Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
code
Clone this repository
https://tangled.org/tjh.dev/kernel
git@gordian.tjh.dev:tjh.dev/kernel
For self-hosted knots, clone URLs may differ based on your setup.
Pull btrfs fixes from David Sterba:
"These are fixes that were found during testing with help of error
injection, plus some other stable material.
There's a fixup to patch added to rc1 causing locking in wrong context
warnings, tests found one more deadlock scenario. The patches are
tagged for stable, two of them now in the queue but we'd like all
three released at the same time.
I'm not happy about fixes to fixes in such a fast succession during
rcs, but I hope we found all the fallouts of commit 28553fa992cb
('Btrfs: fix race between shrinking truncate and fiemap')"
* tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof
Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
btrfs: fix bytes_may_use underflow in prealloc error condtition
btrfs: handle logged extent failure properly
btrfs: do not check delayed items are empty for single transaction cleanup
btrfs: reset fs_root to NULL on error in open_ctree
btrfs: destroy qgroup extent records on transaction abort
Pull ext4 fixes from Ted Ts'o:
"More miscellaneous ext4 bug fixes (all stable fodder)"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix mount failure with quota configured as module
jbd2: fix ocfs2 corrupt when clearing block group bits
ext4: fix race between writepages and enabling EXT4_EXTENTS_FL
ext4: rename s_journal_flag_rwsem to s_writepages_rwsem
ext4: fix potential race between s_flex_groups online resizing and access
ext4: fix potential race between s_group_info online resizing and access
ext4: fix potential race between online resizing and write operations
ext4: add cond_resched() to __ext4_find_entry()
ext4: fix a data race in EXT4_I(inode)->i_disksize
While logging the prealloc extents of an inode during a fast fsync we call
btrfs_truncate_inode_items(), through btrfs_log_prealloc_extents(), while
holding a read lock on a leaf of the inode's root (not the log root, the
fs/subvol root), and then that function locks the file range in the inode's
iotree. This can lead to a deadlock when:
* the fsync is ranged
* the file has prealloc extents beyond eof
* writeback for a range different from the fsync range starts
during the fsync
* the size of the file is not sector size aligned
Because when finishing an ordered extent we lock first a file range and
then try to COW the fs/subvol tree to insert an extent item.
The following diagram shows how the deadlock can happen.
CPU 1 CPU 2
btrfs_sync_file()
--> for range [0, 1MiB)
--> inode has a size of
1MiB and has 1 prealloc
extent beyond the
i_size, starting at offset
4MiB
flushes all delalloc for the
range [0MiB, 1MiB) and waits
for the respective ordered
extents to complete
--> before task at CPU 1 locks the
inode, a write into file range
[1MiB, 2MiB + 1KiB) is made
--> i_size is updated to 2MiB + 1KiB
--> writeback is started for that
range, [1MiB, 2MiB + 4KiB)
--> end offset rounded up to
be sector size aligned
btrfs_log_dentry_safe()
btrfs_log_inode_parent()
btrfs_log_inode()
btrfs_log_changed_extents()
btrfs_log_prealloc_extents()
--> does a search on the
inode's root
--> holds a read lock on
leaf X
btrfs_finish_ordered_io()
--> locks range [1MiB, 2MiB + 4KiB)
--> end offset rounded up
to be sector size aligned
--> tries to cow leaf X, through
insert_reserved_file_extent()
--> already locked by the
task at CPU 1
btrfs_truncate_inode_items()
--> gets an i_size of
2MiB + 1KiB, which is
not sector size
aligned
--> tries to lock file
range [2MiB, (u64)-1)
--> the start range
is rounded down
from 2MiB + 1K
to 2MiB to be sector
size aligned
--> but the subrange
[2MiB, 2MiB + 4KiB) is
already locked by
task at CPU 2 which
is waiting to get a
write lock on leaf X
for which we are
holding a read lock
*** deadlock ***
This results in a stack trace like the following, triggered by test case
generic/561 from fstests:
[ 2779.973608] INFO: task kworker/u8:6:247 blocked for more than 120 seconds.
[ 2779.979536] Not tainted 5.6.0-rc2-btrfs-next-53 #1
[ 2779.984503] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 2779.990136] kworker/u8:6 D 0 247 2 0x80004000
[ 2779.990457] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
[ 2779.990466] Call Trace:
[ 2779.990491] ? __schedule+0x384/0xa30
[ 2779.990521] schedule+0x33/0xe0
[ 2779.990616] btrfs_tree_read_lock+0x19e/0x2e0 [btrfs]
[ 2779.990632] ? remove_wait_queue+0x60/0x60
[ 2779.990730] btrfs_read_lock_root_node+0x2f/0x40 [btrfs]
[ 2779.990782] btrfs_search_slot+0x510/0x1000 [btrfs]
[ 2779.990869] btrfs_lookup_file_extent+0x4a/0x70 [btrfs]
[ 2779.990944] __btrfs_drop_extents+0x161/0x1060 [btrfs]
[ 2779.990987] ? mark_held_locks+0x6d/0xc0
[ 2779.990994] ? __slab_alloc.isra.49+0x99/0x100
[ 2779.991060] ? insert_reserved_file_extent.constprop.19+0x64/0x300 [btrfs]
[ 2779.991145] insert_reserved_file_extent.constprop.19+0x97/0x300 [btrfs]
[ 2779.991222] ? start_transaction+0xdd/0x5c0 [btrfs]
[ 2779.991291] btrfs_finish_ordered_io+0x4f4/0x840 [btrfs]
[ 2779.991405] btrfs_work_helper+0xaa/0x720 [btrfs]
[ 2779.991432] process_one_work+0x26d/0x6a0
[ 2779.991460] worker_thread+0x4f/0x3e0
[ 2779.991481] ? process_one_work+0x6a0/0x6a0
[ 2779.991489] kthread+0x103/0x140
[ 2779.991499] ? kthread_create_worker_on_cpu+0x70/0x70
[ 2779.991515] ret_from_fork+0x3a/0x50
(...)
[ 2780.026211] INFO: task fsstress:17375 blocked for more than 120 seconds.
[ 2780.027480] Not tainted 5.6.0-rc2-btrfs-next-53 #1
[ 2780.028482] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 2780.030035] fsstress D 0 17375 17373 0x00004000
[ 2780.030038] Call Trace:
[ 2780.030044] ? __schedule+0x384/0xa30
[ 2780.030052] schedule+0x33/0xe0
[ 2780.030075] lock_extent_bits+0x20c/0x320 [btrfs]
[ 2780.030094] ? btrfs_truncate_inode_items+0xf4/0x1150 [btrfs]
[ 2780.030098] ? rcu_read_lock_sched_held+0x59/0xa0
[ 2780.030102] ? remove_wait_queue+0x60/0x60
[ 2780.030122] btrfs_truncate_inode_items+0x133/0x1150 [btrfs]
[ 2780.030151] ? btrfs_set_path_blocking+0xb2/0x160 [btrfs]
[ 2780.030165] ? btrfs_search_slot+0x379/0x1000 [btrfs]
[ 2780.030195] btrfs_log_changed_extents.isra.8+0x841/0x93e [btrfs]
[ 2780.030202] ? do_raw_spin_unlock+0x49/0xc0
[ 2780.030215] ? btrfs_get_num_csums+0x10/0x10 [btrfs]
[ 2780.030239] btrfs_log_inode+0xf83/0x1124 [btrfs]
[ 2780.030251] ? __mutex_unlock_slowpath+0x45/0x2a0
[ 2780.030275] btrfs_log_inode_parent+0x2a0/0xe40 [btrfs]
[ 2780.030282] ? dget_parent+0xa1/0x370
[ 2780.030309] btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
[ 2780.030329] btrfs_sync_file+0x3f3/0x490 [btrfs]
[ 2780.030339] do_fsync+0x38/0x60
[ 2780.030343] __x64_sys_fdatasync+0x13/0x20
[ 2780.030345] do_syscall_64+0x5c/0x280
[ 2780.030348] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 2780.030356] RIP: 0033:0x7f2d80f6d5f0
[ 2780.030361] Code: Bad RIP value.
[ 2780.030362] RSP: 002b:00007ffdba3c8548 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[ 2780.030364] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2d80f6d5f0
[ 2780.030365] RDX: 00007ffdba3c84b0 RSI: 00007ffdba3c84b0 RDI: 0000000000000003
[ 2780.030367] RBP: 000000000000004a R08: 0000000000000001 R09: 00007ffdba3c855c
[ 2780.030368] R10: 0000000000000078 R11: 0000000000000246 R12: 00000000000001f4
[ 2780.030369] R13: 0000000051eb851f R14: 00007ffdba3c85f0 R15: 0000557a49220d90
So fix this by making btrfs_truncate_inode_items() not lock the range in
the inode's iotree when the target root is a log root, since it's not
needed to lock the range for log roots as the protection from the inode's
lock and log_mutex are all that's needed.
Fixes: 28553fa992cb28 ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull csky updates from Guo Ren:
"Sorry, I missed 5.6-rc1 merge window, but in this pull request the
most are the fixes and the rests are between fixes and features. The
only outside modification is the MAINTAINERS file update with our
mailing list.
- cache flush implementation fixes
- ftrace modify panic fix
- CONFIG_SMP boot problem fix
- fix pt_regs saving for atomic.S
- fix fixaddr_init without highmem.
- fix stack protector support
- fix fake Tightly-Coupled Memory code compile and use
- fix some typos and coding convention"
* tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linux: (23 commits)
csky: Replace <linux/clk-provider.h> by <linux/of_clk.h>
csky: Implement copy_thread_tls
csky: Add PCI support
csky: Minimize defconfig to support buildroot config.fragment
csky: Add setup_initrd check code
csky: Cleanup old Kconfig options
arch/csky: fix some Kconfig typos
csky: Fixup compile warning for three unimplemented syscalls
csky: Remove unused cache implementation
csky: Fixup ftrace modify panic
csky: Add flush_icache_mm to defer flush icache all
csky: Optimize abiv2 copy_to_user_page with VM_EXEC
csky: Enable defer flush_dcache_page for abiv2 cpus (807/810/860)
csky: Remove unnecessary flush_icache_* implementation
csky: Support icache flush without specific instructions
csky/Kconfig: Add Kconfig.platforms to support some drivers
csky/smp: Fixup boot failed when CONFIG_SMP
csky: Set regs->usp to kernel sp, when the exception is from kernel
csky/mm: Fixup export invalid_pte_table symbol
csky: Separate fixaddr_init from highmem
...
When CONFIG_QFMT_V2 is configured as a module, the test in
ext4_feature_set_ok() fails and so mount of filesystems with quota or
project features fails. Fix the test to use IS_ENABLED macro which
works properly even for modules.
Link: https://lore.kernel.org/r/20200221100835.9332-1-jack@suse.cz
Fixes: d65d87a07476 ("ext4: improve explanation of a mount failure caused by a misconfigured kernel")
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
In btrfs_wait_ordered_range() once we find an ordered extent that has
finished with an error we exit the loop and don't wait for any other
ordered extents that might be still in progress.
All the users of btrfs_wait_ordered_range() expect that there are no more
ordered extents in progress after that function returns. So past fixes
such like the ones from the two following commits:
ff612ba7849964 ("btrfs: fix panic during relocation after ENOSPC before
writeback happens")
28aeeac1dd3080 ("Btrfs: fix panic when starting bg cache writeout after
IO error")
don't work when there are multiple ordered extents in the range.
Fix that by making btrfs_wait_ordered_range() wait for all ordered extents
even after it finds one that had an error.
Link: https://github.com/kdave/btrfs-progs/issues/228#issuecomment-569777554
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull RAS fixes from Thomas Gleixner:
"Two fixes for the AMD MCE driver:
- Populate the per CPU MCA bank descriptor pointer only after it has
been completely set up to prevent a use-after-free in case that one
of the subsequent initialization step fails
- Implement a proper release function for the sysfs entries of MCA
threshold controls instead of freeing the memory right in the CPU
teardown code, which leads to another use-after-free when the
associated sysfs file is opened and accessed"
* tag 'ras-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce/amd: Fix kobject lifetime
x86/mce/amd: Publish the bank pointer only after setup has succeeded
The C-Sky platform code is not a clock provider, and just needs to call
of_clk_init().
Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
I found a NULL pointer dereference in ocfs2_block_group_clear_bits().
The running environment:
kernel version: 4.19
A cluster with two nodes, 5 luns mounted on two nodes, and do some
file operations like dd/fallocate/truncate/rm on every lun with storage
network disconnection.
The fallocate operation on dm-23-45 caused an null pointer dereference.
The information of NULL pointer dereference as follows:
[577992.878282] JBD2: Error -5 detected when updating journal superblock for dm-23-45.
[577992.878290] Aborting journal on device dm-23-45.
...
[577992.890778] JBD2: Error -5 detected when updating journal superblock for dm-24-46.
[577992.890908] __journal_remove_journal_head: freeing b_committed_data
[577992.890916] (fallocate,88392,52):ocfs2_extend_trans:474 ERROR: status = -30
[577992.890918] __journal_remove_journal_head: freeing b_committed_data
[577992.890920] (fallocate,88392,52):ocfs2_rotate_tree_right:2500 ERROR: status = -30
[577992.890922] __journal_remove_journal_head: freeing b_committed_data
[577992.890924] (fallocate,88392,52):ocfs2_do_insert_extent:4382 ERROR: status = -30
[577992.890928] (fallocate,88392,52):ocfs2_insert_extent:4842 ERROR: status = -30
[577992.890928] __journal_remove_journal_head: freeing b_committed_data
[577992.890930] (fallocate,88392,52):ocfs2_add_clusters_in_btree:4947 ERROR: status = -30
[577992.890933] __journal_remove_journal_head: freeing b_committed_data
[577992.890939] __journal_remove_journal_head: freeing b_committed_data
[577992.890949] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
[577992.890950] Mem abort info:
[577992.890951] ESR = 0x96000004
[577992.890952] Exception class = DABT (current EL), IL = 32 bits
[577992.890952] SET = 0, FnV = 0
[577992.890953] EA = 0, S1PTW = 0
[577992.890954] Data abort info:
[577992.890955] ISV = 0, ISS = 0x00000004
[577992.890956] CM = 0, WnR = 0
[577992.890958] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000f8da07a9
[577992.890960] [0000000000000020] pgd=0000000000000000
[577992.890964] Internal error: Oops: 96000004 [#1] SMP
[577992.890965] Process fallocate (pid: 88392, stack limit = 0x00000000013db2fd)
[577992.890968] CPU: 52 PID: 88392 Comm: fallocate Kdump: loaded Tainted: G W OE 4.19.36 #1
[577992.890969] Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019
[577992.890971] pstate: 60400009 (nZCv daif +PAN -UAO)
[577992.891054] pc : _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
[577992.891082] lr : _ocfs2_free_suballoc_bits+0x618/0x968 [ocfs2]
[577992.891084] sp : ffff0000c8e2b810
[577992.891085] x29: ffff0000c8e2b820 x28: 0000000000000000
[577992.891087] x27: 00000000000006f3 x26: ffffa07957b02e70
[577992.891089] x25: ffff807c59d50000 x24: 00000000000006f2
[577992.891091] x23: 0000000000000001 x22: ffff807bd39abc30
[577992.891093] x21: ffff0000811d9000 x20: ffffa07535d6a000
[577992.891097] x19: ffff000001681638 x18: ffffffffffffffff
[577992.891098] x17: 0000000000000000 x16: ffff000080a03df0
[577992.891100] x15: ffff0000811d9708 x14: 203d207375746174
[577992.891101] x13: 73203a524f525245 x12: 20373439343a6565
[577992.891103] x11: 0000000000000038 x10: 0101010101010101
[577992.891106] x9 : ffffa07c68a85d70 x8 : 7f7f7f7f7f7f7f7f
[577992.891109] x7 : 0000000000000000 x6 : 0000000000000080
[577992.891110] x5 : 0000000000000000 x4 : 0000000000000002
[577992.891112] x3 : ffff000001713390 x2 : 2ff90f88b1c22f00
[577992.891114] x1 : ffff807bd39abc30 x0 : 0000000000000000
[577992.891116] Call trace:
[577992.891139] _ocfs2_free_suballoc_bits+0x63c/0x968 [ocfs2]
[577992.891162] _ocfs2_free_clusters+0x100/0x290 [ocfs2]
[577992.891185] ocfs2_free_clusters+0x50/0x68 [ocfs2]
[577992.891206] ocfs2_add_clusters_in_btree+0x198/0x5e0 [ocfs2]
[577992.891227] ocfs2_add_inode_data+0x94/0xc8 [ocfs2]
[577992.891248] ocfs2_extend_allocation+0x1bc/0x7a8 [ocfs2]
[577992.891269] ocfs2_allocate_extents+0x14c/0x338 [ocfs2]
[577992.891290] __ocfs2_change_file_space+0x3f8/0x610 [ocfs2]
[577992.891309] ocfs2_fallocate+0xe4/0x128 [ocfs2]
[577992.891316] vfs_fallocate+0x11c/0x250
[577992.891317] ksys_fallocate+0x54/0x88
[577992.891319] __arm64_sys_fallocate+0x28/0x38
[577992.891323] el0_svc_common+0x78/0x130
[577992.891325] el0_svc_handler+0x38/0x78
[577992.891327] el0_svc+0x8/0xc
My analysis process as follows:
ocfs2_fallocate
__ocfs2_change_file_space
ocfs2_allocate_extents
ocfs2_extend_allocation
ocfs2_add_inode_data
ocfs2_add_clusters_in_btree
ocfs2_insert_extent
ocfs2_do_insert_extent
ocfs2_rotate_tree_right
ocfs2_extend_rotate_transaction
ocfs2_extend_trans
jbd2_journal_restart
jbd2__journal_restart
/* handle->h_transaction is NULL,
* is_handle_aborted(handle) is true
*/
handle->h_transaction = NULL;
start_this_handle
return -EROFS;
ocfs2_free_clusters
_ocfs2_free_clusters
_ocfs2_free_suballoc_bits
ocfs2_block_group_clear_bits
ocfs2_journal_access_gd
__ocfs2_journal_access
jbd2_journal_get_undo_access
/* I think jbd2_write_access_granted() will
* return true, because do_get_write_access()
* will return -EROFS.
*/
if (jbd2_write_access_granted(...)) return 0;
do_get_write_access
/* handle->h_transaction is NULL, it will
* return -EROFS here, so do_get_write_access()
* was not called.
*/
if (is_handle_aborted(handle)) return -EROFS;
/* bh2jh(group_bh) is NULL, caused NULL
pointer dereference */
undo_bg = (struct ocfs2_group_desc *)
bh2jh(group_bh)->b_committed_data;
If handle->h_transaction == NULL, then jbd2_write_access_granted()
does not really guarantee that journal_head will stay around,
not even speaking of its b_committed_data. The bh2jh(group_bh)
can be removed after ocfs2_journal_access_gd() and before call
"bh2jh(group_bh)->b_committed_data". So, we should move
is_handle_aborted() check from do_get_write_access() into
jbd2_journal_get_undo_access() and jbd2_journal_get_write_access()
before the call to jbd2_write_access_granted().
Link: https://lore.kernel.org/r/f72a623f-b3f1-381a-d91d-d22a1c83a336@huawei.com
Signed-off-by: Yan Wang <wangyan122@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
I hit the following warning while running my error injection stress
testing:
WARNING: CPU: 3 PID: 1453 at fs/btrfs/space-info.h:108 btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs]
RIP: 0010:btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs]
Call Trace:
btrfs_free_reserved_data_space+0x4f/0x70 [btrfs]
__btrfs_prealloc_file_range+0x378/0x470 [btrfs]
elfcorehdr_read+0x40/0x40
? elfcorehdr_read+0x40/0x40
? btrfs_commit_transaction+0xca/0xa50 [btrfs]
? dput+0xb4/0x2a0
? btrfs_log_dentry_safe+0x55/0x70 [btrfs]
? btrfs_sync_file+0x30e/0x420 [btrfs]
? do_fsync+0x38/0x70
? __x64_sys_fdatasync+0x13/0x20
? do_syscall_64+0x5b/0x1b0
? entry_SYSCALL_64_after_hwframe+0x44/0xa9
This happens if we fail to insert our reserved file extent. At this
point we've already converted our reservation from ->bytes_may_use to
->bytes_reserved. However once we break we will attempt to free
everything from [cur_offset, end] from ->bytes_may_use, but our extent
reservation will overlap part of this.
Fix this problem by adding ins.offset (our extent allocation size) to
cur_offset so we remove the actual remaining part from ->bytes_may_use.
I validated this fix using my inject-error.py script
python inject-error.py -o should_fail_bio -t cache_save_setup -t \
__btrfs_prealloc_file_range \
-t insert_reserved_file_extent.constprop.0 \
-r "-5" ./run-fsstress.sh
where run-fsstress.sh simply mounts and runs fsstress on a disk.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull irq fixes from Thomas Gleixner:
"Two fixes for the irq core code which are follow ups to the recent MSI
fixes:
- The WARN_ON which was put into the MSI setaffinity callback for
paranoia reasons actually triggered via a callchain which escaped
when all the possible ways to reach that code were analyzed.
The proc/irq/$N/*affinity interfaces have a quirk which came in
when ALPHA moved to the generic interface: In case that the written
affinity mask does not contain any online CPU it calls into ALPHAs
magic auto affinity setting code.
A few years later this mechanism was also made available to x86 for
no good reasons and in a way which circumvents all sanity checks
for interrupts which cannot have their affinity set from process
context on X86 due to the way the X86 interrupt delivery works.
It would be possible to make this work properly, but there is no
point in doing so. If the interrupt is not yet started then the
affinity setting has no effect and if it is started already then it
is already assigned to an online CPU so there is no point to
randomly move it to some other CPU. Just return EINVAL as the code
has done before that change forever.
- The new MSI quirk bit in the irq domain flags turned out to be
already occupied, which escaped the author and the reviewers
because the already in use bits were 0,6,2,3,4,5 listed in that
order.
That bit 6 was simply overlooked because the ordering was straight
forward linear otherwise. So the new bit ended up being a
duplicate.
Fix it up by switching the oddball 6 to the obvious 1"
* tag 'irq-urgent-2020-02-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/irqdomain: Make sure all irq domain flags are distinct
genirq/proc: Reject invalid affinity masks (again)
Accessing the MCA thresholding controls in sysfs concurrently with CPU
hotplug can lead to a couple of KASAN-reported issues:
BUG: KASAN: use-after-free in sysfs_file_ops+0x155/0x180
Read of size 8 at addr ffff888367578940 by task grep/4019
and
BUG: KASAN: use-after-free in show_error_count+0x15c/0x180
Read of size 2 at addr ffff888368a05514 by task grep/4454
for example. Both result from the fact that the threshold block
creation/teardown code frees the descriptor memory itself instead of
defining proper ->release function and leaving it to the driver core to
take care of that, after all sysfs accesses have completed.
Do that and get rid of the custom freeing code, fixing the above UAFs in
the process.
[ bp: write commit message. ]
Fixes: 95268664390b ("[PATCH] x86_64: mce_amd support for family 0x10 processors")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200214082801.13836-1-bp@alien8.de
This is required for clone3 which passes the TLS value through a
struct rather than a register.
Cc: Amanieu d'Antras <amanieu@gmail.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>