August 2025 - Linux-stable-mirror

[merged mm-hotfixes-stable] x86-mm-64-define-arch_page_table_sync_mask-and-arch_sync_kernel_mappings.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: x86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() has been removed from the -mm tree. Its filename was x86-mm-64-define-arch_page_table_sync_mask-and-arch_sync_kernel_mappings.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Harry Yoo <harry.yoo(a)oracle.com> Subject: x86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() Date: Mon, 18 Aug 2025 11:02:06 +0900 Define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure page tables are properly synchronized when calling p*d_populate_kernel(). For 5-level paging, synchronization is performed via pgd_populate_kernel(). In 4-level paging, pgd_populate() is a no-op, so synchronization is instead performed at the P4D level via p4d_populate_kernel(). This fixes intermittent boot failures on systems using 4-level paging and a large amount of persistent memory: BUG: unable to handle page fault for address: ffffe70000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI RIP: 0010:__init_single_page+0x9/0x6d Call Trace: <TASK> __init_zone_device_page+0x17/0x5d memmap_init_zone_device+0x154/0x1bb pagemap_range+0x2e0/0x40f memremap_pages+0x10b/0x2f0 devm_memremap_pages+0x1e/0x60 dev_dax_probe+0xce/0x2ec [device_dax] dax_bus_probe+0x6d/0xc9 [... snip ...] </TASK> It also fixes a crash in vmemmap_set_pmd() caused by accessing vmemmap before sync_global_pgds() [1]: BUG: unable to handle page fault for address: ffffeb3ff1200000 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI Tainted: [W]=WARN RIP: 0010:vmemmap_set_pmd+0xff/0x230 <TASK> vmemmap_populate_hugepages+0x176/0x180 vmemmap_populate+0x34/0x80 __populate_section_memmap+0x41/0x90 sparse_add_section+0x121/0x3e0 __add_pages+0xba/0x150 add_pages+0x1d/0x70 memremap_pages+0x3dc/0x810 devm_memremap_pages+0x1c/0x60 xe_devm_add+0x8b/0x100 [xe] xe_tile_init_noalloc+0x6a/0x70 [xe] xe_device_probe+0x48c/0x740 [xe] [... snip ...] Link: https://lkml.kernel.org/r/20250818020206.4517-4-harry.yoo@oracle.com Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo <harry.yoo(a)oracle.com> Closes: https://lore.kernel.org/linux-mm/20250311114420.240341-1-gwan-gyeong.mun@in… [1] Suggested-by: Dave Hansen <dave.hansen(a)linux.intel.com> Acked-by: Kiryl Shutsemau <kas(a)kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Alistair Popple <apopple(a)nvidia.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar(a)linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual(a)arm.com> Cc: Ard Biesheuvel <ardb(a)kernel.org> Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: bibo mao <maobibo(a)loongson.cn> Cc: Borislav Betkov <bp(a)alien8.de> Cc: Christoph Lameter (Ampere) <cl(a)gentwo.org> Cc: Dennis Zhou <dennis(a)kernel.org> Cc: Dev Jain <dev.jain(a)arm.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jane Chu <jane.chu(a)oracle.com> Cc: Joao Martins <joao.m.martins(a)oracle.com> Cc: Joerg Roedel <joro(a)8bytes.org> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Kevin Brodsky <kevin.brodsky(a)arm.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Peter Xu <peterx(a)redhat.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Qi Zheng <zhengqi.arch(a)bytedance.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Tejun Heo <tj(a)kernel.org> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: Thomas Huth <thuth(a)redhat.com> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/x86/include/asm/pgtable_64_types.h | 3 +++ arch/x86/mm/init_64.c | 18 ++++++++++++++++++ 2 files changed, 21 insertions(+) --- a/arch/x86/include/asm/pgtable_64_types.h~x86-mm-64-define-arch_page_table_sync_mask-and-arch_sync_kernel_mappings +++ a/arch/x86/include/asm/pgtable_64_types.h @@ -36,6 +36,9 @@ static inline bool pgtable_l5_enabled(vo #define pgtable_l5_enabled() cpu_feature_enabled(X86_FEATURE_LA57) #endif /* USE_EARLY_PGTABLE_L5 */ +#define ARCH_PAGE_TABLE_SYNC_MASK \ + (pgtable_l5_enabled() ? PGTBL_PGD_MODIFIED : PGTBL_P4D_MODIFIED) + extern unsigned int pgdir_shift; extern unsigned int ptrs_per_p4d; --- a/arch/x86/mm/init_64.c~x86-mm-64-define-arch_page_table_sync_mask-and-arch_sync_kernel_mappings +++ a/arch/x86/mm/init_64.c @@ -224,6 +224,24 @@ static void sync_global_pgds(unsigned lo } /* + * Make kernel mappings visible in all page tables in the system. + * This is necessary except when the init task populates kernel mappings + * during the boot process. In that case, all processes originating from + * the init task copies the kernel mappings, so there is no issue. + * Otherwise, missing synchronization could lead to kernel crashes due + * to missing page table entries for certain kernel mappings. + * + * Synchronization is performed at the top level, which is the PGD in + * 5-level paging systems. But in 4-level paging systems, however, + * pgd_populate() is a no-op, so synchronization is done at the P4D level. + * sync_global_pgds() handles this difference between paging levels. + */ +void arch_sync_kernel_mappings(unsigned long start, unsigned long end) +{ + sync_global_pgds(start, end); +} + +/* * NOTE: This function is marked __ref because it calls __init function * (alloc_bootmem_pages). It's safe to do it ONLY when after_bootmem == 0. */ _ Patches currently in -mm which might be from harry.yoo(a)oracle.com are

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[merged mm-hotfixes-stable] mm-introduce-and-use-pgdp4d_populate_kernel.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: introduce and use {pgd,p4d}_populate_kernel() has been removed from the -mm tree. Its filename was mm-introduce-and-use-pgdp4d_populate_kernel.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Harry Yoo <harry.yoo(a)oracle.com> Subject: mm: introduce and use {pgd,p4d}_populate_kernel() Date: Mon, 18 Aug 2025 11:02:05 +0900 Introduce and use {pgd,p4d}_populate_kernel() in core MM code when populating PGD and P4D entries for the kernel address space. These helpers ensure proper synchronization of page tables when updating the kernel portion of top-level page tables. Until now, the kernel has relied on each architecture to handle synchronization of top-level page tables in an ad-hoc manner. For example, see commit 9b861528a801 ("x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes"). However, this approach has proven fragile for following reasons: 1) It is easy to forget to perform the necessary page table synchronization when introducing new changes. For instance, commit 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") overlooked the need to synchronize page tables for the vmemmap area. 2) It is also easy to overlook that the vmemmap and direct mapping areas must not be accessed before explicit page table synchronization. For example, commit 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges")) caused crashes by accessing the vmemmap area before calling sync_global_pgds(). To address this, as suggested by Dave Hansen, introduce _kernel() variants of the page table population helpers, which invoke architecture-specific hooks to properly synchronize page tables. These are introduced in a new header file, include/linux/pgalloc.h, so they can be called from common code. They reuse existing infrastructure for vmalloc and ioremap. Synchronization requirements are determined by ARCH_PAGE_TABLE_SYNC_MASK, and the actual synchronization is performed by arch_sync_kernel_mappings(). This change currently targets only x86_64, so only PGD and P4D level helpers are introduced. Currently, these helpers are no-ops since no architecture sets PGTBL_{PGD,P4D}_MODIFIED in ARCH_PAGE_TABLE_SYNC_MASK. In theory, PUD and PMD level helpers can be added later if needed by other architectures. For now, 32-bit architectures (x86-32 and arm) only handle PGTBL_PMD_MODIFIED, so p*d_populate_kernel() will never affect them unless we introduce a PMD level helper. [harry.yoo(a)oracle.com: fix KASAN build error due to p*d_populate_kernel()] Link: https://lkml.kernel.org/r/20250822020727.202749-1-harry.yoo@oracle.com Link: https://lkml.kernel.org/r/20250818020206.4517-3-harry.yoo@oracle.com Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo <harry.yoo(a)oracle.com> Suggested-by: Dave Hansen <dave.hansen(a)linux.intel.com> Acked-by: Kiryl Shutsemau <kas(a)kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Alistair Popple <apopple(a)nvidia.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar(a)linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual(a)arm.com> Cc: Ard Biesheuvel <ardb(a)kernel.org> Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: bibo mao <maobibo(a)loongson.cn> Cc: Borislav Betkov <bp(a)alien8.de> Cc: Christoph Lameter (Ampere) <cl(a)gentwo.org> Cc: Dennis Zhou <dennis(a)kernel.org> Cc: Dev Jain <dev.jain(a)arm.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Gwan-gyeong Mun <gwan-gyeong.mun(a)intel.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jane Chu <jane.chu(a)oracle.com> Cc: Joao Martins <joao.m.martins(a)oracle.com> Cc: Joerg Roedel <joro(a)8bytes.org> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Kevin Brodsky <kevin.brodsky(a)arm.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Peter Xu <peterx(a)redhat.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Qi Zheng <zhengqi.arch(a)bytedance.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Tejun Heo <tj(a)kernel.org> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: Thomas Huth <thuth(a)redhat.com> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/pgalloc.h | 29 +++++++++++++++++++++++++++++ include/linux/pgtable.h | 13 +++++++------ mm/kasan/init.c | 12 ++++++------ mm/percpu.c | 6 +++--- mm/sparse-vmemmap.c | 6 +++--- 5 files changed, 48 insertions(+), 18 deletions(-) diff --git a/include/linux/pgalloc.h a/include/linux/pgalloc.h new file mode 100644 --- /dev/null +++ a/include/linux/pgalloc.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_PGALLOC_H +#define _LINUX_PGALLOC_H + +#include <linux/pgtable.h> +#include <asm/pgalloc.h> + +/* + * {pgd,p4d}_populate_kernel() are defined as macros to allow + * compile-time optimization based on the configured page table levels. + * Without this, linking may fail because callers (e.g., KASAN) may rely + * on calls to these functions being optimized away when passing symbols + * that exist only for certain page table levels. + */ +#define pgd_populate_kernel(addr, pgd, p4d) \ + do { \ + pgd_populate(&init_mm, pgd, p4d); \ + if (ARCH_PAGE_TABLE_SYNC_MASK & PGTBL_PGD_MODIFIED) \ + arch_sync_kernel_mappings(addr, addr); \ + } while (0) + +#define p4d_populate_kernel(addr, p4d, pud) \ + do { \ + p4d_populate(&init_mm, p4d, pud); \ + if (ARCH_PAGE_TABLE_SYNC_MASK & PGTBL_P4D_MODIFIED) \ + arch_sync_kernel_mappings(addr, addr); \ + } while (0) + +#endif /* _LINUX_PGALLOC_H */ --- a/include/linux/pgtable.h~mm-introduce-and-use-pgdp4d_populate_kernel +++ a/include/linux/pgtable.h @@ -1469,8 +1469,8 @@ static inline void modify_prot_commit_pt /* * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values - * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings() - * needs to be called. + * and let generic vmalloc, ioremap and page table update code know when + * arch_sync_kernel_mappings() needs to be called. */ #ifndef ARCH_PAGE_TABLE_SYNC_MASK #define ARCH_PAGE_TABLE_SYNC_MASK 0 @@ -1954,10 +1954,11 @@ static inline bool arch_has_pfn_modify_c /* * Page Table Modification bits for pgtbl_mod_mask. * - * These are used by the p?d_alloc_track*() set of functions an in the generic - * vmalloc/ioremap code to track at which page-table levels entries have been - * modified. Based on that the code can better decide when vmalloc and ioremap - * mapping changes need to be synchronized to other page-tables in the system. + * These are used by the p?d_alloc_track*() and p*d_populate_kernel() + * functions in the generic vmalloc, ioremap and page table update code + * to track at which page-table levels entries have been modified. + * Based on that the code can better decide when page table changes need + * to be synchronized to other page-tables in the system. */ #define __PGTBL_PGD_MODIFIED 0 #define __PGTBL_P4D_MODIFIED 1 --- a/mm/kasan/init.c~mm-introduce-and-use-pgdp4d_populate_kernel +++ a/mm/kasan/init.c @@ -13,9 +13,9 @@ #include <linux/mm.h> #include <linux/pfn.h> #include <linux/slab.h> +#include <linux/pgalloc.h> #include <asm/page.h> -#include <asm/pgalloc.h> #include "kasan.h" @@ -191,7 +191,7 @@ static int __ref zero_p4d_populate(pgd_t pud_t *pud; pmd_t *pmd; - p4d_populate(&init_mm, p4d, + p4d_populate_kernel(addr, p4d, lm_alias(kasan_early_shadow_pud)); pud = pud_offset(p4d, addr); pud_populate(&init_mm, pud, @@ -212,7 +212,7 @@ static int __ref zero_p4d_populate(pgd_t } else { p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); pud_init(p); - p4d_populate(&init_mm, p4d, p); + p4d_populate_kernel(addr, p4d, p); } } zero_pud_populate(p4d, addr, next); @@ -251,10 +251,10 @@ int __ref kasan_populate_early_shadow(co * puds,pmds, so pgd_populate(), pud_populate() * is noops. */ - pgd_populate(&init_mm, pgd, + pgd_populate_kernel(addr, pgd, lm_alias(kasan_early_shadow_p4d)); p4d = p4d_offset(pgd, addr); - p4d_populate(&init_mm, p4d, + p4d_populate_kernel(addr, p4d, lm_alias(kasan_early_shadow_pud)); pud = pud_offset(p4d, addr); pud_populate(&init_mm, pud, @@ -273,7 +273,7 @@ int __ref kasan_populate_early_shadow(co if (!p) return -ENOMEM; } else { - pgd_populate(&init_mm, pgd, + pgd_populate_kernel(addr, pgd, early_alloc(PAGE_SIZE, NUMA_NO_NODE)); } } --- a/mm/percpu.c~mm-introduce-and-use-pgdp4d_populate_kernel +++ a/mm/percpu.c @@ -3108,7 +3108,7 @@ out_free: #endif /* BUILD_EMBED_FIRST_CHUNK */ #ifdef BUILD_PAGE_FIRST_CHUNK -#include <asm/pgalloc.h> +#include <linux/pgalloc.h> #ifndef P4D_TABLE_SIZE #define P4D_TABLE_SIZE PAGE_SIZE @@ -3134,13 +3134,13 @@ void __init __weak pcpu_populate_pte(uns if (pgd_none(*pgd)) { p4d = memblock_alloc_or_panic(P4D_TABLE_SIZE, P4D_TABLE_SIZE); - pgd_populate(&init_mm, pgd, p4d); + pgd_populate_kernel(addr, pgd, p4d); } p4d = p4d_offset(pgd, addr); if (p4d_none(*p4d)) { pud = memblock_alloc_or_panic(PUD_TABLE_SIZE, PUD_TABLE_SIZE); - p4d_populate(&init_mm, p4d, pud); + p4d_populate_kernel(addr, p4d, pud); } pud = pud_offset(p4d, addr); --- a/mm/sparse-vmemmap.c~mm-introduce-and-use-pgdp4d_populate_kernel +++ a/mm/sparse-vmemmap.c @@ -27,9 +27,9 @@ #include <linux/spinlock.h> #include <linux/vmalloc.h> #include <linux/sched.h> +#include <linux/pgalloc.h> #include <asm/dma.h> -#include <asm/pgalloc.h> #include <asm/tlbflush.h> #include "hugetlb_vmemmap.h" @@ -229,7 +229,7 @@ p4d_t * __meminit vmemmap_p4d_populate(p if (!p) return NULL; pud_init(p); - p4d_populate(&init_mm, p4d, p); + p4d_populate_kernel(addr, p4d, p); } return p4d; } @@ -241,7 +241,7 @@ pgd_t * __meminit vmemmap_pgd_populate(u void *p = vmemmap_alloc_block_zero(PAGE_SIZE, node); if (!p) return NULL; - pgd_populate(&init_mm, pgd, p); + pgd_populate_kernel(addr, pgd, p); } return pgd; } _ Patches currently in -mm which might be from harry.yoo(a)oracle.com are

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[merged mm-hotfixes-stable] mm-move-page-table-sync-declarations-to-linux-pgtableh.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: move page table sync declarations to linux/pgtable.h has been removed from the -mm tree. Its filename was mm-move-page-table-sync-declarations-to-linux-pgtableh.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Harry Yoo <harry.yoo(a)oracle.com> Subject: mm: move page table sync declarations to linux/pgtable.h Date: Mon, 18 Aug 2025 11:02:04 +0900 During our internal testing, we started observing intermittent boot failures when the machine uses 4-level paging and has a large amount of persistent memory: BUG: unable to handle page fault for address: ffffe70000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI RIP: 0010:__init_single_page+0x9/0x6d Call Trace: <TASK> __init_zone_device_page+0x17/0x5d memmap_init_zone_device+0x154/0x1bb pagemap_range+0x2e0/0x40f memremap_pages+0x10b/0x2f0 devm_memremap_pages+0x1e/0x60 dev_dax_probe+0xce/0x2ec [device_dax] dax_bus_probe+0x6d/0xc9 [... snip ...] </TASK> It turns out that the kernel panics while initializing vmemmap (struct page array) when the vmemmap region spans two PGD entries, because the new PGD entry is only installed in init_mm.pgd, but not in the page tables of other tasks. And looking at __populate_section_memmap(): if (vmemmap_can_optimize(altmap, pgmap)) // does not sync top level page tables r = vmemmap_populate_compound_pages(pfn, start, end, nid, pgmap); else // sync top level page tables in x86 r = vmemmap_populate(start, end, nid, altmap); In the normal path, vmemmap_populate() in arch/x86/mm/init_64.c synchronizes the top level page table (See commit 9b861528a801 ("x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes")) so that all tasks in the system can see the new vmemmap area. However, when vmemmap_can_optimize() returns true, the optimized path skips synchronization of top-level page tables. This is because vmemmap_populate_compound_pages() is implemented in core MM code, which does not handle synchronization of the top-level page tables. Instead, the core MM has historically relied on each architecture to perform this synchronization manually. We're not the first party to encounter a crash caused by not-sync'd top level page tables: earlier this year, Gwan-gyeong Mun attempted to address the issue [1] [2] after hitting a kernel panic when x86 code accessed the vmemmap area before the corresponding top-level entries were synced. At that time, the issue was believed to be triggered only when struct page was enlarged for debugging purposes, and the patch did not get further updates. It turns out that current approach of relying on each arch to handle the page table sync manually is fragile because 1) it's easy to forget to sync the top level page table, and 2) it's also easy to overlook that the kernel should not access the vmemmap and direct mapping areas before the sync. # The solution: Make page table sync more code robust and harder to miss To address this, Dave Hansen suggested [3] [4] introducing {pgd,p4d}_populate_kernel() for updating kernel portion of the page tables and allow each architecture to explicitly perform synchronization when installing top-level entries. With this approach, we no longer need to worry about missing the sync step, reducing the risk of future regressions. The new interface reuses existing ARCH_PAGE_TABLE_SYNC_MASK, PGTBL_P*D_MODIFIED and arch_sync_kernel_mappings() facility used by vmalloc and ioremap to synchronize page tables. pgd_populate_kernel() looks like this: static inline void pgd_populate_kernel(unsigned long addr, pgd_t *pgd, p4d_t *p4d) { pgd_populate(&init_mm, pgd, p4d); if (ARCH_PAGE_TABLE_SYNC_MASK & PGTBL_PGD_MODIFIED) arch_sync_kernel_mappings(addr, addr); } It is worth noting that vmalloc() and apply_to_range() carefully synchronizes page tables by calling p*d_alloc_track() and arch_sync_kernel_mappings(), and thus they are not affected by this patch series. This series was hugely inspired by Dave Hansen's suggestion and hence added Suggested-by: Dave Hansen. Cc stable because lack of this series opens the door to intermittent boot failures. This patch (of 3): Move ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to linux/pgtable.h so that they can be used outside of vmalloc and ioremap. Link: https://lkml.kernel.org/r/20250818020206.4517-1-harry.yoo@oracle.com Link: https://lkml.kernel.org/r/20250818020206.4517-2-harry.yoo@oracle.com Link: https://lore.kernel.org/linux-mm/20250220064105.808339-1-gwan-gyeong.mun@in… [1] Link: https://lore.kernel.org/linux-mm/20250311114420.240341-1-gwan-gyeong.mun@in… [2] Link: https://lore.kernel.org/linux-mm/d1da214c-53d3-45ac-a8b6-51821c5416e4@intel… [3] Link: https://lore.kernel.org/linux-mm/4d800744-7b88-41aa-9979-b245e8bf794b@intel… [4] Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo <harry.yoo(a)oracle.com> Acked-by: Kiryl Shutsemau <kas(a)kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Reviewed-by: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Acked-by: David Hildenbrand <david(a)redhat.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Alistair Popple <apopple(a)nvidia.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar(a)linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual(a)arm.com> Cc: Ard Biesheuvel <ardb(a)kernel.org> Cc: Arnd Bergmann <arnd(a)arndb.de> Cc: bibo mao <maobibo(a)loongson.cn> Cc: Borislav Betkov <bp(a)alien8.de> Cc: Christoph Lameter (Ampere) <cl(a)gentwo.org> Cc: Dennis Zhou <dennis(a)kernel.org> Cc: Dev Jain <dev.jain(a)arm.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Gwan-gyeong Mun <gwan-gyeong.mun(a)intel.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jane Chu <jane.chu(a)oracle.com> Cc: Joao Martins <joao.m.martins(a)oracle.com> Cc: Joerg Roedel <joro(a)8bytes.org> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Kevin Brodsky <kevin.brodsky(a)arm.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Peter Xu <peterx(a)redhat.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Qi Zheng <zhengqi.arch(a)bytedance.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Tejun Heo <tj(a)kernel.org> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: Thomas Huth <thuth(a)redhat.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/pgtable.h | 16 ++++++++++++++++ include/linux/vmalloc.h | 16 ---------------- 2 files changed, 16 insertions(+), 16 deletions(-) --- a/include/linux/pgtable.h~mm-move-page-table-sync-declarations-to-linux-pgtableh +++ a/include/linux/pgtable.h @@ -1467,6 +1467,22 @@ static inline void modify_prot_commit_pt } #endif +/* + * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values + * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings() + * needs to be called. + */ +#ifndef ARCH_PAGE_TABLE_SYNC_MASK +#define ARCH_PAGE_TABLE_SYNC_MASK 0 +#endif + +/* + * There is no default implementation for arch_sync_kernel_mappings(). It is + * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK + * is 0. + */ +void arch_sync_kernel_mappings(unsigned long start, unsigned long end); + #endif /* CONFIG_MMU */ /* --- a/include/linux/vmalloc.h~mm-move-page-table-sync-declarations-to-linux-pgtableh +++ a/include/linux/vmalloc.h @@ -220,22 +220,6 @@ int vmap_pages_range(unsigned long addr, struct page **pages, unsigned int page_shift); /* - * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values - * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings() - * needs to be called. - */ -#ifndef ARCH_PAGE_TABLE_SYNC_MASK -#define ARCH_PAGE_TABLE_SYNC_MASK 0 -#endif - -/* - * There is no default implementation for arch_sync_kernel_mappings(). It is - * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK - * is 0. - */ -void arch_sync_kernel_mappings(unsigned long start, unsigned long end); - -/* * Lowlevel-APIs (not for driver use!) */ _ Patches currently in -mm which might be from harry.yoo(a)oracle.com are

1 week, 3 days

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[merged mm-hotfixes-stable] proc-fix-missing-pde_set_flags-for-net-proc-files.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: proc: fix missing pde_set_flags() for net proc files has been removed from the -mm tree. Its filename was proc-fix-missing-pde_set_flags-for-net-proc-files.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: wangzijie <wangzijie1(a)honor.com> Subject: proc: fix missing pde_set_flags() for net proc files Date: Mon, 18 Aug 2025 20:31:02 +0800 To avoid potential UAF issues during module removal races, we use pde_set_flags() to save proc_ops flags in PDE itself before proc_register(), and then use pde_has_proc_*() helpers instead of directly dereferencing pde->proc_ops->*. However, the pde_set_flags() call was missing when creating net related proc files. This omission caused incorrect behavior which FMODE_LSEEK was being cleared inappropriately in proc_reg_open() for net proc files. Lars reported it in this link[1]. Fix this by ensuring pde_set_flags() is called when register proc entry, and add NULL check for proc_ops in pde_set_flags(). [wangzijie1(a)honor.com: stash pde->proc_ops in a local const variable, per Christian] Link: https://lkml.kernel.org/r/20250821105806.1453833-1-wangzijie1@honor.com Link: https://lkml.kernel.org/r/20250818123102.959595-1-wangzijie1@honor.com Link: https://lore.kernel.org/all/20250815195616.64497967@chagall.paradoxon.rec/ [1] Fixes: ff7ec8dc1b64 ("proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al") Signed-off-by: wangzijie <wangzijie1(a)honor.com> Reported-by: Lars Wendler <polynomial-c(a)gmx.de> Tested-by: Stefano Brivio <sbrivio(a)redhat.com> Tested-by: Petr Van��k <pv(a)excello.cz> Tested by: Lars Wendler <polynomial-c(a)gmx.de> Cc: Alexei Starovoitov <ast(a)kernel.org> Cc: Alexey Dobriyan <adobriyan(a)gmail.com> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Cc: "Edgecombe, Rick P" <rick.p.edgecombe(a)intel.com> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Jiri Slaby <jirislaby(a)kernel.org> Cc: Kirill A. Shutemov <k.shutemov(a)gmail.com> Cc: wangzijie <wangzijie1(a)honor.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/proc/generic.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-) --- a/fs/proc/generic.c~proc-fix-missing-pde_set_flags-for-net-proc-files +++ a/fs/proc/generic.c @@ -367,6 +367,25 @@ static const struct inode_operations pro .setattr = proc_notify_change, }; +static void pde_set_flags(struct proc_dir_entry *pde) +{ + const struct proc_ops *proc_ops = pde->proc_ops; + + if (!proc_ops) + return; + + if (proc_ops->proc_flags & PROC_ENTRY_PERMANENT) + pde->flags |= PROC_ENTRY_PERMANENT; + if (proc_ops->proc_read_iter) + pde->flags |= PROC_ENTRY_proc_read_iter; +#ifdef CONFIG_COMPAT + if (proc_ops->proc_compat_ioctl) + pde->flags |= PROC_ENTRY_proc_compat_ioctl; +#endif + if (proc_ops->proc_lseek) + pde->flags |= PROC_ENTRY_proc_lseek; +} + /* returns the registered entry, or frees dp and returns NULL on failure */ struct proc_dir_entry *proc_register(struct proc_dir_entry *dir, struct proc_dir_entry *dp) @@ -374,6 +393,8 @@ struct proc_dir_entry *proc_register(str if (proc_alloc_inum(&dp->low_ino)) goto out_free_entry; + pde_set_flags(dp); + write_lock(&proc_subdir_lock); dp->parent = dir; if (pde_subdir_insert(dir, dp) == false) { @@ -561,20 +582,6 @@ struct proc_dir_entry *proc_create_reg(c return p; } -static void pde_set_flags(struct proc_dir_entry *pde) -{ - if (pde->proc_ops->proc_flags & PROC_ENTRY_PERMANENT) - pde->flags |= PROC_ENTRY_PERMANENT; - if (pde->proc_ops->proc_read_iter) - pde->flags |= PROC_ENTRY_proc_read_iter; -#ifdef CONFIG_COMPAT - if (pde->proc_ops->proc_compat_ioctl) - pde->flags |= PROC_ENTRY_proc_compat_ioctl; -#endif - if (pde->proc_ops->proc_lseek) - pde->flags |= PROC_ENTRY_proc_lseek; -} - struct proc_dir_entry *proc_create_data(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops, void *data) @@ -585,7 +592,6 @@ struct proc_dir_entry *proc_create_data( if (!p) return NULL; p->proc_ops = proc_ops; - pde_set_flags(p); return proc_register(parent, p); } EXPORT_SYMBOL(proc_create_data); @@ -636,7 +642,6 @@ struct proc_dir_entry *proc_create_seq_p p->proc_ops = &proc_seq_ops; p->seq_ops = ops; p->state_size = state_size; - pde_set_flags(p); return proc_register(parent, p); } EXPORT_SYMBOL(proc_create_seq_private); @@ -667,7 +672,6 @@ struct proc_dir_entry *proc_create_singl return NULL; p->proc_ops = &proc_single_ops; p->single_show = show; - pde_set_flags(p); return proc_register(parent, p); } EXPORT_SYMBOL(proc_create_single_data); _ Patches currently in -mm which might be from wangzijie1(a)honor.com are

1 week, 3 days

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[merged mm-hotfixes-stable] mm-fix-accounting-of-memmap-pages.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: fix accounting of memmap pages has been removed from the -mm tree. Its filename was mm-fix-accounting-of-memmap-pages.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Sumanth Korikkar <sumanthk(a)linux.ibm.com> Subject: mm: fix accounting of memmap pages Date: Thu, 7 Aug 2025 20:35:45 +0200 For !CONFIG_SPARSEMEM_VMEMMAP, memmap page accounting is currently done upfront in sparse_buffer_init(). However, sparse_buffer_alloc() may return NULL in failure scenario. Also, memmap pages may be allocated either from the memblock allocator during early boot or from the buddy allocator. When removed via arch_remove_memory(), accounting of memmap pages must reflect the original allocation source. To ensure correctness: * Account memmap pages after successful allocation in sparse_init_nid() and section_activate(). * Account memmap pages in section_deactivate() based on allocation source. Link: https://lkml.kernel.org/r/20250807183545.1424509-1-sumanthk@linux.ibm.com Fixes: 15995a352474 ("mm: report per-page metadata information") Signed-off-by: Sumanth Korikkar <sumanthk(a)linux.ibm.com> Suggested-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Wei Yang <richard.weiyang(a)gmail.com> Cc: Alexander Gordeev <agordeev(a)linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer(a)linux.ibm.com> Cc: Heiko Carstens <hca(a)linux.ibm.com> Cc: Vasily Gorbik <gor(a)linux.ibm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/sparse-vmemmap.c | 5 ----- mm/sparse.c | 15 +++++++++------ 2 files changed, 9 insertions(+), 11 deletions(-) --- a/mm/sparse.c~mm-fix-accounting-of-memmap-pages +++ a/mm/sparse.c @@ -454,9 +454,6 @@ static void __init sparse_buffer_init(un */ sparsemap_buf = memmap_alloc(size, section_map_size(), addr, nid, true); sparsemap_buf_end = sparsemap_buf + size; -#ifndef CONFIG_SPARSEMEM_VMEMMAP - memmap_boot_pages_add(DIV_ROUND_UP(size, PAGE_SIZE)); -#endif } static void __init sparse_buffer_fini(void) @@ -567,6 +564,8 @@ static void __init sparse_init_nid(int n sparse_buffer_fini(); goto failed; } + memmap_boot_pages_add(DIV_ROUND_UP(PAGES_PER_SECTION * sizeof(struct page), + PAGE_SIZE)); sparse_init_early_section(nid, map, pnum, 0); } } @@ -680,7 +679,6 @@ static void depopulate_section_memmap(un unsigned long start = (unsigned long) pfn_to_page(pfn); unsigned long end = start + nr_pages * sizeof(struct page); - memmap_pages_add(-1L * (DIV_ROUND_UP(end - start, PAGE_SIZE))); vmemmap_free(start, end, altmap); } static void free_map_bootmem(struct page *memmap) @@ -856,10 +854,14 @@ static void section_deactivate(unsigned * The memmap of early sections is always fully populated. See * section_activate() and pfn_valid() . */ - if (!section_is_early) + if (!section_is_early) { + memmap_pages_add(-1L * (DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE))); depopulate_section_memmap(pfn, nr_pages, altmap); - else if (memmap) + } else if (memmap) { + memmap_boot_pages_add(-1L * (DIV_ROUND_UP(nr_pages * sizeof(struct page), + PAGE_SIZE))); free_map_bootmem(memmap); + } if (empty) ms->section_mem_map = (unsigned long)NULL; @@ -904,6 +906,7 @@ static struct page * __meminit section_a section_deactivate(pfn, nr_pages, altmap); return ERR_PTR(-ENOMEM); } + memmap_pages_add(DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE)); return memmap; } --- a/mm/sparse-vmemmap.c~mm-fix-accounting-of-memmap-pages +++ a/mm/sparse-vmemmap.c @@ -578,11 +578,6 @@ struct page * __meminit __populate_secti if (r < 0) return NULL; - if (system_state == SYSTEM_BOOTING) - memmap_boot_pages_add(DIV_ROUND_UP(end - start, PAGE_SIZE)); - else - memmap_pages_add(DIV_ROUND_UP(end - start, PAGE_SIZE)); - return pfn_to_page(pfn); } _ Patches currently in -mm which might be from sumanthk(a)linux.ibm.com are

1 week, 3 days

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[merged mm-hotfixes-stable] mm-damon-core-prevent-unnecessary-overflow-in-damos_set_effective_quota.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/damon/core: prevent unnecessary overflow in damos_set_effective_quota() has been removed from the -mm tree. Its filename was mm-damon-core-prevent-unnecessary-overflow-in-damos_set_effective_quota.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Quanmin Yan <yanquanmin1(a)huawei.com> Subject: mm/damon/core: prevent unnecessary overflow in damos_set_effective_quota() Date: Thu, 21 Aug 2025 20:55:55 +0800 On 32-bit systems, the throughput calculation in damos_set_effective_quota() is prone to unnecessary multiplication overflow. Using mult_frac() to fix it. Andrew Paniakin also recently found and privately reported this issue, on 64 bit systems. This can also happen on 64-bit systems, once the charged size exceeds ~17 TiB. On systems running for long time in production, this issue can actually happen. More specifically, when a DAMOS scheme having the time quota run for longtime, throughput calculation can overflow and set esz too small. As a result, speed of the scheme get unexpectedly slow. Link: https://lkml.kernel.org/r/20250821125555.3020951-1-yanquanmin1@huawei.com Fixes: 1cd243030059 ("mm/damon/schemes: implement time quota") Signed-off-by: Quanmin Yan <yanquanmin1(a)huawei.com> Reported-by: Andrew Paniakin <apanyaki(a)amazon.com> Reviewed-by: SeongJae Park <sj(a)kernel.org> Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com> Cc: ze zuo <zuoze1(a)huawei.com> Cc: <stable(a)vger.kernel.org> [5.16+] Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/damon/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/damon/core.c~mm-damon-core-prevent-unnecessary-overflow-in-damos_set_effective_quota +++ a/mm/damon/core.c @@ -2073,8 +2073,8 @@ static void damos_set_effective_quota(st if (quota->ms) { if (quota->total_charged_ns) - throughput = quota->total_charged_sz * 1000000 / - quota->total_charged_ns; + throughput = mult_frac(quota->total_charged_sz, 1000000, + quota->total_charged_ns); else throughput = PAGE_SIZE * 1024; esz = min(throughput * quota->ms, esz); _ Patches currently in -mm which might be from yanquanmin1(a)huawei.com are mm-damon-lru_sort-avoid-divide-by-zero-in-damon_lru_sort_apply_parameters.patch mm-damon-reclaim-avoid-divide-by-zero-in-damon_reclaim_apply_parameters.patch

1 week, 3 days

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[merged mm-hotfixes-stable] kasan-fix-gcc-mem-intrinsic-prefix-with-sw-tags.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: kasan: fix GCC mem-intrinsic prefix with sw tags has been removed from the -mm tree. Its filename was kasan-fix-gcc-mem-intrinsic-prefix-with-sw-tags.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Ada Couprie Diaz <ada.coupriediaz(a)arm.com> Subject: kasan: fix GCC mem-intrinsic prefix with sw tags Date: Thu, 21 Aug 2025 13:07:35 +0100 GCC doesn't support "hwasan-kernel-mem-intrinsic-prefix", only "asan-kernel-mem-intrinsic-prefix"[0], while LLVM supports both. This is already taken into account when checking "CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX", but not in the KASAN Makefile adding those parameters when "CONFIG_KASAN_SW_TAGS" is enabled. Replace the version check with "CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX", which already validates that mem-intrinsic prefix parameter can be used, and choose the correct name depending on compiler. GCC 13 and above trigger "CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX" which prevents `mem{cpy,move,set}()` being redefined in "mm/kasan/shadow.c" since commit 36be5cba99f6 ("kasan: treat meminstrinsic as builtins in uninstrumented files"), as we expect the compiler to prefix those calls with `__(hw)asan_` instead. But as the option passed to GCC has been incorrect, the compiler has not been emitting those prefixes, effectively never calling the instrumented versions of `mem{cpy,move,set}()` with "CONFIG_KASAN_SW_TAGS" enabled. If "CONFIG_FORTIFY_SOURCES" is enabled, this issue would be mitigated as it redefines `mem{cpy,move,set}()` and properly aliases the `__underlying_mem*()` that will be called to the instrumented versions. Link: https://lkml.kernel.org/r/20250821120735.156244-1-ada.coupriediaz@arm.com Link: https://gcc.gnu.org/onlinedocs/gcc-13.4.0/gcc/Optimize-Options.html [0] Signed-off-by: Ada Couprie Diaz <ada.coupriediaz(a)arm.com> Fixes: 36be5cba99f6 ("kasan: treat meminstrinsic as builtins in uninstrumented files") Reviewed-by: Yeoreum Yun <yeoreum.yun(a)arm.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Marco Elver <elver(a)google.com> Cc: Marc Rutland <mark.rutland(a)arm.com> Cc: Michael Ellerman <mpe(a)ellerman.id.au> Cc: Nathan Chancellor <nathan(a)kernel.org> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- scripts/Makefile.kasan | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/scripts/Makefile.kasan~kasan-fix-gcc-mem-intrinsic-prefix-with-sw-tags +++ a/scripts/Makefile.kasan @@ -86,10 +86,14 @@ kasan_params += hwasan-instrument-stack= hwasan-use-short-granules=0 \ hwasan-inline-all-checks=0 -# Instrument memcpy/memset/memmove calls by using instrumented __hwasan_mem*(). -ifeq ($(call clang-min-version, 150000)$(call gcc-min-version, 130000),y) - kasan_params += hwasan-kernel-mem-intrinsic-prefix=1 -endif +# Instrument memcpy/memset/memmove calls by using instrumented __(hw)asan_mem*(). +ifdef CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX + ifdef CONFIG_CC_IS_GCC + kasan_params += asan-kernel-mem-intrinsic-prefix=1 + else + kasan_params += hwasan-kernel-mem-intrinsic-prefix=1 + endif +endif # CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX endif # CONFIG_KASAN_SW_TAGS _ Patches currently in -mm which might be from ada.coupriediaz(a)arm.com are

1 week, 3 days

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[merged mm-hotfixes-stable] kunit-kasan_test-disable-fortify-string-checker-on-kasan_strings-test.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: kunit: kasan_test: disable fortify string checker on kasan_strings() test has been removed from the -mm tree. Its filename was kunit-kasan_test-disable-fortify-string-checker-on-kasan_strings-test.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Yeoreum Yun <yeoreum.yun(a)arm.com> Subject: kunit: kasan_test: disable fortify string checker on kasan_strings() test Date: Fri, 1 Aug 2025 13:02:36 +0100 Similar to commit 09c6304e38e4 ("kasan: test: fix compatibility with FORTIFY_SOURCE") the kernel is panicing in kasan_string(). This is due to the `src` and `ptr` not being hidden from the optimizer which would disable the runtime fortify string checker. Call trace: __fortify_panic+0x10/0x20 (P) kasan_strings+0x980/0x9b0 kunit_try_run_case+0x68/0x190 kunit_generic_run_threadfn_adapter+0x34/0x68 kthread+0x1c4/0x228 ret_from_fork+0x10/0x20 Code: d503233f a9bf7bfd 910003fd 9424b243 (d4210000) ---[ end trace 0000000000000000 ]--- note: kunit_try_catch[128] exited with irqs disabled note: kunit_try_catch[128] exited with preempt_count 1 # kasan_strings: try faulted: last ** replaying previous printk message ** # kasan_strings: try faulted: last line seen mm/kasan/kasan_test_c.c:1600 # kasan_strings: internal error occurred preventing test case from running: -4 Link: https://lkml.kernel.org/r/20250801120236.2962642-1-yeoreum.yun@arm.com Fixes: 73228c7ecc5e ("KASAN: port KASAN Tests to KUnit") Signed-off-by: Yeoreum Yun <yeoreum.yun(a)arm.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/kasan/kasan_test_c.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/kasan/kasan_test_c.c~kunit-kasan_test-disable-fortify-string-checker-on-kasan_strings-test +++ a/mm/kasan/kasan_test_c.c @@ -1578,9 +1578,11 @@ static void kasan_strings(struct kunit * ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); + OPTIMIZER_HIDE_VAR(ptr); src = kmalloc(KASAN_GRANULE_SIZE, GFP_KERNEL | __GFP_ZERO); strscpy(src, "f0cacc1a0000000", KASAN_GRANULE_SIZE); + OPTIMIZER_HIDE_VAR(src); /* * Make sure that strscpy() does not trigger KASAN if it overreads into _ Patches currently in -mm which might be from yeoreum.yun(a)arm.com are kasan-hw-tags-introduce-kasanwrite_only-option.patch kasan-apply-write-only-mode-in-kasan-kunit-testcases.patch

1 week, 3 days

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[merged mm-hotfixes-stable] mm-userfaultfd-fix-kmap_local-lifo-ordering-for-config_highpte.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE has been removed from the -mm tree. Its filename was mm-userfaultfd-fix-kmap_local-lifo-ordering-for-config_highpte.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Sasha Levin <sashal(a)kernel.org> Subject: mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE Date: Thu, 31 Jul 2025 10:44:31 -0400 With CONFIG_HIGHPTE on 32-bit ARM, move_pages_pte() maps PTE pages using kmap_local_page(), which requires unmapping in Last-In-First-Out order. The current code maps dst_pte first, then src_pte, but unmaps them in the same order (dst_pte, src_pte), violating the LIFO requirement. This causes the warning in kunmap_local_indexed(): WARNING: CPU: 0 PID: 604 at mm/highmem.c:622 kunmap_local_indexed+0x178/0x17c addr \!= __fix_to_virt(FIX_KMAP_BEGIN + idx) Fix this by reversing the unmap order to respect LIFO ordering. This issue follows the same pattern as similar fixes: - commit eca6828403b8 ("crypto: skcipher - fix mismatch between mapping and unmapping order") - commit 8cf57c6df818 ("nilfs2: eliminate staggered calls to kunmap in nilfs_rename") Both of which addressed the same fundamental requirement that kmap_local operations must follow LIFO ordering. Link: https://lkml.kernel.org/r/20250731144431.773923-1-sashal@kernel.org Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Sasha Levin <sashal(a)kernel.org> Acked-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Suren Baghdasaryan <surenb(a)google.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/userfaultfd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/mm/userfaultfd.c~mm-userfaultfd-fix-kmap_local-lifo-ordering-for-config_highpte +++ a/mm/userfaultfd.c @@ -1453,10 +1453,15 @@ out: folio_unlock(src_folio); folio_put(src_folio); } - if (dst_pte) - pte_unmap(dst_pte); + /* + * Unmap in reverse order (LIFO) to maintain proper kmap_local + * index ordering when CONFIG_HIGHPTE is enabled. We mapped dst_pte + * first, then src_pte, so we must unmap src_pte first, then dst_pte. + */ if (src_pte) pte_unmap(src_pte); + if (dst_pte) + pte_unmap(dst_pte); mmu_notifier_invalidate_range_end(&range); if (si) put_swap_device(si); _ Patches currently in -mm which might be from sashal(a)kernel.org are

1 week, 3 days

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[merged mm-hotfixes-stable] ocfs2-prevent-release-journal-inode-after-journal-shutdown.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: ocfs2: prevent release journal inode after journal shutdown has been removed from the -mm tree. Its filename was ocfs2-prevent-release-journal-inode-after-journal-shutdown.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Edward Adam Davis <eadavis(a)qq.com> Subject: ocfs2: prevent release journal inode after journal shutdown Date: Tue, 19 Aug 2025 21:41:02 +0800 Before calling ocfs2_delete_osb(), ocfs2_journal_shutdown() has already been executed in ocfs2_dismount_volume(), so osb->journal must be NULL. Therefore, the following calltrace will inevitably fail when it reaches jbd2_journal_release_jbd_inode(). ocfs2_dismount_volume()-> ocfs2_delete_osb()-> ocfs2_free_slot_info()-> __ocfs2_free_slot_info()-> evict()-> ocfs2_evict_inode()-> ocfs2_clear_inode()-> jbd2_journal_release_jbd_inode(osb->journal->j_journal, Adding osb->journal checks will prevent null-ptr-deref during the above execution path. Link: https://lkml.kernel.org/r/tencent_357489BEAEE4AED74CBD67D246DBD2C4C606@qq.c… Fixes: da5e7c87827e ("ocfs2: cleanup journal init and shutdown") Signed-off-by: Edward Adam Davis <eadavis(a)qq.com> Reported-by: syzbot+47d8cb2f2cc1517e515a(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=47d8cb2f2cc1517e515a Tested-by: syzbot+47d8cb2f2cc1517e515a(a)syzkaller.appspotmail.com Reviewed-by: Mark Tinguely <mark.tinguely(a)oracle.com> Reviewed-by: Joseph Qi <joseph.qi(a)linux.alibaba.com> Cc: Mark Fasheh <mark(a)fasheh.com> Cc: Joel Becker <jlbec(a)evilplan.org> Cc: Junxiao Bi <junxiao.bi(a)oracle.com> Cc: Changwei Ge <gechangwei(a)live.cn> Cc: Jun Piao <piaojun(a)huawei.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/ocfs2/inode.c | 3 +++ 1 file changed, 3 insertions(+) --- a/fs/ocfs2/inode.c~ocfs2-prevent-release-journal-inode-after-journal-shutdown +++ a/fs/ocfs2/inode.c @@ -1281,6 +1281,9 @@ static void ocfs2_clear_inode(struct ino * the journal is flushed before journal shutdown. Thus it is safe to * have inodes get cleaned up after journal shutdown. */ + if (!osb->journal) + return; + jbd2_journal_release_jbd_inode(osb->journal->j_journal, &oi->ip_jinode); } _ Patches currently in -mm which might be from eadavis(a)qq.com are

1 week, 3 days

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