c0ef717305
When replaying pending soft-masked interrupts when an interrupt returns to an irqs-enabled context, there is a special case required if this was an asynchronous interrupt to avoid unbounded interrupt recursion. This case was not tested for in the case the asynchronous interrupt hit in user context, because a subsequent nested interrupt would by definition hit in kernel mode, which then exits via the kernel path which does test this case. There is no reason to allow this for such interrupts. While recursion is bounded at the next level, it's simpler and uses less stack to apply the replay logic consistently. This also expands the comment which was really pretty poor and didn't explain the problem (I can say that because I wrote it). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-2-npiggin@gmail.com
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 Restructured Text 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.