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[merged mm-hotfixes-stable] mm-userfaultfd-fix-release-hang-over-concurrent-gup.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/userfaultfd: fix release hang over concurrent GUP has been removed from the -mm tree. Its filename was mm-userfaultfd-fix-release-hang-over-concurrent-gup.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: Peter Xu <peterx(a)redhat.com> Subject: mm/userfaultfd: fix release hang over concurrent GUP Date: Wed, 12 Mar 2025 10:51:31 -0400 This patch should fix a possible userfaultfd release() hang during concurrent GUP. This problem was initially reported by Dimitris Siakavaras in July 2023 [1] in a firecracker use case. Firecracker has a separate process handling page faults remotely, and when the process releases the userfaultfd it can race with a concurrent GUP from KVM trying to fault in a guest page during the secondary MMU page fault process. A similar problem was reported recently again by Jinjiang Tu in March 2025 [2], even though the race happened this time with a mlockall() operation, which does GUP in a similar fashion. In 2017, commit 656710a60e36 ("userfaultfd: non-cooperative: closing the uffd without triggering SIGBUS") was trying to fix this issue. AFAIU, that fixes well the fault paths but may not work yet for GUP. In GUP, the issue is NOPAGE will be almost treated the same as "page fault resolved" in faultin_page(), then the GUP will follow page again, seeing page missing, and it'll keep going into a live lock situation as reported. This change makes core mm return RETRY instead of NOPAGE for both the GUP and fault paths, proactively releasing the mmap read lock. This should guarantee the other release thread make progress on taking the write lock and avoid the live lock even for GUP. When at it, rearrange the comments to make sure it's uptodate. [1] https://lore.kernel.org/r/79375b71-db2e-3e66-346b-254c90d915e2@cslab.ece.nt… [2] https://lore.kernel.org/r/20250307072133.3522652-1-tujinjiang@huawei.com Link: https://lkml.kernel.org/r/20250312145131.1143062-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx(a)redhat.com> Cc: Andrea Arcangeli <aarcange(a)redhat.com> Cc: Mike Rapoport (IBM) <rppt(a)kernel.org> Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: Jinjiang Tu <tujinjiang(a)huawei.com> Cc: Dimitris Siakavaras <jimsiak(a)cslab.ece.ntua.gr> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/userfaultfd.c | 51 ++++++++++++++++++++++----------------------- 1 file changed, 25 insertions(+), 26 deletions(-) --- a/fs/userfaultfd.c~mm-userfaultfd-fix-release-hang-over-concurrent-gup +++ a/fs/userfaultfd.c @@ -396,32 +396,6 @@ vm_fault_t handle_userfault(struct vm_fa goto out; /* - * If it's already released don't get it. This avoids to loop - * in __get_user_pages if userfaultfd_release waits on the - * caller of handle_userfault to release the mmap_lock. - */ - if (unlikely(READ_ONCE(ctx->released))) { - /* - * Don't return VM_FAULT_SIGBUS in this case, so a non - * cooperative manager can close the uffd after the - * last UFFDIO_COPY, without risking to trigger an - * involuntary SIGBUS if the process was starting the - * userfaultfd while the userfaultfd was still armed - * (but after the last UFFDIO_COPY). If the uffd - * wasn't already closed when the userfault reached - * this point, that would normally be solved by - * userfaultfd_must_wait returning 'false'. - * - * If we were to return VM_FAULT_SIGBUS here, the non - * cooperative manager would be instead forced to - * always call UFFDIO_UNREGISTER before it can safely - * close the uffd. - */ - ret = VM_FAULT_NOPAGE; - goto out; - } - - /* * Check that we can return VM_FAULT_RETRY. * * NOTE: it should become possible to return VM_FAULT_RETRY @@ -457,6 +431,31 @@ vm_fault_t handle_userfault(struct vm_fa if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT) goto out; + if (unlikely(READ_ONCE(ctx->released))) { + /* + * If a concurrent release is detected, do not return + * VM_FAULT_SIGBUS or VM_FAULT_NOPAGE, but instead always + * return VM_FAULT_RETRY with lock released proactively. + * + * If we were to return VM_FAULT_SIGBUS here, the non + * cooperative manager would be instead forced to + * always call UFFDIO_UNREGISTER before it can safely + * close the uffd, to avoid involuntary SIGBUS triggered. + * + * If we were to return VM_FAULT_NOPAGE, it would work for + * the fault path, in which the lock will be released + * later. However for GUP, faultin_page() does nothing + * special on NOPAGE, so GUP would spin retrying without + * releasing the mmap read lock, causing possible livelock. + * + * Here only VM_FAULT_RETRY would make sure the mmap lock + * be released immediately, so that the thread concurrently + * releasing the userfault would always make progress. + */ + release_fault_lock(vmf); + goto out; + } + /* take the reference before dropping the mmap_lock */ userfaultfd_ctx_get(ctx); _ Patches currently in -mm which might be from peterx(a)redhat.com are maintainers-add-myself-as-userfaultfd-reviewer.patch

9 months, 2 weeks

[to-be-updated] x86-vmemmap-use-direct-mapped-va-instead-of-vmemmap-based-va.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: x86/vmemmap: use direct-mapped VA instead of vmemmap-based VA has been removed from the -mm tree. Its filename was x86-vmemmap-use-direct-mapped-va-instead-of-vmemmap-based-va.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Gwan-gyeong Mun <gwan-gyeong.mun(a)intel.com> Subject: x86/vmemmap: use direct-mapped VA instead of vmemmap-based VA Date: Mon, 17 Feb 2025 13:41:33 +0200 Address an Oops issues when performing test of loading XE GPU driver module after applying the GPU SVM and Xe SVM patch series[1] and the Dept patch series[2]. The issue occurs when loading the xe driver via modprobe [3], which adds a struct page for device memory via devm_memremap_pages(). When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This patch translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. [1] https://lore.kernel.org/dri-devel/20250213021112.1228481-1-matthew.brost@in… [2] https://lore.kernel.org/lkml/20240508094726.35754-1-byungchul@sk.com/ [3] [ 49.103630] xe 0000:00:04.0: [drm] Available VRAM: 0x0000000800000000, 0x00000002fb800000 [ 49.116710] BUG: unable to handle page fault for address: ffffeb3ff1200000 [ 49.117175] #PF: supervisor write access in kernel mode [ 49.117511] #PF: error_code(0x0002) - not-present page [ 49.117835] PGD 0 P4D 0 [ 49.118015] Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI [ 49.118366] CPU: 3 UID: 0 PID: 302 Comm: modprobe Tainted: G W 6.13.0-drm-tip-test+ #62 [ 49.118976] Tainted: [W]=WARN [ 49.119179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 49.119710] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.120011] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.121158] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.121502] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.121966] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.122499] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.123032] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.123566] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.124096] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.124698] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.125129] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.125662] PKRU: 55555554 [ 49.125880] Call Trace: [ 49.126078] <TASK> [ 49.126252] ? __die_body.cold+0x19/0x26 [ 49.126509] ? page_fault_oops+0xa2/0x240 [ 49.126736] ? preempt_count_add+0x47/0xa0 [ 49.126968] ? search_module_extables+0x4a/0x80 [ 49.127224] ? exc_page_fault+0x206/0x230 [ 49.127454] ? asm_exc_page_fault+0x22/0x30 [ 49.127691] ? vmemmap_set_pmd+0xff/0x230 [ 49.127919] vmemmap_populate_hugepages+0x176/0x180 [ 49.128194] vmemmap_populate+0x34/0x80 [ 49.128416] __populate_section_memmap+0x41/0x90 [ 49.128676] sparse_add_section+0x121/0x3e0 [ 49.128914] __add_pages+0xba/0x150 [ 49.129116] add_pages+0x1d/0x70 [ 49.129305] memremap_pages+0x3dc/0x810 [ 49.129529] devm_memremap_pages+0x1c/0x60 [ 49.129762] xe_devm_add+0x8b/0x100 [xe] [ 49.130072] xe_tile_init_noalloc+0x6a/0x70 [xe] [ 49.130408] xe_device_probe+0x48c/0x740 [xe] [ 49.130714] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.130982] ? __drmm_add_action+0x85/0xd0 [ 49.131208] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.131478] xe_pci_probe+0x7ef/0xd90 [xe] [ 49.131777] ? _raw_spin_unlock_irqrestore+0x66/0x90 [ 49.132049] ? lockdep_hardirqs_on+0xba/0x140 [ 49.132290] pci_device_probe+0x99/0x110 [ 49.132510] really_probe+0xdb/0x340 [ 49.132710] ? pm_runtime_barrier+0x50/0x90 [ 49.132941] ? __pfx___driver_attach+0x10/0x10 [ 49.133190] __driver_probe_device+0x78/0x110 [ 49.133433] driver_probe_device+0x1f/0xa0 [ 49.133661] __driver_attach+0xba/0x1c0 [ 49.133874] bus_for_each_dev+0x7a/0xd0 [ 49.134089] bus_add_driver+0x114/0x200 [ 49.134302] driver_register+0x6e/0xc0 [ 49.134515] xe_init+0x1e/0x50 [xe] [ 49.134827] ? __pfx_xe_init+0x10/0x10 [xe] [ 49.134926] xe 0000:00:04.0: [drm:process_one_work] GT1: GuC CT safe-mode canceled [ 49.135112] do_one_initcall+0x5b/0x2b0 [ 49.135734] ? rcu_is_watching+0xd/0x40 [ 49.135995] ? __kmalloc_cache_noprof+0x231/0x310 [ 49.136315] do_init_module+0x60/0x210 [ 49.136572] init_module_from_file+0x86/0xc0 [ 49.136863] idempotent_init_module+0x12b/0x340 [ 49.137156] __x64_sys_finit_module+0x61/0xc0 [ 49.137437] do_syscall_64+0x69/0x140 [ 49.137681] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 49.137953] RIP: 0033:0x7f53ae1261fd [ 49.138153] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 fa 0c 00 f7 d8 64 89 01 48 [ 49.139117] RSP: 002b:00007ffd0e9021e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 49.139525] RAX: ffffffffffffffda RBX: 000055c02951ee50 RCX: 00007f53ae1261fd [ 49.139905] RDX: 0000000000000000 RSI: 000055bfff125478 RDI: 0000000000000010 [ 49.140282] RBP: 000055bfff125478 R08: 00007f53ae1f6b20 R09: 00007ffd0e902230 [ 49.140663] R10: 000055c029522000 R11: 0000000000000246 R12: 0000000000040000 [ 49.141040] R13: 000055c02951ef80 R14: 0000000000000000 R15: 000055c029521fc0 [ 49.141424] </TASK> [ 49.141552] Modules linked in: xe(+) drm_ttm_helper gpu_sched drm_suballoc_helper drm_gpuvm drm_exec drm_gpusvm i2c_algo_bit drm_buddy video wmi ttm drm_display_helper drm_kms_helper crct10dif_pclmul crc32_pclmul i2c_piix4 e1000 ghash_clmulni_intel i2c_smbus fuse [ 49.142824] CR2: ffffeb3ff1200000 [ 49.143010] ---[ end trace 0000000000000000 ]--- [ 49.143268] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.143523] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.144489] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.144775] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.145154] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.145536] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.145914] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.146292] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.146671] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.147097] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.147407] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.147786] PKRU: 55555554 [ 49.147941] note: modprobe[302] exited with irqs disabled When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. Link: https://lkml.kernel.org/r/20250217114133.400063-2-gwan-gyeong.mun@intel.com Fixes: faf1c0008a33 ("x86/vmemmap: optimize for consecutive sections in partial populated PMDs") Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun(a)intel.com> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Hyeonggon Yoo <42.hyeyoo(a)gmail.com> Cc: Byungchul Park <byungchul(a)sk.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/x86/mm/init_64.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) --- a/arch/x86/mm/init_64.c~x86-vmemmap-use-direct-mapped-va-instead-of-vmemmap-based-va +++ a/arch/x86/mm/init_64.c @@ -844,6 +844,17 @@ void __init paging_init(void) */ static unsigned long unused_pmd_start __meminitdata; +static void * __meminit vmemmap_va_to_kaddr(unsigned long vmemmap_va) +{ + void *kaddr = (void *)vmemmap_va; + pgd_t *pgd = __va(read_cr3_pa()); + + if (init_mm.pgd != pgd) + kaddr = __va(slow_virt_to_phys(kaddr)); + + return kaddr; +} + static void __meminit vmemmap_flush_unused_pmd(void) { if (!unused_pmd_start) @@ -851,7 +862,7 @@ static void __meminit vmemmap_flush_unus /* * Clears (unused_pmd_start, PMD_END] */ - memset((void *)unused_pmd_start, PAGE_UNUSED, + memset(vmemmap_va_to_kaddr(unused_pmd_start), PAGE_UNUSED, ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start); unused_pmd_start = 0; } @@ -882,7 +893,7 @@ static void __meminit __vmemmap_use_sub_ * case the first memmap never gets initialized e.g., because the memory * block never gets onlined). */ - memset((void *)start, 0, sizeof(struct page)); + memset(vmemmap_va_to_kaddr(start), 0, sizeof(struct page)); } static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end) @@ -924,7 +935,7 @@ static void __meminit vmemmap_use_new_su * Mark with PAGE_UNUSED the unused parts of the new memmap range */ if (!IS_ALIGNED(start, PMD_SIZE)) - memset((void *)page, PAGE_UNUSED, start - page); + memset(vmemmap_va_to_kaddr(page), PAGE_UNUSED, start - page); /* * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of _ Patches currently in -mm which might be from gwan-gyeong.mun(a)intel.com are

9 months, 2 weeks

+ x86-vmemmap-use-direct-mapped-va-instead-of-vmemmap-based-va.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: x86/vmemmap: use direct-mapped VA instead of vmemmap-based VA has been added to the -mm mm-hotfixes-unstable branch. Its filename is x86-vmemmap-use-direct-mapped-va-instead-of-vmemmap-based-va.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Gwan-gyeong Mun <gwan-gyeong.mun(a)intel.com> Subject: x86/vmemmap: use direct-mapped VA instead of vmemmap-based VA Date: Mon, 17 Feb 2025 13:41:33 +0200 Address an Oops issues when performing test of loading XE GPU driver module after applying the GPU SVM and Xe SVM patch series[1] and the Dept patch series[2]. The issue occurs when loading the xe driver via modprobe [3], which adds a struct page for device memory via devm_memremap_pages(). When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This patch translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. [1] https://lore.kernel.org/dri-devel/20250213021112.1228481-1-matthew.brost@in… [2] https://lore.kernel.org/lkml/20240508094726.35754-1-byungchul@sk.com/ [3] [ 49.103630] xe 0000:00:04.0: [drm] Available VRAM: 0x0000000800000000, 0x00000002fb800000 [ 49.116710] BUG: unable to handle page fault for address: ffffeb3ff1200000 [ 49.117175] #PF: supervisor write access in kernel mode [ 49.117511] #PF: error_code(0x0002) - not-present page [ 49.117835] PGD 0 P4D 0 [ 49.118015] Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI [ 49.118366] CPU: 3 UID: 0 PID: 302 Comm: modprobe Tainted: G W 6.13.0-drm-tip-test+ #62 [ 49.118976] Tainted: [W]=WARN [ 49.119179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 49.119710] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.120011] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.121158] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.121502] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.121966] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.122499] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.123032] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.123566] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.124096] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.124698] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.125129] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.125662] PKRU: 55555554 [ 49.125880] Call Trace: [ 49.126078] <TASK> [ 49.126252] ? __die_body.cold+0x19/0x26 [ 49.126509] ? page_fault_oops+0xa2/0x240 [ 49.126736] ? preempt_count_add+0x47/0xa0 [ 49.126968] ? search_module_extables+0x4a/0x80 [ 49.127224] ? exc_page_fault+0x206/0x230 [ 49.127454] ? asm_exc_page_fault+0x22/0x30 [ 49.127691] ? vmemmap_set_pmd+0xff/0x230 [ 49.127919] vmemmap_populate_hugepages+0x176/0x180 [ 49.128194] vmemmap_populate+0x34/0x80 [ 49.128416] __populate_section_memmap+0x41/0x90 [ 49.128676] sparse_add_section+0x121/0x3e0 [ 49.128914] __add_pages+0xba/0x150 [ 49.129116] add_pages+0x1d/0x70 [ 49.129305] memremap_pages+0x3dc/0x810 [ 49.129529] devm_memremap_pages+0x1c/0x60 [ 49.129762] xe_devm_add+0x8b/0x100 [xe] [ 49.130072] xe_tile_init_noalloc+0x6a/0x70 [xe] [ 49.130408] xe_device_probe+0x48c/0x740 [xe] [ 49.130714] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.130982] ? __drmm_add_action+0x85/0xd0 [ 49.131208] ? __pfx___drmm_mutex_release+0x10/0x10 [ 49.131478] xe_pci_probe+0x7ef/0xd90 [xe] [ 49.131777] ? _raw_spin_unlock_irqrestore+0x66/0x90 [ 49.132049] ? lockdep_hardirqs_on+0xba/0x140 [ 49.132290] pci_device_probe+0x99/0x110 [ 49.132510] really_probe+0xdb/0x340 [ 49.132710] ? pm_runtime_barrier+0x50/0x90 [ 49.132941] ? __pfx___driver_attach+0x10/0x10 [ 49.133190] __driver_probe_device+0x78/0x110 [ 49.133433] driver_probe_device+0x1f/0xa0 [ 49.133661] __driver_attach+0xba/0x1c0 [ 49.133874] bus_for_each_dev+0x7a/0xd0 [ 49.134089] bus_add_driver+0x114/0x200 [ 49.134302] driver_register+0x6e/0xc0 [ 49.134515] xe_init+0x1e/0x50 [xe] [ 49.134827] ? __pfx_xe_init+0x10/0x10 [xe] [ 49.134926] xe 0000:00:04.0: [drm:process_one_work] GT1: GuC CT safe-mode canceled [ 49.135112] do_one_initcall+0x5b/0x2b0 [ 49.135734] ? rcu_is_watching+0xd/0x40 [ 49.135995] ? __kmalloc_cache_noprof+0x231/0x310 [ 49.136315] do_init_module+0x60/0x210 [ 49.136572] init_module_from_file+0x86/0xc0 [ 49.136863] idempotent_init_module+0x12b/0x340 [ 49.137156] __x64_sys_finit_module+0x61/0xc0 [ 49.137437] do_syscall_64+0x69/0x140 [ 49.137681] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 49.137953] RIP: 0033:0x7f53ae1261fd [ 49.138153] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 fa 0c 00 f7 d8 64 89 01 48 [ 49.139117] RSP: 002b:00007ffd0e9021e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 [ 49.139525] RAX: ffffffffffffffda RBX: 000055c02951ee50 RCX: 00007f53ae1261fd [ 49.139905] RDX: 0000000000000000 RSI: 000055bfff125478 RDI: 0000000000000010 [ 49.140282] RBP: 000055bfff125478 R08: 00007f53ae1f6b20 R09: 00007ffd0e902230 [ 49.140663] R10: 000055c029522000 R11: 0000000000000246 R12: 0000000000040000 [ 49.141040] R13: 000055c02951ef80 R14: 0000000000000000 R15: 000055c029521fc0 [ 49.141424] </TASK> [ 49.141552] Modules linked in: xe(+) drm_ttm_helper gpu_sched drm_suballoc_helper drm_gpuvm drm_exec drm_gpusvm i2c_algo_bit drm_buddy video wmi ttm drm_display_helper drm_kms_helper crct10dif_pclmul crc32_pclmul i2c_piix4 e1000 ghash_clmulni_intel i2c_smbus fuse [ 49.142824] CR2: ffffeb3ff1200000 [ 49.143010] ---[ end trace 0000000000000000 ]--- [ 49.143268] RIP: 0010:vmemmap_set_pmd+0xff/0x230 [ 49.143523] Code: 77 22 02 a9 ff ff 1f 00 74 58 48 8b 3d 62 77 22 02 48 85 ff 0f 85 9a 00 00 00 48 8d 7d 08 48 89 e9 31 c0 48 89 ea 48 83 e7 f8 <48> c7 45 00 00 00 00 00 48 29 f9 48 c7 45 48 00 00 00 00 83 c1 50 [ 49.144489] RSP: 0018:ffffc900016d37a8 EFLAGS: 00010282 [ 49.144775] RAX: 0000000000000000 RBX: ffff888164000000 RCX: ffffeb3ff1200000 [ 49.145154] RDX: ffffeb3ff1200000 RSI: 80000000000001e3 RDI: ffffeb3ff1200008 [ 49.145536] RBP: ffffeb3ff1200000 R08: ffffeb3ff1280000 R09: 0000000000000000 [ 49.145914] R10: ffff88817b94dc48 R11: 0000000000000003 R12: ffffeb3ff1280000 [ 49.146292] R13: 0000000000000000 R14: ffff88817b94dc48 R15: 8000000163e001e3 [ 49.146671] FS: 00007f53ae71d740(0000) GS:ffff88843fd80000(0000) knlGS:0000000000000000 [ 49.147097] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 49.147407] CR2: ffffeb3ff1200000 CR3: 000000017c7d2000 CR4: 0000000000750ef0 [ 49.147786] PKRU: 55555554 [ 49.147941] note: modprobe[302] exited with irqs disabled When a process leads the addition of a struct page to vmemmap (e.g. hot-plug), the page table update for the newly added vmemmap-based virtual address is updated first in init_mm's page table and then synchronized later. If the vmemmap-based virtual address is accessed through the process's page table before this sync, a page fault will occur. This translates vmemmap-based virtual address to direct-mapped virtual address and use it, if the current top-level page table is not init_mm's page table when accessing a vmemmap-based virtual address before this sync. Link: https://lkml.kernel.org/r/20250217114133.400063-2-gwan-gyeong.mun@intel.com Fixes: faf1c0008a33 ("x86/vmemmap: optimize for consecutive sections in partial populated PMDs") Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun(a)intel.com> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: Hyeonggon Yoo <42.hyeyoo(a)gmail.com> Cc: Byungchul Park <byungchul(a)sk.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/x86/mm/init_64.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) --- a/arch/x86/mm/init_64.c~x86-vmemmap-use-direct-mapped-va-instead-of-vmemmap-based-va +++ a/arch/x86/mm/init_64.c @@ -844,6 +844,17 @@ void __init paging_init(void) */ static unsigned long unused_pmd_start __meminitdata; +static void * __meminit vmemmap_va_to_kaddr(unsigned long vmemmap_va) +{ + void *kaddr = (void *)vmemmap_va; + pgd_t *pgd = __va(read_cr3_pa()); + + if (init_mm.pgd != pgd) + kaddr = __va(slow_virt_to_phys(kaddr)); + + return kaddr; +} + static void __meminit vmemmap_flush_unused_pmd(void) { if (!unused_pmd_start) @@ -851,7 +862,7 @@ static void __meminit vmemmap_flush_unus /* * Clears (unused_pmd_start, PMD_END] */ - memset((void *)unused_pmd_start, PAGE_UNUSED, + memset(vmemmap_va_to_kaddr(unused_pmd_start), PAGE_UNUSED, ALIGN(unused_pmd_start, PMD_SIZE) - unused_pmd_start); unused_pmd_start = 0; } @@ -882,7 +893,7 @@ static void __meminit __vmemmap_use_sub_ * case the first memmap never gets initialized e.g., because the memory * block never gets onlined). */ - memset((void *)start, 0, sizeof(struct page)); + memset(vmemmap_va_to_kaddr(start), 0, sizeof(struct page)); } static void __meminit vmemmap_use_sub_pmd(unsigned long start, unsigned long end) @@ -924,7 +935,7 @@ static void __meminit vmemmap_use_new_su * Mark with PAGE_UNUSED the unused parts of the new memmap range */ if (!IS_ALIGNED(start, PMD_SIZE)) - memset((void *)page, PAGE_UNUSED, start - page); + memset(vmemmap_va_to_kaddr(page), PAGE_UNUSED, start - page); /* * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of _ Patches currently in -mm which might be from gwan-gyeong.mun(a)intel.com are x86-vmemmap-use-direct-mapped-va-instead-of-vmemmap-based-va.patch

9 months, 2 weeks

[PATCH v4 4/4] ring-buffer: Use flush_kernel_vmap_range() over flush_dcache_folio()

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> Some architectures do not have data cache coherency between user and kernel space. For these architectures, the cache needs to be flushed on both the kernel and user addresses so that user space can see the updates the kernel has made. Instead of using flush_dcache_folio() and playing with virt_to_folio() within the call to that function, use flush_kernel_vmap_range() which takes the virtual address and does the work for those architectures that need it. This also fixes a bug where the flush of the reader page only flushed one page. If the sub-buffer order is 1 or more, where the sub-buffer size would be greater than a page, it would miss the rest of the sub-buffer content, as the "reader page" is not just a page, but the size of a sub-buffer. Link: https://lore.kernel.org/all/CAG48ez3w0my4Rwttbc5tEbNsme6tc0mrSN95thjXUFaJ3a… Cc: stable(a)vger.kernel.org Fixes: 117c39200d9d7 ("ring-buffer: Introducing ring-buffer mapping functions"); Suggested-by: Jann Horn <jannh(a)google.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/ring_buffer.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index d8d7b28e2c2f..c0f877d39a24 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -6016,7 +6016,7 @@ static void rb_update_meta_page(struct ring_buffer_per_cpu *cpu_buffer) meta->read = cpu_buffer->read; /* Some archs do not have data cache coherency between kernel and user-space */ - flush_dcache_folio(virt_to_folio(cpu_buffer->meta_page)); + flush_kernel_vmap_range(cpu_buffer->meta_page, PAGE_SIZE); } static void @@ -7319,7 +7319,8 @@ int ring_buffer_map_get_reader(struct trace_buffer *buffer, int cpu) out: /* Some archs do not have data cache coherency between kernel and user-space */ - flush_dcache_folio(virt_to_folio(cpu_buffer->reader_page->page)); + flush_kernel_vmap_range(cpu_buffer->reader_page->page, + buffer->subbuf_size + BUF_PAGE_HDR_SIZE); rb_update_meta_page(cpu_buffer); -- 2.47.2

9 months, 2 weeks

[PATCH] HID: wacom: fix shift OOB in kfifo allocation for zero pktlen

by Qasim Ijaz

During wacom_parse_and_register() the code calls wacom_devm_kfifo_alloc to allocate a fifo. During this operation it passes kfifo_alloc a fifo_size of 0. Kfifo attempts to round the size passed to it to the next power of 2 via roundup_pow_of_two (queue-type data structures do this to maintain efficiency of operations). However during this phase a problem arises when the roundup_pow_of_two() function utilises a shift exponent of fls_long(n-1), where n is the fifo_size. Since n is 0 in this case and n is also an unsigned long, doing n-1 causes unsigned integer wrap-around to occur making the fifo_size 4294967295. So the code effectively does fls_long(4294967295) which results in 64. Returning back to roundup_pow_of_two(), the code utilises a shift exponent of 64. When a shift exponent of 64 is used on a 64-bit type such as 1UL it results in a shift-out-of-bounds. The root cause of the issue seems to stem from insufficient validation of wacom_compute_pktlen(), since in this case the fifo_size comes from wacom_wac->features.pktlen. During wacom_parse_and_register() the wacom_compute_pktlen() function sets the pktlen as 0. To fix this, we should handle cases where wacom_compute_pktlen() results in 0. Reported-by: syzbot <syzbot+d5204cbbdd921f1f7cad(a)syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=d5204cbbdd921f1f7cad Tested-by: Qasim Ijaz <qasdev00(a)gmail.com> Cc: stable(a)vger.kernel.org Signed-off-by: Qasim Ijaz <qasdev00(a)gmail.com> --- drivers/hid/wacom_sys.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c index 97393a3083ca..9b2f3dbca467 100644 --- a/drivers/hid/wacom_sys.c +++ b/drivers/hid/wacom_sys.c @@ -2361,6 +2361,8 @@ static int wacom_parse_and_register(struct wacom *wacom, bool wireless) unsigned int connect_mask = HID_CONNECT_HIDRAW; features->pktlen = wacom_compute_pktlen(hdev); + if (!features->pktlen) + return -ENODEV; if (!devres_open_group(&hdev->dev, wacom, GFP_KERNEL)) return -ENOMEM; -- 2.39.5

9 months, 2 weeks

[PATCH] perf/x86/intel/uncore: Add error handling for uncore_msr_box_ctl()

by Wentao Liang

In mtl_uncore_msr_init_box(), the return value of uncore_msr_box_ctl() needs to be checked before being used as the parameter of wrmsrl(). A proper implementation can be found in ivbep_uncore_msr_init_box(). Add error handling for uncore_msr_box_ctl() to ensure the MSR write operation is only performed when a valid MSR address is returned. Fixes: c828441f21dd ("perf/x86/intel/uncore: Add Meteor Lake support") Cc: stable(a)vger.kernel.org # v6.3+ Signed-off-by: Wentao Liang <vulab(a)iscas.ac.cn> --- arch/x86/events/intel/uncore_snb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c index 3934e1e4e3b1..84070388f495 100644 --- a/arch/x86/events/intel/uncore_snb.c +++ b/arch/x86/events/intel/uncore_snb.c @@ -691,7 +691,10 @@ static struct intel_uncore_type mtl_uncore_hac_cbox = { static void mtl_uncore_msr_init_box(struct intel_uncore_box *box) { - wrmsrl(uncore_msr_box_ctl(box), SNB_UNC_GLOBAL_CTL_EN); + unsigned int msr = uncore_msr_box_ctl(box); + + if (msr) + wrmsrl(msr, SNB_UNC_GLOBAL_CTL_EN); } static struct intel_uncore_ops mtl_uncore_msr_ops = { -- 2.42.0.windows.2

9 months, 2 weeks

[PATCH V2 1/3] drm/amd/display: Protect FPU in dml21_copy()

by Huacai Chen

Commit 7da55c27e76749b9 ("drm/amd/display: Remove incorrect FP context start") removes the FP context protection of dml2_create(), and it said "All the DC_FP_START/END should be used before call anything from DML2". However, dml21_copy() are not protected from their callers, causing such errors: do_fpu invoked from kernel context![#1]: CPU: 0 UID: 0 PID: 240 Comm: kworker/0:5 Not tainted 6.14.0-rc6+ #1 Workqueue: events work_for_cpu_fn pc ffff80000318bd2c ra ffff80000315750c tp 9000000105910000 sp 9000000105913810 a0 0000000000000000 a1 0000000000000002 a2 900000013140d728 a3 900000013140d720 a4 0000000000000000 a5 9000000131592d98 a6 0000000000017ae8 a7 00000000001312d0 t0 9000000130751ff0 t1 ffff800003790000 t2 ffff800003790000 t3 9000000131592e28 t4 000000000004c6a8 t5 00000000001b7740 t6 0000000000023e38 t7 0000000000249f00 t8 0000000000000002 u0 0000000000000000 s9 900000012b010000 s0 9000000131400000 s1 9000000130751fd8 s2 ffff800003408000 s3 9000000130752c78 s4 9000000131592da8 s5 9000000131592120 s6 9000000130751ff0 s7 9000000131592e28 s8 9000000131400008 ra: ffff80000315750c dml2_top_soc15_initialize_instance+0x20c/0x300 [amdgpu] ERA: ffff80000318bd2c mcg_dcn4_build_min_clock_table+0x14c/0x600 [amdgpu] CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) ESTAT: 000f0000 [FPD] (IS= ECode=15 EsubCode=0) PRID: 0014d010 (Loongson-64bit, Loongson-3C6000/S) Process kworker/0:5 (pid: 240, threadinfo=00000000f1700428, task=0000000020d2e962) Stack : 0000000000000000 0000000000000000 0000000000000000 9000000130751fd8 9000000131400000 ffff8000031574e0 9000000130751ff0 0000000000000000 9000000131592e28 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 f9175936df5d7fd2 900000012b00ff08 900000012b000000 ffff800003409000 ffff8000034a1780 90000001019634c0 900000012b000010 90000001307beeb8 90000001306b0000 0000000000000001 ffff8000031942b4 9000000130780000 90000001306c0000 9000000130780000 ffff8000031c276c 900000012b044bd0 ffff800003408000 ... Call Trace: [<ffff80000318bd2c>] mcg_dcn4_build_min_clock_table+0x14c/0x600 [amdgpu] [<ffff800003157508>] dml2_top_soc15_initialize_instance+0x208/0x300 [amdgpu] [<ffff8000031942b0>] dml21_create_copy+0x30/0x60 [amdgpu] [<ffff8000031c2768>] dc_state_create_copy+0x68/0xe0 [amdgpu] [<ffff800002e98ea0>] amdgpu_dm_init+0x8c0/0x2060 [amdgpu] [<ffff800002e9a658>] dm_hw_init+0x18/0x60 [amdgpu] [<ffff800002b0a738>] amdgpu_device_init+0x1938/0x27e0 [amdgpu] [<ffff800002b0ce80>] amdgpu_driver_load_kms+0x20/0xa0 [amdgpu] [<ffff800002b008f0>] amdgpu_pci_probe+0x1b0/0x580 [amdgpu] [<9000000003c7eae4>] local_pci_probe+0x44/0xc0 [<90000000032f2b18>] work_for_cpu_fn+0x18/0x40 [<90000000032f5da0>] process_one_work+0x160/0x300 [<90000000032f6718>] worker_thread+0x318/0x440 [<9000000003301b8c>] kthread+0x12c/0x220 [<90000000032b1484>] ret_from_kernel_thread+0x8/0xa4 Unfortunately, protecting dml21_copy() out of DML2 causes "sleeping function called from invalid context", so protect them with DC_FP_START() and DC_FP_END() inside. Cc: stable(a)vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn> --- drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c index fb80ba9287b6..a6b8df1d96e8 100644 --- a/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c +++ b/drivers/gpu/drm/amd/display/dc/dml2/dml21/dml21_wrapper.c @@ -412,8 +412,12 @@ void dml21_copy(struct dml2_context *dst_dml_ctx, dst_dml_ctx->v21.mode_programming.programming = dst_dml2_programming; + DC_FP_START(); + /* need to initialize copied instance for internal references to be correct */ dml2_initialize_instance(&dst_dml_ctx->v21.dml_init); + + DC_FP_END(); } bool dml21_create_copy(struct dml2_context **dst_dml_ctx, -- 2.47.1

9 months, 2 weeks

[PATCH] kernfs: fix potential NULL dereference in mmap handler

by Wentao Liang

The kernfs_fop_mmap() invokes the '->mmap' callback without verifying its existence. This leads to a NULL pointer dereference when the kernfs node does not define the operation, resulting in an invalid memory access. Add a check to ensure the '->mmap' callback is present before invocation. Return -EINVAL when uninitialized to prevent the invalid access. Fixes: 324a56e16e44 ("kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly") Cc: stable(a)vger.kernel.org # 3.14+ Signed-off-by: Wentao Liang <vulab(a)iscas.ac.cn> --- fs/kernfs/file.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 8502ef68459b..7d8434a97487 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -459,9 +459,14 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma) goto out_unlock; ops = kernfs_ops(of->kn); - rc = ops->mmap(of, vma); - if (rc) + if (ops->mmap) { + rc = ops->mmap(of, vma); + if (rc) + goto out_put; + } else { + rc = -EINVAL; goto out_put; + } /* * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() -- 2.42.0.windows.2

9 months, 2 weeks

Investment H e l p

by Calib Cassim

Good Day, How are you? My name is Calib Cassim from Eskom Holdings Ltd. SA. I got your email from my personal search. I have in my position an (over-invoice / over-estimated) contract amount executed by a Foreign Contractor through my Department, which the contractor has been paid, and left the excess amount with the payment Management. So, I need your help to receive the $25.5M on my behalf for an investment, I will obtain all the needed legal documents for the transfer. If you can help, please send me your phone number for more discussion. Thanks, Mr. Calib

9 months, 2 weeks

[PATCH v2 1/1] x86/fred: Fix system hang during S4 resume with FRED enabled

by Xin Li (Intel)

Upon a wakeup from S4, the restore kernel starts and initializes the FRED MSRs as needed from its perspective. It then loads a hibernation image, including the image kernel, and attempts to load image pages directly into their original page frames used before hibernation unless those frames are currently in use. Once all pages are moved to their original locations, it jumps to a "trampoline" page in the image kernel. At this point, the image kernel takes control, but the FRED MSRs still contain values set by the restore kernel, which may differ from those set by the image kernel before hibernation. Therefore, the image kernel must ensure the FRED MSRs have the same values as before hibernation. Since these values depend only on the location of the kernel text and data, they can be recomputed from scratch. Reported-by: Xi Pardee <xi.pardee(a)intel.com> Reported-by: Todd Brandt <todd.e.brandt(a)intel.com> Suggested-by: H. Peter Anvin (Intel) <hpa(a)zytor.com> Signed-off-by: Xin Li (Intel) <xin(a)zytor.com> Tested-by: Todd Brandt <todd.e.brandt(a)intel.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Brian Gerst <brgerst(a)gmail.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: stable(a)vger.kernel.org # 6.9+ --- Change in v2: * Rewrite the change log and in-code comments based on Rafael's feedback. --- arch/x86/power/cpu.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c index 63230ff8cf4f..08e76a5ca155 100644 --- a/arch/x86/power/cpu.c +++ b/arch/x86/power/cpu.c @@ -27,6 +27,7 @@ #include <asm/mmu_context.h> #include <asm/cpu_device_id.h> #include <asm/microcode.h> +#include <asm/fred.h> #ifdef CONFIG_X86_32 __visible unsigned long saved_context_ebx; @@ -231,6 +232,19 @@ static void notrace __restore_processor_state(struct saved_context *ctxt) */ #ifdef CONFIG_X86_64 wrmsrl(MSR_GS_BASE, ctxt->kernelmode_gs_base); + + /* + * Reinitialize FRED to ensure the FRED MSRs contain the same values + * as before hibernation. + * + * Note, the setup of FRED RSPs requires access to percpu data + * structures. Therefore, FRED reinitialization can only occur after + * the percpu access pointer (i.e., MSR_GS_BASE) is restored. + */ + if (ctxt->cr4 & X86_CR4_FRED) { + cpu_init_fred_exceptions(); + cpu_init_fred_rsps(); + } #else loadsegment(fs, __KERNEL_PERCPU); #endif base-commit: 535bd326c5657fe570f41b1f76941e449d9e2062 -- 2.49.0

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