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Add doc covering when module parameters are set #150
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Check failures seem to be due to the llvm mirror sync in progress. |
Yeah, please feel free to force-push after a while. |
rust/kernel/module_param.rs
Outdated
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.
LGTM |
… 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]>
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]>
Add documentation with guidance on allocating when setting module parameters and change the StringParam implementation to handle allocation failures.