Peter Zijlstra ef1ea98c8f task_work: Fix NMI race condition
__schedule()
  // disable irqs
      <NMI>
	  task_work_add(current, work, TWA_NMI_CURRENT);
      </NMI>
  // current = next;
  // enable irqs
      <IRQ>
	  task_work_set_notify_irq()
	  test_and_set_tsk_thread_flag(current,
                                       TIF_NOTIFY_RESUME); // wrong task!
      </IRQ>
  // original task skips task work on its next return to user (or exit!)

Fixes: 466e4d801c ("task_work: Add TWA_NMI_CURRENT as an additional notify mode.")
Reported-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://patch.msgid.link/20250924080118.425949403@infradead.org
2025-10-29 10:29:54 +01:00
2025-10-29 10:29:54 +01:00
…
…
2025-10-12 13:42:36 -07:00
…

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 reStructuredText 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.
S
Description
No description provided
Readme
5.7 GiB
Languages
C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%