linux.git/include/linux/rculist.h, branch v5.7-rc2

rculist: Add brackets around cond argument in __list_check_rcu macro

2020-02-20T23:58:23+00:00

Passing a complex lockdep condition to __list_check_rcu results
in false positive lockdep splat due to incorrect expression
evaluation.

For example, a lockdep check condition `cond1 || cond2` is
evaluated as `!cond1 || cond2 && !rcu_read_lock_any_held()`
which, according to operator precedence, evaluates to
`!cond1 || (cond2 && !rcu_read_lock_any_held())`.
This would result in a lockdep splat when cond1 is false
and cond2 is true which is logically incorrect.

Signed-off-by: Amol Grover 
Acked-by: Joel Fernandes (Google) 
Signed-off-by: Paul E. McKenney

rculist.h: Add list_tail_rcu()

2020-01-10T22:00:58+00:00

This patch adds the macro list_tail_rcu() and documents it.

Signed-off-by: Madhuparna Bhowmik 
[ paulmck: Reword a bit. ]
Signed-off-by: Paul E. McKenney

list: Add hlist_unhashed_lockless()

2019-12-09T20:36:58+00:00

We would like to use hlist_unhashed() from timer_pending(),
which runs without protection of a lock.

Note that other callers might also want to use this variant.

Instead of forcing a READ_ONCE() for all hlist_unhashed()
callers, add a new helper with an explicit _lockless suffix
in the name to better document what is going on.

Also add various WRITE_ONCE() in __hlist_del(), hlist_add_head()
and hlist_add_before()/hlist_add_behind() to pair with
the READ_ONCE().

Signed-off-by: Eric Dumazet 
Cc: Thomas Gleixner 
[ paulmck: Also add WRITE_ONCE() to rculist.h. ]
Signed-off-by: Paul E. McKenney

rculist: Describe variadic macro argument in a Sphinx-compatible way

2019-12-09T20:36:57+00:00

Without this patch, Sphinx shows "variable arguments" as the description
of the cond argument, rather than the intended description, and prints
the following warnings:

./include/linux/rculist.h:374: warning: Excess function parameter 'cond' description in 'list_for_each_entry_rcu'
./include/linux/rculist.h:651: warning: Excess function parameter 'cond' description in 'hlist_for_each_entry_rcu'

Signed-off-by: Jonathan Neuschäfer 
Acked-by: Joel Fernandes (Google) 
Signed-off-by: Paul E. McKenney

rcu: Add support for consolidated-RCU reader checking

2019-08-09T18:00:35+00:00

This commit adds RCU-reader checks to list_for_each_entry_rcu() and
hlist_for_each_entry_rcu().  These checks are optional, and are indicated
by a lockdep expression passed to a new optional argument to these two
macros.  If this optional lockdep expression is omitted, these two macros
act as before, checking for an RCU read-side critical section.

Signed-off-by: Joel Fernandes (Google) 
[ paulmck: Update to eliminate return within macro and update comment. ]
Signed-off-by: Paul E. McKenney

treewide: Rename rcu_dereference_raw_notrace() to _check()

2019-08-01T21:16:21+00:00

The rcu_dereference_raw_notrace() API name is confusing.  It is equivalent
to rcu_dereference_raw() except that it also does sparse pointer checking.

There are only a few users of rcu_dereference_raw_notrace(). This patches
renames all of them to be rcu_dereference_raw_check() with the "_check()"
indicating sparse checking.

Signed-off-by: Joel Fernandes (Google) 
[ paulmck: Fix checkpatch warnings about parentheses. ]
Signed-off-by: Paul E. McKenney

rcu: Clean up flavor-related definitions and comments in rculist.h

2018-08-30T23:03:31+00:00

Signed-off-by: Paul E. McKenney

rculist: Improve documentation for list_for_each_entry_from_rcu()

2018-07-12T22:39:25+00:00

Unfortunately the patch for adding list_for_each_entry_from_rcu()
wasn't the final patch after all review.  It is functionally
correct but the documentation was incomplete.

This patch adds this missing documentation which includes an update to
the documentation for list_for_each_entry_continue_rcu() to match the
documentation for the new list_for_each_entry_from_rcu(), and adds
list_for_each_entry_from_rcu() and the already existing
hlist_for_each_entry_from_rcu() to section 7 of whatisRCU.txt.

Reviewed-by: Paul E. McKenney 
Signed-off-by: NeilBrown 
Signed-off-by: Paul E. McKenney

rculist: add list_for_each_entry_from_rcu()

2018-05-31T18:59:19+00:00

list_for_each_entry_from_rcu() is an RCU version of
list_for_each_entry_from().  It walks a linked list under rcu
protection, from a given start point.

It is similar to list_for_each_entry_continue_rcu() but starts *at*
the given position rather than *after* it.

Naturally, the start point must be known to be in the list.

Signed-off-by: NeilBrown 
Signed-off-by: Trond Myklebust

Merge branch 'linus' into locking/core, to resolve conflicts

2017-11-07T09:32:44+00:00

Conflicts:
	include/linux/compiler-clang.h
	include/linux/compiler-gcc.h
	include/linux/compiler-intel.h
	include/uapi/linux/stddef.h

Signed-off-by: Ingo Molnar