ] The KVM_S390_GET_CMMA_BITS ioctl may return incorrect values when userspace specifies a start_gfn outside of memslots. This can occur when a VM has multiple memslots with a hole in between: +-----+----------+--------+--------+ | ... | Slot N-1 | <hole> | Slot N | +-----+----------+--------+--------+ ^ ^ ^ ^ | | | | GFN A A+B | | A+B+C | A+B+C+D When userspace specifies a GFN in [A+B, A+B+C), it would expect to get the CMMA values of the first dirty page in Slot N. However, userspace may get a start_gfn of A+B+C+D with a count of 0, hence completely skipping over any dirty pages in slot N. The error is in kvm_s390_next_dirty_cmma(), which assumes gfn_to_memslot_approx() will return the memslot _below_ the specified GFN when the specified GFN lies outside a memslot. In reality it may return either the memslot below or above the specified GFN. When a memslot above the specified GFN is returned this happens: - ofs is calculated, but since the memslot's base_gfn is larger than the specified cur_gfn, ofs will underflow to a huge number. - ofs is passed to find_next_bit(). Since ofs will exceed the memslot's number of pages, the number of pages in the memslot is returned, completely skipping over all bits in the memslot userspace would be interested in. Fix this by resetting ofs to zero when a memslot _above_ cur_gfn is returned (cur_gfn < ms->base_gfn). Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: afdad61615cc ("KVM: s390: Fix storage attributes migration with memory slots") Message-Id: <20230324145424.293889-2-nrb@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* treewide: Remove uninitialized_var() usageKees Cook2023-08-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream. Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/ptrace: fix PTRACE_GET_LAST_BREAK error handlingHeiko Carstens2023-04-261-6/+2
| | | | | | | | | | | | [ Upstream commit f9bbf25e7b2b74b52b2f269216a92657774f239c ] Return -EFAULT if put_user() for the PTRACE_GET_LAST_BREAK request fails, instead of silently ignoring it. 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>
* s390/uaccess: add missing earlyclobber annotations to __clear_user()Heiko Carstens2023-04-051-1/+1
| | | | | | | | | | | | | | | | | | commit 89aba4c26fae4e459f755a18912845c348ee48f3 upstream. Add missing earlyclobber annotation to size, to, and tmp2 operands of the __clear_user() inline assembly since they are modified or written to before the last usage of all input operands. This can lead to incorrect register allocation for the inline assembly. Fixes: 6c2a9e6df604 ("[S390] Use alternative user-copy operations for new hardware.") Reported-by: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/all/20230321122514.1743889-3-mark.rutland@arm.com/ Cc: stable@vger.kernel.org Reviewed-by: Gerald Schaefer <gerald.schaefer@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>
* s390/setup: init jump labels before command line parsingVasily Gorbik2023-03-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | commit 95e61b1b5d6394b53d147c0fcbe2ae70fbe09446 upstream. Command line parameters might set static keys. This is true for s390 at least since commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options"). To avoid the following WARN: static_key_enable_cpuslocked(): static key 'init_on_alloc+0x0/0x40' used before call to jump_label_init() call jump_label_init() just before parse_early_param(). jump_label_init() is safe to call multiple times (x86 does that), doesn't do any memory allocations and hence should be safe to call that early. Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options") Cc: <stable@vger.kernel.org> # 5.3: d6df52e9996d: s390/maccess: add no DAT mode to kernel_write Cc: <stable@vger.kernel.org> # 5.3 Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/maccess: add no DAT mode to kernel_writeVasily Gorbik2023-03-111-5/+11
| | | | | | | | | | | | | commit d6df52e9996dcc2062c3d9c9123288468bb95b52 upstream. To be able to patch kernel code before paging is initialized do plain memcpy if DAT is off. This is required to enable early jump label initialization. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/kprobes: fix current_kprobe never cleared after kprobes reenterVasily Gorbik2023-03-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit cd57953936f2213dfaccce10d20f396956222c7d upstream. Recent test_kprobe_missed kprobes kunit test uncovers the following problem. Once kprobe is triggered from another kprobe (kprobe reenter), all future kprobes on this cpu are considered as kprobe reenter, thus pre_handler and post_handler are not being called and kprobes are counted as "missed". Commit b9599798f953 ("[S390] kprobes: activation and deactivation") introduced a simpler scheme for kprobes (de)activation and status tracking by using push_kprobe/pop_kprobe, which supposed to work for both initial kprobe entry as well as kprobe reentry and helps to avoid handling those two cases differently. The problem is that a sequence of calls in case of kprobes reenter: push_kprobe() <- NULL (current_kprobe) push_kprobe() <- kprobe1 (current_kprobe) pop_kprobe() -> kprobe1 (current_kprobe) pop_kprobe() -> kprobe1 (current_kprobe) leaves "kprobe1" as "current_kprobe" on this cpu, instead of setting it to NULL. In fact push_kprobe/pop_kprobe can only store a single state (there is just one prev_kprobe in kprobe_ctlblk). Which is a hack but sufficient, there is no need to have another prev_kprobe just to store NULL. To make a simple and backportable fix simply reset "prev_kprobe" when kprobe is poped from this "stack". No need to worry about "kprobe_status" in this case, because its value is only checked when current_kprobe != NULL. Cc: stable@vger.kernel.org Fixes: b9599798f953 ("[S390] kprobes: activation and deactivation") 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>
* s390/kprobes: fix irq mask clobbering on kprobe reenter from post_handlerVasily Gorbik2023-03-111-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 42e19e6f04984088b6f9f0507c4c89a8152d9730 upstream. Recent test_kprobe_missed kprobes kunit test uncovers the following error (reported when CONFIG_DEBUG_ATOMIC_SLEEP is enabled): BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 662, name: kunit_try_catch preempt_count: 0, expected: 0 RCU nest depth: 0, expected: 0 no locks held by kunit_try_catch/662. irq event stamp: 280 hardirqs last enabled at (279): [<00000003e60a3d42>] __do_pgm_check+0x17a/0x1c0 hardirqs last disabled at (280): [<00000003e3bd774a>] kprobe_exceptions_notify+0x27a/0x318 softirqs last enabled at (0): [<00000003e3c5c890>] copy_process+0x14a8/0x4c80 softirqs last disabled at (0): [<0000000000000000>] 0x0 CPU: 46 PID: 662 Comm: kunit_try_catch Tainted: G N 6.2.0-173644-g44c18d77f0c0 #2 Hardware name: IBM 3931 A01 704 (LPAR) Call Trace: [<00000003e60a3a00>] dump_stack_lvl+0x120/0x198 [<00000003e3d02e82>] __might_resched+0x60a/0x668 [<00000003e60b9908>] __mutex_lock+0xc0/0x14e0 [<00000003e60bad5a>] mutex_lock_nested+0x32/0x40 [<00000003e3f7b460>] unregister_kprobe+0x30/0xd8 [<00000003e51b2602>] test_kprobe_missed+0xf2/0x268 [<00000003e51b5406>] kunit_try_run_case+0x10e/0x290 [<00000003e51b7dfa>] kunit_generic_run_threadfn_adapter+0x62/0xb8 [<00000003e3ce30f8>] kthread+0x2d0/0x398 [<00000003e3b96afa>] __ret_from_fork+0x8a/0xe8 [<00000003e60ccada>] ret_from_fork+0xa/0x40 The reason for this error report is that kprobes handling code failed to restore irqs. The problem is that when kprobe is triggered from another kprobe post_handler current sequence of enable_singlestep / disable_singlestep is the following: enable_singlestep <- original kprobe (saves kprobe_saved_imask) enable_singlestep <- kprobe triggered from post_handler (clobbers kprobe_saved_imask) disable_singlestep <- kprobe triggered from post_handler (restores kprobe_saved_imask) disable_singlestep <- original kprobe (restores wrong clobbered kprobe_saved_imask) There is just one kprobe_ctlblk per cpu and both calls saves and loads irq mask to kprobe_saved_imask. To fix the problem simply move resume_execution (which calls disable_singlestep) before calling post_handler. This also fixes the problem that post_handler is called with pt_regs which were not yet adjusted after single-stepping. Cc: stable@vger.kernel.org Fixes: 4ba069b802c2 ("[S390] add kprobes support.") 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>
* s390: discard .interp sectionIlya Leoshkevich2023-03-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e9c9cb90e76ffaabcc7ca8f275d9e82195fd6367 upstream. When debugging vmlinux with QEMU + GDB, the following GDB error may occur: (gdb) c Continuing. Warning: Cannot insert breakpoint -1. Cannot access memory at address 0xffffffffffff95c0 Command aborted. (gdb) The reason is that, when .interp section is present, GDB tries to locate the file specified in it in memory and put a number of breakpoints there (see enable_break() function in gdb/solib-svr4.c). Sometimes GDB finds a bogus location that matches its heuristics, fails to set a breakpoint and stops. This makes further debugging impossible. The .interp section contains misleading information anyway (vmlinux does not need ld.so), so fix by discarding it. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* exit: Add and use make_task_dead.Eric W. Biederman2023-02-062-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream. There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/percpu: add READ_ONCE() to arch_this_cpu_to_op_simple()Heiko Carstens2023-01-181-1/+1
| | | | | | | | | | | | | commit e3f360db08d55a14112bd27454e616a24296a8b0 upstream. Make sure that *ptr__ within arch_this_cpu_to_op_simple() is only dereferenced once by using READ_ONCE(). Otherwise the compiler could generate incorrect code. Cc: <stable@vger.kernel.org> Reviewed-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>
* KVM: s390: vsie: Fix the initialization of the epoch extension (epdx) fieldThomas Huth2022-12-141-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | commit 0dd4cdccdab3d74bd86b868768a7dca216bcce7e upstream. We recently experienced some weird huge time jumps in nested guests when rebooting them in certain cases. After adding some debug code to the epoch handling in vsie.c (thanks to David Hildenbrand for the idea!), it was obvious that the "epdx" field (the multi-epoch extension) did not get set to 0xff in case the "epoch" field was negative. Seems like the code misses to copy the value from the epdx field from the guest to the shadow control block. By doing so, the weird time jumps are gone in our scenarios. Link: https://bugzilla.redhat.com/show_bug.cgi?id=2140899 Fixes: 8fa1696ea781 ("KVM: s390: Multiple Epoch Facility support") Signed-off-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Cc: stable@vger.kernel.org # 4.19+ Link: https://lore.kernel.org/r/20221123090833.292938-1-thuth@redhat.com Message-Id: <20221123090833.292938-1-thuth@redhat.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/crashdump: fix TOD programmable field sizeHeiko Carstens2022-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit f44e07a8afdd713ddc1a8832c39372fe5dd86895 ] The size of the TOD programmable field was incorrectly increased from four to eight bytes with commit 1a2c5840acf9 ("s390/dump: cleanup CPU save area handling"). This leads to an elf notes section NT_S390_TODPREG which has a size of eight instead of four bytes in case of kdump, however even worse is that the contents is incorrect: it is supposed to contain only the contents of the TOD programmable field, but in fact contains a mix of the TOD programmable field (32 bit upper bits) and parts of the CPU timer register (lower 32 bits). Fix this by simply changing the size of the todpreg field within the save area structure. This will implicitly also fix the size of the corresponding elf notes sections. This also gets rid of this compile time warning: in function ‘fortify_memcpy_chk’, inlined from ‘save_area_add_regs’ at arch/s390/kernel/crash_dump.c:99:2: ./include/linux/fortify-string.h:413:25: error: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Werror=attribute-warning] 413 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 1a2c5840acf9 ("s390/dump: cleanup CPU save area handling") Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/futex: add missing EX_TABLE entry to __futex_atomic_op()Heiko Carstens2022-11-031-1/+2
| | | | | | | | | | | | | | commit a262d3ad6a433e4080cecd0a8841104a5906355e upstream. For some exception types the instruction address points behind the instruction that caused the exception. Take that into account and add the missing exception table entry. Cc: <stable@vger.kernel.org> Reviewed-by: Vasily Gorbik <gor@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>
* s390: fix nospec table alignmentsJosh Poimboeuf2022-09-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit c9305b6c1f52060377c72aebe3a701389e9f3172 upstream. Add proper alignment for .nospec_call_table and .nospec_return_table in vmlinux. [hca@linux.ibm.com]: The problem with the missing alignment of the nospec tables exist since a long time, however only since commit e6ed91fd0768 ("s390/alternatives: remove padding generation code") and with CONFIG_RELOCATABLE=n the kernel may also crash at boot time. The above named commit reduced the size of struct alt_instr by one byte, so its new size is 11 bytes. Therefore depending on the number of cpu alternatives the size of the __alt_instructions array maybe odd, which again also causes that the addresses of the nospec tables will be odd. If the address of __nospec_call_start is odd and the kernel is compiled With CONFIG_RELOCATABLE=n the compiler may generate code that loads the address of __nospec_call_start with a 'larl' instruction. This will generate incorrect code since the 'larl' instruction only works with even addresses. In result the members of the nospec tables will be accessed with an off-by-one offset, which subsequently may lead to addressing exceptions within __nospec_revert(). Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/8719bf1ce4a72ebdeb575200290094e9ce047bcc.1661557333.git.jpoimboe@kernel.org Cc: <stable@vger.kernel.org> # 4.16 Reviewed-by: Heiko Carstens <hca@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>
* s390/hugetlb: fix prepare_hugepage_range() check for 2 GB hugepagesGerald Schaefer2022-09-151-2/+4
| | | | | | | | | | | | | | | | | | | | | commit 7c8d42fdf1a84b1a0dd60d6528309c8ec127e87c upstream. The alignment check in prepare_hugepage_range() is wrong for 2 GB hugepages, it only checks for 1 MB hugepage alignment. This can result in kernel crash in __unmap_hugepage_range() at the BUG_ON(start & ~huge_page_mask(h)) alignment check, for mappings created with MAP_FIXED at unaligned address. Fix this by correctly handling multiple hugepage sizes, similar to the generic version of prepare_hugepage_range(). Fixes: d08de8e2d867 ("s390/mm: add support for 2GB hugepages") Cc: <stable@vger.kernel.org> # 4.8+ Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-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>
* s390/hypfs: avoid error message under KVMJuergen Gross2022-09-052-2/+2
| | | | | | | | | | | | | | | | | | | | [ Upstream commit 7b6670b03641ac308aaa6fa2e6f964ac993b5ea3 ] When booting under KVM the following error messages are issued: hypfs.7f5705: The hardware system does not support hypfs hypfs.7a79f0: Initialization of hypfs failed with rc=-61 Demote the severity of first message from "error" to "info" and issue the second message only in other error cases. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220620094534.18967-1-jgross@suse.com [arch/s390/hypfs/hypfs_diag.c changed description] Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/mm: do not trigger write fault when vma does not allow VM_WRITEGerald Schaefer2022-09-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 41ac42f137080bc230b5882e3c88c392ab7f2d32 upstream. For non-protection pXd_none() page faults in do_dat_exception(), we call do_exception() with access == (VM_READ | VM_WRITE | VM_EXEC). In do_exception(), vma->vm_flags is checked against that before calling handle_mm_fault(). Since commit 92f842eac7ee3 ("[S390] store indication fault optimization"), we call handle_mm_fault() with FAULT_FLAG_WRITE, when recognizing that it was a write access. However, the vma flags check is still only checking against (VM_READ | VM_WRITE | VM_EXEC), and therefore also calling handle_mm_fault() with FAULT_FLAG_WRITE in cases where the vma does not allow VM_WRITE. Fix this by changing access check in do_exception() to VM_WRITE only, when recognizing write access. Link: https://lkml.kernel.org/r/20220811103435.188481-3-david@redhat.com Fixes: 92f842eac7ee3 ("[S390] store indication fault optimization") Cc: <stable@vger.kernel.org> Reported-by: David Hildenbrand <david@redhat.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390: fix double free of GS and RI CBs on fork() failureBrian Foster2022-09-051-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 13cccafe0edcd03bf1c841de8ab8a1c8e34f77d9 upstream. The pointers for guarded storage and runtime instrumentation control blocks are stored in the thread_struct of the associated task. These pointers are initially copied on fork() via arch_dup_task_struct() and then cleared via copy_thread() before fork() returns. If fork() happens to fail after the initial task dup and before copy_thread(), the newly allocated task and associated thread_struct memory are freed via free_task() -> arch_release_task_struct(). This results in a double free of the guarded storage and runtime info structs because the fields in the failed task still refer to memory associated with the source task. This problem can manifest as a BUG_ON() in set_freepointer() (with CONFIG_SLAB_FREELIST_HARDENED enabled) or KASAN splat (if enabled) when running trinity syscall fuzz tests on s390x. To avoid this problem, clear the associated pointer fields in arch_dup_task_struct() immediately after the new task is copied. Note that the RI flag is still cleared in copy_thread() because it resides in thread stack memory and that is where stack info is copied. Signed-off-by: Brian Foster <bfoster@redhat.com> Fixes: 8d9047f8b967c ("s390/runtime instrumentation: simplify task exit handling") Fixes: 7b83c6297d2fc ("s390/guarded storage: simplify task exit handling") Cc: <stable@vger.kernel.org> # 4.15 Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20220816155407.537372-1-bfoster@redhat.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/archrandom: prevent CPACF trng invocations in interrupt contextHarald Freudenberger2022-08-111-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 918e75f77af7d2e049bb70469ec0a2c12782d96a upstream. This patch slightly reworks the s390 arch_get_random_seed_{int,long} implementation: Make sure the CPACF trng instruction is never called in any interrupt context. This is done by adding an additional condition in_task(). Justification: There are some constrains to satisfy for the invocation of the arch_get_random_seed_{int,long}() functions: - They should provide good random data during kernel initialization. - They should not be called in interrupt context as the TRNG instruction is relatively heavy weight and may for example make some network loads cause to timeout and buck. However, it was not clear what kind of interrupt context is exactly encountered during kernel init or network traffic eventually calling arch_get_random_seed_long(). After some days of investigations it is clear that the s390 start_kernel function is not running in any interrupt context and so the trng is called: Jul 11 18:33:39 t35lp54 kernel: [<00000001064e90ca>] arch_get_random_seed_long.part.0+0x32/0x70 Jul 11 18:33:39 t35lp54 kernel: [<000000010715f246>] random_init+0xf6/0x238 Jul 11 18:33:39 t35lp54 kernel: [<000000010712545c>] start_kernel+0x4a4/0x628 Jul 11 18:33:39 t35lp54 kernel: [<000000010590402a>] startup_continue+0x2a/0x40 The condition in_task() is true and the CPACF trng provides random data during kernel startup. The network traffic however, is more difficult. A typical call stack looks like this: Jul 06 17:37:07 t35lp54 kernel: [<000000008b5600fc>] extract_entropy.constprop.0+0x23c/0x240 Jul 06 17:37:07 t35lp54 kernel: [<000000008b560136>] crng_reseed+0x36/0xd8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b5604b8>] crng_make_state+0x78/0x340 Jul 06 17:37:07 t35lp54 kernel: [<000000008b5607e0>] _get_random_bytes+0x60/0xf8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b56108a>] get_random_u32+0xda/0x248 Jul 06 17:37:07 t35lp54 kernel: [<000000008aefe7a8>] kfence_guarded_alloc+0x48/0x4b8 Jul 06 17:37:07 t35lp54 kernel: [<000000008aeff35e>] __kfence_alloc+0x18e/0x1b8 Jul 06 17:37:07 t35lp54 kernel: [<000000008aef7f10>] __kmalloc_node_track_caller+0x368/0x4d8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b611eac>] kmalloc_reserve+0x44/0xa0 Jul 06 17:37:07 t35lp54 kernel: [<000000008b611f98>] __alloc_skb+0x90/0x178 Jul 06 17:37:07 t35lp54 kernel: [<000000008b6120dc>] __napi_alloc_skb+0x5c/0x118 Jul 06 17:37:07 t35lp54 kernel: [<000000008b8f06b4>] qeth_extract_skb+0x13c/0x680 Jul 06 17:37:07 t35lp54 kernel: [<000000008b8f6526>] qeth_poll+0x256/0x3f8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b63d76e>] __napi_poll.constprop.0+0x46/0x2f8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b63dbec>] net_rx_action+0x1cc/0x408 Jul 06 17:37:07 t35lp54 kernel: [<000000008b937302>] __do_softirq+0x132/0x6b0 Jul 06 17:37:07 t35lp54 kernel: [<000000008abf46ce>] __irq_exit_rcu+0x13e/0x170 Jul 06 17:37:07 t35lp54 kernel: [<000000008abf531a>] irq_exit_rcu+0x22/0x50 Jul 06 17:37:07 t35lp54 kernel: [<000000008b922506>] do_io_irq+0xe6/0x198 Jul 06 17:37:07 t35lp54 kernel: [<000000008b935826>] io_int_handler+0xd6/0x110 Jul 06 17:37:07 t35lp54 kernel: [<000000008b9358a6>] psw_idle_exit+0x0/0xa Jul 06 17:37:07 t35lp54 kernel: ([<000000008ab9c59a>] arch_cpu_idle+0x52/0xe0) Jul 06 17:37:07 t35lp54 kernel: [<000000008b933cfe>] default_idle_call+0x6e/0xd0 Jul 06 17:37:07 t35lp54 kernel: [<000000008ac59f4e>] do_idle+0xf6/0x1b0 Jul 06 17:37:07 t35lp54 kernel: [<000000008ac5a28e>] cpu_startup_entry+0x36/0x40 Jul 06 17:37:07 t35lp54 kernel: [<000000008abb0d90>] smp_start_secondary+0x148/0x158 Jul 06 17:37:07 t35lp54 kernel: [<000000008b935b9e>] restart_int_handler+0x6e/0x90 which confirms that the call is in softirq context. So in_task() covers exactly the cases where we want to have CPACF trng called: not in nmi, not in hard irq, not in soft irq but in normal task context and during kernel init. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Link: https://lore.kernel.org/r/20220713131721.257907-1-freude@linux.ibm.com Fixes: e4f74400308c ("s390/archrandom: simplify back to earlier design and initialize earlier") [agordeev@linux.ibm.com changed desc, added Fixes and Link, removed -stable] Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/archrandom: simplify back to earlier design and initialize earlierJason A. Donenfeld2022-07-073-119/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e4f74400308cb8abde5fdc9cad609c2aba32110c upstream. s390x appears to present two RNG interfaces: - a "TRNG" that gathers entropy using some hardware function; and - a "DRBG" that takes in a seed and expands it. Previously, the TRNG was wired up to arch_get_random_{long,int}(), but it was observed that this was being called really frequently, resulting in high overhead. So it was changed to be wired up to arch_get_random_ seed_{long,int}(), which was a reasonable decision. Later on, the DRBG was then wired up to arch_get_random_{long,int}(), with a complicated buffer filling thread, to control overhead and rate. Fortunately, none of the performance issues matter much now. The RNG always attempts to use arch_get_random_seed_{long,int}() first, which means a complicated implementation of arch_get_random_{long,int}() isn't really valuable or useful to have around. And it's only used when reseeding, which means it won't hit the high throughput complications that were faced before. So this commit returns to an earlier design of just calling the TRNG in arch_get_random_seed_{long,int}(), and returning false in arch_get_ random_{long,int}(). Part of what makes the simplification possible is that the RNG now seeds itself using the TRNG at bootup. But this only works if the TRNG is detected early in boot, before random_init() is called. So this commit also causes that check to happen in setup_arch(). Cc: stable@vger.kernel.org Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Ingo Franzki <ifranzki@linux.ibm.com> Cc: Juergen Christ <jchrist@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20220610222023.378448-1-Jason@zx2c4.com Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]Naveen N. Rao2022-07-021-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | commit 3e35142ef99fe6b4fe5d834ad43ee13cca10a2dc upstream. Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") [1], binutils (v2.36+) started dropping section symbols that it thought were unused. This isn't an issue in general, but with kexec_file.c, gcc is placing kexec_arch_apply_relocations[_add] into a separate .text.unlikely section and the section symbol ".text.unlikely" is being dropped. Due to this, recordmcount is unable to find a non-weak symbol in .text.unlikely to generate a relocation record against. Address this by dropping the weak attribute from these functions. Instead, follow the existing pattern of having architectures #define the name of the function they want to override in their headers. [1] https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=d1bcae833b32f1 [akpm@linux-foundation.org: arch/s390/include/asm/kexec.h needs linux/module.h] Link: https://lkml.kernel.org/r/20220519091237.676736-1-naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/mm: use non-quiescing sske for KVM switch to keyed guestChristian Borntraeger2022-06-251-1/+1
| | | | | | | | | | | | | | | | commit 3ae11dbcfac906a8c3a480e98660a823130dc16a upstream. The switch to a keyed guest does not require a classic sske as the other guest CPUs are not accessing the key before the switch is complete. By using the NQ SSKE things are faster especially with multiple guests. Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Suggested-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220530092706.11637-3-borntraeger@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390: define get_cycles macro for arch-overrideJason A. Donenfeld2022-06-251-0/+1
| | | | | | | | | | | | | | | | | | | | | commit 2e3df523256cb9836de8441e9c791a796759bb3c upstream. S390x defines a get_cycles() function, but it does not do the usual `#define get_cycles get_cycles` dance, making it impossible for generic code to see if an arch-specific function was defined. While the get_cycles() ifdef is not currently used, the following timekeeping patch in this series will depend on the macro existing (or not existing) when defining random_get_entropy(). Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Sven Schnelle <svens@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390: Remove arch_has_random, arch_has_random_seedRichard Henderson2022-06-251-12/+0
| | | | | | | | | | | | | | commit 5e054c820f59bbb9714d5767f5f476581c309ca8 upstream. These symbols are currently part of the generic archrandom.h interface, but are currently unused and can be removed. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20200110145422.49141-4-broonie@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* s390/crypto: fix scatterwalk_unmap() callers in AES-GCMJann Horn2022-06-141-2/+2
| | | | | | | | | | | | | | | | | | | [ Upstream commit bd52cd5e23f134019b23f0c389db0f9a436e4576 ] The argument of scatterwalk_unmap() is supposed to be the void* that was returned by the previous scatterwalk_map() call. The s390 AES-GCM implementation was instead passing the pointer to the struct scatter_walk. This doesn't actually break anything because scatterwalk_unmap() only uses its argument under CONFIG_HIGHMEM and ARCH_HAS_FLUSH_ON_KUNMAP. Fixes: bf7fa038707c ("s390/crypto: add s390 platform specific aes gcm support.") Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Harald Freudenberger <freude@linux.ibm.com> Link: https://lore.kernel.org/r/20220517143047.3054498-1-jannh@google.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/preempt: disable __preempt_count_add() optimization for ↵Heiko Carstens2022-06-141-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | PROFILE_ALL_BRANCHES [ Upstream commit 63678eecec57fc51b778be3da35a397931287170 ] gcc 12 does not (always) optimize away code that should only be generated if parameters are constant and within in a certain range. This depends on various obscure kernel config options, however in particular PROFILE_ALL_BRANCHES can trigger this compile error: In function ‘__atomic_add_const’, inlined from ‘__preempt_count_add.part.0’ at ./arch/s390/include/asm/preempt.h:50:3: ./arch/s390/include/asm/atomic_ops.h:80:9: error: impossible constraint in ‘asm’ 80 | asm volatile( \ | ^~~ Workaround this by simply disabling the optimization for PROFILE_ALL_BRANCHES, since the kernel will be so slow, that this optimization won't matter at all. Reported-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390: disable -Warray-boundsSven Schnelle2022-05-181-0/+10
| | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 8b202ee218395319aec1ef44f72043e1fbaccdd6 ] gcc-12 shows a lot of array bound warnings on s390. This is caused by the S390_lowcore macro which uses a hardcoded address of 0. Wrapping that with absolute_pointer() works, but gcc no longer knows that a 12 bit displacement is sufficient to access lowcore. So it emits instructions like 'lghi %r1,0; l %rx,xxx(%r1)' instead of a single load/store instruction. As s390 stores variables often read/written in lowcore, this is considered problematic. Therefore disable -Warray-bounds on s390 for gcc-12 for the time being, until there is a better solution. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Link: https://lore.kernel.org/r/yt9dzgkelelc.fsf@linux.ibm.com Link: https://lore.kernel.org/r/20220422134308.1613610-1-svens@linux.ibm.com Link: https://lore.kernel.org/r/20220425121742.3222133-1-svens@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* s390/hypfs: include z/VM guests with access control group setVasily Gorbik2022-02-081-2/+4
| | | | | | | | | | | | | | | | | | | 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>
generated by cgit v1.2.3 (git 2.46.0) at 2025-04-24 02:28:28 +0000