October 2024 - Linux-stable-mirror

[merged mm-hotfixes-stable] revert-selftests-mm-fix-deadlock-for-fork-after-pthread_create-on-arm.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: Revert "selftests/mm: fix deadlock for fork after pthread_create on ARM" has been removed from the -mm tree. Its filename was revert-selftests-mm-fix-deadlock-for-fork-after-pthread_create-on-arm.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 Liaw <edliaw(a)google.com> Subject: Revert "selftests/mm: fix deadlock for fork after pthread_create on ARM" Date: Fri, 18 Oct 2024 17:17:22 +0000 Patch series "selftests/mm: revert pthread_barrier change" On Android arm, pthread_create followed by a fork caused a deadlock in the case where the fork required work to be completed by the created thread. The previous patches incorrectly assumed that the parent would always initialize the pthread_barrier for the child thread. This reverts the change and replaces the fix for wp-fork-with-event with the original use of atomic_bool. This patch (of 3): This reverts commit e142cc87ac4ec618f2ccf5f68aedcd6e28a59d9d. fork_event_consumer may be called by other tests that do not initialize the pthread_barrier, so this approach is not correct. The subsequent patch will revert to using atomic_bool instead. Link: https://lkml.kernel.org/r/20241018171734.2315053-1-edliaw@google.com Link: https://lkml.kernel.org/r/20241018171734.2315053-2-edliaw@google.com Fixes: e142cc87ac4e ("fix deadlock for fork after pthread_create on ARM") Signed-off-by: Edward Liaw <edliaw(a)google.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- tools/testing/selftests/mm/uffd-unit-tests.c | 7 ------- 1 file changed, 7 deletions(-) --- a/tools/testing/selftests/mm/uffd-unit-tests.c~revert-selftests-mm-fix-deadlock-for-fork-after-pthread_create-on-arm +++ a/tools/testing/selftests/mm/uffd-unit-tests.c @@ -241,9 +241,6 @@ static void *fork_event_consumer(void *d fork_event_args *args = data; struct uffd_msg msg = { 0 }; - /* Ready for parent thread to fork */ - pthread_barrier_wait(&ready_for_fork); - /* Read until a full msg received */ while (uffd_read_msg(args->parent_uffd, &msg)); @@ -311,12 +308,8 @@ static int pagemap_test_fork(int uffd, b /* Prepare a thread to resolve EVENT_FORK */ if (with_event) { - pthread_barrier_init(&ready_for_fork, NULL, 2); if (pthread_create(&thread, NULL, fork_event_consumer, &args)) err("pthread_create()"); - /* Wait for child thread to start before forking */ - pthread_barrier_wait(&ready_for_fork); - pthread_barrier_destroy(&ready_for_fork); } child = fork(); _ Patches currently in -mm which might be from edliaw(a)google.com are

6 months

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[merged mm-hotfixes-stable] resourcekexec-walk_system_ram_res_rev-must-retain-resource-flags.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: resource,kexec: walk_system_ram_res_rev must retain resource flags has been removed from the -mm tree. Its filename was resourcekexec-walk_system_ram_res_rev-must-retain-resource-flags.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: Gregory Price <gourry(a)gourry.net> Subject: resource,kexec: walk_system_ram_res_rev must retain resource flags Date: Thu, 17 Oct 2024 15:03:47 -0400 walk_system_ram_res_rev() erroneously discards resource flags when passing the information to the callback. This causes systems with IORESOURCE_SYSRAM_DRIVER_MANAGED memory to have these resources selected during kexec to store kexec buffers if that memory happens to be at placed above normal system ram. This leads to undefined behavior after reboot. If the kexec buffer is never touched, nothing happens. If the kexec buffer is touched, it could lead to a crash (like below) or undefined behavior. Tested on a system with CXL memory expanders with driver managed memory, TPM enabled, and CONFIG_IMA_KEXEC=y. Adding printk's showed the flags were being discarded and as a result the check for IORESOURCE_SYSRAM_DRIVER_MANAGED passes. find_next_iomem_res: name(System RAM (kmem)) start(10000000000) end(1034fffffff) flags(83000200) locate_mem_hole_top_down: start(10000000000) end(1034fffffff) flags(0) [.] BUG: unable to handle page fault for address: ffff89834ffff000 [.] #PF: supervisor read access in kernel mode [.] #PF: error_code(0x0000) - not-present page [.] PGD c04c8bf067 P4D c04c8bf067 PUD c04c8be067 PMD 0 [.] Oops: 0000 [#1] SMP [.] RIP: 0010:ima_restore_measurement_list+0x95/0x4b0 [.] RSP: 0018:ffffc900000d3a80 EFLAGS: 00010286 [.] RAX: 0000000000001000 RBX: 0000000000000000 RCX: ffff89834ffff000 [.] RDX: 0000000000000018 RSI: ffff89834ffff000 RDI: ffff89834ffff018 [.] RBP: ffffc900000d3ba0 R08: 0000000000000020 R09: ffff888132b8a900 [.] R10: 4000000000000000 R11: 000000003a616d69 R12: 0000000000000000 [.] R13: ffffffff8404ac28 R14: 0000000000000000 R15: ffff89834ffff000 [.] FS: 0000000000000000(0000) GS:ffff893d44640000(0000) knlGS:0000000000000000 [.] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [.] ata5: SATA link down (SStatus 0 SControl 300) [.] CR2: ffff89834ffff000 CR3: 000001034d00f001 CR4: 0000000000770ef0 [.] PKRU: 55555554 [.] Call Trace: [.] <TASK> [.] ? __die+0x78/0xc0 [.] ? page_fault_oops+0x2a8/0x3a0 [.] ? exc_page_fault+0x84/0x130 [.] ? asm_exc_page_fault+0x22/0x30 [.] ? ima_restore_measurement_list+0x95/0x4b0 [.] ? template_desc_init_fields+0x317/0x410 [.] ? crypto_alloc_tfm_node+0x9c/0xc0 [.] ? init_ima_lsm+0x30/0x30 [.] ima_load_kexec_buffer+0x72/0xa0 [.] ima_init+0x44/0xa0 [.] __initstub__kmod_ima__373_1201_init_ima7+0x1e/0xb0 [.] ? init_ima_lsm+0x30/0x30 [.] do_one_initcall+0xad/0x200 [.] ? idr_alloc_cyclic+0xaa/0x110 [.] ? new_slab+0x12c/0x420 [.] ? new_slab+0x12c/0x420 [.] ? number+0x12a/0x430 [.] ? sysvec_apic_timer_interrupt+0xa/0x80 [.] ? asm_sysvec_apic_timer_interrupt+0x16/0x20 [.] ? parse_args+0xd4/0x380 [.] ? parse_args+0x14b/0x380 [.] kernel_init_freeable+0x1c1/0x2b0 [.] ? rest_init+0xb0/0xb0 [.] kernel_init+0x16/0x1a0 [.] ret_from_fork+0x2f/0x40 [.] ? rest_init+0xb0/0xb0 [.] ret_from_fork_asm+0x11/0x20 [.] </TASK> Link: https://lore.kernel.org/all/20231114091658.228030-1-bhe@redhat.com/ Link: https://lkml.kernel.org/r/20241017190347.5578-1-gourry@gourry.net Fixes: 7acf164b259d ("resource: add walk_system_ram_res_rev()") Signed-off-by: Gregory Price <gourry(a)gourry.net> Reviewed-by: Dan Williams <dan.j.williams(a)intel.com> Acked-by: Baoquan He <bhe(a)redhat.com> Cc: AKASHI Takahiro <takahiro.akashi(a)linaro.org> Cc: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com> Cc: Bjorn Helgaas <bhelgaas(a)google.com> Cc: "Huang, Ying" <ying.huang(a)intel.com> Cc: Ilpo J��rvinen <ilpo.jarvinen(a)linux.intel.com> Cc: Mika Westerberg <mika.westerberg(a)linux.intel.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- kernel/resource.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/kernel/resource.c~resourcekexec-walk_system_ram_res_rev-must-retain-resource-flags +++ a/kernel/resource.c @@ -459,9 +459,7 @@ int walk_system_ram_res_rev(u64 start, u rams_size += 16; } - rams[i].start = res.start; - rams[i++].end = res.end; - + rams[i++] = res; start = res.end + 1; } _ Patches currently in -mm which might be from gourry(a)gourry.net are

6 months

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[merged mm-hotfixes-stable] nilfs2-fix-kernel-bug-due-to-missing-clearing-of-checked-flag.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: nilfs2: fix kernel bug due to missing clearing of checked flag has been removed from the -mm tree. Its filename was nilfs2-fix-kernel-bug-due-to-missing-clearing-of-checked-flag.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: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Subject: nilfs2: fix kernel bug due to missing clearing of checked flag Date: Fri, 18 Oct 2024 04:33:10 +0900 Syzbot reported that in directory operations after nilfs2 detects filesystem corruption and degrades to read-only, __block_write_begin_int(), which is called to prepare block writes, may fail the BUG_ON check for accesses exceeding the folio/page size, triggering a kernel bug. This was found to be because the "checked" flag of a page/folio was not cleared when it was discarded by nilfs2's own routine, which causes the sanity check of directory entries to be skipped when the directory page/folio is reloaded. So, fix that. This was necessary when the use of nilfs2's own page discard routine was applied to more than just metadata files. Link: https://lkml.kernel.org/r/20241017193359.5051-1-konishi.ryusuke@gmail.com Fixes: 8c26c4e2694a ("nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption") Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com> Reported-by: syzbot+d6ca2daf692c7a82f959(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d6ca2daf692c7a82f959 Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/nilfs2/page.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/nilfs2/page.c~nilfs2-fix-kernel-bug-due-to-missing-clearing-of-checked-flag +++ a/fs/nilfs2/page.c @@ -400,6 +400,7 @@ void nilfs_clear_folio_dirty(struct foli folio_clear_uptodate(folio); folio_clear_mappedtodisk(folio); + folio_clear_checked(folio); head = folio_buffers(folio); if (head) { _ Patches currently in -mm which might be from konishi.ryusuke(a)gmail.com are nilfs2-fix-potential-deadlock-with-newly-created-symlinks.patch

6 months

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[merged mm-hotfixes-stable] ocfs2-pass-u64-to-ocfs2_truncate_inline-maybe-overflow.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: ocfs2: pass u64 to ocfs2_truncate_inline maybe overflow has been removed from the -mm tree. Its filename was ocfs2-pass-u64-to-ocfs2_truncate_inline-maybe-overflow.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: pass u64 to ocfs2_truncate_inline maybe overflow Date: Wed, 16 Oct 2024 19:43:47 +0800 Syzbot reported a kernel BUG in ocfs2_truncate_inline. There are two reasons for this: first, the parameter value passed is greater than ocfs2_max_inline_data_with_xattr, second, the start and end parameters of ocfs2_truncate_inline are "unsigned int". So, we need to add a sanity check for byte_start and byte_len right before ocfs2_truncate_inline() in ocfs2_remove_inode_range(), if they are greater than ocfs2_max_inline_data_with_xattr return -EINVAL. Link: https://lkml.kernel.org/r/tencent_D48DB5122ADDAEDDD11918CFB68D93258C07@qq.c… Fixes: 1afc32b95233 ("ocfs2: Write support for inline data") Signed-off-by: Edward Adam Davis <eadavis(a)qq.com> Reported-by: syzbot+81092778aac03460d6b7(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=81092778aac03460d6b7 Reviewed-by: Joseph Qi <joseph.qi(a)linux.alibaba.com> Cc: Joel Becker <jlbec(a)evilplan.org> Cc: Joseph Qi <joseph.qi(a)linux.alibaba.com> Cc: Mark Fasheh <mark(a)fasheh.com> Cc: Junxiao Bi <junxiao.bi(a)oracle.com> Cc: Changwei Ge <gechangwei(a)live.cn> Cc: Gang He <ghe(a)suse.com> 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/file.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/fs/ocfs2/file.c~ocfs2-pass-u64-to-ocfs2_truncate_inline-maybe-overflow +++ a/fs/ocfs2/file.c @@ -1784,6 +1784,14 @@ int ocfs2_remove_inode_range(struct inod return 0; if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) { + int id_count = ocfs2_max_inline_data_with_xattr(inode->i_sb, di); + + if (byte_start > id_count || byte_start + byte_len > id_count) { + ret = -EINVAL; + mlog_errno(ret); + goto out; + } + ret = ocfs2_truncate_inline(inode, di_bh, byte_start, byte_start + byte_len, 0); if (ret) { _ Patches currently in -mm which might be from eadavis(a)qq.com are

6 months

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[merged mm-hotfixes-stable] mm-shmem-fix-data-race-in-shmem_getattr.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: shmem: fix data-race in shmem_getattr() has been removed from the -mm tree. Its filename was mm-shmem-fix-data-race-in-shmem_getattr.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: Jeongjun Park <aha310510(a)gmail.com> Subject: mm: shmem: fix data-race in shmem_getattr() Date: Mon, 9 Sep 2024 21:35:58 +0900 I got the following KCSAN report during syzbot testing: ================================================================== BUG: KCSAN: data-race in generic_fillattr / inode_set_ctime_current write to 0xffff888102eb3260 of 4 bytes by task 6565 on cpu 1: inode_set_ctime_to_ts include/linux/fs.h:1638 [inline] inode_set_ctime_current+0x169/0x1d0 fs/inode.c:2626 shmem_mknod+0x117/0x180 mm/shmem.c:3443 shmem_create+0x34/0x40 mm/shmem.c:3497 lookup_open fs/namei.c:3578 [inline] open_last_lookups fs/namei.c:3647 [inline] path_openat+0xdbc/0x1f00 fs/namei.c:3883 do_filp_open+0xf7/0x200 fs/namei.c:3913 do_sys_openat2+0xab/0x120 fs/open.c:1416 do_sys_open fs/open.c:1431 [inline] __do_sys_openat fs/open.c:1447 [inline] __se_sys_openat fs/open.c:1442 [inline] __x64_sys_openat+0xf3/0x120 fs/open.c:1442 x64_sys_call+0x1025/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e read to 0xffff888102eb3260 of 4 bytes by task 3498 on cpu 0: inode_get_ctime_nsec include/linux/fs.h:1623 [inline] inode_get_ctime include/linux/fs.h:1629 [inline] generic_fillattr+0x1dd/0x2f0 fs/stat.c:62 shmem_getattr+0x17b/0x200 mm/shmem.c:1157 vfs_getattr_nosec fs/stat.c:166 [inline] vfs_getattr+0x19b/0x1e0 fs/stat.c:207 vfs_statx_path fs/stat.c:251 [inline] vfs_statx+0x134/0x2f0 fs/stat.c:315 vfs_fstatat+0xec/0x110 fs/stat.c:341 __do_sys_newfstatat fs/stat.c:505 [inline] __se_sys_newfstatat+0x58/0x260 fs/stat.c:499 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:499 x64_sys_call+0x141f/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:263 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x54/0x120 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e value changed: 0x2755ae53 -> 0x27ee44d3 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 3498 Comm: udevd Not tainted 6.11.0-rc6-syzkaller-00326-gd1f2d51b711a-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 ================================================================== When calling generic_fillattr(), if you don't hold read lock, data-race will occur in inode member variables, which can cause unexpected behavior. Since there is no special protection when shmem_getattr() calls generic_fillattr(), data-race occurs by functions such as shmem_unlink() or shmem_mknod(). This can cause unexpected results, so commenting it out is not enough. Therefore, when calling generic_fillattr() from shmem_getattr(), it is appropriate to protect the inode using inode_lock_shared() and inode_unlock_shared() to prevent data-race. Link: https://lkml.kernel.org/r/20240909123558.70229-1-aha310510@gmail.com Fixes: 44a30220bc0a ("shmem: recalculate file inode when fstat") Signed-off-by: Jeongjun Park <aha310510(a)gmail.com> Reported-by: syzbot <syzkaller(a)googlegroup.com> Cc: Hugh Dickins <hughd(a)google.com> Cc: Yu Zhao <yuzhao(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/shmem.c~mm-shmem-fix-data-race-in-shmem_getattr +++ a/mm/shmem.c @@ -1166,7 +1166,9 @@ static int shmem_getattr(struct mnt_idma stat->attributes_mask |= (STATX_ATTR_APPEND | STATX_ATTR_IMMUTABLE | STATX_ATTR_NODUMP); + inode_lock_shared(inode); generic_fillattr(idmap, request_mask, inode, stat); + inode_unlock_shared(inode); if (shmem_huge_global_enabled(inode, 0, 0, false, NULL, 0)) stat->blksize = HPAGE_PMD_SIZE; _ Patches currently in -mm which might be from aha310510(a)gmail.com are

6 months

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[merged mm-hotfixes-stable] x86-traps-move-kmsan-check-after-instrumentation_begin.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: x86/traps: move kmsan check after instrumentation_begin has been removed from the -mm tree. Its filename was x86-traps-move-kmsan-check-after-instrumentation_begin.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: Sabyrzhan Tasbolatov <snovitoll(a)gmail.com> Subject: x86/traps: move kmsan check after instrumentation_begin Date: Wed, 16 Oct 2024 20:24:07 +0500 During x86_64 kernel build with CONFIG_KMSAN, the objtool warns following: AR built-in.a AR vmlinux.a LD vmlinux.o vmlinux.o: warning: objtool: handle_bug+0x4: call to kmsan_unpoison_entry_regs() leaves .noinstr.text section OBJCOPY modules.builtin.modinfo GEN modules.builtin MODPOST Module.symvers CC .vmlinux.export.o Moving kmsan_unpoison_entry_regs() _after_ instrumentation_begin() fixes the warning. There is decode_bug(regs->ip, &imm) is left before KMSAN unpoisoining, but it has the return condition and if we include it after instrumentation_begin() it results the warning "return with instrumentation enabled", hence, I'm concerned that regs will not be KMSAN unpoisoned if `ud_type == BUG_NONE` is true. Link: https://lkml.kernel.org/r/20241016152407.3149001-1-snovitoll@gmail.com Fixes: ba54d194f8da ("x86/traps: avoid KMSAN bugs originating from handle_bug()") Signed-off-by: Sabyrzhan Tasbolatov <snovitoll(a)gmail.com> Reviewed-by: Alexander Potapenko <glider(a)google.com> Cc: Borislav Petkov (AMD) <bp(a)alien8.de> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/x86/kernel/traps.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) --- a/arch/x86/kernel/traps.c~x86-traps-move-kmsan-check-after-instrumentation_begin +++ a/arch/x86/kernel/traps.c @@ -261,12 +261,6 @@ static noinstr bool handle_bug(struct pt int ud_type; u32 imm; - /* - * Normally @regs are unpoisoned by irqentry_enter(), but handle_bug() - * is a rare case that uses @regs without passing them to - * irqentry_enter(). - */ - kmsan_unpoison_entry_regs(regs); ud_type = decode_bug(regs->ip, &imm); if (ud_type == BUG_NONE) return handled; @@ -276,6 +270,12 @@ static noinstr bool handle_bug(struct pt */ instrumentation_begin(); /* + * Normally @regs are unpoisoned by irqentry_enter(), but handle_bug() + * is a rare case that uses @regs without passing them to + * irqentry_enter(). + */ + kmsan_unpoison_entry_regs(regs); + /* * Since we're emulating a CALL with exceptions, restore the interrupt * state to what it was at the exception site. */ _ Patches currently in -mm which might be from snovitoll(a)gmail.com are mm-kasan-kmsan-copy_from-to_kernel_nofault.patch kasan-move-checks-to-do_strncpy_from_user.patch kasan-migrate-copy_user_test-to-kunit.patch kasan-delete-config_kasan_module_test.patch kasan-delete-config_kasan_module_test-fix.patch

6 months

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[merged mm-hotfixes-stable] mm-page_alloc-let-gfp_atomic-order-0-allocs-access-highatomic-reserves.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/page_alloc: let GFP_ATOMIC order-0 allocs access highatomic reserves has been removed from the -mm tree. Its filename was mm-page_alloc-let-gfp_atomic-order-0-allocs-access-highatomic-reserves.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: Matt Fleming <mfleming(a)cloudflare.com> Subject: mm/page_alloc: let GFP_ATOMIC order-0 allocs access highatomic reserves Date: Fri, 11 Oct 2024 13:07:37 +0100 Under memory pressure it's possible for GFP_ATOMIC order-0 allocations to fail even though free pages are available in the highatomic reserves. GFP_ATOMIC allocations cannot trigger unreserve_highatomic_pageblock() since it's only run from reclaim. Given that such allocations will pass the watermarks in __zone_watermark_unusable_free(), it makes sense to fallback to highatomic reserves the same way that ALLOC_OOM can. This fixes order-0 page allocation failures observed on Cloudflare's fleet when handling network packets: kswapd1: page allocation failure: order:0, mode:0x820(GFP_ATOMIC), nodemask=(null),cpuset=/,mems_allowed=0-7 CPU: 10 PID: 696 Comm: kswapd1 Kdump: loaded Tainted: G O 6.6.43-CUSTOM #1 Hardware name: MACHINE Call Trace: <IRQ> dump_stack_lvl+0x3c/0x50 warn_alloc+0x13a/0x1c0 __alloc_pages_slowpath.constprop.0+0xc9d/0xd10 __alloc_pages+0x327/0x340 __napi_alloc_skb+0x16d/0x1f0 bnxt_rx_page_skb+0x96/0x1b0 [bnxt_en] bnxt_rx_pkt+0x201/0x15e0 [bnxt_en] __bnxt_poll_work+0x156/0x2b0 [bnxt_en] bnxt_poll+0xd9/0x1c0 [bnxt_en] __napi_poll+0x2b/0x1b0 bpf_trampoline_6442524138+0x7d/0x1000 __napi_poll+0x5/0x1b0 net_rx_action+0x342/0x740 handle_softirqs+0xcf/0x2b0 irq_exit_rcu+0x6c/0x90 sysvec_apic_timer_interrupt+0x72/0x90 </IRQ> [mfleming(a)cloudflare.com: update comment] Link: https://lkml.kernel.org/r/20241015125158.3597702-1-matt@readmodwrite.com Link: https://lkml.kernel.org/r/20241011120737.3300370-1-matt@readmodwrite.com Link: https://lore.kernel.org/all/CAGis_TWzSu=P7QJmjD58WWiu3zjMTVKSzdOwWE8ORaGytz… Fixes: 1d91df85f399 ("mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore} APIs") Signed-off-by: Matt Fleming <mfleming(a)cloudflare.com> Suggested-by: Vlastimil Babka <vbabka(a)suse.cz> Reviewed-by: Vlastimil Babka <vbabka(a)suse.cz> Cc: Mel Gorman <mgorman(a)techsingularity.net> Cc: Michal Hocko <mhocko(a)kernel.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/page_alloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-let-gfp_atomic-order-0-allocs-access-highatomic-reserves +++ a/mm/page_alloc.c @@ -2893,12 +2893,12 @@ struct page *rmqueue_buddy(struct zone * page = __rmqueue(zone, order, migratetype, alloc_flags); /* - * If the allocation fails, allow OOM handling access - * to HIGHATOMIC reserves as failing now is worse than - * failing a high-order atomic allocation in the - * future. + * If the allocation fails, allow OOM handling and + * order-0 (atomic) allocs access to HIGHATOMIC + * reserves as failing now is worse than failing a + * high-order atomic allocation in the future. */ - if (!page && (alloc_flags & ALLOC_OOM)) + if (!page && (alloc_flags & (ALLOC_OOM|ALLOC_NON_BLOCK))) page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC); if (!page) { _ Patches currently in -mm which might be from mfleming(a)cloudflare.com are

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[merged mm-hotfixes-stable] fork-only-invoke-khugepaged-ksm-hooks-if-no-error.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: fork: only invoke khugepaged, ksm hooks if no error has been removed from the -mm tree. Its filename was fork-only-invoke-khugepaged-ksm-hooks-if-no-error.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: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Subject: fork: only invoke khugepaged, ksm hooks if no error Date: Tue, 15 Oct 2024 18:56:06 +0100 There is no reason to invoke these hooks early against an mm that is in an incomplete state. The change in commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") makes this more pertinent as we may be in a state where entries in the maple tree are not yet consistent. Their placement early in dup_mmap() only appears to have been meaningful for early error checking, and since functionally it'd require a very small allocation to fail (in practice 'too small to fail') that'd only occur in the most dire circumstances, meaning the fork would fail or be OOM'd in any case. Since both khugepaged and KSM tracking are there to provide optimisations to memory performance rather than critical functionality, it doesn't really matter all that much if, under such dire memory pressure, we fail to register an mm with these. As a result, we follow the example of commit d2081b2bf819 ("mm: khugepaged: make khugepaged_enter() void function") and make ksm_fork() a void function also. We only expose the mm to these functions once we are done with them and only if no error occurred in the fork operation. Link: https://lkml.kernel.org/r/e0cb8b840c9d1d5a6e84d4f8eff5f3f2022aa10c.17290143… Fixes: d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Reported-by: Jann Horn <jannh(a)google.com> Reviewed-by: Liam R. Howlett <Liam.Howlett(a)Oracle.com> Reviewed-by: Vlastimil Babka <vbabka(a)suse.cz> Reviewed-by: Jann Horn <jannh(a)google.com> Cc: Alexander Viro <viro(a)zeniv.linux.org.uk> Cc: Christian Brauner <brauner(a)kernel.org> Cc: Jan Kara <jack(a)suse.cz> Cc: Linus Torvalds <torvalds(a)linuxfoundation.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/ksm.h | 10 ++++------ kernel/fork.c | 7 ++----- 2 files changed, 6 insertions(+), 11 deletions(-) --- a/include/linux/ksm.h~fork-only-invoke-khugepaged-ksm-hooks-if-no-error +++ a/include/linux/ksm.h @@ -54,12 +54,11 @@ static inline long mm_ksm_zero_pages(str return atomic_long_read(&mm->ksm_zero_pages); } -static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) +static inline void ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) { + /* Adding mm to ksm is best effort on fork. */ if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags)) - return __ksm_enter(mm); - - return 0; + __ksm_enter(mm); } static inline int ksm_execve(struct mm_struct *mm) @@ -107,9 +106,8 @@ static inline int ksm_disable(struct mm_ return 0; } -static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) +static inline void ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) { - return 0; } static inline int ksm_execve(struct mm_struct *mm) --- a/kernel/fork.c~fork-only-invoke-khugepaged-ksm-hooks-if-no-error +++ a/kernel/fork.c @@ -653,11 +653,6 @@ static __latent_entropy int dup_mmap(str mm->exec_vm = oldmm->exec_vm; mm->stack_vm = oldmm->stack_vm; - retval = ksm_fork(mm, oldmm); - if (retval) - goto out; - khugepaged_fork(mm, oldmm); - /* Use __mt_dup() to efficiently build an identical maple tree. */ retval = __mt_dup(&oldmm->mm_mt, &mm->mm_mt, GFP_KERNEL); if (unlikely(retval)) @@ -760,6 +755,8 @@ loop_out: vma_iter_free(&vmi); if (!retval) { mt_set_in_rcu(vmi.mas.tree); + ksm_fork(mm, oldmm); + khugepaged_fork(mm, oldmm); } else if (mpnt) { /* * The entire maple tree has already been duplicated. If the _ Patches currently in -mm which might be from lorenzo.stoakes(a)oracle.com are mm-avoid-unsafe-vma-hook-invocation-when-error-arises-on-mmap-hook.patch mm-unconditionally-close-vmas-on-error.patch mm-refactor-map_deny_write_exec.patch mm-resolve-faulty-mmap_region-error-path-behaviour.patch selftests-mm-add-pkey_sighandler_xx-hugetlb_dio-to-gitignore.patch mm-refactor-mm_access-to-not-return-null.patch mm-refactor-mm_access-to-not-return-null-fix.patch mm-madvise-unrestrict-process_madvise-for-current-process.patch maple_tree-do-not-hash-pointers-on-dump-in-debug-mode.patch tools-testing-fix-phys_addr_t-size-on-64-bit-systems.patch tools-testing-fix-phys_addr_t-size-on-64-bit-systems-fix.patch tools-testing-add-additional-vma_internalh-stubs.patch mm-isolate-mmap-internal-logic-to-mm-vmac.patch mm-refactor-__mmap_region.patch mm-defer-second-attempt-at-merge-on-mmap.patch mm-pagewalk-add-the-ability-to-install-ptes.patch mm-add-pte_marker_guard-pte-marker.patch mm-madvise-implement-lightweight-guard-page-mechanism.patch tools-testing-update-tools-uapi-header-for-mman-commonh.patch selftests-mm-add-self-tests-for-guard-page-feature.patch

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[merged mm-hotfixes-stable] fork-do-not-invoke-uffd-on-fork-if-error-occurs.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: fork: do not invoke uffd on fork if error occurs has been removed from the -mm tree. Its filename was fork-do-not-invoke-uffd-on-fork-if-error-occurs.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: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Subject: fork: do not invoke uffd on fork if error occurs Date: Tue, 15 Oct 2024 18:56:05 +0100 Patch series "fork: do not expose incomplete mm on fork". During fork we may place the virtual memory address space into an inconsistent state before the fork operation is complete. In addition, we may encounter an error during the fork operation that indicates that the virtual memory address space is invalidated. As a result, we should not be exposing it in any way to external machinery that might interact with the mm or VMAs, machinery that is not designed to deal with incomplete state. We specifically update the fork logic to defer khugepaged and ksm to the end of the operation and only to be invoked if no error arose, and disallow uffd from observing fork events should an error have occurred. This patch (of 2): Currently on fork we expose the virtual address space of a process to userland unconditionally if uffd is registered in VMAs, regardless of whether an error arose in the fork. This is performed in dup_userfaultfd_complete() which is invoked unconditionally, and performs two duties - invoking registered handlers for the UFFD_EVENT_FORK event via dup_fctx(), and clearing down userfaultfd_fork_ctx objects established in dup_userfaultfd(). This is problematic, because the virtual address space may not yet be correctly initialised if an error arose. The change in commit d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") makes this more pertinent as we may be in a state where entries in the maple tree are not yet consistent. We address this by, on fork error, ensuring that we roll back state that we would otherwise expect to clean up through the event being handled by userland and perform the memory freeing duty otherwise performed by dup_userfaultfd_complete(). We do this by implementing a new function, dup_userfaultfd_fail(), which performs the same loop, only decrementing reference counts. Note that we perform mmgrab() on the parent and child mm's, however userfaultfd_ctx_put() will mmdrop() this once the reference count drops to zero, so we will avoid memory leaks correctly here. Link: https://lkml.kernel.org/r/cover.1729014377.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/d3691d58bb58712b6fb3df2be441d175bd3cdf07.17290143… Fixes: d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()") Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Reported-by: Jann Horn <jannh(a)google.com> Reviewed-by: Jann Horn <jannh(a)google.com> Reviewed-by: Liam R. Howlett <Liam.Howlett(a)Oracle.com> Cc: Alexander Viro <viro(a)zeniv.linux.org.uk> Cc: Christian Brauner <brauner(a)kernel.org> Cc: Jan Kara <jack(a)suse.cz> Cc: Linus Torvalds <torvalds(a)linuxfoundation.org> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- fs/userfaultfd.c | 28 ++++++++++++++++++++++++++++ include/linux/userfaultfd_k.h | 5 +++++ kernel/fork.c | 5 ++++- 3 files changed, 37 insertions(+), 1 deletion(-) --- a/fs/userfaultfd.c~fork-do-not-invoke-uffd-on-fork-if-error-occurs +++ a/fs/userfaultfd.c @@ -692,6 +692,34 @@ void dup_userfaultfd_complete(struct lis } } +void dup_userfaultfd_fail(struct list_head *fcs) +{ + struct userfaultfd_fork_ctx *fctx, *n; + + /* + * An error has occurred on fork, we will tear memory down, but have + * allocated memory for fctx's and raised reference counts for both the + * original and child contexts (and on the mm for each as a result). + * + * These would ordinarily be taken care of by a user handling the event, + * but we are no longer doing so, so manually clean up here. + * + * mm tear down will take care of cleaning up VMA contexts. + */ + list_for_each_entry_safe(fctx, n, fcs, list) { + struct userfaultfd_ctx *octx = fctx->orig; + struct userfaultfd_ctx *ctx = fctx->new; + + atomic_dec(&octx->mmap_changing); + VM_BUG_ON(atomic_read(&octx->mmap_changing) < 0); + userfaultfd_ctx_put(octx); + userfaultfd_ctx_put(ctx); + + list_del(&fctx->list); + kfree(fctx); + } +} + void mremap_userfaultfd_prep(struct vm_area_struct *vma, struct vm_userfaultfd_ctx *vm_ctx) { --- a/include/linux/userfaultfd_k.h~fork-do-not-invoke-uffd-on-fork-if-error-occurs +++ a/include/linux/userfaultfd_k.h @@ -249,6 +249,7 @@ static inline bool vma_can_userfault(str extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *); extern void dup_userfaultfd_complete(struct list_head *); +void dup_userfaultfd_fail(struct list_head *); extern void mremap_userfaultfd_prep(struct vm_area_struct *, struct vm_userfaultfd_ctx *); @@ -351,6 +352,10 @@ static inline void dup_userfaultfd_compl { } +static inline void dup_userfaultfd_fail(struct list_head *l) +{ +} + static inline void mremap_userfaultfd_prep(struct vm_area_struct *vma, struct vm_userfaultfd_ctx *ctx) { --- a/kernel/fork.c~fork-do-not-invoke-uffd-on-fork-if-error-occurs +++ a/kernel/fork.c @@ -775,7 +775,10 @@ out: mmap_write_unlock(mm); flush_tlb_mm(oldmm); mmap_write_unlock(oldmm); - dup_userfaultfd_complete(&uf); + if (!retval) + dup_userfaultfd_complete(&uf); + else + dup_userfaultfd_fail(&uf); fail_uprobe_end: uprobe_end_dup_mmap(); return retval; _ Patches currently in -mm which might be from lorenzo.stoakes(a)oracle.com are mm-avoid-unsafe-vma-hook-invocation-when-error-arises-on-mmap-hook.patch mm-unconditionally-close-vmas-on-error.patch mm-refactor-map_deny_write_exec.patch mm-resolve-faulty-mmap_region-error-path-behaviour.patch selftests-mm-add-pkey_sighandler_xx-hugetlb_dio-to-gitignore.patch mm-refactor-mm_access-to-not-return-null.patch mm-refactor-mm_access-to-not-return-null-fix.patch mm-madvise-unrestrict-process_madvise-for-current-process.patch maple_tree-do-not-hash-pointers-on-dump-in-debug-mode.patch tools-testing-fix-phys_addr_t-size-on-64-bit-systems.patch tools-testing-fix-phys_addr_t-size-on-64-bit-systems-fix.patch tools-testing-add-additional-vma_internalh-stubs.patch mm-isolate-mmap-internal-logic-to-mm-vmac.patch mm-refactor-__mmap_region.patch mm-defer-second-attempt-at-merge-on-mmap.patch mm-pagewalk-add-the-ability-to-install-ptes.patch mm-add-pte_marker_guard-pte-marker.patch mm-madvise-implement-lightweight-guard-page-mechanism.patch tools-testing-update-tools-uapi-header-for-mman-commonh.patch selftests-mm-add-self-tests-for-guard-page-feature.patch

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[PATCH xe-i915-for-6.11 01/22] drm/i915: Skip programming FIA link enable bits for MTL+

by Lucas De Marchi

From: Gustavo Sousa <gustavo.sousa(a)intel.com> commit 9fc97277eb2d17492de636b68cf7d2f5c4f15c1b upstream. Starting with Xe_LPD+, although FIA is still used to readout Type-C pin assignment, part of Type-C support is moved to PICA and programming PORT_TX_DFLEXDPMLE1(*) registers is not applicable anymore like it was for previous display IPs (e.g. see BSpec 49190). v2: - Mention Bspec 49190 as a reference of instructions for previous IPs. (Shekhar Chauhan) - s/Xe_LPDP/Xe_LPD+/ in the commit message. (Matt Roper) - Update commit message to be more accurate to the changes in the IP. (Imre Deak) Bspec: 65750, 65448 Reviewed-by: Shekhar Chauhan <shekhar.chauhan(a)intel.com> Reviewed-by: Imre Deak <imre.deak(a)intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20240625202652.315936-1-gusta… Signed-off-by: Gustavo Sousa <gustavo.sousa(a)intel.com> Signed-off-by: Lucas De Marchi <lucas.demarchi(a)intel.com> --- drivers/gpu/drm/i915/display/intel_tc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c index 9887967b2ca5c..6f2ee7dbc43b3 100644 --- a/drivers/gpu/drm/i915/display/intel_tc.c +++ b/drivers/gpu/drm/i915/display/intel_tc.c @@ -393,6 +393,9 @@ void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port, bool lane_reversal = dig_port->saved_port_bits & DDI_BUF_PORT_REVERSAL; u32 val; + if (DISPLAY_VER(i915) >= 14) + return; + drm_WARN_ON(&i915->drm, lane_reversal && tc->mode != TC_PORT_LEGACY); -- 2.47.0

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