8cbd0e38a9
People running automated tests have asked for a way to make RCU minimize grace-period duration in order to increase the probability of KASAN detecting a pointer being improperly leaked from an RCU read-side critical section, for example, like this: rcu_read_lock(); p = rcu_dereference(gp); do_something_with(p); // OK rcu_read_unlock(); do_something_else_with(p); // BUG!!! The rcupdate.rcu_expedited boot parameter is a start in this direction, given that it makes calls to synchronize_rcu() instead invoke the faster (and more wasteful) synchronize_rcu_expedited(). However, this does nothing to shorten RCU grace periods that are instead initiated by call_rcu(), and RCU pointer-leak bugs can involve call_rcu() just as surely as they can synchronize_rcu(). This commit therefore adds a RCU_STRICT_GRACE_PERIOD Kconfig option that will be used to shorten normal (non-expedited) RCU grace periods. This commit also dumps out a message when this option is in effect. Later commits will actually shorten grace periods. Reported-by Jann Horn <jannh@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.