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[patch 2/7] mm: disable deferred struct page for 32-bit arches

by akpm＠linux-foundation.org

From: Pasha Tatashin <Pavel.Tatashin(a)microsoft.com> Subject: mm: disable deferred struct page for 32-bit arches Deferred struct page init is needed only on systems with large amount of physical memory to improve boot performance. 32-bit systems do not benefit from this feature. Jiri reported a problem where deferred struct pages do not work well with x86-32: [ 0.035162] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) [ 0.035725] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) [ 0.036269] Initializing CPU#0 [ 0.036513] Initializing HighMem for node 0 (00036ffe:0007ffe0) [ 0.038459] page:f6780000 is uninitialized and poisoned [ 0.038460] raw: ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff [ 0.039509] page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page)) [ 0.040038] ------------[ cut here ]------------ [ 0.040399] kernel BUG at include/linux/page-flags.h:293! [ 0.040823] invalid opcode: 0000 [#1] SMP PTI [ 0.041166] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc1_pt_jiri #9 [ 0.041694] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014 [ 0.042496] EIP: free_highmem_page+0x64/0x80 [ 0.042839] Code: 13 46 d8 c1 e8 18 5d 83 e0 03 8d 04 c0 c1 e0 06 ff 80 ec 5f 44 d8 c3 8d b4 26 00 00 00 00 ba 08 65 28 d8 89 d8 e8 fc 71 02 00 <0f> 0b 8d 76 00 8d bc 27 00 00 00 00 ba d0 b1 26 d8 89 d8 e8 e4 71 [ 0.044338] EAX: 0000003c EBX: f6780000 ECX: 00000000 EDX: d856cbe8 [ 0.044868] ESI: 0007ffe0 EDI: d838df20 EBP: d838df00 ESP: d838defc [ 0.045372] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00210086 [ 0.045913] CR0: 80050033 CR2: 00000000 CR3: 18556000 CR4: 00040690 [ 0.046413] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.046913] DR6: fffe0ff0 DR7: 00000400 [ 0.047220] Call Trace: [ 0.047419] add_highpages_with_active_regions+0xbd/0x10d [ 0.047854] set_highmem_pages_init+0x5b/0x71 [ 0.048202] mem_init+0x2b/0x1e8 [ 0.048460] start_kernel+0x1d2/0x425 [ 0.048757] i386_start_kernel+0x93/0x97 [ 0.049073] startup_32_smp+0x164/0x168 [ 0.049379] Modules linked in: [ 0.049626] ---[ end trace 337949378db0abbb ]--- We free highmem pages before their struct pages are initialized: mem_init() set_highmem_pages_init() add_highpages_with_active_regions() free_highmem_page() .. Access uninitialized struct page here.. Because there is no reason to have this feature on 32-bit systems, just disable it. Link: http://lkml.kernel.org/r/20180831150506.31246-1-pavel.tatashin@microsoft.com Fixes: 2e3ca40f03bb ("mm: relax deferred struct page requirements") Signed-off-by: Pavel Tatashin <pavel.tatashin(a)microsoft.com> Reported-by: Jiri Slaby <jslaby(a)suse.cz> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- diff -puN mm/Kconfig~mm-disable-deferred-struct-page-for-32-bit-arches mm/Kconfig --- a/mm/Kconfig~mm-disable-deferred-struct-page-for-32-bit-arches +++ a/mm/Kconfig @@ -637,6 +637,7 @@ config DEFERRED_STRUCT_PAGE_INIT depends on NO_BOOTMEM depends on SPARSEMEM depends on !NEED_PER_CPU_KM + depends on 64BIT help Ordinarily all struct pages are initialised during early boot in a single thread. On very large machines this can take a considerable _

6 years, 10 months

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[patch 1/7] fork: report pid exhaustion correctly

by akpm＠linux-foundation.org

From: KJ Tsanaktsidis <ktsanaktsidis(a)zendesk.com> Subject: fork: report pid exhaustion correctly Make the clone and fork syscalls return EAGAIN when the limit on the number of pids /proc/sys/kernel/pid_max is exceeded. Currently, when the pid_max limit is exceeded, the kernel will return ENOSPC from the fork and clone syscalls. This is contrary to the documented behaviour, which explicitly calls out the pid_max case as one where EAGAIN should be returned. It also leads to really confusing error messages in userspace programs which will complain about a lack of disk space when they fail to create processes/threads for this reason. This error is being returned because alloc_pid() uses the idr api to find a new pid; when there are none available, idr_alloc_cyclic() returns -ENOSPC, and this is being propagated back to userspace. This behaviour has been broken before, and was explicitly fixed in commit 35f71bc0a09a ("fork: report pid reservation failure properly"), so I think -EAGAIN is definitely the right thing to return in this case. The current behaviour change dates from commit 95846ecf9dac ("pid: replace pid bitmap implementation with IDR AIP") and was I believe unintentional. This patch has no impact on the case where allocating a pid fails because the child reaper for the namespace is dead; that case will still return -ENOMEM. Link: http://lkml.kernel.org/r/20180903111016.46461-1-ktsanaktsidis@zendesk.com Fixes: 95846ecf9dac ("pid: replace pid bitmap implementation with IDR AIP") Signed-off-by: KJ Tsanaktsidis <ktsanaktsidis(a)zendesk.com> Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: Gargi Sharma <gs051095(a)gmail.com> Cc: Rik van Riel <riel(a)redhat.com> Cc: Oleg Nesterov <oleg(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- diff -puN kernel/pid.c~fork-report-pid-exhaustion-correctly kernel/pid.c --- a/kernel/pid.c~fork-report-pid-exhaustion-correctly +++ a/kernel/pid.c @@ -195,7 +195,7 @@ struct pid *alloc_pid(struct pid_namespa idr_preload_end(); if (nr < 0) { - retval = nr; + retval = (nr == -ENOSPC) ? -EAGAIN : nr; goto out_free; } _

6 years, 10 months

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[patch 1/7] fork: report pid exhaustion correctly

by akpm＠linux-foundation.org

From: KJ Tsanaktsidis <ktsanaktsidis(a)zendesk.com> Subject: fork: report pid exhaustion correctly Make the clone and fork syscalls return EAGAIN when the limit on the number of pids /proc/sys/kernel/pid_max is exceeded. Currently, when the pid_max limit is exceeded, the kernel will return ENOSPC from the fork and clone syscalls. This is contrary to the documented behaviour, which explicitly calls out the pid_max case as one where EAGAIN should be returned. It also leads to really confusing error messages in userspace programs which will complain about a lack of disk space when they fail to create processes/threads for this reason. This error is being returned because alloc_pid() uses the idr api to find a new pid; when there are none available, idr_alloc_cyclic() returns -ENOSPC, and this is being propagated back to userspace. This behaviour has been broken before, and was explicitly fixed in commit 35f71bc0a09a ("fork: report pid reservation failure properly"), so I think -EAGAIN is definitely the right thing to return in this case. The current behaviour change dates from commit 95846ecf9dac ("pid: replace pid bitmap implementation with IDR AIP") and was I believe unintentional. This patch has no impact on the case where allocating a pid fails because the child reaper for the namespace is dead; that case will still return -ENOMEM. Link: http://lkml.kernel.org/r/20180903111016.46461-1-ktsanaktsidis@zendesk.com Fixes: 95846ecf9dac ("pid: replace pid bitmap implementation with IDR AIP") Signed-off-by: KJ Tsanaktsidis <ktsanaktsidis(a)zendesk.com> Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: Gargi Sharma <gs051095(a)gmail.com> Cc: Rik van Riel <riel(a)redhat.com> Cc: Oleg Nesterov <oleg(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- diff -puN kernel/pid.c~fork-report-pid-exhaustion-correctly kernel/pid.c --- a/kernel/pid.c~fork-report-pid-exhaustion-correctly +++ a/kernel/pid.c @@ -195,7 +195,7 @@ struct pid *alloc_pid(struct pid_namespa idr_preload_end(); if (nr < 0) { - retval = nr; + retval = (nr == -ENOSPC) ? -EAGAIN : nr; goto out_free; } _

6 years, 10 months

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[patch 7/7] ocfs2: fix ocfs2 read block panic

by akpm＠linux-foundation.org

From: Junxiao Bi <junxiao.bi(a)oracle.com> Subject: ocfs2: fix ocfs2 read block panic While reading block, it is possible that io error return due to underlying storage issue, in this case, BH_NeedsValidate was left in the buffer head. Then when reading the very block next time, if it was already linked into journal, that will trigger the following panic. [203748.702517] kernel BUG at fs/ocfs2/buffer_head_io.c:342! [203748.702533] invalid opcode: 0000 [#1] SMP [203748.702561] Modules linked in: ocfs2 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sunrpc dm_switch dm_queue_length dm_multipath bonding be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i iw_cxgb4 cxgb4 cxgb3i libcxgbi iw_cxgb3 cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_devintf iTCO_wdt iTCO_vendor_support dcdbas ipmi_ssif i2c_core ipmi_si ipmi_msghandler acpi_pad pcspkr sb_edac edac_core lpc_ich mfd_core shpchp sg tg3 ptp pps_core ext4 jbd2 mbcache2 sr_mod cdrom sd_mod ahci libahci megaraid_sas wmi dm_mirror dm_region_hash dm_log dm_mod [203748.703024] CPU: 7 PID: 38369 Comm: touch Not tainted 4.1.12-124.18.6.el6uek.x86_64 #2 [203748.703045] Hardware name: Dell Inc. PowerEdge R620/0PXXHP, BIOS 2.5.2 01/28/2015 [203748.703067] task: ffff880768139c00 ti: ffff88006ff48000 task.ti: ffff88006ff48000 [203748.703088] RIP: 0010:[<ffffffffa05e9f09>] [<ffffffffa05e9f09>] ocfs2_read_blocks+0x669/0x7f0 [ocfs2] [203748.703130] RSP: 0018:ffff88006ff4b818 EFLAGS: 00010206 [203748.703389] RAX: 0000000008620029 RBX: ffff88006ff4b910 RCX: 0000000000000000 [203748.703885] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000023079fe [203748.704382] RBP: ffff88006ff4b8d8 R08: 0000000000000000 R09: ffff8807578c25b0 [203748.704877] R10: 000000000f637376 R11: 000000003030322e R12: 0000000000000000 [203748.705373] R13: ffff88006ff4b910 R14: ffff880732fe38f0 R15: 0000000000000000 [203748.705871] FS: 00007f401992c700(0000) GS:ffff880bfebc0000(0000) knlGS:0000000000000000 [203748.706370] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [203748.706627] CR2: 00007f4019252440 CR3: 00000000a621e000 CR4: 0000000000060670 [203748.707124] Stack: [203748.707371] ffff88006ff4b828 ffffffffa0609f52 ffff88006ff4b838 0000000000000001 [203748.707885] 0000000000000000 0000000000000000 ffff880bf67c3800 ffffffffa05eca00 [203748.708399] 00000000023079ff ffffffff81c58b80 0000000000000000 0000000000000000 [203748.708915] Call Trace: [203748.709175] [<ffffffffa0609f52>] ? ocfs2_inode_cache_io_unlock+0x12/0x20 [ocfs2] [203748.709680] [<ffffffffa05eca00>] ? ocfs2_empty_dir_filldir+0x80/0x80 [ocfs2] [203748.710185] [<ffffffffa05ec0cb>] ocfs2_read_dir_block_direct+0x3b/0x200 [ocfs2] [203748.710691] [<ffffffffa05f0fbf>] ocfs2_prepare_dx_dir_for_insert.isra.57+0x19f/0xf60 [ocfs2] [203748.711204] [<ffffffffa065660f>] ? ocfs2_metadata_cache_io_unlock+0x1f/0x30 [ocfs2] [203748.711716] [<ffffffffa05f4f3a>] ocfs2_prepare_dir_for_insert+0x13a/0x890 [ocfs2] [203748.712227] [<ffffffffa05f442e>] ? ocfs2_check_dir_for_entry+0x8e/0x140 [ocfs2] [203748.712737] [<ffffffffa061b2f2>] ocfs2_mknod+0x4b2/0x1370 [ocfs2] [203748.713003] [<ffffffffa061c385>] ocfs2_create+0x65/0x170 [ocfs2] [203748.713263] [<ffffffff8121714b>] vfs_create+0xdb/0x150 [203748.713518] [<ffffffff8121b225>] do_last+0x815/0x1210 [203748.713772] [<ffffffff812192e9>] ? path_init+0xb9/0x450 [203748.714123] [<ffffffff8121bca0>] path_openat+0x80/0x600 [203748.714378] [<ffffffff811bcd45>] ? handle_pte_fault+0xd15/0x1620 [203748.714634] [<ffffffff8121d7ba>] do_filp_open+0x3a/0xb0 [203748.714888] [<ffffffff8122a767>] ? __alloc_fd+0xa7/0x130 [203748.715143] [<ffffffff81209ffc>] do_sys_open+0x12c/0x220 [203748.715403] [<ffffffff81026ddb>] ? syscall_trace_enter_phase1+0x11b/0x180 [203748.715668] [<ffffffff816f0c9f>] ? system_call_after_swapgs+0xe9/0x190 [203748.715928] [<ffffffff8120a10e>] SyS_open+0x1e/0x20 [203748.716184] [<ffffffff816f0d5e>] system_call_fastpath+0x18/0xd7 [203748.716440] Code: 00 00 48 8b 7b 08 48 83 c3 10 45 89 f8 44 89 e1 44 89 f2 4c 89 ee e8 07 06 11 e1 48 8b 03 48 85 c0 75 df 8b 5d c8 e9 4d fa ff ff <0f> 0b 48 8b 7d a0 e8 dc c6 06 00 48 b8 00 00 00 00 00 00 00 10 [203748.717505] RIP [<ffffffffa05e9f09>] ocfs2_read_blocks+0x669/0x7f0 [ocfs2] [203748.717775] RSP <ffff88006ff4b818> Joesph ever reported a similar panic. Link: https://oss.oracle.com/pipermail/ocfs2-devel/2013-May/008931.html Link: http://lkml.kernel.org/r/20180912063207.29484-1-junxiao.bi@oracle.com Signed-off-by: Junxiao Bi <junxiao.bi(a)oracle.com> Cc: Joseph Qi <jiangqi903(a)gmail.com> Cc: Mark Fasheh <mark(a)fasheh.com> Cc: Joel Becker <jlbec(a)evilplan.org> Cc: Changwei Ge <ge.changwei(a)h3c.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- diff -puN fs/ocfs2/buffer_head_io.c~ocfs2-fix-ocfs2-read-block-panic fs/ocfs2/buffer_head_io.c --- a/fs/ocfs2/buffer_head_io.c~ocfs2-fix-ocfs2-read-block-panic +++ a/fs/ocfs2/buffer_head_io.c @@ -342,6 +342,7 @@ int ocfs2_read_blocks(struct ocfs2_cachi * for this bh as it's not marked locally * uptodate. */ status = -EIO; + clear_buffer_needs_validate(bh); put_bh(bh); bhs[i] = NULL; continue; _

6 years, 10 months

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[patch 4/7] mm: shmem.c: Correctly annotate new inodes for lockdep

by akpm＠linux-foundation.org

From: "Joel Fernandes (Google)" <joel(a)joelfernandes.org> Subject: mm: shmem.c: Correctly annotate new inodes for lockdep Directories and inodes don't necessarily need to be in the same lockdep class. For ex, hugetlbfs splits them out too to prevent false positives in lockdep. Annotate correctly after new inode creation. If its a directory inode, it will be put into a different class. This should fix a lockdep splat reported by syzbot: > ====================================================== > WARNING: possible circular locking dependency detected > 4.18.0-rc8-next-20180810+ #36 Not tainted > ------------------------------------------------------ > syz-executor900/4483 is trying to acquire lock: > 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at: inode_lock > include/linux/fs.h:765 [inline] > 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at: > shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602 > > but task is already holding lock: > 0000000025208078 (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x630 > drivers/staging/android/ashmem.c:448 > > which lock already depends on the new lock. > > -> #2 (ashmem_mutex){+.+.}: > __mutex_lock_common kernel/locking/mutex.c:925 [inline] > __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073 > mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 > ashmem_mmap+0x55/0x520 drivers/staging/android/ashmem.c:361 > call_mmap include/linux/fs.h:1844 [inline] > mmap_region+0xf27/0x1c50 mm/mmap.c:1762 > do_mmap+0xa10/0x1220 mm/mmap.c:1535 > do_mmap_pgoff include/linux/mm.h:2298 [inline] > vm_mmap_pgoff+0x213/0x2c0 mm/util.c:357 > ksys_mmap_pgoff+0x4da/0x660 mm/mmap.c:1585 > __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] > __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] > __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > -> #1 (&mm->mmap_sem){++++}: > __might_fault+0x155/0x1e0 mm/memory.c:4568 > _copy_to_user+0x30/0x110 lib/usercopy.c:25 > copy_to_user include/linux/uaccess.h:155 [inline] > filldir+0x1ea/0x3a0 fs/readdir.c:196 > dir_emit_dot include/linux/fs.h:3464 [inline] > dir_emit_dots include/linux/fs.h:3475 [inline] > dcache_readdir+0x13a/0x620 fs/libfs.c:193 > iterate_dir+0x48b/0x5d0 fs/readdir.c:51 > __do_sys_getdents fs/readdir.c:231 [inline] > __se_sys_getdents fs/readdir.c:212 [inline] > __x64_sys_getdents+0x29f/0x510 fs/readdir.c:212 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > -> #0 (&sb->s_type->i_mutex_key#9){++++}: > lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924 > down_write+0x8f/0x130 kernel/locking/rwsem.c:70 > inode_lock include/linux/fs.h:765 [inline] > shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602 > ashmem_shrink_scan+0x236/0x630 drivers/staging/android/ashmem.c:455 > ashmem_ioctl+0x3ae/0x13a0 drivers/staging/android/ashmem.c:797 > vfs_ioctl fs/ioctl.c:46 [inline] > file_ioctl fs/ioctl.c:501 [inline] > do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 > ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 > __do_sys_ioctl fs/ioctl.c:709 [inline] > __se_sys_ioctl fs/ioctl.c:707 [inline] > __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > other info that might help us debug this: > > Chain exists of: > &sb->s_type->i_mutex_key#9 --> &mm->mmap_sem --> ashmem_mutex > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(ashmem_mutex); > lock(&mm->mmap_sem); > lock(ashmem_mutex); > lock(&sb->s_type->i_mutex_key#9); > > *** DEADLOCK *** > > 1 lock held by syz-executor900/4483: > #0: 0000000025208078 (ashmem_mutex){+.+.}, at: > ashmem_shrink_scan+0xb4/0x630 drivers/staging/android/ashmem.c:448 Link: http://lkml.kernel.org/r/20180821231835.166639-1-joel@joelfernandes.org Signed-off-by: Joel Fernandes (Google) <joel(a)joelfernandes.org> Reported-by: syzbot <syzkaller(a)googlegroups.com> Reviewed-by: NeilBrown <neilb(a)suse.com> Suggested-by: NeilBrown <neilb(a)suse.com> Cc: Matthew Wilcox <willy(a)infradead.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Hugh Dickins <hughd(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- diff -puN mm/shmem.c~mm-shmem-correctly-annotate-new-inodes-for-lockdep mm/shmem.c --- a/mm/shmem.c~mm-shmem-correctly-annotate-new-inodes-for-lockdep +++ a/mm/shmem.c @@ -2227,6 +2227,8 @@ static struct inode *shmem_get_inode(str mpol_shared_policy_init(&info->policy, NULL); break; } + + lockdep_annotate_inode_mutex_key(inode); } else shmem_free_inode(sb); return inode; _

6 years, 10 months

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[patch 2/7] mm: disable deferred struct page for 32-bit arches

by akpm＠linux-foundation.org

From: Pasha Tatashin <Pavel.Tatashin(a)microsoft.com> Subject: mm: disable deferred struct page for 32-bit arches Deferred struct page init is needed only on systems with large amount of physical memory to improve boot performance. 32-bit systems do not benefit from this feature. Jiri reported a problem where deferred struct pages do not work well with x86-32: [ 0.035162] Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) [ 0.035725] Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) [ 0.036269] Initializing CPU#0 [ 0.036513] Initializing HighMem for node 0 (00036ffe:0007ffe0) [ 0.038459] page:f6780000 is uninitialized and poisoned [ 0.038460] raw: ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff [ 0.039509] page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page)) [ 0.040038] ------------[ cut here ]------------ [ 0.040399] kernel BUG at include/linux/page-flags.h:293! [ 0.040823] invalid opcode: 0000 [#1] SMP PTI [ 0.041166] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc1_pt_jiri #9 [ 0.041694] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014 [ 0.042496] EIP: free_highmem_page+0x64/0x80 [ 0.042839] Code: 13 46 d8 c1 e8 18 5d 83 e0 03 8d 04 c0 c1 e0 06 ff 80 ec 5f 44 d8 c3 8d b4 26 00 00 00 00 ba 08 65 28 d8 89 d8 e8 fc 71 02 00 <0f> 0b 8d 76 00 8d bc 27 00 00 00 00 ba d0 b1 26 d8 89 d8 e8 e4 71 [ 0.044338] EAX: 0000003c EBX: f6780000 ECX: 00000000 EDX: d856cbe8 [ 0.044868] ESI: 0007ffe0 EDI: d838df20 EBP: d838df00 ESP: d838defc [ 0.045372] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00210086 [ 0.045913] CR0: 80050033 CR2: 00000000 CR3: 18556000 CR4: 00040690 [ 0.046413] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.046913] DR6: fffe0ff0 DR7: 00000400 [ 0.047220] Call Trace: [ 0.047419] add_highpages_with_active_regions+0xbd/0x10d [ 0.047854] set_highmem_pages_init+0x5b/0x71 [ 0.048202] mem_init+0x2b/0x1e8 [ 0.048460] start_kernel+0x1d2/0x425 [ 0.048757] i386_start_kernel+0x93/0x97 [ 0.049073] startup_32_smp+0x164/0x168 [ 0.049379] Modules linked in: [ 0.049626] ---[ end trace 337949378db0abbb ]--- We free highmem pages before their struct pages are initialized: mem_init() set_highmem_pages_init() add_highpages_with_active_regions() free_highmem_page() .. Access uninitialized struct page here.. Because there is no reason to have this feature on 32-bit systems, just disable it. Link: http://lkml.kernel.org/r/20180831150506.31246-1-pavel.tatashin@microsoft.com Fixes: 2e3ca40f03bb ("mm: relax deferred struct page requirements") Signed-off-by: Pavel Tatashin <pavel.tatashin(a)microsoft.com> Reported-by: Jiri Slaby <jslaby(a)suse.cz> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- diff -puN mm/Kconfig~mm-disable-deferred-struct-page-for-32-bit-arches mm/Kconfig --- a/mm/Kconfig~mm-disable-deferred-struct-page-for-32-bit-arches +++ a/mm/Kconfig @@ -637,6 +637,7 @@ config DEFERRED_STRUCT_PAGE_INIT depends on NO_BOOTMEM depends on SPARSEMEM depends on !NEED_PER_CPU_KM + depends on 64BIT help Ordinarily all struct pages are initialised during early boot in a single thread. On very large machines this can take a considerable _

6 years, 10 months

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[patch 1/7] fork: report pid exhaustion correctly

by akpm＠linux-foundation.org

From: KJ Tsanaktsidis <ktsanaktsidis(a)zendesk.com> Subject: fork: report pid exhaustion correctly Make the clone and fork syscalls return EAGAIN when the limit on the number of pids /proc/sys/kernel/pid_max is exceeded. Currently, when the pid_max limit is exceeded, the kernel will return ENOSPC from the fork and clone syscalls. This is contrary to the documented behaviour, which explicitly calls out the pid_max case as one where EAGAIN should be returned. It also leads to really confusing error messages in userspace programs which will complain about a lack of disk space when they fail to create processes/threads for this reason. This error is being returned because alloc_pid() uses the idr api to find a new pid; when there are none available, idr_alloc_cyclic() returns -ENOSPC, and this is being propagated back to userspace. This behaviour has been broken before, and was explicitly fixed in commit 35f71bc0a09a ("fork: report pid reservation failure properly"), so I think -EAGAIN is definitely the right thing to return in this case. The current behaviour change dates from commit 95846ecf9dac ("pid: replace pid bitmap implementation with IDR AIP") and was I believe unintentional. This patch has no impact on the case where allocating a pid fails because the child reaper for the namespace is dead; that case will still return -ENOMEM. Link: http://lkml.kernel.org/r/20180903111016.46461-1-ktsanaktsidis@zendesk.com Fixes: 95846ecf9dac ("pid: replace pid bitmap implementation with IDR AIP") Signed-off-by: KJ Tsanaktsidis <ktsanaktsidis(a)zendesk.com> Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: Gargi Sharma <gs051095(a)gmail.com> Cc: Rik van Riel <riel(a)redhat.com> Cc: Oleg Nesterov <oleg(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- diff -puN kernel/pid.c~fork-report-pid-exhaustion-correctly kernel/pid.c --- a/kernel/pid.c~fork-report-pid-exhaustion-correctly +++ a/kernel/pid.c @@ -195,7 +195,7 @@ struct pid *alloc_pid(struct pid_namespa idr_preload_end(); if (nr < 0) { - retval = nr; + retval = (nr == -ENOSPC) ? -EAGAIN : nr; goto out_free; } _

6 years, 10 months

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Applied "regulator: fix crash caused by null driver data" to the regulator tree

by Mark Brown

The patch regulator: fix crash caused by null driver data has been applied to the regulator tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From fb6de923ca3358a91525552b4907d4cb38730bdd Mon Sep 17 00:00:00 2001 From: Yu Zhao <yuzhao(a)google.com> Date: Wed, 19 Sep 2018 15:30:51 -0600 Subject: [PATCH] regulator: fix crash caused by null driver data dev_set_drvdata() needs to be called before device_register() exposes device to userspace. Otherwise kernel crashes after it gets null pointer from dev_get_drvdata() when userspace tries to access sysfs entries. [Removed backtrace for length -- broonie] Signed-off-by: Yu Zhao <yuzhao(a)google.com> Signed-off-by: Mark Brown <broonie(a)kernel.org> Cc: stable(a)vger.kernel.org --- drivers/regulator/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 90215f57270f..9577d8941846 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4395,13 +4395,13 @@ regulator_register(const struct regulator_desc *regulator_desc, !rdev->desc->fixed_uV) rdev->is_switch = true; + dev_set_drvdata(&rdev->dev, rdev); ret = device_register(&rdev->dev); if (ret != 0) { put_device(&rdev->dev); goto unset_supplies; } - dev_set_drvdata(&rdev->dev, rdev); rdev_init_debugfs(rdev); /* try to resolve regulators supply since a new one was registered */ -- 2.19.0

6 years, 10 months

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[PATCH] xen/x86/vpmu: Zero struct pt_regs before calling into sample handling code

by Boris Ostrovsky

Otherwise we may leak kernel stack for events that sample user registers. Reported-by: Mark Rutland <mark.rutland(a)arm.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky(a)oracle.com> Cc: stable(a)vger.kernel.org --- arch/x86/xen/pmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c index 7d00d4a..95997e6 100644 --- a/arch/x86/xen/pmu.c +++ b/arch/x86/xen/pmu.c @@ -478,7 +478,7 @@ static void xen_convert_regs(const struct xen_pmu_regs *xen_regs, irqreturn_t xen_pmu_irq_handler(int irq, void *dev_id) { int err, ret = IRQ_NONE; - struct pt_regs regs; + struct pt_regs regs = {0}; const struct xen_pmu_data *xenpmu_data = get_xenpmu_data(); uint8_t xenpmu_flags = get_xenpmu_flags(); -- 1.8.3.1

6 years, 10 months

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[PATCH v2 3/3] usb: typec: pci: Enable Intel USB role mux on Apollo Lake platforms

by Mathias Nyman

From: Heikki Krogerus <heikki.krogerus(a)linux.intel.com> Intel Apollo Lake has the same internal USB role mux as Intel Cherry Trail. Cc: <stable(a)vger.kernel.org> Signed-off-by: Heikki Krogerus <heikki.krogerus(a)linux.intel.com> Signed-off-by: Mathias Nyman <mathias.nyman(a)linux.intel.com> --- drivers/usb/host/xhci-pci.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 722860e..51dd8e0 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -179,10 +179,12 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci) xhci->quirks |= XHCI_PME_STUCK_QUIRK; } if (pdev->vendor == PCI_VENDOR_ID_INTEL && - pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) { + pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) xhci->quirks |= XHCI_SSIC_PORT_UNUSED; + if (pdev->vendor == PCI_VENDOR_ID_INTEL && + (pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI || + pdev->device == PCI_DEVICE_ID_INTEL_APL_XHCI)) xhci->quirks |= XHCI_INTEL_USB_ROLE_SW; - } if (pdev->vendor == PCI_VENDOR_ID_INTEL && (pdev->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI || pdev->device == PCI_DEVICE_ID_INTEL_SUNRISEPOINT_LP_XHCI || -- 2.7.4

6 years, 10 months

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