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2023-12-29mm/rmap: introduce folio_try_dup_anon_rmap_[pte|ptes|pmd]()David Hildenbrand
The last user of page_needs_cow_for_dma() and __page_dup_rmap() are gone, remove them. Add folio_try_dup_anon_rmap_ptes() right away, we want to perform rmap baching during fork() soon. Link: https://lkml.kernel.org/r/20231220224504.646757-35-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: convert page_dup_file_rmap() to folio_dup_file_rmap_[pte|ptes|pmd]()David Hildenbrand
Let's convert page_dup_file_rmap() like the other rmap functions. As there is only a single caller, convert that single caller right away and remove page_dup_file_rmap(). Add folio_dup_file_rmap_ptes() right away, we want to perform rmap baching during fork() soon. Link: https://lkml.kernel.org/r/20231220224504.646757-34-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: remove page_remove_rmap()David Hildenbrand
All callers are gone, let's remove it and some leftover traces. Link: https://lkml.kernel.org/r/20231220224504.646757-33-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: introduce folio_remove_rmap_[pte|ptes|pmd]()David Hildenbrand
Let's mimic what we did with folio_add_file_rmap_*() and folio_add_anon_rmap_*() so we can similarly replace page_remove_rmap() next. Make the compiler always special-case on the granularity by using __always_inline. We're adding folio_remove_rmap_ptes() handling right away, as we want to use that soon for batching rmap operations when unmapping PTE-mapped large folios. Link: https://lkml.kernel.org/r/20231220224504.646757-24-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: remove RMAP_COMPOUNDDavid Hildenbrand
No longer used, let's remove it and clarify RMAP_NONE/RMAP_EXCLUSIVE a bit. Link: https://lkml.kernel.org/r/20231220224504.646757-23-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: remove page_add_anon_rmap()David Hildenbrand
All users are gone, remove it and all traces. Link: https://lkml.kernel.org/r/20231220224504.646757-22-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: introduce folio_add_anon_rmap_[pte|ptes|pmd]()David Hildenbrand
Let's mimic what we did with folio_add_file_rmap_*() so we can similarly replace page_add_anon_rmap() next. Make the compiler always special-case on the granularity by using __always_inline. For the PageAnonExclusive sanity checks, when adding a PMD mapping, we're now also checking each individual subpage covered by that PMD, instead of only the head page. Note that the new functions ignore the RMAP_COMPOUND flag, which we will remove as soon as page_add_anon_rmap() is gone. Link: https://lkml.kernel.org/r/20231220224504.646757-15-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: remove page_add_file_rmap()David Hildenbrand
All users are gone, let's remove it. Link: https://lkml.kernel.org/r/20231220224504.646757-13-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: convert folio_add_file_rmap_range() into ↵David Hildenbrand
folio_add_file_rmap_[pte|ptes|pmd]() Let's get rid of the compound parameter and instead define explicitly which mappings we're adding. That is more future proof, easier to read and harder to mess up. Use an enum to express the granularity internally. Make the compiler always special-case on the granularity by using __always_inline. Replace the "compound" check by a switch-case that will be removed by the compiler completely. Add plenty of sanity checks with CONFIG_DEBUG_VM. Replace the folio_test_pmd_mappable() check by a config check in the caller and sanity checks. Convert the single user of folio_add_file_rmap_range(). While at it, consistently use "int" instead of "unisgned int" in rmap code when dealing with mapcounts and the number of pages. This function design can later easily be extended to PUDs and to batch PMDs. Note that for now we don't support anything bigger than PMD-sized folios (as we cleanly separated hugetlb handling). Sanity checks will catch if that ever changes. Next up is removing page_remove_rmap() along with its "compound" parameter and smilarly converting all other rmap functions. Link: https://lkml.kernel.org/r/20231220224504.646757-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: introduce and use hugetlb_try_share_anon_rmap()David Hildenbrand
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. So let's introduce and use hugetlb_try_dup_anon_rmap() to make all hugetlb handling use dedicated hugetlb_* rmap functions. Add sanity checks that we end up with the right folios in the right functions. Note that try_to_unmap_one() does not need care. Easy to spot because among all that nasty hugetlb special-casing in that function, we're not using set_huge_pte_at() on the anon path -- well, and that code assumes that we would want to swapout. Link: https://lkml.kernel.org/r/20231220224504.646757-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: introduce and use hugetlb_try_dup_anon_rmap()David Hildenbrand
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. So let's introduce and use hugetlb_try_dup_anon_rmap() to make all hugetlb handling use dedicated hugetlb_* rmap functions. Add sanity checks that we end up with the right folios in the right functions. Note that is_device_private_page() does not apply to hugetlb. Link: https://lkml.kernel.org/r/20231220224504.646757-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: introduce and use hugetlb_add_file_rmap()David Hildenbrand
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. Right now we're using page_dup_file_rmap() in some cases where "ordinary" rmap code would have used page_add_file_rmap(). So let's introduce and use hugetlb_add_file_rmap() instead. We won't be adding a "hugetlb_dup_file_rmap()" functon for the fork() case, as it would be doing the same: "dup" is just an optimization for "add". What remains is a single page_dup_file_rmap() call in fork() code. Add sanity checks that we end up with the right folios in the right functions. Link: https://lkml.kernel.org/r/20231220224504.646757-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: introduce and use hugetlb_remove_rmap()David Hildenbrand
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. Let's introduce and use hugetlb_remove_rmap() and remove the hugetlb code from page_remove_rmap(). This effectively removes one check on the small-folio path as well. Add sanity checks that we end up with the right folios in the right functions. Note: all possible candidates that need care are page_remove_rmap() that pass compound=true. Link: https://lkml.kernel.org/r/20231220224504.646757-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Hugh Dickins <hughd@google.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/rmap: rename hugepage_add* to hugetlb_add*David Hildenbrand
Patch series "mm/rmap: interface overhaul", v2. This series overhauls the rmap interface, to get rid of the "bool compound" / RMAP_COMPOUND parameter with the goal of making the interface less error prone, more future proof, and more natural to extend to "batching". Also, this converts the interface to always consume folio+subpage, which speeds up operations on large folios. Further, this series adds PTE-batching variants for 4 rmap functions, whereby only folio_add_anon_rmap_ptes() is used for batching in this series when PTE-remapping a PMD-mapped THP. folio_remove_rmap_ptes(), folio_try_dup_anon_rmap_ptes() and folio_dup_file_rmap_ptes() will soon come in handy[1,2]. This series performs a lot of folio conversion along the way. Most of the added LOC in the diff are only due to documentation. As we're moving to a pte/pmd interface where we clearly express the mapping granularity we are dealing with, we first get the remainder of hugetlb out of the way, as it is special and expected to remain special: it treats everything as a "single logical PTE" and only currently allows entire mappings. Even if we'd ever support partial mappings, I strongly assume the interface and implementation will still differ heavily: hopefull we can avoid working on subpages/subpage mapcounts completely and only add a "count" parameter for them to enable batching. New (extended) hugetlb interface that operates on entire folio: * hugetlb_add_new_anon_rmap() -> Already existed * hugetlb_add_anon_rmap() -> Already existed * hugetlb_try_dup_anon_rmap() * hugetlb_try_share_anon_rmap() * hugetlb_add_file_rmap() * hugetlb_remove_rmap() New "ordinary" interface for small folios / THP:: * folio_add_new_anon_rmap() -> Already existed * folio_add_anon_rmap_[pte|ptes|pmd]() * folio_try_dup_anon_rmap_[pte|ptes|pmd]() * folio_try_share_anon_rmap_[pte|pmd]() * folio_add_file_rmap_[pte|ptes|pmd]() * folio_dup_file_rmap_[pte|ptes|pmd]() * folio_remove_rmap_[pte|ptes|pmd]() folio_add_new_anon_rmap() will always map at the largest granularity possible (currently, a single PMD to cover a PMD-sized THP). Could be extended if ever required. In the future, we might want "_pud" variants and eventually "_pmds" variants for batching. I ran some simple microbenchmarks on an Intel(R) Xeon(R) Silver 4210R: measuring munmap(), fork(), cow, MADV_DONTNEED on each PTE ... and PTE remapping PMD-mapped THPs on 1 GiB of memory. For small folios, there is barely a change (< 1% improvement for me). For PTE-mapped THP: * PTE-remapping a PMD-mapped THP is more than 10% faster. * fork() is more than 4% faster. * MADV_DONTNEED is 2% faster * COW when writing only a single byte on a COW-shared PTE is 1% faster * munmap() barely changes (< 1%). [1] https://lkml.kernel.org/r/20230810103332.3062143-1-ryan.roberts@arm.com [2] https://lkml.kernel.org/r/20231204105440.61448-1-ryan.roberts@arm.com This patch (of 40): Let's just call it "hugetlb_". Yes, it's all already inconsistent and confusing because we have a lot of "hugepage_" functions for legacy reasons. But "hugetlb" cannot possibly be confused with transparent huge pages, and it matches "hugetlb.c" and "folio_test_hugetlb()". So let's minimize confusion in rmap code. Link: https://lkml.kernel.org/r/20231220224504.646757-1-david@redhat.com Link: https://lkml.kernel.org/r/20231220224504.646757-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm, kasan: use KASAN_TAG_KERNEL instead of 0xffAndrey Konovalov
Use the KASAN_TAG_KERNEL marco instead of open-coding 0xff in the mm code. This macro is provided by include/linux/kasan-tags.h, which does not include any other headers, so it's safe to include it into mm.h without causing circular include dependencies. Link: https://lkml.kernel.org/r/71db9087b0aebb6c4dccbc609cc0cd50621533c7.1703188911.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/sparsemem: fix race in accessing memory_section->usageCharan Teja Kalla
The below race is observed on a PFN which falls into the device memory region with the system memory configuration where PFN's are such that [ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL]. Since normal zone start and end pfn contains the device memory PFN's as well, the compaction triggered will try on the device memory PFN's too though they end up in NOP(because pfn_to_online_page() returns NULL for ZONE_DEVICE memory sections). When from other core, the section mappings are being removed for the ZONE_DEVICE region, that the PFN in question belongs to, on which compaction is currently being operated is resulting into the kernel crash with CONFIG_SPASEMEM_VMEMAP enabled. The crash logs can be seen at [1]. compact_zone() memunmap_pages ------------- --------------- __pageblock_pfn_to_page ...... (a)pfn_valid(): valid_section()//return true (b)__remove_pages()-> sparse_remove_section()-> section_deactivate(): [Free the array ms->usage and set ms->usage = NULL] pfn_section_valid() [Access ms->usage which is NULL] NOTE: From the above it can be said that the race is reduced to between the pfn_valid()/pfn_section_valid() and the section deactivate with SPASEMEM_VMEMAP enabled. The commit b943f045a9af("mm/sparse: fix kernel crash with pfn_section_valid check") tried to address the same problem by clearing the SECTION_HAS_MEM_MAP with the expectation of valid_section() returns false thus ms->usage is not accessed. Fix this issue by the below steps: a) Clear SECTION_HAS_MEM_MAP before freeing the ->usage. b) RCU protected read side critical section will either return NULL when SECTION_HAS_MEM_MAP is cleared or can successfully access ->usage. c) Free the ->usage with kfree_rcu() and set ms->usage = NULL. No attempt will be made to access ->usage after this as the SECTION_HAS_MEM_MAP is cleared thus valid_section() return false. Thanks to David/Pavan for their inputs on this patch. [1] https://lore.kernel.org/linux-mm/994410bb-89aa-d987-1f50-f514903c55aa@quicinc.com/ On Snapdragon SoC, with the mentioned memory configuration of PFN's as [ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL], we are able to see bunch of issues daily while testing on a device farm. For this particular issue below is the log. Though the below log is not directly pointing to the pfn_section_valid(){ ms->usage;}, when we loaded this dump on T32 lauterbach tool, it is pointing. [ 540.578056] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 540.578068] Mem abort info: [ 540.578070] ESR = 0x0000000096000005 [ 540.578073] EC = 0x25: DABT (current EL), IL = 32 bits [ 540.578077] SET = 0, FnV = 0 [ 540.578080] EA = 0, S1PTW = 0 [ 540.578082] FSC = 0x05: level 1 translation fault [ 540.578085] Data abort info: [ 540.578086] ISV = 0, ISS = 0x00000005 [ 540.578088] CM = 0, WnR = 0 [ 540.579431] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBSBTYPE=--) [ 540.579436] pc : __pageblock_pfn_to_page+0x6c/0x14c [ 540.579454] lr : compact_zone+0x994/0x1058 [ 540.579460] sp : ffffffc03579b510 [ 540.579463] x29: ffffffc03579b510 x28: 0000000000235800 x27:000000000000000c [ 540.579470] x26: 0000000000235c00 x25: 0000000000000068 x24:ffffffc03579b640 [ 540.579477] x23: 0000000000000001 x22: ffffffc03579b660 x21:0000000000000000 [ 540.579483] x20: 0000000000235bff x19: ffffffdebf7e3940 x18:ffffffdebf66d140 [ 540.579489] x17: 00000000739ba063 x16: 00000000739ba063 x15:00000000009f4bff [ 540.579495] x14: 0000008000000000 x13: 0000000000000000 x12:0000000000000001 [ 540.579501] x11: 0000000000000000 x10: 0000000000000000 x9 :ffffff897d2cd440 [ 540.579507] x8 : 0000000000000000 x7 : 0000000000000000 x6 :ffffffc03579b5b4 [ 540.579512] x5 : 0000000000027f25 x4 : ffffffc03579b5b8 x3 :0000000000000001 [ 540.579518] x2 : ffffffdebf7e3940 x1 : 0000000000235c00 x0 :0000000000235800 [ 540.579524] Call trace: [ 540.579527] __pageblock_pfn_to_page+0x6c/0x14c [ 540.579533] compact_zone+0x994/0x1058 [ 540.579536] try_to_compact_pages+0x128/0x378 [ 540.579540] __alloc_pages_direct_compact+0x80/0x2b0 [ 540.579544] __alloc_pages_slowpath+0x5c0/0xe10 [ 540.579547] __alloc_pages+0x250/0x2d0 [ 540.579550] __iommu_dma_alloc_noncontiguous+0x13c/0x3fc [ 540.579561] iommu_dma_alloc+0xa0/0x320 [ 540.579565] dma_alloc_attrs+0xd4/0x108 [quic_charante@quicinc.com: use kfree_rcu() in place of synchronize_rcu(), per David] Link: https://lkml.kernel.org/r/1698403778-20938-1-git-send-email-quic_charante@quicinc.com Link: https://lkml.kernel.org/r/1697202267-23600-1-git-send-email-quic_charante@quicinc.com Fixes: f46edbd1b151 ("mm/sparsemem: add helpers track active portions of a section at boot") Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: remove VM_EXEC requirement for THP eligibilityFangrui Song
Commit e6be37b2e7bd ("mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled()") introduced the VM_EXEC requirement, which is not strictly needed. lld's default --rosegment option and GNU ld's -z separate-code option (default on Linux/x86 since binutils 2.31) create a read-only PT_LOAD segment without the PF_X flag, which should be eligible for THP. Certain architectures support medium and large code models, where .lrodata may be placed in a separate read-only PT_LOAD segment, which should be eligible for THP as well. Link: https://lkml.kernel.org/r/20231220054123.1266001-1-maskray@google.com Signed-off-by: Fangrui Song <maskray@google.com> Acked-by: Yang Shi <shy828301@gmail.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Song Liu <songliubraving@fb.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29lib/stackdepot: fix comment in include/linux/stackdepot.hAndrey Konovalov
As stack traces can now be evicted from the stack depot, remove the comment saying that they are never removed. Link: https://lkml.kernel.org/r/0ebe712d91f8d302a8947d3c9e9123bc2b1b8440.1703020707.git.andreyknvl@google.com Fixes: 108be8def46e ("lib/stackdepot: allow users to evict stack traces") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: rename and document kasan_(un)poison_object_dataAndrey Konovalov
Rename kasan_unpoison_object_data to kasan_unpoison_new_object and add a documentation comment. Do the same for kasan_poison_object_data. The new names and the comments should suggest the users that these hooks are intended for internal use by the slab allocator. The following patch will remove non-slab-internal uses of these hooks. No functional changes. [andreyknvl@google.com: update references to renamed functions in comments] Link: https://lkml.kernel.org/r/20231221180637.105098-1-andrey.konovalov@linux.dev Link: https://lkml.kernel.org/r/eab156ebbd635f9635ef67d1a4271f716994e628.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mempool: introduce mempool_use_prealloc_onlyAndrey Konovalov
Introduce a new mempool_alloc_preallocated API that asks the mempool to only use the elements preallocated during the mempool's creation when allocating and to not attempt allocating new ones from the underlying allocator. This API is required to test the KASAN poisoning/unpoisoning functionality in KASAN tests, but it might be also useful on its own. Link: https://lkml.kernel.org/r/a14d809dbdfd04cc33bcacc632fee2abd6b83c00.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: save alloc stack traces for mempoolAndrey Konovalov
Update kasan_mempool_unpoison_object to properly poison the redzone and save alloc strack traces for kmalloc and slab pools. As a part of this change, split out and use a unpoison_slab_object helper function from __kasan_slab_alloc. [nathan@kernel.org: mark unpoison_slab_object() as static] Link: https://lkml.kernel.org/r/20231221180042.104694-1-andrey.konovalov@linux.dev Link: https://lkml.kernel.org/r/05ad235da8347cfe14d496d01b2aaf074b4f607c.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: save free stack traces for slab mempoolsAndrey Konovalov
Make kasan_mempool_poison_object save free stack traces for slab and kmalloc mempools when the object is freed into the mempool. Also simplify and rename ____kasan_slab_free to poison_slab_object and do a few other reability changes. Link: https://lkml.kernel.org/r/413a7c7c3344fb56809853339ffaabc9e4905e94.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: introduce kasan_mempool_unpoison_pagesAndrey Konovalov
Introduce and document a new kasan_mempool_unpoison_pages hook to be used by the mempool code instead of kasan_unpoison_pages. This hook is not functionally different from kasan_unpoison_pages, but using it improves the mempool code readability. Link: https://lkml.kernel.org/r/239bd9af6176f2cc59f5c25893eb36143184daff.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: introduce kasan_mempool_poison_pagesAndrey Konovalov
Introduce and document a kasan_mempool_poison_pages hook to be used by the mempool code instead of kasan_poison_pages. Compated to kasan_poison_pages, the new hook: 1. For the tag-based modes, skips checking and poisoning allocations that were not tagged due to sampling. 2. Checks for double-free and invalid-free bugs. In the future, kasan_poison_pages can also be updated to handle #2, but this is out-of-scope of this series. Link: https://lkml.kernel.org/r/88dc7340cce28249abf789f6e0c792c317df9ba5.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: introduce kasan_mempool_unpoison_objectAndrey Konovalov
Introduce and document a kasan_mempool_unpoison_object hook. This hook serves as a replacement for the generic kasan_unpoison_range that the mempool code relies on right now. mempool will be updated to use the new hook in one of the following patches. For now, define the new hook to be identical to kasan_unpoison_range. One of the following patches will update it to add stack trace collection. Link: https://lkml.kernel.org/r/dae25f0e18ed8fd50efe509c5b71a0592de5c18d.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: add return value for kasan_mempool_poison_objectAndrey Konovalov
Add a return value for kasan_mempool_poison_object that lets the caller know whether the allocation is affected by a double-free or an invalid-free bug. The caller can use this return value to stop operating on the object. Also introduce a check_page_allocation helper function to improve the code readability. Link: https://lkml.kernel.org/r/618af65273875fb9f56954285443279b15f1fcd9.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: document kasan_mempool_poison_objectAndrey Konovalov
Add documentation comment for kasan_mempool_poison_object. Link: https://lkml.kernel.org/r/af33ba8cabfa1ad731fe23a3f874bfc8d3b7fed4.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: move kasan_mempool_poison_objectAndrey Konovalov
Move kasan_mempool_poison_object after all slab-related KASAN hooks. This is a preparatory change for the following patches in this series. No functional changes. Link: https://lkml.kernel.org/r/23ea215409f43c13cdf9ecc454501a264c107d67.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29kasan: rename kasan_slab_free_mempool to kasan_mempool_poison_objectAndrey Konovalov
Patch series "kasan: save mempool stack traces". This series updates KASAN to save alloc and free stack traces for secondary-level allocators that cache and reuse allocations internally instead of giving them back to the underlying allocator (e.g. mempool). As a part of this change, introduce and document a set of KASAN hooks: bool kasan_mempool_poison_pages(struct page *page, unsigned int order); void kasan_mempool_unpoison_pages(struct page *page, unsigned int order); bool kasan_mempool_poison_object(void *ptr); void kasan_mempool_unpoison_object(void *ptr, size_t size); and use them in the mempool code. Besides mempool, skbuff and io_uring also cache allocations and already use KASAN hooks to poison those. Their code is updated to use the new mempool hooks. The new hooks save alloc and free stack traces (for normal kmalloc and slab objects; stack traces for large kmalloc objects and page_alloc are not supported by KASAN yet), improve the readability of the users' code, and also allow the users to prevent double-free and invalid-free bugs; see the patches for the details. This patch (of 21): Rename kasan_slab_free_mempool to kasan_mempool_poison_object. kasan_slab_free_mempool is a slightly confusing name: it is unclear whether this function poisons the object when it is freed into mempool or does something when the object is freed from mempool to the underlying allocator. The new name also aligns with other mempool-related KASAN hooks added in the following patches in this series. Link: https://lkml.kernel.org/r/cover.1703024586.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/c5618685abb7cdbf9fb4897f565e7759f601da84.1703024586.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Lobakin <alobakin@pm.me> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Breno Leitao <leitao@debian.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29fs: remove the bh_end_io argument from __block_write_full_folioMatthew Wilcox (Oracle)
All callers are passing end_buffer_async_write as this argument, so we can hardcode references to it within __block_write_full_folio(). That lets us make end_buffer_async_write() static. Link: https://lkml.kernel.org/r/20231215200245.748418-15-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29fs: convert block_write_full_page to block_write_full_folioMatthew Wilcox (Oracle)
Convert the function to be compatible with writepage_t so that it can be passed to write_cache_pages() by blkdev. This removes a call to compound_head(). We can also remove the function export as both callers are built-in. Link: https://lkml.kernel.org/r/20231215200245.748418-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29fs: remove clean_page_buffers()Matthew Wilcox (Oracle)
Patch series "Clean up the writeback paths". Most of these patches verge on the trivial, converting filesystems that just use block_write_full_page() to use mpage_writepages(). But as we saw with Christoph's earlier patchset, there can be some "interesting" gotchas, and I clearly haven't tested the majority of filesystems I've touched here. Patches 3 & 4 get rid of a lot of stack usage on architectures with larger page sizes; 1024 bytes on 64-bit systems with 64KiB pages. It starts to open the door to larger folio sizes on all architectures, but it's certainly not enough yet. Patch 14 is kind of trivial, but it's nice to get that simplification in. This patch (of 14): This function has been unused since the removal of bdev_write_page(). Link: https://lkml.kernel.org/r/20231215200245.748418-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231215200245.748418-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: remove page_swap_info()Matthew Wilcox (Oracle)
It's more efficient to get the swap_info_struct by calling swp_swap_info() directly. Link: https://lkml.kernel.org/r/20231213215842.671461-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: convert swap_page_sector() to swap_folio_sector()Matthew Wilcox (Oracle)
All callers have a folio, so pass it in. Saves a couple of calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: return the folio from __read_swap_cache_async()Matthew Wilcox (Oracle)
Patch series "More swap folio conversions". These all seem like fairly straightforward conversions to me. A lot of compound_head() calls get removed. And page_swap_info(), which is nice. This patch (of 13): Move the folio->page conversion into the callers that actually want that. Most of the callers are happier with the folio anyway. If the page_allocated boolean is set, the folio allocated is of order-0, so it is safe to pass the page directly to swap_readpage(). Link: https://lkml.kernel.org/r/20231213215842.671461-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231213215842.671461-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm/zswap: change per-cpu mutex and buffer to per-acomp_ctxChengming Zhou
First of all, we need to rename acomp_ctx->dstmem field to buffer, since we are now using for purposes other than compression. Then we change per-cpu mutex and buffer to per-acomp_ctx, since them belong to the acomp_ctx and are necessary parts when used in the compress/decompress contexts. So we can remove the old per-cpu mutex and dstmem. Link: https://lkml.kernel.org/r/20231213-zswap-dstmem-v5-5-9382162bbf05@bytedance.com Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Acked-by: Chris Li <chrisl@kernel.org> (Google) Reviewed-by: Nhat Pham <nphamcs@gmail.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: remove page_add_new_anon_rmap and lru_cache_add_inactive_or_unevictableMatthew Wilcox (Oracle)
All callers have now been converted to folio_add_new_anon_rmap() and folio_add_lru_vma() so we can remove the wrapper. Link: https://lkml.kernel.org/r/20231211162214.2146080-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: convert ksm_might_need_to_copy() to work on foliosMatthew Wilcox (Oracle)
Patch series "Finish two folio conversions". Most callers of page_add_new_anon_rmap() and lru_cache_add_inactive_or_unevictable() have been converted to their folio equivalents, but there are still a few stragglers. There's a bit of preparatory work in ksm and unuse_pte(), but after that it's pretty mechanical. This patch (of 9): Accept a folio as an argument and return a folio result. Removes a call to compound_head() in do_swap_page(), and prevents folio & page from getting out of sync in unuse_pte(). Reviewed-by: David Hildenbrand <david@redhat.com> [willy@infradead.org: fix smatch warning] Link: https://lkml.kernel.org/r/ZXnPtblC6A1IkyAB@casper.infradead.org [david@redhat.com: only adjust the page if the folio changed] Link: https://lkml.kernel.org/r/6a8f2110-fa91-4c10-9eae-88315309a6e3@redhat.com Link: https://lkml.kernel.org/r/20231211162214.2146080-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231211162214.2146080-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29userfaultfd: UFFDIO_MOVE uABIAndrea Arcangeli
Implement the uABI of UFFDIO_MOVE ioctl. UFFDIO_COPY performs ~20% better than UFFDIO_MOVE when the application needs pages to be allocated [1]. However, with UFFDIO_MOVE, if pages are available (in userspace) for recycling, as is usually the case in heap compaction algorithms, then we can avoid the page allocation and memcpy (done by UFFDIO_COPY). Also, since the pages are recycled in the userspace, we avoid the need to release (via madvise) the pages back to the kernel [2]. We see over 40% reduction (on a Google pixel 6 device) in the compacting thread's completion time by using UFFDIO_MOVE vs. UFFDIO_COPY. This was measured using a benchmark that emulates a heap compaction implementation using userfaultfd (to allow concurrent accesses by application threads). More details of the usecase are explained in [2]. Furthermore, UFFDIO_MOVE enables moving swapped-out pages without touching them within the same vma. Today, it can only be done by mremap, however it forces splitting the vma. [1] https://lore.kernel.org/all/1425575884-2574-1-git-send-email-aarcange@redhat.com/ [2] https://lore.kernel.org/linux-mm/CA+EESO4uO84SSnBhArH4HvLNhaUQ5nZKNKXqxRCyjniNVjp0Aw@mail.gmail.com/ Update for the ioctl_userfaultfd(2) manpage: UFFDIO_MOVE (Since Linux xxx) Move a continuous memory chunk into the userfault registered range and optionally wake up the blocked thread. The source and destination addresses and the number of bytes to move are specified by the src, dst, and len fields of the uffdio_move structure pointed to by argp: struct uffdio_move { __u64 dst; /* Destination of move */ __u64 src; /* Source of move */ __u64 len; /* Number of bytes to move */ __u64 mode; /* Flags controlling behavior of move */ __s64 move; /* Number of bytes moved, or negated error */ }; The following value may be bitwise ORed in mode to change the behavior of the UFFDIO_MOVE operation: UFFDIO_MOVE_MODE_DONTWAKE Do not wake up the thread that waits for page-fault resolution UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES Allow holes in the source virtual range that is being moved. When not specified, the holes will result in ENOENT error. When specified, the holes will be accounted as successfully moved memory. This is mostly useful to move hugepage aligned virtual regions without knowing if there are transparent hugepages in the regions or not, but preventing the risk of having to split the hugepage during the operation. The move field is used by the kernel to return the number of bytes that was actually moved, or an error (a negated errno- style value). If the value returned in move doesn't match the value that was specified in len, the operation fails with the error EAGAIN. The move field is output-only; it is not read by the UFFDIO_MOVE operation. The operation may fail for various reasons. Usually, remapping of pages that are not exclusive to the given process fail; once KSM might deduplicate pages or fork() COW-shares pages during fork() with child processes, they are no longer exclusive. Further, the kernel might only perform lightweight checks for detecting whether the pages are exclusive, and return -EBUSY in case that check fails. To make the operation more likely to succeed, KSM should be disabled, fork() should be avoided or MADV_DONTFORK should be configured for the source VMA before fork(). This ioctl(2) operation returns 0 on success. In this case, the entire area was moved. On error, -1 is returned and errno is set to indicate the error. Possible errors include: EAGAIN The number of bytes moved (i.e., the value returned in the move field) does not equal the value that was specified in the len field. EINVAL Either dst or len was not a multiple of the system page size, or the range specified by src and len or dst and len was invalid. EINVAL An invalid bit was specified in the mode field. ENOENT The source virtual memory range has unmapped holes and UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES is not set. EEXIST The destination virtual memory range is fully or partially mapped. EBUSY The pages in the source virtual memory range are either pinned or not exclusive to the process. The kernel might only perform lightweight checks for detecting whether the pages are exclusive. To make the operation more likely to succeed, KSM should be disabled, fork() should be avoided or MADV_DONTFORK should be configured for the source virtual memory area before fork(). ENOMEM Allocating memory needed for the operation failed. ESRCH The target process has exited at the time of a UFFDIO_MOVE operation. Link: https://lkml.kernel.org/r/20231206103702.3873743-3-surenb@google.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29Merge tag 'block-6.7-2023-12-29' of git://git.kernel.dk/linuxLinus Torvalds
Pull block fixes from Jens Axboe: "Fix for a badly numbered flag, and a regression fix for the badblocks updates from this merge window" * tag 'block-6.7-2023-12-29' of git://git.kernel.dk/linux: block: renumber QUEUE_FLAG_HW_WC badblocks: avoid checking invalid range in badblocks_check()
2023-12-29thermal/sysfs: Update governors when the 'weight' has changedLukasz Luba
Support governors update when the thermal instance's weight has changed. This allows to adjust internal state for the governor. Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> [ rjw: Add two empty code lines aroung the locking ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-29thermal: core: Add governor callback for thermal zone changeLukasz Luba
Add a new callback to the struct thermal_governor. It can be used for updating governors when there is a change in the thermal zone internals, e.g. thermal cooling device is bind to the thermal zone. That makes possible to move some heavy operations like memory allocations related to the number of cooling instances out of the throttle() callback. Both callback code paths (throttle() and update_tz()) are protected with the same thermal zone lock, which guaranties the consistency. Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-29ethtool: reformat kerneldoc for struct ethtool_fec_statsJonathan Corbet
The kerneldoc comment for struct ethtool_fec_stats attempts to describe the "total" and "lanes" fields of the ethtool_fec_stat substructure in a way leading to these warnings: ./include/linux/ethtool.h:424: warning: Excess struct member 'lane' description in 'ethtool_fec_stats' ./include/linux/ethtool.h:424: warning: Excess struct member 'total' description in 'ethtool_fec_stats' Reformat the comment to retain the information while eliminating the warnings. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-28Merge tag 'kbuild-fixes-v6.7-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild fixes from Masahiro Yamada: - Revive proper alignment for the ksymtab and kcrctab sections - Fix gen_compile_commands.py tool to resolve symbolic links - Fix symbolic links to installed debug VDSO files - Update MAINTAINERS * tag 'kbuild-fixes-v6.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: linux/export: Ensure natural alignment of kcrctab array kbuild: fix build ID symlinks to installed debug VDSO files gen_compile_commands.py: fix path resolve with symlinks in it MAINTAINERS: Add scripts/clang-tools to Kbuild section linux/export: Fix alignment for 64-bit ksymtab entries
2023-12-29linux/export: Ensure natural alignment of kcrctab arrayHelge Deller
The ___kcrctab section holds an array of 32-bit CRC values. Add a .balign 4 to tell the linker the correct memory alignment. Fixes: f3304ecd7f06 ("linux/export: use inline assembler to populate symbol CRCs") Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2023-12-28thermal: core: Fix thermal zone suspend-resume synchronizationRafael J. Wysocki
There are 3 synchronization issues with thermal zone suspend-resume during system-wide transitions: 1. The resume code runs in a PM notifier which is invoked after user space has been thawed, so it can run concurrently with user space which can trigger a thermal zone device removal. If that happens, the thermal zone resume code may use a stale pointer to the next list element and crash, because it does not hold thermal_list_lock while walking thermal_tz_list. 2. The thermal zone resume code calls thermal_zone_device_init() outside the zone lock, so user space or an update triggered by the platform firmware may see an inconsistent state of a thermal zone leading to unexpected behavior. 3. Clearing the in_suspend global variable in thermal_pm_notify() allows __thermal_zone_device_update() to continue for all thermal zones and it may as well run before the thermal_tz_list walk (or at any point during the list walk for that matter) and attempt to operate on a thermal zone that has not been resumed yet. It may also race destructively with thermal_zone_device_init(). To address these issues, add thermal_list_lock locking to thermal_pm_notify(), especially arount the thermal_tz_list, make it call thermal_zone_device_init() back-to-back with __thermal_zone_device_update() under the zone lock and replace in_suspend with per-zone bool "suspend" indicators set and unset under the given zone's lock. Link: https://lore.kernel.org/linux-pm/20231218162348.69101-1-bo.ye@mediatek.com/ Reported-by: Bo Ye <bo.ye@mediatek.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-28sysctl: remove struct ctl_pathThomas Weißschuh
All usages of this struct have been removed from the kernel tree. The struct is still referenced by scripts/check-sysctl-docs but that script is broken anyways as it only supports the register_sysctl_paths() API and not the currently used register_sysctl() one. Fixes: 0199849acd07 ("sysctl: remove register_sysctl_paths()") Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Reviewed-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-12-28sysctl: delete unused define SYSCTL_PERM_EMPTY_DIRThomas Weißschuh
It seems it was never used. Fixes: 2f2665c13af4 ("sysctl: replace child with an enumeration") Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-12-28fs: fix __sb_write_started() kerneldoc formattingVegard Nossum
When running 'make htmldocs', I see the following warning: Documentation/filesystems/api-summary:14: ./include/linux/fs.h:1659: WARNING: Definition list ends without a blank line; unexpected unindent. The official guidance [1] seems to be to use lists, which will prevent both the "unexpected unindent" warning as well as ensure that each line is formatted on a separate line in the HTML output instead of being all considered a single paragraph. [1]: https://docs.kernel.org/doc-guide/kernel-doc.html#return-values Fixes: 8802e580ee64 ("fs: create __sb_write_started() helper") Cc: Amir Goldstein <amir73il@gmail.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Link: https://lore.kernel.org/r/20231228100608.3123987-1-vegard.nossum@oracle.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-12-28netfs: Optimise away reads above the point at which there can be no dataDavid Howells
Track the file position above which the server is not expected to have any data (the "zero point") and preemptively assume that we can satisfy requests by filling them with zeroes locally rather than attempting to download them if they're over that line - even if we've written data back to the server. Assume that any data that was written back above that position is held in the local cache. Note that we have to split requests that straddle the line. Make use of this to optimise away some reads from the server. We need to set the zero point in the following circumstances: (1) When we see an extant remote inode and have no cache for it, we set the zero_point to i_size. (2) On local inode creation, we set zero_point to 0. (3) On local truncation down, we reduce zero_point to the new i_size if the new i_size is lower. (4) On local truncation up, we don't change zero_point. (5) On local modification, we don't change zero_point. (6) On remote invalidation, we set zero_point to the new i_size. (7) If stored data is discarded from the pagecache or culled from fscache, we must set zero_point above that if the data also got written to the server. (8) If dirty data is written back to the server, but not fscache, we must set zero_point above that. (9) If a direct I/O write is made, set zero_point above that. Assuming the above, any read from the server at or above the zero_point position will return all zeroes. The zero_point value can be stored in the cache, provided the above rules are applied to it by any code that culls part of the local cache. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org