kernel/linux.git/include/linux/seq_file.h, branch v5.15.72

rxrpc: Fix locking issue

2022-07-12T14:35:08+00:00

[ Upstream commit ad25f5cb39872ca14bcbe00816ae65c22fe04b89 ] There's a locking issue with the per-netns list of calls in rxrpc. The pieces of code that add and remove a call from the list use write_lock() and the calls procfile uses read_lock() to access it. However, the timer callback function may trigger a removal by trying to queue a call for processing and finding that it's already queued - at which point it has a spare refcount that it has to do something with. Unfortunately, if it puts the call and this reduces the refcount to 0, the call will be removed from the list. Unfortunately, since the _bh variants of the locking functions aren't used, this can deadlock. ================================ WARNING: inconsistent lock state 5.18.0-rc3-build4+ #10 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. ksoftirqd/2/25 [HC0[0]:SC1[1]:HE1:SE0] takes: ffff888107ac4038 (&rxnet->call_lock){+.?.}-{2:2}, at: rxrpc_put_call+0x103/0x14b {SOFTIRQ-ON-W} state was registered at: ... Possible unsafe locking scenario: CPU0 ---- lock(&rxnet->call_lock); lock(&rxnet->call_lock); *** DEADLOCK *** 1 lock held by ksoftirqd/2/25: #0: ffff8881008ffdb0 ((&call->timer)){+.-.}-{0:0}, at: call_timer_fn+0x5/0x23d Changes ======= ver #2) - Changed to using list_next_rcu() rather than rcu_dereference() directly. Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

seq_file: fix passing wrong private data

2021-11-18T18:17:12+00:00

[ Upstream commit 10a6de19cad6efb9b49883513afb810dc265fca2 ] DEFINE_PROC_SHOW_ATTRIBUTE() is supposed to be used to define a series of functions and variables to register proc file easily. And the users can use proc_create_data() to pass their own private data and get it via seq->private in the callback. Unfortunately, the proc file system use PDE_DATA() to get private data instead of inode->i_private. So fix it. Fortunately, there only one user of it which does not pass any private data, so this bug does not break any in-tree codes. Link: https://lkml.kernel.org/r/20211029032638.84884-1-songmuchun@bytedance.com Fixes: 97a32539b956 ("proc: convert everything to "struct proc_ops"") Signed-off-by: Muchun Song Cc: Andy Shevchenko Cc: Stephen Rothwell Cc: Florent Revest Cc: Alexey Dobriyan Cc: Christian Brauner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

seq_file: drop unused *_escape_mem_ascii()

2021-07-01T18:06:05+00:00

There are no more users of the seq_escape_mem_ascii() followed by string_escape_mem_ascii(). Remove them for good. Link: https://lkml.kernel.org/r/20210504180819.73127-16-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Cc: Alexander Viro Cc: Chuck Lever Cc: "J. Bruce Fields" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

seq_file: add seq_escape_str() as replica of string_escape_str()

2021-07-01T18:06:05+00:00

In some cases we want to escape characters from NULL-terminated strings. Add seq_escape_str() as replica of string_escape_str() for that. Link: https://lkml.kernel.org/r/20210504180819.73127-13-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Cc: Alexander Viro Cc: Chuck Lever Cc: "J. Bruce Fields" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

seq_file: introduce seq_escape_mem()

2021-07-01T18:06:05+00:00

Introduce seq_escape_mem() to allow users to pass additional parameters to string_escape_mem(). Link: https://lkml.kernel.org/r/20210504180819.73127-12-andriy.shevchenko@linux.intel.com Suggested-by: Al Viro Signed-off-by: Andy Shevchenko Cc: Chuck Lever Cc: "J. Bruce Fields" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

seq_file: Add a seq_bprintf function

2021-04-27T22:50:15+00:00

Similarly to seq_buf_bprintf in lib/seq_buf.c, this function writes a printf formatted string with arguments provided in a "binary representation" built by functions such as vbin_printf. Signed-off-by: Florent Revest Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210427174313.860948-2-revest@chromium.org

seq_file: add seq_read_iter

2020-11-06T18:05:18+00:00

iov_iter based variant for reading a seq_file. seq_read is reimplemented on top of the iter variant. Signed-off-by: Christoph Hellwig Tested-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds

include/linux/seq_file.h: introduce DEFINE_SEQ_ATTRIBUTE() helper macro

2020-06-05T02:06:26+00:00

Patch series "seq_file: Introduce DEFINE_SEQ_ATTRIBUTE() helper macro". As discussed in https://lore.kernel.org/lkml/20191129222310.GA3712618@kroah.com/, we could introduce a new helper macro to reduce losts of boilerplate code, vmstat and kprobes is the example which covert to use it, if this is accepted, I will send out more cleanups. This patch (of 3): Introduce DEFINE_SEQ_ATTRIBUTE() helper macro to decrease code duplication. [akpm@linux-foundation.org: coding style fixes] Signed-off-by: Kefeng Wang Signed-off-by: Andrew Morton Cc: Greg KH Cc: Ingo Molnar Cc: Kefeng Wang Cc: Anil S Keshavamurthy Cc: "David S. Miller" Cc: Masami Hiramatsu Cc: Al Viro Link: http://lkml.kernel.org/r/20200509064031.181091-1-wangkefeng.wang@huawei.com Link: http://lkml.kernel.org/r/20200509064031.181091-2-wangkefeng.wang@huawei.com Signed-off-by: Linus Torvalds

seq_file: remove m->version

2020-04-07T17:43:42+00:00

The process maps file was the only user of version (introduced back in 2005). Now that it uses ppos instead, we can remove it. Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/20200317193201.9924-4-adobriyan@gmail.com Signed-off-by: Linus Torvalds

proc: convert everything to "struct proc_ops"

2020-02-04T03:05:26+00:00

The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in seq_file.h. Conversion rule is: llseek => proc_lseek unlocked_ioctl => proc_ioctl xxx => proc_xxx delete ".owner = THIS_MODULE" line [akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c] [sfr@canb.auug.org.au: fix kernel/sched/psi.c] Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2 Signed-off-by: Alexey Dobriyan Signed-off-by: Stephen Rothwell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds