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* LoongArch: enable ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAPFeiyang Chen2022-12-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | The feature of minimizing overhead of struct page associated with each HugeTLB page is implemented on x86_64. However, the infrastructure of this feature is already there, so just select ARCH_WANT_HUGETLB_PAGE_ OPTIMIZE_VMEMMAP is enough to enable this feature for LoongArch. Link: https://lkml.kernel.org/r/20221027125253.3458989-5-chenhuacai@loongson.cn Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Acked-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Min Zhou <zhoumin@loongson.cn> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Will Deacon <will@kernel.org> Cc: Xuefeng Li <lixuefeng@loongson.cn> Cc: Xuerui Wang <kernel@xen0n.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/sparse-vmemmap: generalise vmemmap_populate_hugepages()Feiyang Chen2022-12-113-143/+63
| | | | | | | | | | | | | | | | | | | | | | | | | Generalise vmemmap_populate_hugepages() so ARM64 & X86 & LoongArch can share its implementation. Link: https://lkml.kernel.org/r/20221027125253.3458989-4-chenhuacai@loongson.cn Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Acked-by: Will Deacon <will@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Min Zhou <zhoumin@loongson.cn> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Philippe Mathieu-Daudé <philmd@linaro.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Xuefeng Li <lixuefeng@loongson.cn> Cc: Xuerui Wang <kernel@xen0n.name> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* LoongArch: add sparse memory vmemmap supportFeiyang Chen2022-12-114-4/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add sparse memory vmemmap support for LoongArch. SPARSEMEM_VMEMMAP uses a virtually mapped memmap to optimise pfn_to_page and page_to_pfn operations. This is the most efficient option when sufficient kernel resources are available. Link: https://lkml.kernel.org/r/20221027125253.3458989-3-chenhuacai@loongson.cn Signed-off-by: Min Zhou <zhoumin@loongson.cn> Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Philippe Mathieu-Daudé <philmd@linaro.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Will Deacon <will@kernel.org> Cc: Xuefeng Li <lixuefeng@loongson.cn> Cc: Xuerui Wang <kernel@xen0n.name> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* MIPS&LoongArch&NIOS2: adjust prototypes of p?d_init()Feiyang Chen2022-12-1111-57/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm/sparse-vmemmap: Generalise helpers and enable for LoongArch", v14. This series is in order to enable sparse-vmemmap for LoongArch. But LoongArch cannot use generic helpers directly because MIPS&LoongArch need to call pgd_init()/pud_init()/pmd_init() when populating page tables. So we adjust the prototypes of p?d_init() to make generic helpers can call them, then enable sparse-vmemmap with generic helpers, and to be further, generalise vmemmap_populate_hugepages() for ARM64, X86 and LoongArch. This patch (of 4): We are preparing to add sparse vmemmap support to LoongArch. MIPS and LoongArch need to call pgd_init()/pud_init()/pmd_init() when populating page tables, so adjust their prototypes to make generic helpers can call them. NIOS2 declares pmd_init() but doesn't use, just remove it to avoid build errors. Link: https://lkml.kernel.org/r/20221027125253.3458989-1-chenhuacai@loongson.cn Link: https://lkml.kernel.org/r/20221027125253.3458989-2-chenhuacai@loongson.cn Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Will Deacon <will@kernel.org> Cc: Xuefeng Li <lixuefeng@loongson.cn> Cc: Xuerui Wang <kernel@xen0n.name> Cc: Min Zhou <zhoumin@loongson.cn> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* s390/mm: use pmd_pgtable_page() helper in __gmap_segment_gaddr()Anshuman Khandual2022-11-301-3/+2
| | | | | | | | | | | | | | | In __gmap_segment_gaddr() pmd level page table page is being extracted from the pmd pointer, similar to pmd_pgtable_page() implementation. This reduces some redundancy by directly using pmd_pgtable_page() instead, though first making it available. Link: https://lkml.kernel.org/r/20221125034502.1559986-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/uffd: sanity check write bit for uffd-wp protected ptesPeter Xu2022-11-301-1/+17
| | | | | | | | | | | | | | | | | Let's add one sanity check for CONFIG_DEBUG_VM on the write bit in whatever chance we have when walking through the pgtables. It can bring the error earlier even before the app notices the data was corrupted on the snapshot. Also it helps us to identify this is a wrong pgtable setup, so hopefully a great information to have for debugging too. Link: https://lkml.kernel.org/r/20221114000447.1681003-3-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: delay page_remove_rmap() until after the TLB has been flushedLinus Torvalds2022-11-301-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we remove a page table entry, we are very careful to only free the page after we have flushed the TLB, because other CPUs could still be using the page through stale TLB entries until after the flush. However, we have removed the rmap entry for that page early, which means that functions like folio_mkclean() would end up not serializing with the page table lock because the page had already been made invisible to rmap. And that is a problem, because while the TLB entry exists, we could end up with the following situation: (a) one CPU could come in and clean it, never seeing our mapping of the page (b) another CPU could continue to use the stale and dirty TLB entry and continue to write to said page resulting in a page that has been dirtied, but then marked clean again, all while another CPU might have dirtied it some more. End result: possibly lost dirty data. This extends our current TLB gather infrastructure to optionally track a "should I do a delayed page_remove_rmap() for this page after flushing the TLB". It uses the newly introduced 'encoded page pointer' to do that without having to keep separate data around. Note, this is complicated by a couple of issues: - we want to delay the rmap removal, but not past the page table lock, because that simplifies the memcg accounting - only SMP configurations want to delay TLB flushing, since on UP there are obviously no remote TLBs to worry about, and the page table lock means there are no preemption issues either - s390 has its own mmu_gather model that doesn't delay TLB flushing, and as a result also does not want the delayed rmap. As such, we can treat S390 like the UP case and use a common fallback for the "no delays" case. - we can track an enormous number of pages in our mmu_gather structure, with MAX_GATHER_BATCH_COUNT batches of MAX_TABLE_BATCH pages each, all set up to be approximately 10k pending pages. We do not want to have a huge number of batched pages that we then need to check for delayed rmap handling inside the page table lock. Particularly that last point results in a noteworthy detail, where the normal page batch gathering is limited once we have delayed rmaps pending, in such a way that only the last batch (the so-called "active batch") in the mmu_gather structure can have any delayed entries. NOTE! While the "possibly lost dirty data" sounds catastrophic, for this all to happen you need to have a user thread doing either madvise() with MADV_DONTNEED or a full re-mmap() of the area concurrently with another thread continuing to use said mapping. So arguably this is about user space doing crazy things, but from a VM consistency standpoint it's better if we track the dirty bit properly even when user space goes off the rails. [akpm@linux-foundation.org: fix UP build, per Linus] Link: https://lore.kernel.org/all/B88D3073-440A-41C7-95F4-895D3F657EF2@gmail.com/ Link: https://lkml.kernel.org/r/20221109203051.1835763-4-torvalds@linux-foundation.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hugh Dickins <hughd@google.com> Reported-by: Nadav Amit <nadav.amit@gmail.com> Tested-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: mmu_gather: prepare to gather encoded page pointers with flagsLinus Torvalds2022-11-301-3/+5
| | | | | | | | | | | | | | | This is purely a preparatory patch that makes all the data structures ready for encoding flags with the mmu_gather page pointers. The code currently always sets the flag to zero and doesn't use it yet, but now it's tracking the type state along. The next step will be to actually start using it. Link: https://lkml.kernel.org/r/20221109203051.1835763-3-torvalds@linux-foundation.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: remove unused savedwrite infrastructureDavid Hildenbrand2022-11-302-77/+5
| | | | | | | | | | | | | | | | | | | | | | NUMA hinting no longer uses savedwrite, let's rip it out. ... and while at it, drop __pte_write() and __pmd_write() on ppc64. Link: https://lkml.kernel.org/r/20221108174652.198904-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Hugh Dickins <hughd@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge branch 'mm-hotfixes-stable' into mm-stableAndrew Morton2022-11-309-0/+28
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| * mm: introduce arch_has_hw_nonleaf_pmd_young()Juergen Gross2022-11-301-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When running as a Xen PV guests commit eed9a328aa1a ("mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG") can cause a protection violation in pmdp_test_and_clear_young(): BUG: unable to handle page fault for address: ffff8880083374d0 #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation PGD 3026067 P4D 3026067 PUD 3027067 PMD 7fee5067 PTE 8010000008337065 Oops: 0003 [#1] PREEMPT SMP NOPTI CPU: 7 PID: 158 Comm: kswapd0 Not tainted 6.1.0-rc5-20221118-doflr+ #1 RIP: e030:pmdp_test_and_clear_young+0x25/0x40 This happens because the Xen hypervisor can't emulate direct writes to page table entries other than PTEs. This can easily be fixed by introducing arch_has_hw_nonleaf_pmd_young() similar to arch_has_hw_pte_young() and test that instead of CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG. Link: https://lkml.kernel.org/r/20221123064510.16225-1-jgross@suse.com Fixes: eed9a328aa1a ("mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG") Signed-off-by: Juergen Gross <jgross@suse.com> Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Acked-by: Yu Zhao <yuzhao@google.com> Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Acked-by: David Hildenbrand <david@redhat.com> [core changes] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: add dummy pmd_young() for architectures not having itJuergen Gross2022-11-306-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to avoid #ifdeffery add a dummy pmd_young() implementation as a fallback. This is required for the later patch "mm: introduce arch_has_hw_nonleaf_pmd_young()". Link: https://lkml.kernel.org/r/fd3ac3cd-7349-6bbd-890a-71a9454ca0b3@suse.com Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Yu Zhao <yuzhao@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Sander Eikelenboom <linux@eikelenboom.it> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * arch/x86/mm/hugetlbpage.c: pud_huge() returns 0 when using 2-level pagingNaoya Horiguchi2022-11-081-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following bug is reported to be triggered when starting X on x86-32 system with i915: [ 225.777375] kernel BUG at mm/memory.c:2664! [ 225.777391] invalid opcode: 0000 [#1] PREEMPT SMP [ 225.777405] CPU: 0 PID: 2402 Comm: Xorg Not tainted 6.1.0-rc3-bdg+ #86 [ 225.777415] Hardware name: /8I865G775-G, BIOS F1 08/29/2006 [ 225.777421] EIP: __apply_to_page_range+0x24d/0x31c [ 225.777437] Code: ff ff 8b 55 e8 8b 45 cc e8 0a 11 ec ff 89 d8 83 c4 28 5b 5e 5f 5d c3 81 7d e0 a0 ef 96 c1 74 ad 8b 45 d0 e8 2d 83 49 00 eb a3 <0f> 0b 25 00 f0 ff ff 81 eb 00 00 00 40 01 c3 8b 45 ec 8b 00 e8 76 [ 225.777446] EAX: 00000001 EBX: c53a3b58 ECX: b5c00000 EDX: c258aa00 [ 225.777454] ESI: b5c00000 EDI: b5900000 EBP: c4b0fdb4 ESP: c4b0fd80 [ 225.777462] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010202 [ 225.777470] CR0: 80050033 CR2: b5900000 CR3: 053a3000 CR4: 000006d0 [ 225.777479] Call Trace: [ 225.777486] ? i915_memcpy_init_early+0x63/0x63 [i915] [ 225.777684] apply_to_page_range+0x21/0x27 [ 225.777694] ? i915_memcpy_init_early+0x63/0x63 [i915] [ 225.777870] remap_io_mapping+0x49/0x75 [i915] [ 225.778046] ? i915_memcpy_init_early+0x63/0x63 [i915] [ 225.778220] ? mutex_unlock+0xb/0xd [ 225.778231] ? i915_vma_pin_fence+0x6d/0xf7 [i915] [ 225.778420] vm_fault_gtt+0x2a9/0x8f1 [i915] [ 225.778644] ? lock_is_held_type+0x56/0xe7 [ 225.778655] ? lock_is_held_type+0x7a/0xe7 [ 225.778663] ? 0xc1000000 [ 225.778670] __do_fault+0x21/0x6a [ 225.778679] handle_mm_fault+0x708/0xb21 [ 225.778686] ? mt_find+0x21e/0x5ae [ 225.778696] exc_page_fault+0x185/0x705 [ 225.778704] ? doublefault_shim+0x127/0x127 [ 225.778715] handle_exception+0x130/0x130 [ 225.778723] EIP: 0xb700468a Recently pud_huge() got aware of non-present entry by commit 3a194f3f8ad0 ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry") to handle some special states of gigantic page. However, it's overlooked that pud_none() always returns false when running with 2-level paging, and as a result pud_huge() can return true pointlessly. Introduce "#if CONFIG_PGTABLE_LEVELS > 2" to pud_huge() to deal with this. Link: https://lkml.kernel.org/r/20221107021010.2449306-1-naoya.horiguchi@linux.dev Fixes: 3a194f3f8ad0 ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry") Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * x86/traps: avoid KMSAN bugs originating from handle_bug()Alexander Potapenko2022-11-081-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a case in exc_invalid_op handler that is executed outside the irqentry_enter()/irqentry_exit() region when an UD2 instruction is used to encode a call to __warn(). In that case the `struct pt_regs` passed to the interrupt handler is never unpoisoned by KMSAN (this is normally done in irqentry_enter()), which leads to false positives inside handle_bug(). Use kmsan_unpoison_entry_regs() to explicitly unpoison those registers before using them. Link: https://lkml.kernel.org/r/20221102110611.1085175-5-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * x86/uaccess: instrument copy_from_user_nmi()Alexander Potapenko2022-11-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure usercopy hooks from linux/instrumented.h are invoked for copy_from_user_nmi(). This fixes KMSAN false positives reported when dumping opcodes for a stack trace. Link: https://lkml.kernel.org/r/20221102110611.1085175-2-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Marco Elver <elver@google.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | mm/hwpoison: pass pfn to num_poisoned_pages_*()Naoya Horiguchi2022-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No functional change. Link: https://lkml.kernel.org/r/20221024062012.1520887-4-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | mm/hwpoison: move definitions of num_poisoned_pages_* to memory-failure.cNaoya Horiguchi2022-11-081-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These interfaces will be used by drivers/base/memory.c by later patch, so as a preparatory work move them to more common header file visible to the file. Link: https://lkml.kernel.org/r/20221024062012.1520887-3-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | x86/sgx: use VM_ACCESS_FLAGSKefeng Wang2022-11-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify VM_READ|VM_WRITE|VM_EXEC with VM_ACCESS_FLAGS. Link: https://lkml.kernel.org/r/20221019034945.93081-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "Christian König" <christian.koenig@amd.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@gmail.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | nios2: remove unused INIT_MMAPKefeng Wang2022-11-081-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: cleanup with VM_ACCESS_FLAGS". This patch (of 5): It seems that INIT_MMAP is gone in 2.4.10, not sure, anyways, it is useless now, kill it. Link: https://lkml.kernel.org/r/20221019034945.93081-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20221019034945.93081-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "Christian König" <christian.koenig@amd.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@gmail.com> Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | mm: remove kern_addr_valid() completelyKefeng Wang2022-11-0830-193/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most architectures (except arm64/x86/sparc) simply return 1 for kern_addr_valid(), which is only used in read_kcore(), and it calls copy_from_kernel_nofault() which could check whether the address is a valid kernel address. So as there is no need for kern_addr_valid(), let's remove it. Link: https://lkml.kernel.org/r/20221018074014.185687-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390] Acked-by: Christoph Hellwig <hch@lst.de> Acked-by: Helge Deller <deller@gmx.de> [parisc] Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Acked-by: Guo Ren <guoren@kernel.org> [csky] Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: <aou@eecs.berkeley.edu> Cc: Borislav Petkov <bp@alien8.de> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Chris Zankel <chris@zankel.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jonas Bonn <jonas@southpole.se> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Xuerui Wang <kernel@xen0n.name> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | hugetlb: simplify hugetlb handling in follow_page_maskMike Kravetz2022-11-082-52/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During discussions of this series [1], it was suggested that hugetlb handling code in follow_page_mask could be simplified. At the beginning of follow_page_mask, there currently is a call to follow_huge_addr which 'may' handle hugetlb pages. ia64 is the only architecture which provides a follow_huge_addr routine that does not return error. Instead, at each level of the page table a check is made for a hugetlb entry. If a hugetlb entry is found, a call to a routine associated with that entry is made. Currently, there are two checks for hugetlb entries at each page table level. The first check is of the form: if (p?d_huge()) page = follow_huge_p?d(); the second check is of the form: if (is_hugepd()) page = follow_huge_pd(). We can replace these checks, as well as the special handling routines such as follow_huge_p?d() and follow_huge_pd() with a single routine to handle hugetlb vmas. A new routine hugetlb_follow_page_mask is called for hugetlb vmas at the beginning of follow_page_mask. hugetlb_follow_page_mask will use the existing routine huge_pte_offset to walk page tables looking for hugetlb entries. huge_pte_offset can be overwritten by architectures, and already handles special cases such as hugepd entries. [1] https://lore.kernel.org/linux-mm/cover.1661240170.git.baolin.wang@linux.alibaba.com/ [mike.kravetz@oracle.com: remove vma (pmd sharing) per Peter] Link: https://lkml.kernel.org/r/20221028181108.119432-1-mike.kravetz@oracle.com [mike.kravetz@oracle.com: remove left over hugetlb_vma_unlock_read()] Link: https://lkml.kernel.org/r/20221030225825.40872-1-mike.kravetz@oracle.com Link: https://lkml.kernel.org/r/20220919021348.22151-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'perf_urgent_for_v6.1_rc4' of ↵Linus Torvalds2022-11-063-9/+16
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Borislav Petkov: - Add Cooper Lake's stepping to the PEBS guest/host events isolation fixed microcode revisions checking quirk - Update Icelake and Sapphire Rapids events constraints - Use the standard energy unit for Sapphire Rapids in RAPL - Fix the hw_breakpoint test to fail more graciously on !SMP configs * tag 'perf_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Add Cooper Lake stepping to isolation_ucodes[] perf/x86/intel: Fix pebs event constraints for SPR perf/x86/intel: Fix pebs event constraints for ICL perf/x86/rapl: Use standard Energy Unit for SPR Dram RAPL domain perf/hw_breakpoint: test: Skip the test if dependencies unmet
| * perf/x86/intel: Add Cooper Lake stepping to isolation_ucodes[]Kan Liang2022-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The intel_pebs_isolation quirk checks both model number and stepping. Cooper Lake has a different stepping (11) than the other Skylake Xeon. It cannot benefit from the optimization in commit 9b545c04abd4f ("perf/x86/kvm: Avoid unnecessary work in guest filtering"). Add the stepping of Cooper Lake into the isolation_ucodes[] table. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20221031154550.571663-1-kan.liang@linux.intel.com
| * perf/x86/intel: Fix pebs event constraints for SPRKan Liang2022-11-021-2/+7
| | | | | | | | | | | | | | | | | | | | | | According to the latest event list, update the MEM_INST_RETIRED events which support the DataLA facility for SPR. Fixes: 61b985e3e775 ("perf/x86/intel: Add perf core PMU support for Sapphire Rapids") Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20221031154119.571386-2-kan.liang@linux.intel.com
| * perf/x86/intel: Fix pebs event constraints for ICLKan Liang2022-11-021-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | According to the latest event list, update the MEM_INST_RETIRED events which support the DataLA facility. Fixes: 6017608936c1 ("perf/x86/intel: Add Icelake support") Reported-by: Jannis Klinkenberg <jannis.klinkenberg@rwth-aachen.de> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20221031154119.571386-1-kan.liang@linux.intel.com
| * perf/x86/rapl: Use standard Energy Unit for SPR Dram RAPL domainZhang Rui2022-11-021-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel Xeon servers used to use a fixed energy resolution (15.3uj) for Dram RAPL domain. But on SPR, Dram RAPL domain follows the standard energy resolution as described in MSR_RAPL_POWER_UNIT. Remove the SPR Dram energy unit quirk. Fixes: bcfd218b6679 ("perf/x86/rapl: Add support for Intel SPR platform") Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Tested-by: Wang Wendy <wendy.wang@intel.com> Link: https://lkml.kernel.org/r/20220924054738.12076-3-rui.zhang@intel.com
* | Merge tag 'x86_urgent_for_v6.1_rc4' of ↵Linus Torvalds2022-11-063-9/+29
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Borislav Petkov: - Add new Intel CPU models - Enforce that TDX guests are successfully loaded only on TDX hardware where virtualization exception (#VE) delivery on kernel memory is disabled because handling those in all possible cases is "essentially impossible" - Add the proper include to the syscall wrappers so that BTF can see the real pt_regs definition and not only the forward declaration * tag 'x86_urgent_for_v6.1_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add several Intel server CPU model numbers x86/tdx: Panic on bad configs that #VE on "private" memory access x86/tdx: Prepare for using "INFO" call for a second purpose x86/syscall: Include asm/ptrace.h in syscall_wrapper header
| * | x86/cpu: Add several Intel server CPU model numbersTony Luck2022-11-041-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These servers are all on the public versions of the roadmap. The model numbers for Grand Ridge, Granite Rapids, and Sierra Forest were included in the September 2022 edition of the Instruction Set Extensions document. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/r/20221103203310.5058-1-tony.luck@intel.com
| * | x86/tdx: Panic on bad configs that #VE on "private" memory accessKirill A. Shutemov2022-11-011-5/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All normal kernel memory is "TDX private memory". This includes everything from kernel stacks to kernel text. Handling exceptions on arbitrary accesses to kernel memory is essentially impossible because they can happen in horribly nasty places like kernel entry/exit. But, TDX hardware can theoretically _deliver_ a virtualization exception (#VE) on any access to private memory. But, it's not as bad as it sounds. TDX can be configured to never deliver these exceptions on private memory with a "TD attribute" called ATTR_SEPT_VE_DISABLE. The guest has no way to *set* this attribute, but it can check it. Ensure ATTR_SEPT_VE_DISABLE is set in early boot. panic() if it is unset. There is no sane way for Linux to run with this attribute clear so a panic() is appropriate. There's small window during boot before the check where kernel has an early #VE handler. But the handler is only for port I/O and will also panic() as soon as it sees any other #VE, such as a one generated by a private memory access. [ dhansen: Rewrite changelog and rebase on new tdx_parse_tdinfo(). Add Kirill's tested-by because I made changes since he wrote this. ] Fixes: 9a22bf6debbf ("x86/traps: Add #VE support for TDX guest") Reported-by: ruogui.ygr@alibaba-inc.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20221028141220.29217-3-kirill.shutemov%40linux.intel.com
| * | x86/tdx: Prepare for using "INFO" call for a second purposeDave Hansen2022-11-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The TDG.VP.INFO TDCALL provides the guest with various details about the TDX system that the guest needs to run. Only one field is currently used: 'gpa_width' which tells the guest which PTE bits mark pages shared or private. A second field is now needed: the guest "TD attributes" to tell if virtualization exceptions are configured in a way that can harm the guest. Make the naming and calling convention more generic and discrete from the mask-centric one. Thanks to Sathya for the inspiration here, but there's no code, comments or changelogs left from where he started. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: stable@vger.kernel.org
| * | x86/syscall: Include asm/ptrace.h in syscall_wrapper headerJiri Olsa2022-10-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With just the forward declaration of the 'struct pt_regs' in syscall_wrapper.h, the syscall stub functions: __[x64|ia32]_sys_*(struct pt_regs *regs) will have different definition of 'regs' argument in BTF data based on which object file they are defined in. If the syscall's object includes 'struct pt_regs' definition, the BTF argument data will point to a 'struct pt_regs' record, like: [226] STRUCT 'pt_regs' size=168 vlen=21 'r15' type_id=1 bits_offset=0 'r14' type_id=1 bits_offset=64 'r13' type_id=1 bits_offset=128 ... If not, it will point to a fwd declaration record: [15439] FWD 'pt_regs' fwd_kind=struct and make bpf tracing program hooking on those functions unable to access fields from 'struct pt_regs'. Include asm/ptrace.h directly in syscall_wrapper.h to make sure all syscalls see 'struct pt_regs' definition. This then results in BTF for '__*_sys_*(struct pt_regs *regs)' functions to point to the actual struct, not just the forward declaration. [ bp: No Fixes tag as this is not really a bug fix but "adjustment" so that BTF is happy. ] Reported-by: Akihiro HARAI <jharai0815@gmail.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andrii Nakryiko <andrii@kernel.org> Cc: <stable@vger.kernel.org> # this is needed only for BTF so kernels >= 5.15 Link: https://lore.kernel.org/r/20221018122708.823792-1-jolsa@kernel.org
* | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2022-11-069-60/+41
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm fixes from Paolo Bonzini: "ARM: - Fix the pKVM stage-1 walker erronously using the stage-2 accessor - Correctly convert vcpu->kvm to a hyp pointer when generating an exception in a nVHE+MTE configuration - Check that KVM_CAP_DIRTY_LOG_* are valid before enabling them - Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE - Document the boot requirements for FGT when entering the kernel at EL1 x86: - Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit() - Make argument order consistent for kvcalloc() - Userspace API fixes for DEBUGCTL and LBRs" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Fix a typo about the usage of kvcalloc() KVM: x86: Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit() KVM: VMX: Ignore guest CPUID for host userspace writes to DEBUGCTL KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl() KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRs arm64: booting: Document our requirements for fine grained traps with SME KVM: arm64: Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE KVM: Check KVM_CAP_DIRTY_LOG_{RING, RING_ACQ_REL} prior to enabling them KVM: arm64: Fix bad dereference on MTE-enabled systems KVM: arm64: Use correct accessor to parse stage-1 PTEs
| * \ \ Merge tag 'kvmarm-fixes-6.1-3' of ↵Paolo Bonzini2022-11-065-36/+23
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD * Fix the pKVM stage-1 walker erronously using the stage-2 accessor * Correctly convert vcpu->kvm to a hyp pointer when generating an exception in a nVHE+MTE configuration * Check that KVM_CAP_DIRTY_LOG_* are valid before enabling them * Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHE * Document the boot requirements for FGT when entering the kernel at EL1
| | * | | KVM: arm64: Fix SMPRI_EL1/TPIDR2_EL0 trapping on VHEMarc Zyngier2022-11-013-34/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trapping of SMPRI_EL1 and TPIDR2_EL0 currently only really work on nVHE, as only this mode uses the fine-grained trapping that controls these two registers. Move the trapping enable/disable code into __{de,}activate_traps_common(), allowing it to be called when it actually matters on VHE, and remove the flipping of EL2 control for TPIDR2_EL0, which only affects the host access of this register. Fixes: 861262ab8627 ("KVM: arm64: Handle SME host state when running guests") Reported-by: Mark Brown <broonie@kernel.org> Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/86bkpqer4z.wl-maz@kernel.org
| | * | | KVM: arm64: Fix bad dereference on MTE-enabled systemsRyan Roberts2022-10-271-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enter_exception64() performs an MTE check, which involves dereferencing vcpu->kvm. While vcpu has already been fixed up to be a HYP VA pointer, kvm is still a pointer in the kernel VA space. This only affects nVHE configurations with MTE enabled, as in other cases, the pointer is either valid (VHE) or not dereferenced (!MTE). Fix this by first converting kvm to a HYP VA pointer. Fixes: ea7fc1bb1cd1 ("KVM: arm64: Introduce MTE VM feature") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Steven Price <steven.price@arm.com> [maz: commit message tidy-up] Signed-off-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20221027120945.29679-1-ryan.roberts@arm.com
| | * | | KVM: arm64: Use correct accessor to parse stage-1 PTEsQuentin Perret2022-10-251-1/+1
| | |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hyp_get_page_state() is used with pKVM to retrieve metadata about a page by parsing a hypervisor stage-1 PTE. However, it incorrectly uses a helper which parses *stage-2* mappings. Ouch. Luckily, pkvm_getstate() only looks at the software bits, which happen to be in the same place for stage-1 and stage-2 PTEs, and this all ends up working correctly by accident. But clearly, we should do better. Fix hyp_get_page_state() to use the correct helper. Fixes: e82edcc75c4e ("KVM: arm64: Implement do_share() helper for sharing memory") Signed-off-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221025145156.855308-1-qperret@google.com
| * | | Merge branch 'kvm-master' into HEADPaolo Bonzini2022-11-064-24/+18
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | x86: * Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit() * Make argument order consistent for kvcalloc() * Userspace API fixes for DEBUGCTL and LBRs
| | * | | KVM: x86: Fix a typo about the usage of kvcalloc()Liao Chang2022-11-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Swap the 1st and 2nd arguments to be consistent with the usage of kvcalloc(). Fixes: c9b8fecddb5b ("KVM: use kvcalloc for array allocations") Signed-off-by: Liao Chang <liaochang1@huawei.com> Message-Id: <20221103011749.139262-1-liaochang1@huawei.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | KVM: x86: Use SRCU to protect zap in __kvm_set_or_clear_apicv_inhibit()Ben Gardon2022-11-031-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kvm_zap_gfn_range() must be called in an SRCU read-critical section, but there is no SRCU annotation in __kvm_set_or_clear_apicv_inhibit(). This can lead to the following warning via kvm_arch_vcpu_ioctl_set_guest_debug() if a Shadow MMU is in use (TDP MMU disabled or nesting): [ 1416.659809] ============================= [ 1416.659810] WARNING: suspicious RCU usage [ 1416.659839] 6.1.0-dbg-DEV #1 Tainted: G S I [ 1416.659853] ----------------------------- [ 1416.659854] include/linux/kvm_host.h:954 suspicious rcu_dereference_check() usage! [ 1416.659856] ... [ 1416.659904] dump_stack_lvl+0x84/0xaa [ 1416.659910] dump_stack+0x10/0x15 [ 1416.659913] lockdep_rcu_suspicious+0x11e/0x130 [ 1416.659919] kvm_zap_gfn_range+0x226/0x5e0 [ 1416.659926] ? kvm_make_all_cpus_request_except+0x18b/0x1e0 [ 1416.659935] __kvm_set_or_clear_apicv_inhibit+0xcc/0x100 [ 1416.659940] kvm_arch_vcpu_ioctl_set_guest_debug+0x350/0x390 [ 1416.659946] kvm_vcpu_ioctl+0x2fc/0x620 [ 1416.659955] __se_sys_ioctl+0x77/0xc0 [ 1416.659962] __x64_sys_ioctl+0x1d/0x20 [ 1416.659965] do_syscall_64+0x3d/0x80 [ 1416.659969] entry_SYSCALL_64_after_hwframe+0x63/0xcd Always take the KVM SRCU read lock in __kvm_set_or_clear_apicv_inhibit() to protect the GFN to memslot translation. The SRCU read lock is not technically required when no Shadow MMUs are in use, since the TDP MMU walks the paging structures from the roots and does not need to look up GFN translations in the memslots, but make the SRCU locking unconditional for simplicty. In most cases, the SRCU locking is taken care of in the vCPU run loop, but when called through other ioctls (such as KVM_SET_GUEST_DEBUG) there is no srcu_read_lock. Tested: ran tools/testing/selftests/kvm/x86_64/debug_regs on a DBG build. This patch causes the suspicious RCU warning to disappear. Note that the warning is hit in __kvm_zap_rmaps(), so kvm_memslots_have_rmaps() must return true in order for this to repro (i.e. the TDP MMU must be off or nesting in use.) Reported-by: Greg Thelen <gthelen@google.com> Fixes: 36222b117e36 ("KVM: x86: don't disable APICv memslot when inhibited") Signed-off-by: Ben Gardon <bgardon@google.com> Message-Id: <20221102205359.1260980-1-bgardon@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | KVM: VMX: Ignore guest CPUID for host userspace writes to DEBUGCTLSean Christopherson2022-11-021-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ignore guest CPUID for host userspace writes to the DEBUGCTL MSR, KVM's ABI is that setting CPUID vs. state can be done in any order, i.e. KVM allows userspace to stuff MSRs prior to setting the guest's CPUID that makes the new MSR "legal". Keep the vmx_get_perf_capabilities() check for guest writes, even though it's technically unnecessary since the vCPU's PERF_CAPABILITIES is consulted when refreshing LBR support. A future patch will clean up vmx_get_perf_capabilities() to avoid the RDMSR on every call, at which point the paranoia will incur no meaningful overhead. Note, prior to vmx_get_perf_capabilities() checking that the host fully supports LBRs via x86_perf_get_lbr(), KVM effectively relied on intel_pmu_lbr_is_enabled() to guard against host userspace enabling LBRs on platforms without full support. Fixes: c646236344e9 ("KVM: vmx/pmu: Add PMU_CAP_LBR_FMT check when guest LBR is enabled") Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221006000314.73240-5-seanjc@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | KVM: VMX: Fold vmx_supported_debugctl() into vcpu_supported_debugctl()Sean Christopherson2022-11-022-20/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fold vmx_supported_debugctl() into vcpu_supported_debugctl(), its only caller. Setting bits only to clear them a few instructions later is rather silly, and splitting the logic makes things seem more complicated than they actually are. Opportunistically drop DEBUGCTLMSR_LBR_MASK now that there's a single reference to the pair of bits. The extra layer of indirection provides no meaningful value and makes it unnecessarily tedious to understand what KVM is doing. No functional change. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221006000314.73240-4-seanjc@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| | * | | KVM: VMX: Advertise PMU LBRs if and only if perf supports LBRsSean Christopherson2022-11-021-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Advertise LBR support to userspace via MSR_IA32_PERF_CAPABILITIES if and only if perf fully supports LBRs. Perf may disable LBRs (by zeroing the number of LBRs) even on platforms the allegedly support LBRs, e.g. if probing any LBR MSRs during setup fails. Fixes: be635e34c284 ("KVM: vmx/pmu: Expose LBR_FMT in the MSR_IA32_PERF_CAPABILITIES") Reported-by: Like Xu <like.xu.linux@gmail.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20221006000314.73240-3-seanjc@google.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | | Merge tag 'for-linus-6.1-rc4-tag' of ↵Linus Torvalds2022-11-062-18/+7
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes from Juergen Gross: "One fix for silencing a smatch warning, and a small cleanup patch" * tag 'for-linus-6.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: simplify sysenter and syscall setup x86/xen: silence smatch warning in pmu_msr_chk_emulated()
| * | | | | x86/xen: simplify sysenter and syscall setupJuergen Gross2022-11-031-17/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | xen_enable_sysenter() and xen_enable_syscall() can be simplified a lot. While at it, switch to use cpu_feature_enabled() instead of boot_cpu_has(). Signed-off-by: Juergen Gross <jgross@suse.com>
| * | | | | x86/xen: silence smatch warning in pmu_msr_chk_emulated()Juergen Gross2022-11-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 8714f7bcd3c2 ("xen/pv: add fault recovery control to pmu msr accesses") introduced code resulting in a warning issued by the smatch static checker, claiming to use an uninitialized variable. This is a false positive, but work around the warning nevertheless. Fixes: 8714f7bcd3c2 ("xen/pv: add fault recovery control to pmu msr accesses") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* | | | | | Merge tag 'arm64-fixes' of ↵Linus Torvalds2022-11-042-10/+35
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - Avoid kprobe recursion when cortex_a76_erratum_1463225_debug_handler() is not inlined (change to __always_inline). - Fix the visibility of compat hwcaps, broken by recent changes to consolidate the visibility of hwcaps and the user-space view of the ID registers. * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: cpufeature: Fix the visibility of compat hwcaps arm64: entry: avoid kprobe recursion
| * | | | | | arm64: cpufeature: Fix the visibility of compat hwcapsAmit Daniel Kachhap2022-11-031-9/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 237405ebef58 ("arm64: cpufeature: Force HWCAP to be based on the sysreg visible to user-space") forced the hwcaps to use sanitised user-space view of the id registers. However, the ID register structures used to select few compat cpufeatures (vfp, crc32, ...) are masked and hence such hwcaps do not appear in /proc/cpuinfo anymore for PER_LINUX32 personality. Add the ID register structures explicitly and set the relevant entry as visible. As these ID registers are now of type visible so make them available in 64-bit userspace by making necessary changes in register emulation logic and documentation. While at it, update the comment for structure ftr_generic_32bits[] which lists the ID register that use it. Fixes: 237405ebef58 ("arm64: cpufeature: Force HWCAP to be based on the sysreg visible to user-space") Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Link: https://lore.kernel.org/r/20221103082232.19189-1-amit.kachhap@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
| * | | | | | arm64: entry: avoid kprobe recursionMark Rutland2022-11-011-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cortex_a76_erratum_1463225_debug_handler() function is called when handling debug exceptions (and synchronous exceptions from BRK instructions), and so is called when a probed function executes. If the compiler does not inline cortex_a76_erratum_1463225_debug_handler(), it can be probed. If cortex_a76_erratum_1463225_debug_handler() is probed, any debug exception or software breakpoint exception will result in recursive exceptions leading to a stack overflow. This can be triggered with the ftrace multiple_probes selftest, and as per the example splat below. This is a regression caused by commit: 6459b8469753e9fe ("arm64: entry: consolidate Cortex-A76 erratum 1463225 workaround") ... which removed the NOKPROBE_SYMBOL() annotation associated with the function. My intent was that cortex_a76_erratum_1463225_debug_handler() would be inlined into its caller, el1_dbg(), which is marked noinstr and cannot be probed. Mark cortex_a76_erratum_1463225_debug_handler() as __always_inline to ensure this. Example splat prior to this patch (with recursive entries elided): | # echo p cortex_a76_erratum_1463225_debug_handler > /sys/kernel/debug/tracing/kprobe_events | # echo p do_el0_svc >> /sys/kernel/debug/tracing/kprobe_events | # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable | Insufficient stack space to handle exception! | ESR: 0x0000000096000047 -- DABT (current EL) | FAR: 0xffff800009cefff0 | Task stack: [0xffff800009cf0000..0xffff800009cf4000] | IRQ stack: [0xffff800008000000..0xffff800008004000] | Overflow stack: [0xffff00007fbc00f0..0xffff00007fbc10f0] | CPU: 0 PID: 145 Comm: sh Not tainted 6.0.0 #2 | Hardware name: linux,dummy-virt (DT) | pstate: 604003c5 (nZCv DAIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : arm64_enter_el1_dbg+0x4/0x20 | lr : el1_dbg+0x24/0x5c | sp : ffff800009cf0000 | x29: ffff800009cf0000 x28: ffff000002c74740 x27: 0000000000000000 | x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 | x23: 00000000604003c5 x22: ffff80000801745c x21: 0000aaaac95ac068 | x20: 00000000f2000004 x19: ffff800009cf0040 x18: 0000000000000000 | x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 | x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 | x11: 0000000000000010 x10: ffff800008c87190 x9 : ffff800008ca00d0 | x8 : 000000000000003c x7 : 0000000000000000 x6 : 0000000000000000 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : 00000000000043a4 | x2 : 00000000f2000004 x1 : 00000000f2000004 x0 : ffff800009cf0040 | Kernel panic - not syncing: kernel stack overflow | CPU: 0 PID: 145 Comm: sh Not tainted 6.0.0 #2 | Hardware name: linux,dummy-virt (DT) | Call trace: | dump_backtrace+0xe4/0x104 | show_stack+0x18/0x4c | dump_stack_lvl+0x64/0x7c | dump_stack+0x18/0x38 | panic+0x14c/0x338 | test_taint+0x0/0x2c | panic_bad_stack+0x104/0x118 | handle_bad_stack+0x34/0x48 | __bad_stack+0x78/0x7c | arm64_enter_el1_dbg+0x4/0x20 | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 ... | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 ... | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | cortex_a76_erratum_1463225_debug_handler+0x0/0x34 | el1h_64_sync_handler+0x40/0x98 | el1h_64_sync+0x64/0x68 | do_el0_svc+0x0/0x28 | el0t_64_sync_handler+0x84/0xf0 | el0t_64_sync+0x18c/0x190 | Kernel Offset: disabled | CPU features: 0x0080,00005021,19001080 | Memory Limit: none | ---[ end Kernel panic - not syncing: kernel stack overflow ]--- With this patch, cortex_a76_erratum_1463225_debug_handler() is inlined into el1_dbg(), and el1_dbg() cannot be probed: | # echo p cortex_a76_erratum_1463225_debug_handler > /sys/kernel/debug/tracing/kprobe_events | sh: write error: No such file or directory | # grep -w cortex_a76_erratum_1463225_debug_handler /proc/kallsyms | wc -l | 0 | # echo p el1_dbg > /sys/kernel/debug/tracing/kprobe_events | sh: write error: Invalid argument | # grep -w el1_dbg /proc/kallsyms | wc -l | 1 Fixes: 6459b8469753 ("arm64: entry: consolidate Cortex-A76 erratum 1463225 workaround") Cc: <stable@vger.kernel.org> # 5.12.x Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20221017090157.2881408-1-mark.rutland@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | | | | | | Merge tag 'efi-fixes-for-v6.1-2' of ↵Linus Torvalds2022-11-044-2/+69
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI fixes from Ard Biesheuvel: - A pair of tweaks to the EFI random seed code so that externally provided version of this config table are handled more robustly - Another fix for the v6.0 EFI variable refactor that turned out to break Apple machines which don't provide QueryVariableInfo() - Add some guard rails to the EFI runtime service call wrapper so we can recover from synchronous exceptions caused by firmware * tag 'efi-fixes-for-v6.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: arm64: efi: Recover from synchronous exceptions occurring in firmware efi: efivars: Fix variable writes with unsupported query_variable_store() efi: random: Use 'ACPI reclaim' memory for random seed efi: random: reduce seed size to 32 bytes efi/tpm: Pass correct address to memblock_reserve
| * | | | | | | arm64: efi: Recover from synchronous exceptions occurring in firmwareArd Biesheuvel2022-11-034-2/+69
| |/ / / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike x86, which has machinery to deal with page faults that occur during the execution of EFI runtime services, arm64 has nothing like that, and a synchronous exception raised by firmware code brings down the whole system. With more EFI based systems appearing that were not built to run Linux (such as the Windows-on-ARM laptops based on Qualcomm SOCs), as well as the introduction of PRM (platform specific firmware routines that are callable just like EFI runtime services), we are more likely to run into issues of this sort, and it is much more likely that we can identify and work around such issues if they don't bring down the system entirely. Since we already use a EFI runtime services call wrapper in assembler, we can quite easily add some code that captures the execution state at the point where the call is made, allowing us to revert to this state and proceed execution if the call triggered a synchronous exception. Given that the kernel and the firmware don't share any data structures that could end up in an indeterminate state, we can happily continue running, as long as we mark the EFI runtime services as unavailable from that point on. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-27 18:29:39 +0000