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Merged
merged 1 commit into from
Apr 1, 2021

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adamrk
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@adamrk adamrk commented Mar 29, 2021

Add documentation with guidance on allocating when setting module parameters and change the StringParam implementation to handle allocation failures.

@adamrk adamrk force-pushed the doc-param-set branch 2 times, most recently from dab4bc3 to 80015ca Compare March 29, 2021 20:28
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adamrk commented Mar 29, 2021

Check failures seem to be due to the llvm mirror sync in progress.

@ojeda
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ojeda commented Mar 29, 2021

Yeah, please feel free to force-push after a while.

if slab_available {
let mut vec = alloc::vec::Vec::new();
vec.try_reserve(arg.len()).ok()?;
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Should this be try_reserve_exact()? i.e. do we expect further allocations?

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Ah, yep. exact is better.

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ojeda commented Mar 31, 2021

LGTM

@ojeda ojeda merged commit 101e008 into Rust-for-Linux:rust Apr 1, 2021
ojeda pushed a commit that referenced this pull request May 4, 2022
… abort

we got issue as follows:
[   72.796117] EXT4-fs error (device sda): ext4_journal_check_start:83: comm fallocate: Detected aborted journal
[   72.826847] EXT4-fs (sda): Remounting filesystem read-only
fallocate: fallocate failed: Read-only file system
[   74.791830] jbd2_journal_commit_transaction: jh=0xffff9cfefe725d90 bh=0x0000000000000000 end delay
[   74.793597] ------------[ cut here ]------------
[   74.794203] kernel BUG at fs/jbd2/transaction.c:2063!
[   74.794886] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[   74.795533] CPU: 4 PID: 2260 Comm: jbd2/sda-8 Not tainted 5.17.0-rc8-next-20220315-dirty #150
[   74.798327] RIP: 0010:__jbd2_journal_unfile_buffer+0x3e/0x60
[   74.801971] RSP: 0018:ffffa828c24a3cb8 EFLAGS: 00010202
[   74.802694] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[   74.803601] RDX: 0000000000000001 RSI: ffff9cfefe725d90 RDI: ffff9cfefe725d90
[   74.804554] RBP: ffff9cfefe725d90 R08: 0000000000000000 R09: ffffa828c24a3b20
[   74.805471] R10: 0000000000000001 R11: 0000000000000001 R12: ffff9cfefe725d90
[   74.806385] R13: ffff9cfefe725d98 R14: 0000000000000000 R15: ffff9cfe833a4d00
[   74.807301] FS:  0000000000000000(0000) GS:ffff9d01afb00000(0000) knlGS:0000000000000000
[   74.808338] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   74.809084] CR2: 00007f2b81bf4000 CR3: 0000000100056000 CR4: 00000000000006e0
[   74.810047] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   74.810981] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   74.811897] Call Trace:
[   74.812241]  <TASK>
[   74.812566]  __jbd2_journal_refile_buffer+0x12f/0x180
[   74.813246]  jbd2_journal_refile_buffer+0x4c/0xa0
[   74.813869]  jbd2_journal_commit_transaction.cold+0xa1/0x148
[   74.817550]  kjournald2+0xf8/0x3e0
[   74.819056]  kthread+0x153/0x1c0
[   74.819963]  ret_from_fork+0x22/0x30

Above issue may happen as follows:
        write                   truncate                   kjournald2
generic_perform_write
 ext4_write_begin
  ext4_walk_page_buffers
   do_journal_get_write_access ->add BJ_Reserved list
 ext4_journalled_write_end
  ext4_walk_page_buffers
   write_end_fn
    ext4_handle_dirty_metadata
                ***************JBD2 ABORT**************
     jbd2_journal_dirty_metadata
 -> return -EROFS, jh in reserved_list
                                                   jbd2_journal_commit_transaction
                                                    while (commit_transaction->t_reserved_list)
                                                      jh = commit_transaction->t_reserved_list;
                        truncate_pagecache_range
                         do_invalidatepage
			  ext4_journalled_invalidatepage
			   jbd2_journal_invalidatepage
			    journal_unmap_buffer
			     __dispose_buffer
			      __jbd2_journal_unfile_buffer
			       jbd2_journal_put_journal_head ->put last ref_count
			        __journal_remove_journal_head
				 bh->b_private = NULL;
				 jh->b_bh = NULL;
				                      jbd2_journal_refile_buffer(journal, jh);
							bh = jh2bh(jh);
							->bh is NULL, later will trigger null-ptr-deref
				 journal_free_journal_head(jh);

After commit 96f1e09, we no longer hold the j_state_lock while
iterating over the list of reserved handles in
jbd2_journal_commit_transaction().  This potentially allows the
journal_head to be freed by journal_unmap_buffer while the commit
codepath is also trying to free the BJ_Reserved buffers.  Keeping
j_state_lock held while trying extends hold time of the lock
minimally, and solves this issue.

Fixes: 96f1e09("jbd2: avoid long hold times of j_state_lock while committing a transaction")
Signed-off-by: Ye Bin <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>
ojeda pushed a commit that referenced this pull request Apr 6, 2023
Because headroom is not passed to page_to_skb(), this causes the shinfo
exceeds the range. Then the frags of shinfo are changed by other process.

[  157.724634] stack segment: 0000 [#1] PREEMPT SMP NOPTI
[  157.725358] CPU: 3 PID: 679 Comm: xdp_pass_user_f Tainted: G            E      6.2.0+ #150
[  157.726401] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/4
[  157.727820] RIP: 0010:skb_release_data+0x11b/0x180
[  157.728449] Code: 44 24 02 48 83 c3 01 39 d8 7e be 48 89 d8 48 c1 e0 04 41 80 7d 7e 00 49 8b 6c 04 30 79 0c 48 89 ef e8 89 b
[  157.730751] RSP: 0018:ffffc90000178b48 EFLAGS: 00010202
[  157.731383] RAX: 0000000000000010 RBX: 0000000000000001 RCX: 0000000000000000
[  157.732270] RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff888100dd0b00
[  157.733117] RBP: 5d5d76010f6e2408 R08: ffff888100dd0b2c R09: 0000000000000000
[  157.734013] R10: ffffffff82effd30 R11: 000000000000a14e R12: ffff88810981ffc0
[  157.734904] R13: ffff888100dd0b00 R14: 0000000000000002 R15: 0000000000002310
[  157.735793] FS:  00007f06121d9740(0000) GS:ffff88842fcc0000(0000) knlGS:0000000000000000
[  157.736794] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  157.737522] CR2: 00007ffd9a56c084 CR3: 0000000104bda001 CR4: 0000000000770ee0
[  157.738420] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  157.739283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  157.740146] PKRU: 55555554
[  157.740502] Call Trace:
[  157.740843]  <IRQ>
[  157.741117]  kfree_skb_reason+0x50/0x120
[  157.741613]  __udp4_lib_rcv+0x52b/0x5e0
[  157.742132]  ip_protocol_deliver_rcu+0xaf/0x190
[  157.742715]  ip_local_deliver_finish+0x77/0xa0
[  157.743280]  ip_sublist_rcv_finish+0x80/0x90
[  157.743834]  ip_list_rcv_finish.constprop.0+0x16f/0x190
[  157.744493]  ip_list_rcv+0x126/0x140
[  157.744952]  __netif_receive_skb_list_core+0x29b/0x2c0
[  157.745602]  __netif_receive_skb_list+0xed/0x160
[  157.746190]  ? udp4_gro_receive+0x275/0x350
[  157.746732]  netif_receive_skb_list_internal+0xf2/0x1b0
[  157.747398]  napi_gro_receive+0xd1/0x210
[  157.747911]  virtnet_receive+0x75/0x1c0
[  157.748422]  virtnet_poll+0x48/0x1b0
[  157.748878]  __napi_poll+0x29/0x1b0
[  157.749330]  net_rx_action+0x27a/0x340
[  157.749812]  __do_softirq+0xf3/0x2fb
[  157.750298]  do_softirq+0xa2/0xd0
[  157.750745]  </IRQ>
[  157.751563]  <TASK>
[  157.752329]  __local_bh_enable_ip+0x6d/0x80
[  157.753178]  virtnet_xdp_set+0x482/0x860
[  157.754159]  ? __pfx_virtnet_xdp+0x10/0x10
[  157.755129]  dev_xdp_install+0xa4/0xe0
[  157.756033]  dev_xdp_attach+0x20b/0x5e0
[  157.756933]  do_setlink+0x82e/0xc90
[  157.757777]  ? __nla_validate_parse+0x12b/0x1e0
[  157.758744]  rtnl_setlink+0xd8/0x170
[  157.759549]  ? mod_objcg_state+0xcb/0x320
[  157.760328]  ? security_capable+0x37/0x60
[  157.761209]  ? security_capable+0x37/0x60
[  157.762072]  rtnetlink_rcv_msg+0x145/0x3d0
[  157.762929]  ? ___slab_alloc+0x327/0x610
[  157.763754]  ? __alloc_skb+0x141/0x170
[  157.764533]  ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[  157.765422]  netlink_rcv_skb+0x58/0x110
[  157.766229]  netlink_unicast+0x21f/0x330
[  157.766951]  netlink_sendmsg+0x240/0x4a0
[  157.767654]  sock_sendmsg+0x93/0xa0
[  157.768434]  ? sockfd_lookup_light+0x12/0x70
[  157.769245]  __sys_sendto+0xfe/0x170
[  157.770079]  ? handle_mm_fault+0xe9/0x2d0
[  157.770859]  ? preempt_count_add+0x51/0xa0
[  157.771645]  ? up_read+0x3c/0x80
[  157.772340]  ? do_user_addr_fault+0x1e9/0x710
[  157.773166]  ? kvm_read_and_reset_apf_flags+0x49/0x60
[  157.774087]  __x64_sys_sendto+0x29/0x30
[  157.774856]  do_syscall_64+0x3c/0x90
[  157.775518]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[  157.776382] RIP: 0033:0x7f06122def70

Fixes: 18117a8 ("virtio-net: remove xdp related info from page_to_skb()")
Signed-off-by: Xuan Zhuo <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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