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2023-04-28Merge tag 'trace-v6.4' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - User events are finally ready! After lots of collaboration between various parties, we finally locked down on a stable interface for user events that can also work with user space only tracing. This is implemented by telling the kernel (or user space library, but that part is user space only and not part of this patch set), where the variable is that the application uses to know if something is listening to the trace. There's also an interface to tell the kernel about these events, which will show up in the /sys/kernel/tracing/events/user_events/ directory, where it can be enabled. When it's enabled, the kernel will update the variable, to tell the application to start writing to the kernel. See https://lwn.net/Articles/927595/ - Cleaned up the direct trampolines code to simplify arm64 addition of direct trampolines. Direct trampolines use the ftrace interface but instead of jumping to the ftrace trampoline, applications (mostly BPF) can register their own trampoline for performance reasons. - Some updates to the fprobe infrastructure. fprobes are more efficient than kprobes, as it does not need to save all the registers that kprobes on ftrace do. More work needs to be done before the fprobes will be exposed as dynamic events. - More updates to references to the obsolete path of /sys/kernel/debug/tracing for the new /sys/kernel/tracing path. - Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer line by line instead of all at once. There are users in production kernels that have a large data dump that originally used printk() directly, but the data dump was larger than what printk() allowed as a single print. Using seq_buf() to do the printing fixes that. - Add /sys/kernel/tracing/touched_functions that shows all functions that was every traced by ftrace or a direct trampoline. This is used for debugging issues where a traced function could have caused a crash by a bpf program or live patching. - Add a "fields" option that is similar to "raw" but outputs the fields of the events. It's easier to read by humans. - Some minor fixes and clean ups. * tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (41 commits) ring-buffer: Sync IRQ works before buffer destruction tracing: Add missing spaces in trace_print_hex_seq() ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus recordmcount: Fix memory leaks in the uwrite function tracing/user_events: Limit max fault-in attempts tracing/user_events: Prevent same address and bit per process tracing/user_events: Ensure bit is cleared on unregister tracing/user_events: Ensure write index cannot be negative seq_buf: Add seq_buf_do_printk() helper tracing: Fix print_fields() for __dyn_loc/__rel_loc tracing/user_events: Set event filter_type from type ring-buffer: Clearly check null ptr returned by rb_set_head_page() tracing: Unbreak user events tracing/user_events: Use print_format_fields() for trace output tracing/user_events: Align structs with tabs for readability tracing/user_events: Limit global user_event count tracing/user_events: Charge event allocs to cgroups tracing/user_events: Update documentation for ABI tracing/user_events: Use write ABI in example tracing/user_events: Add ABI self-test ...
2023-04-28NFSv4.2: Rework scratch handling for READ_PLUSAnna Schumaker2-7/+14
Instead of using a tiny, static scratch buffer, we should use a kmalloc()-ed buffer that is allocated when checking for read plus usage. This lets us use the buffer before decoding any part of the READ_PLUS operation instead of setting it right before segment decoding, meaning it should be a little more robust. Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2023-04-28fs/9p: Fix bit operation logic errorEric Van Hensbergen2-2/+2
This re-introduces a fix that somehow got dropped during rebase of the current series in for-next. When writeback is enabled, opens are forced to support both read and write operations but with the logic error other flags may be dropped unintentionaly. Reported-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr> Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2023-04-28ext4: clean up error handling in __ext4_fill_super()Theodore Ts'o1-22/+29
There were two ways to return an error code; one was via setting the 'err' variable, and the second, if err was zero, was via the 'ret' variable. This was both confusing and fragile, and when code was factored out of __ext4_fill_super(), some of the error codes returned by the original code was replaced by -EINVAL, and in one case, the error code was placed by 0, triggering a kernel null pointer dereference. Clean this up by removing the 'ret' variable, leaving only one way to set the error code to be returned, and restore the errno codes that were returned via the the mount system call as they were before we started refactoring __ext4_fill_super(). Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jason Yan <yanaijie@huawei.com>
2023-04-28ext4: reflect error codes from ext4_multi_mount_protect() to its callersTheodore Ts'o2-8/+17
This will allow more fine-grained errno codes to be returned by the mount system call. Cc: Andreas Dilger <adilger.kernel@dilger.ca> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-28ext4: fix lost error code reporting in __ext4_fill_super()Theodore Ts'o1-1/+2
When code was factored out of __ext4_fill_super() into ext4_percpu_param_init() the error return was discarded. This meant that it was possible for __ext4_fill_super() to return zero, indicating success, without the struct super getting completely filled in, leading to a potential NULL pointer dereference. Reported-by: syzbot+bbf0f9a213c94f283a5c@syzkaller.appspotmail.com Fixes: 1f79467c8a6b ("ext4: factor out ext4_percpu_param_init() ...") Link: https://syzkaller.appspot.com/bug?id=6dac47d5e58af770c0055f680369586ec32e144c Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jason Yan <yanaijie@huawei.com>
2023-04-28ext4: fix unused iterator variable warningsNathan Chancellor1-4/+3
When CONFIG_QUOTA is disabled, there are warnings around unused iterator variables: fs/ext4/super.c: In function 'ext4_put_super': fs/ext4/super.c:1262:13: error: unused variable 'i' [-Werror=unused-variable] 1262 | int i, err; | ^ fs/ext4/super.c: In function '__ext4_fill_super': fs/ext4/super.c:5200:22: error: unused variable 'i' [-Werror=unused-variable] 5200 | unsigned int i; | ^ cc1: all warnings being treated as errors The kernel has updated to GNU11, allowing the variables to be declared within the for loop. Do so to clear up the warnings. Fixes: dcbf87589d90 ("ext4: factor out ext4_flex_groups_free()") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jason Yan <yanaijie@huawei.com> Link: https://lore.kernel.org/r/20230420-ext4-unused-variables-super-c-v1-1-138b6db6c21c@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-28ext4: fix use-after-free read in ext4_find_extent for bigalloc + inlineYe Bin1-1/+2
Syzbot found the following issue: loop0: detected capacity change from 0 to 2048 EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none. ================================================================== BUG: KASAN: use-after-free in ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline] BUG: KASAN: use-after-free in ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931 Read of size 4 at addr ffff888073644750 by task syz-executor420/5067 CPU: 0 PID: 5067 Comm: syz-executor420 Not tainted 6.2.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:306 print_report+0x107/0x1f0 mm/kasan/report.c:417 kasan_report+0xcd/0x100 mm/kasan/report.c:517 ext4_ext_binsearch_idx fs/ext4/extents.c:768 [inline] ext4_find_extent+0x76e/0xd90 fs/ext4/extents.c:931 ext4_clu_mapped+0x117/0x970 fs/ext4/extents.c:5809 ext4_insert_delayed_block fs/ext4/inode.c:1696 [inline] ext4_da_map_blocks fs/ext4/inode.c:1806 [inline] ext4_da_get_block_prep+0x9e8/0x13c0 fs/ext4/inode.c:1870 ext4_block_write_begin+0x6a8/0x2290 fs/ext4/inode.c:1098 ext4_da_write_begin+0x539/0x760 fs/ext4/inode.c:3082 generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772 ext4_buffered_write_iter+0x122/0x3a0 fs/ext4/file.c:285 ext4_file_write_iter+0x1d0/0x18f0 call_write_iter include/linux/fs.h:2186 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7dc/0xc50 fs/read_write.c:584 ksys_write+0x177/0x2a0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4b7a9737b9 RSP: 002b:00007ffc5cac3668 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4b7a9737b9 RDX: 00000000175d9003 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 00007f4b7a933050 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000079f R11: 0000000000000246 R12: 00007f4b7a9330e0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 </TASK> Above issue is happens when enable bigalloc and inline data feature. As commit 131294c35ed6 fixed delayed allocation bug in ext4_clu_mapped for bigalloc + inline. But it only resolved issue when has inline data, if inline data has been converted to extent(ext4_da_convert_inline_data_to_extent) before writepages, there is no EXT4_STATE_MAY_INLINE_DATA flag. However i_data is still store inline data in this scene. Then will trigger UAF when find extent. To resolve above issue, there is need to add judge "ext4_has_inline_data(inode)" in ext4_clu_mapped(). Fixes: 131294c35ed6 ("ext4: fix delayed allocation bug in ext4_clu_mapped for bigalloc + inline") Reported-by: syzbot+bf4bb7731ef73b83a3b4@syzkaller.appspotmail.com Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org> Tested-by: Tudor Ambarus <tudor.ambarus@linaro.org> Link: https://lore.kernel.org/r/20230406111627.1916759-1-tudor.ambarus@linaro.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-28Merge tag 'x86_mm_for_6.4' of ↵Linus Torvalds2-2/+14
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 LAM (Linear Address Masking) support from Dave Hansen: "Add support for the new Linear Address Masking CPU feature. This is similar to ARM's Top Byte Ignore and allows userspace to store metadata in some bits of pointers without masking it out before use" * tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm/iommu/sva: Do not allow to set FORCE_TAGGED_SVA bit from outside x86/mm/iommu/sva: Fix error code for LAM enabling failure due to SVA selftests/x86/lam: Add test cases for LAM vs thread creation selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA test cases for linear-address masking selftests/x86/lam: Add inherit test cases for linear-address masking selftests/x86/lam: Add io_uring test cases for linear-address masking selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address masking selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking x86/mm/iommu/sva: Make LAM and SVA mutually exclusive iommu/sva: Replace pasid_valid() helper with mm_valid_pasid() mm: Expose untagging mask in /proc/$PID/status x86/mm: Provide arch_prctl() interface for LAM x86/mm: Reduce untagged_addr() overhead for systems without LAM x86/uaccess: Provide untagged_addr() and remove tags before address check mm: Introduce untagged_addr_remote() x86/mm: Handle LAM on context switch x86: CPUID and CR3/CR4 flags for Linear Address Masking x86: Allow atomic MM_CONTEXT flags setting x86/mm: Rework address range check in get_user() and put_user()
2023-04-28writeback: fix call of incorrect macroMaxim Korotkov1-1/+1
the variable 'history' is of type u16, it may be an error that the hweight32 macro was used for it I guess macro hweight16 should be used Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 2a81490811d0 ("writeback: implement foreign cgroup inode detection") Signed-off-by: Maxim Korotkov <korotkov.maxim.s@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230119104443.3002-1-korotkov.maxim.s@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-04-28btrfs: zoned: fix wrong use of bitops API in btrfs_ensure_empty_zonesNaohiro Aota1-3/+3
find_next_bit and find_next_zero_bit take @size as the second parameter and @offset as the third parameter. They are specified opposite in btrfs_ensure_empty_zones(). Thanks to the later loop, it never failed to detect the empty zones. Fix them and (maybe) return the result a bit faster. Note: the naming is a bit confusing, size has two meanings here, bitmap and our range size. Fixes: 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-28ext4: fix i_disksize exceeding i_size problem in paritally written caseZhihao Cheng1-0/+3
It is possible for i_disksize can exceed i_size, triggering a warning. generic_perform_write copied = iov_iter_copy_from_user_atomic(len) // copied < len ext4_da_write_end | ext4_update_i_disksize | new_i_size = pos + copied; | WRITE_ONCE(EXT4_I(inode)->i_disksize, newsize) // update i_disksize | generic_write_end | copied = block_write_end(copied, len) // copied = 0 | if (unlikely(copied < len)) | if (!PageUptodate(page)) | copied = 0; | if (pos + copied > inode->i_size) // return false if (unlikely(copied == 0)) goto again; if (unlikely(iov_iter_fault_in_readable(i, bytes))) { status = -EFAULT; break; } We get i_disksize greater than i_size here, which could trigger WARNING check 'i_size_read(inode) < EXT4_I(inode)->i_disksize' while doing dio: ext4_dio_write_iter iomap_dio_rw __iomap_dio_rw // return err, length is not aligned to 512 ext4_handle_inode_extension WARN_ON_ONCE(i_size_read(inode) < EXT4_I(inode)->i_disksize) // Oops WARNING: CPU: 2 PID: 2609 at fs/ext4/file.c:319 CPU: 2 PID: 2609 Comm: aa Not tainted 6.3.0-rc2 RIP: 0010:ext4_file_write_iter+0xbc7 Call Trace: vfs_write+0x3b1 ksys_write+0x77 do_syscall_64+0x39 Fix it by updating 'copied' value before updating i_disksize just like ext4_write_inline_data_end() does. A reproducer can be found in the buganizer link below. Link: https://bugzilla.kernel.org/show_bug.cgi?id=217209 Fixes: 64769240bd07 ("ext4: Add delayed allocation support in data=writeback mode") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230321013721.89818-1-chengzhihao1@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2023-04-28btrfs: properly reject clear_cache and v1 cache for block-group-treeQu Wenruo1-1/+6
[BUG] With block-group-tree feature enabled, mounting it with clear_cache would cause the following transaction abort at mount or remount: BTRFS info (device dm-4): force clearing of disk cache BTRFS info (device dm-4): using free space tree BTRFS info (device dm-4): auto enabling async discard BTRFS info (device dm-4): clearing free space tree BTRFS info (device dm-4): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1) BTRFS info (device dm-4): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2) BTRFS error (device dm-4): block-group-tree feature requires fres-space-tree and no-holes BTRFS error (device dm-4): super block corruption detected before writing it to disk BTRFS: error (device dm-4) in write_all_supers:4288: errno=-117 Filesystem corrupted (unexpected superblock corruption detected) BTRFS warning (device dm-4: state E): Skipping commit of aborted transaction. [CAUSE] For block-group-tree feature, we have an artificial dependency on free-space-tree. This means if we detect block-group-tree without v2 cache, we consider it a corruption and cause the problem. For clear_cache mount option, it would temporary disable v2 cache, then re-enable it. But unfortunately for that temporary v2 cache disabled status, we refuse to write a superblock with bg tree only flag, thus leads to the above transaction abortion. [FIX] For now, just reject clear_cache and v1 cache mount option for block group tree. So now we got a graceful rejection other than a transaction abort: BTRFS info (device dm-4): force clearing of disk cache BTRFS error (device dm-4): cannot disable free space tree with block-group-tree feature BTRFS error (device dm-4): open_ctree failed CC: stable@vger.kernel.org # 6.1+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-28btrfs: print extent buffers when sibling keys check failsFilipe Manana1-0/+4
When trying to move keys from one node/leaf to another sibling node/leaf, if the sibling keys check fails we just print an error message with the last key of the left sibling and the first key of the right sibling. However it's also useful to print all the keys of each sibling, as it may provide some clues to what went wrong, which code path may be inserting keys in an incorrect order. So just do that, print the siblings with btrfs_print_tree(), as it works for both leaves and nodes. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-28btrfs: abort transaction when sibling keys check fails for leavesFilipe Manana1-0/+2
If the sibling keys check fails before we move keys from one sibling leaf to another, we are not aborting the transaction - we leave that to some higher level caller of btrfs_search_slot() (or anything else that uses it to insert items into a b+tree). This means that the transaction abort will provide a stack trace that omits the b+tree modification call chain. So change this to immediately abort the transaction and therefore get a more useful stack trace that shows us the call chain in the bt+tree modification code. It's also important to immediately abort the transaction just in case some higher level caller is not doing it, as this indicates a very serious corruption and we should stop the possibility of doing further damage. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-28btrfs: fix leak of source device allocation state after device replaceFilipe Manana1-0/+1
When a device replace finishes, the source device is freed by calling btrfs_free_device() at btrfs_rm_dev_replace_free_srcdev(), but the allocation state, tracked in the device's alloc_state io tree, is never freed. This is a regression recently introduced by commit f0bb5474cff0 ("btrfs: remove redundant release of btrfs_device::alloc_state"), which removed a call to extent_io_tree_release() from btrfs_free_device(), with the rationale that btrfs_close_one_device() already releases the allocation state from a device and btrfs_close_one_device() is always called before a device is freed with btrfs_free_device(). However that is not true for the device replace case, as btrfs_free_device() is called without any previous call to btrfs_close_one_device(). The issue is trivial to reproduce, for example, by running test btrfs/027 from fstests: $ ./check btrfs/027 $ rmmod btrfs $ dmesg (...) [84519.395485] BTRFS info (device sdc): dev_replace from <missing disk> (devid 2) to /dev/sdg started [84519.466224] BTRFS info (device sdc): dev_replace from <missing disk> (devid 2) to /dev/sdg finished [84519.552251] BTRFS info (device sdc): scrub: started on devid 1 [84519.552277] BTRFS info (device sdc): scrub: started on devid 2 [84519.552332] BTRFS info (device sdc): scrub: started on devid 3 [84519.552705] BTRFS info (device sdc): scrub: started on devid 4 [84519.604261] BTRFS info (device sdc): scrub: finished on devid 4 with status: 0 [84519.609374] BTRFS info (device sdc): scrub: finished on devid 3 with status: 0 [84519.610818] BTRFS info (device sdc): scrub: finished on devid 1 with status: 0 [84519.610927] BTRFS info (device sdc): scrub: finished on devid 2 with status: 0 [84559.503795] BTRFS: state leak: start 1048576 end 1351614463 state 1 in tree 1 refs 1 [84559.506764] BTRFS: state leak: start 1048576 end 1347420159 state 1 in tree 1 refs 1 [84559.510294] BTRFS: state leak: start 1048576 end 1351614463 state 1 in tree 1 refs 1 So fix this by adding back the call to extent_io_tree_release() at btrfs_free_device(). Fixes: f0bb5474cff0 ("btrfs: remove redundant release of btrfs_device::alloc_state") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-28btrfs: fix assertion of exclop condition when starting balancexiaoshoukui1-1/+3
Balance as exclusive state is compatible with paused balance and device add, which makes some things more complicated. The assertion of valid states when starting from paused balance needs to take into account two more states, the combinations can be hit when there are several threads racing to start balance and device add. This won't typically happen when the commands are started from command line. Scenario 1: With exclusive_operation state == BTRFS_EXCLOP_NONE. Concurrently adding multiple devices to the same mount point and btrfs_exclop_finish executed finishes before assertion in btrfs_exclop_balance, exclusive_operation will changed to BTRFS_EXCLOP_NONE state which lead to assertion failed: fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE || fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD, in fs/btrfs/ioctl.c:456 Call Trace: <TASK> btrfs_exclop_balance+0x13c/0x310 ? memdup_user+0xab/0xc0 ? PTR_ERR+0x17/0x20 btrfs_ioctl_add_dev+0x2ee/0x320 btrfs_ioctl+0x9d5/0x10d0 ? btrfs_ioctl_encoded_write+0xb80/0xb80 __x64_sys_ioctl+0x197/0x210 do_syscall_64+0x3c/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd Scenario 2: With exclusive_operation state == BTRFS_EXCLOP_BALANCE_PAUSED. Concurrently adding multiple devices to the same mount point and btrfs_exclop_balance executed finish before the latter thread execute assertion in btrfs_exclop_balance, exclusive_operation will changed to BTRFS_EXCLOP_BALANCE_PAUSED state which lead to assertion failed: fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE || fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD || fs_info->exclusive_operation == BTRFS_EXCLOP_NONE, fs/btrfs/ioctl.c:458 Call Trace: <TASK> btrfs_exclop_balance+0x240/0x410 ? memdup_user+0xab/0xc0 ? PTR_ERR+0x17/0x20 btrfs_ioctl_add_dev+0x2ee/0x320 btrfs_ioctl+0x9d5/0x10d0 ? btrfs_ioctl_encoded_write+0xb80/0xb80 __x64_sys_ioctl+0x197/0x210 do_syscall_64+0x3c/0xb0 entry_SYSCALL_64_after_hwframe+0x63/0xcd An example of the failed assertion is below, which shows that the paused balance is also needed to be checked. root@syzkaller:/home/xsk# ./repro Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 [ 416.611428][ T7970] BTRFS info (device loop0): fs_info exclusive_operation: 0 Failed to add device /dev/vda, errno 14 [ 416.613973][ T7971] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.615456][ T7972] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.617528][ T7973] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.618359][ T7974] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.622589][ T7975] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.624034][ T7976] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.626420][ T7977] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.627643][ T7978] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.629006][ T7979] BTRFS info (device loop0): fs_info exclusive_operation: 3 [ 416.630298][ T7980] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 Failed to add device /dev/vda, errno 14 [ 416.632787][ T7981] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.634282][ T7982] BTRFS info (device loop0): fs_info exclusive_operation: 3 Failed to add device /dev/vda, errno 14 [ 416.636202][ T7983] BTRFS info (device loop0): fs_info exclusive_operation: 3 [ 416.637012][ T7984] BTRFS info (device loop0): fs_info exclusive_operation: 1 Failed to add device /dev/vda, errno 14 [ 416.637759][ T7984] assertion failed: fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE || fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD || fs_info->exclusive_operation == BTRFS_EXCLOP_NONE, in fs/btrfs/ioctl.c:458 [ 416.639845][ T7984] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 416.640485][ T7984] CPU: 0 PID: 7984 Comm: repro Not tainted 6.2.0 #7 [ 416.641172][ T7984] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 [ 416.642090][ T7984] RIP: 0010:btrfs_assertfail+0x2c/0x2e [ 416.644423][ T7984] RSP: 0018:ffffc90003ea7e28 EFLAGS: 00010282 [ 416.645018][ T7984] RAX: 00000000000000cc RBX: 0000000000000000 RCX: 0000000000000000 [ 416.645763][ T7984] RDX: ffff88801d030000 RSI: ffffffff81637e7c RDI: fffff520007d4fb7 [ 416.646554][ T7984] RBP: ffffffff8a533de0 R08: 00000000000000cc R09: 0000000000000000 [ 416.647299][ T7984] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8a533da0 [ 416.648041][ T7984] R13: 00000000000001ca R14: 000000005000940a R15: 0000000000000000 [ 416.648785][ T7984] FS: 00007fa2985d4640(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000 [ 416.649616][ T7984] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 416.650238][ T7984] CR2: 0000000000000000 CR3: 0000000018e5e000 CR4: 0000000000750ef0 [ 416.650980][ T7984] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 416.651725][ T7984] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 416.652502][ T7984] PKRU: 55555554 [ 416.652888][ T7984] Call Trace: [ 416.653241][ T7984] <TASK> [ 416.653527][ T7984] btrfs_exclop_balance+0x240/0x410 [ 416.654036][ T7984] ? memdup_user+0xab/0xc0 [ 416.654465][ T7984] ? PTR_ERR+0x17/0x20 [ 416.654874][ T7984] btrfs_ioctl_add_dev+0x2ee/0x320 [ 416.655380][ T7984] btrfs_ioctl+0x9d5/0x10d0 [ 416.655822][ T7984] ? btrfs_ioctl_encoded_write+0xb80/0xb80 [ 416.656400][ T7984] __x64_sys_ioctl+0x197/0x210 [ 416.656874][ T7984] do_syscall_64+0x3c/0xb0 [ 416.657346][ T7984] entry_SYSCALL_64_after_hwframe+0x63/0xcd [ 416.657922][ T7984] RIP: 0033:0x4546af [ 416.660170][ T7984] RSP: 002b:00007fa2985d4150 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 416.660972][ T7984] RAX: ffffffffffffffda RBX: 00007fa2985d4640 RCX: 00000000004546af [ 416.661714][ T7984] RDX: 0000000000000000 RSI: 000000005000940a RDI: 0000000000000003 [ 416.662449][ T7984] RBP: 00007fa2985d41d0 R08: 0000000000000000 R09: 00007ffee37a4c4f [ 416.663195][ T7984] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa2985d4640 [ 416.663951][ T7984] R13: 0000000000000009 R14: 000000000041b320 R15: 00007fa297dd4000 [ 416.664703][ T7984] </TASK> [ 416.665040][ T7984] Modules linked in: [ 416.665590][ T7984] ---[ end trace 0000000000000000 ]--- [ 416.666176][ T7984] RIP: 0010:btrfs_assertfail+0x2c/0x2e [ 416.668775][ T7984] RSP: 0018:ffffc90003ea7e28 EFLAGS: 00010282 [ 416.669425][ T7984] RAX: 00000000000000cc RBX: 0000000000000000 RCX: 0000000000000000 [ 416.670235][ T7984] RDX: ffff88801d030000 RSI: ffffffff81637e7c RDI: fffff520007d4fb7 [ 416.671050][ T7984] RBP: ffffffff8a533de0 R08: 00000000000000cc R09: 0000000000000000 [ 416.671867][ T7984] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8a533da0 [ 416.672685][ T7984] R13: 00000000000001ca R14: 000000005000940a R15: 0000000000000000 [ 416.673501][ T7984] FS: 00007fa2985d4640(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000 [ 416.674425][ T7984] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 416.675114][ T7984] CR2: 0000000000000000 CR3: 0000000018e5e000 CR4: 0000000000750ef0 [ 416.675933][ T7984] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 416.676760][ T7984] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Link: https://lore.kernel.org/linux-btrfs/20230324031611.98986-1-xiaoshoukui@gmail.com/ CC: stable@vger.kernel.org # 6.1+ Signed-off-by: xiaoshoukui <xiaoshoukui@ruijie.com.cn> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-28btrfs: fix btrfs_prev_leaf() to not return the same key twiceFilipe Manana1-1/+31
A call to btrfs_prev_leaf() may end up returning a path that points to the same item (key) again. This happens if while btrfs_prev_leaf(), after we release the path, a concurrent insertion happens, which moves items off from a sibling into the front of the previous leaf, and an item with the computed previous key does not exists. For example, suppose we have the two following leaves: Leaf A ------------------------------------------------------------- | ... key (300 96 10) key (300 96 15) key (300 96 16) | ------------------------------------------------------------- slot 20 slot 21 slot 22 Leaf B ------------------------------------------------------------- | key (300 96 20) key (300 96 21) key (300 96 22) ... | ------------------------------------------------------------- slot 0 slot 1 slot 2 If we call btrfs_prev_leaf(), from btrfs_previous_item() for example, with a path pointing to leaf B and slot 0 and the following happens: 1) At btrfs_prev_leaf() we compute the previous key to search as: (300 96 19), which is a key that does not exists in the tree; 2) Then we call btrfs_release_path() at btrfs_prev_leaf(); 3) Some other task inserts a key at leaf A, that sorts before the key at slot 20, for example it has an objectid of 299. In order to make room for the new key, the key at slot 22 is moved to the front of leaf B. This happens at push_leaf_right(), called from split_leaf(). After this leaf B now looks like: -------------------------------------------------------------------------------- | key (300 96 16) key (300 96 20) key (300 96 21) key (300 96 22) ... | -------------------------------------------------------------------------------- slot 0 slot 1 slot 2 slot 3 4) At btrfs_prev_leaf() we call btrfs_search_slot() for the computed previous key: (300 96 19). Since the key does not exists, btrfs_search_slot() returns 1 and with a path pointing to leaf B and slot 1, the item with key (300 96 20); 5) This makes btrfs_prev_leaf() return a path that points to slot 1 of leaf B, the same key as before it was called, since the key at slot 0 of leaf B (300 96 16) is less than the computed previous key, which is (300 96 19); 6) As a consequence btrfs_previous_item() returns a path that points again to the item with key (300 96 20). For some users of btrfs_prev_leaf() or btrfs_previous_item() this may not be functional a problem, despite not making sense to return a new path pointing again to the same item/key. However for a caller such as tree-log.c:log_dir_items(), this has a bad consequence, as it can result in not logging some dir index deletions in case the directory is being logged without holding the inode's VFS lock (logging triggered while logging a child inode for example) - for the example scenario above, in case the dir index keys 17, 18 and 19 were deleted in the current transaction. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2023-04-27Merge tag 'mm-nonmm-stable-2023-04-27-16-01' of ↵Linus Torvalds11-138/+176
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: "Mainly singleton patches all over the place. Series of note are: - updates to scripts/gdb from Glenn Washburn - kexec cleanups from Bjorn Helgaas" * tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (50 commits) mailmap: add entries for Paul Mackerras libgcc: add forward declarations for generic library routines mailmap: add entry for Oleksandr ocfs2: reduce ioctl stack usage fs/proc: add Kthread flag to /proc/$pid/status ia64: fix an addr to taddr in huge_pte_offset() checkpatch: introduce proper bindings license check epoll: rename global epmutex scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry() scripts/gdb: create linux/vfs.py for VFS related GDB helpers uapi/linux/const.h: prefer ISO-friendly __typeof__ delayacct: track delays from IRQ/SOFTIRQ scripts/gdb: timerlist: convert int chunks to str scripts/gdb: print interrupts scripts/gdb: raise error with reduced debugging information scripts/gdb: add a Radix Tree Parser lib/rbtree: use '+' instead of '|' for setting color. proc/stat: remove arch_idle_time() checkpatch: check for misuse of the link tags checkpatch: allow Closes tags with links ...
2023-04-27Merge tag 'mm-stable-2023-04-27-15-30' of ↵Linus Torvalds30-210/+275
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...
2023-04-27Merge tag 'pstore-v6.4-rc1' of ↵Linus Torvalds1-4/+3
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull pstore update from Kees Cook: - Revert pmsg_lock back to a normal mutex (John Stultz) * tag 'pstore-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: pstore: Revert pmsg_lock back to a normal mutex
2023-04-27Merge tag 'sysctl-6.4-rc1' of ↵Linus Torvalds10-140/+86
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "This only does a few sysctl moves from the kernel/sysctl.c file, the rest of the work has been put towards deprecating two API calls which incur recursion and prevent us from simplifying the registration process / saving memory per move. Most of the changes have been soaking on linux-next since v6.3-rc3. I've slowed down the kernel/sysctl.c moves due to Matthew Wilcox's feedback that we should see if we could *save* memory with these moves instead of incurring more memory. We currently incur more memory since when we move a syctl from kernel/sysclt.c out to its own file we end up having to add a new empty sysctl used to register it. To achieve saving memory we want to allow syctls to be passed without requiring the end element being empty, and just have our registration process rely on ARRAY_SIZE(). Without this, supporting both styles of sysctls would make the sysctl registration pretty brittle, hard to read and maintain as can be seen from Meng Tang's efforts to do just this [0]. Fortunately, in order to use ARRAY_SIZE() for all sysctl registrations also implies doing the work to deprecate two API calls which use recursion in order to support sysctl declarations with subdirectories. And so during this development cycle quite a bit of effort went into this deprecation effort. I've annotated the following two APIs are deprecated and in few kernel releases we should be good to remove them: - register_sysctl_table() - register_sysctl_paths() During this merge window we should be able to deprecate and unexport register_sysctl_paths(), we can probably do that towards the end of this merge window. Deprecating register_sysctl_table() will take a bit more time but this pull request goes with a few example of how to do this. As it turns out each of the conversions to move away from either of these two API calls *also* saves memory. And so long term, all these changes *will* prove to have saved a bit of memory on boot. The way I see it then is if remove a user of one deprecated call, it gives us enough savings to move one kernel/sysctl.c out from the generic arrays as we end up with about the same amount of bytes. Since deprecating register_sysctl_table() and register_sysctl_paths() does not require maintainer coordination except the final unexport you'll see quite a bit of these changes from other pull requests, I've just kept the stragglers after rc3" Link: https://lkml.kernel.org/r/ZAD+cpbrqlc5vmry@bombadil.infradead.org [0] * tag 'sysctl-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (29 commits) fs: fix sysctls.c built mm: compaction: remove incorrect #ifdef checks mm: compaction: move compaction sysctl to its own file mm: memory-failure: Move memory failure sysctls to its own file arm: simplify two-level sysctl registration for ctl_isa_vars ia64: simplify one-level sysctl registration for kdump_ctl_table utsname: simplify one-level sysctl registration for uts_kern_table ntfs: simplfy one-level sysctl registration for ntfs_sysctls coda: simplify one-level sysctl registration for coda_table fs/cachefiles: simplify one-level sysctl registration for cachefiles_sysctls xfs: simplify two-level sysctl registration for xfs_table nfs: simplify two-level sysctl registration for nfs_cb_sysctls nfs: simplify two-level sysctl registration for nfs4_cb_sysctls lockd: simplify two-level sysctl registration for nlm_sysctls proc_sysctl: enhance documentation xen: simplify sysctl registration for balloon md: simplify sysctl registration hv: simplify sysctl registration scsi: simplify sysctl registration with register_sysctl() csky: simplify alignment sysctl registration ...
2023-04-27Merge tag 'modules-6.4-rc1' of ↵Linus Torvalds3-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull module updates from Luis Chamberlain: "The summary of the changes for this pull requests is: - Song Liu's new struct module_memory replacement - Nick Alcock's MODULE_LICENSE() removal for non-modules - My cleanups and enhancements to reduce the areas where we vmalloc module memory for duplicates, and the respective debug code which proves the remaining vmalloc pressure comes from userspace. Most of the changes have been in linux-next for quite some time except the minor fixes I made to check if a module was already loaded prior to allocating the final module memory with vmalloc and the respective debug code it introduces to help clarify the issue. Although the functional change is small it is rather safe as it can only *help* reduce vmalloc space for duplicates and is confirmed to fix a bootup issue with over 400 CPUs with KASAN enabled. I don't expect stable kernels to pick up that fix as the cleanups would have also had to have been picked up. Folks on larger CPU systems with modules will want to just upgrade if vmalloc space has been an issue on bootup. Given the size of this request, here's some more elaborate details: The functional change change in this pull request is the very first patch from Song Liu which replaces the 'struct module_layout' with a new 'struct module_memory'. The old data structure tried to put together all types of supported module memory types in one data structure, the new one abstracts the differences in memory types in a module to allow each one to provide their own set of details. This paves the way in the future so we can deal with them in a cleaner way. If you look at changes they also provide a nice cleanup of how we handle these different memory areas in a module. This change has been in linux-next since before the merge window opened for v6.3 so to provide more than a full kernel cycle of testing. It's a good thing as quite a bit of fixes have been found for it. Jason Baron then made dynamic debug a first class citizen module user by using module notifier callbacks to allocate / remove module specific dynamic debug information. Nick Alcock has done quite a bit of work cross-tree to remove module license tags from things which cannot possibly be module at my request so to: a) help him with his longer term tooling goals which require a deterministic evaluation if a piece a symbol code could ever be part of a module or not. But quite recently it is has been made clear that tooling is not the only one that would benefit. Disambiguating symbols also helps efforts such as live patching, kprobes and BPF, but for other reasons and R&D on this area is active with no clear solution in sight. b) help us inch closer to the now generally accepted long term goal of automating all the MODULE_LICENSE() tags from SPDX license tags In so far as a) is concerned, although module license tags are a no-op for non-modules, tools which would want create a mapping of possible modules can only rely on the module license tag after the commit 8b41fc4454e ("kbuild: create modules.builtin without Makefile.modbuiltin or tristate.conf"). Nick has been working on this *for years* and AFAICT I was the only one to suggest two alternatives to this approach for tooling. The complexity in one of my suggested approaches lies in that we'd need a possible-obj-m and a could-be-module which would check if the object being built is part of any kconfig build which could ever lead to it being part of a module, and if so define a new define -DPOSSIBLE_MODULE [0]. A more obvious yet theoretical approach I've suggested would be to have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as well but that means getting kconfig symbol names mapping to modules always, and I don't think that's the case today. I am not aware of Nick or anyone exploring either of these options. Quite recently Josh Poimboeuf has pointed out that live patching, kprobes and BPF would benefit from resolving some part of the disambiguation as well but for other reasons. The function granularity KASLR (fgkaslr) patches were mentioned but Joe Lawrence has clarified this effort has been dropped with no clear solution in sight [1]. In the meantime removing module license tags from code which could never be modules is welcomed for both objectives mentioned above. Some developers have also welcomed these changes as it has helped clarify when a module was never possible and they forgot to clean this up, and so you'll see quite a bit of Nick's patches in other pull requests for this merge window. I just picked up the stragglers after rc3. LWN has good coverage on the motivation behind this work [2] and the typical cross-tree issues he ran into along the way. The only concrete blocker issue he ran into was that we should not remove the MODULE_LICENSE() tags from files which have no SPDX tags yet, even if they can never be modules. Nick ended up giving up on his efforts due to having to do this vetting and backlash he ran into from folks who really did *not understand* the core of the issue nor were providing any alternative / guidance. I've gone through his changes and dropped the patches which dropped the module license tags where an SPDX license tag was missing, it only consisted of 11 drivers. To see if a pull request deals with a file which lacks SPDX tags you can just use: ./scripts/spdxcheck.py -f \ $(git diff --name-only commid-id | xargs echo) You'll see a core module file in this pull request for the above, but that's not related to his changes. WE just need to add the SPDX license tag for the kernel/module/kmod.c file in the future but it demonstrates the effectiveness of the script. Most of Nick's changes were spread out through different trees, and I just picked up the slack after rc3 for the last kernel was out. Those changes have been in linux-next for over two weeks. The cleanups, debug code I added and final fix I added for modules were motivated by David Hildenbrand's report of boot failing on a systems with over 400 CPUs when KASAN was enabled due to running out of virtual memory space. Although the functional change only consists of 3 lines in the patch "module: avoid allocation if module is already present and ready", proving that this was the best we can do on the modules side took quite a bit of effort and new debug code. The initial cleanups I did on the modules side of things has been in linux-next since around rc3 of the last kernel, the actual final fix for and debug code however have only been in linux-next for about a week or so but I think it is worth getting that code in for this merge window as it does help fix / prove / evaluate the issues reported with larger number of CPUs. Userspace is not yet fixed as it is taking a bit of time for folks to understand the crux of the issue and find a proper resolution. Worst come to worst, I have a kludge-of-concept [3] of how to make kernel_read*() calls for modules unique / converge them, but I'm currently inclined to just see if userspace can fix this instead" Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0] Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1] Link: https://lwn.net/Articles/927569/ [2] Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3] * tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits) module: add debugging auto-load duplicate module support module: stats: fix invalid_mod_bytes typo module: remove use of uninitialized variable len module: fix building stats for 32-bit targets module: stats: include uapi/linux/module.h module: avoid allocation if m