kernel/linux.git/arch/s390/include, branch linux-5.9.y

s390/mm: make pmd/pud_deref() large page aware

2020-11-10T11:39:08+00:00

commit b0e98aa9c411585eb586b2fa98873c936735008e upstream. pmd/pud_deref() assume that they will never operate on large pmd/pud entries, and therefore only use the non-large _xxx_ENTRY_ORIGIN mask. With commit 9ec8fa8dc331b ("s390/vmemmap: extend modify_pagetable() to handle vmemmap"), that assumption is no longer true, at least for pmd_deref(). In theory, we could end up with wrong addresses because some of the non-address bits of a large entry would not be masked out. In practice, this does not (yet) show any impact, because vmemmap_free() is currently never used for s390. Fix pmd/pud_deref() to check for the entry type and use the _xxx_ENTRY_ORIGIN_LARGE mask for large entries. While at it, also move pmd/pud_pfn() around, in order to avoid code duplication, because they do the same thing. Fixes: 9ec8fa8dc331b ("s390/vmemmap: extend modify_pagetable() to handle vmemmap") Cc: # 5.9 Signed-off-by: Gerald Schaefer Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

mm/gup: fix gup_fast with dynamic page table folding

2020-09-26T17:33:57+00:00

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

s390: don't trace preemption in percpu macros

2020-08-26T16:07:04+00:00

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

Merge tag 's390-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2020-08-13T19:38:32+00:00

Pull more s390 updates from Heiko Carstens: - Allow s390 debug feature to handle finally more than 256 CPU numbers, instead of truncating the most significant bits. - Improve THP splitting required by qemu processes by making use of walk_page_vma() instead of calling follow_page() for every single page within each vma. - Add missing ZCRYPT dependency to VFIO_AP to fix potential compile problems. - Remove not required select CLOCKSOURCE_VALIDATE_LAST_CYCLE again. - Set node distance to LOCAL_DISTANCE instead of 0, since e.g. libnuma translates a node distance of 0 to "no NUMA support available". - Couple of other minor fixes and improvements. * tag 's390-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/numa: move code to arch/s390/kernel s390/time: remove select CLOCKSOURCE_VALIDATE_LAST_CYCLE again s390/debug: debug feature version 3 s390/Kconfig: add missing ZCRYPT dependency to VFIO_AP s390/numa: set node distance to LOCAL_DISTANCE s390/pkey: remove redundant variable initialization s390/test_unwind: fix possible memleak in test_unwind() s390/gmap: improve THP splitting s390/atomic: circumvent gcc 10 build regression

uaccess: remove segment_eq

2020-08-12T17:57:58+00:00

segment_eq is only used to implement uaccess_kernel. Just open code uaccess_kernel in the arch uaccess headers and remove one layer of indirection. Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Acked-by: Linus Torvalds Acked-by: Greentime Hu Acked-by: Geert Uytterhoeven Cc: Nick Hu Cc: Vincent Chen Cc: Paul Walmsley Cc: Palmer Dabbelt Link: http://lkml.kernel.org/r/20200710135706.537715-5-hch@lst.de Signed-off-by: Linus Torvalds

s390/debug: debug feature version 3

2020-08-11T16:16:43+00:00

Change __debug_entry structure in the following way: - remove redundant union - Field containing cpuid is expanded to 16 bits. 8-bit width was not enough since we already support up to 512 cpus. - Field containing the timestamp is expanded to 60 bits. The timestamp itself is now stored in the absolute Unix time format in microseconds taking the Epoch Index into acount. Adjust default header for debug entries by setting minimum width for cpuid to 4 digits. Reviewed-by: Heiko Carstens Signed-off-by: Mikhail Zaslonko Signed-off-by: Heiko Carstens

s390/numa: set node distance to LOCAL_DISTANCE

2020-08-11T16:16:35+00:00

The node distance is hardcoded to 0, which causes a trouble for some user-level applications. In particular, "libnuma" expects the distance of a node to itself as LOCAL_DISTANCE. This update removes the offending node distance override. Cc: # 4.4 Fixes: 3a368f742da1 ("s390/numa: add core infrastructure") Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/atomic: circumvent gcc 10 build regression

2020-08-11T16:16:08+00:00

Circumvent the following gcc 10 allyesconfig build regression: CC drivers/leds/trigger/ledtrig-cpu.o In file included from ./arch/s390/include/asm/bitops.h:39, from ./include/linux/bitops.h:29, from ./include/linux/kernel.h:12, from drivers/leds/trigger/ledtrig-cpu.c:18: ./arch/s390/include/asm/atomic_ops.h: In function 'ledtrig_cpu': ./arch/s390/include/asm/atomic_ops.h:46:2: warning: 'asm' operand 1 probably does not match constraints 46 | asm volatile( \ | ^~~ ./arch/s390/include/asm/atomic_ops.h:53:2: note: in expansion of macro '__ATOMIC_CONST_OP' 53 | __ATOMIC_CONST_OP(op_name, op_type, op_string, "\n") \ | ^~~~~~~~~~~~~~~~~ ./arch/s390/include/asm/atomic_ops.h:56:1: note: in expansion of macro '__ATOMIC_CONST_OPS' 56 | __ATOMIC_CONST_OPS(__atomic_add_const, int, "asi") | ^~~~~~~~~~~~~~~~~~ ./arch/s390/include/asm/atomic_ops.h:46:2: error: impossible constraint in 'asm' 46 | asm volatile( \ | ^~~ ./arch/s390/include/asm/atomic_ops.h:53:2: note: in expansion of macro '__ATOMIC_CONST_OP' 53 | __ATOMIC_CONST_OP(op_name, op_type, op_string, "\n") \ | ^~~~~~~~~~~~~~~~~ ./arch/s390/include/asm/atomic_ops.h:56:1: note: in expansion of macro '__ATOMIC_CONST_OPS' 56 | __ATOMIC_CONST_OPS(__atomic_add_const, int, "asi") | ^~~~~~~~~~~~~~~~~~ scripts/Makefile.build:280: recipe for target 'drivers/leds/trigger/ledtrig-cpu.o' failed By swapping conditions as proposed here: https://gcc.gnu.org/pipermail/gcc-patches/2020-July/549318.html Suggested-by: Ilya Leoshkevich Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

mm: remove unneeded includes of

2020-08-07T18:33:26+00:00

Patch series "mm: cleanup usage of " Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in and enable use of the generic functions where appropriate. In addition, functions declared and defined in headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the included all over the place. The first patch in this series removes unneeded includes of In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in and do not require that header. As for the other header files that used to include , it is possible to move that include into the .c file that actually uses symbols from and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Reviewed-by: Pekka Enberg Acked-by: Geert Uytterhoeven [m68k] Cc: Abdul Haleem Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Christophe Leroy Cc: Joerg Roedel Cc: Max Filippov Cc: Peter Zijlstra Cc: Satheesh Rajendran Cc: Stafford Horne Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Joerg Roedel Cc: Matthew Wilcox Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2020-08-06T19:59:31+00:00

Pull KVM updates from Paolo Bonzini: "s390: - implement diag318 x86: - Report last CPU for debugging - Emulate smaller MAXPHYADDR in the guest than in the host - .noinstr and tracing fixes from Thomas - nested SVM page table switching optimization and fixes Generic: - Unify shadow MMU cache data structures across architectures" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits) KVM: SVM: Fix sev_pin_memory() error handling KVM: LAPIC: Set the TDCR settable bits KVM: x86: Specify max TDP level via kvm_configure_mmu() KVM: x86/mmu: Rename max_page_level to max_huge_page_level KVM: x86: Dynamically calculate TDP level from max level and MAXPHYADDR KVM: VXM: Remove temporary WARN on expected vs. actual EPTP level mismatch KVM: x86: Pull the PGD's level from the MMU instead of recalculating it KVM: VMX: Make vmx_load_mmu_pgd() static KVM: x86/mmu: Add separate helper for shadow NPT root page role calc KVM: VMX: Drop a duplicate declaration of construct_eptp() KVM: nSVM: Correctly set the shadow NPT root level in its MMU role KVM: Using macros instead of magic values MIPS: KVM: Fix build error caused by 'kvm_run' cleanup KVM: nSVM: remove nonsensical EXITINFO1 adjustment on nested NPF KVM: x86: Add a capability for GUEST_MAXPHYADDR < HOST_MAXPHYADDR support KVM: VMX: optimize #PF injection when MAXPHYADDR does not match KVM: VMX: Add guest physical address check in EPT violation and misconfig KVM: VMX: introduce vmx_need_pf_intercept KVM: x86: update exception bitmap on CPUID changes KVM: x86: rename update_bp_intercept to update_exception_bitmap ...