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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-26 16:02:40 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-11-26 16:02:40 -0800 |
commit | 168829ad09ca9cdfdc664b2110d0e3569932c12d (patch) | |
tree | 1b6351ab5766a272dec1fc08f77272a199bba978 /kernel/fork.c | |
parent | 1ae78780eda54023a0fb49ee743dbba39da148e0 (diff) | |
parent | 500543c53a54134ced386aed85cd93cf1363f981 (diff) | |
download | linux-stable-168829ad09ca9cdfdc664b2110d0e3569932c12d.tar.gz linux-stable-168829ad09ca9cdfdc664b2110d0e3569932c12d.tar.bz2 linux-stable-168829ad09ca9cdfdc664b2110d0e3569932c12d.zip |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"The main changes in this cycle were:
- A comprehensive rewrite of the robust/PI futex code's exit handling
to fix various exit races. (Thomas Gleixner et al)
- Rework the generic REFCOUNT_FULL implementation using
atomic_fetch_* operations so that the performance impact of the
cmpxchg() loops is mitigated for common refcount operations.
With these performance improvements the generic implementation of
refcount_t should be good enough for everybody - and this got
confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and
REFCOUNT_FULL entirely, leaving the generic implementation enabled
unconditionally. (Will Deacon)
- Other misc changes, fixes, cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
lkdtm: Remove references to CONFIG_REFCOUNT_FULL
locking/refcount: Remove unused 'refcount_error_report()' function
locking/refcount: Consolidate implementations of refcount_t
locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions
locking/refcount: Move saturation warnings out of line
locking/refcount: Improve performance of generic REFCOUNT_FULL code
locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the <linux/refcount.h> header
locking/refcount: Remove unused refcount_*_checked() variants
locking/refcount: Ensure integer operands are treated as signed
locking/refcount: Define constants for saturation and max refcount values
futex: Prevent exit livelock
futex: Provide distinct return value when owner is exiting
futex: Add mutex around futex exit
futex: Provide state handling for exec() as well
futex: Sanitize exit state handling
futex: Mark the begin of futex exit explicitly
futex: Set task::futex_state to DEAD right after handling futex exit
futex: Split futex_mm_release() for exit/exec
exit/exec: Seperate mm_release()
futex: Replace PF_EXITPIDONE with a state
...
Diffstat (limited to 'kernel/fork.c')
-rw-r--r-- | kernel/fork.c | 40 |
1 files changed, 15 insertions, 25 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 35f91ee91057..00b64f41c2b4 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1283,24 +1283,8 @@ static int wait_for_vfork_done(struct task_struct *child, * restoring the old one. . . * Eric Biederman 10 January 1998 */ -void mm_release(struct task_struct *tsk, struct mm_struct *mm) +static void mm_release(struct task_struct *tsk, struct mm_struct *mm) { - /* Get rid of any futexes when releasing the mm */ -#ifdef CONFIG_FUTEX - if (unlikely(tsk->robust_list)) { - exit_robust_list(tsk); - tsk->robust_list = NULL; - } -#ifdef CONFIG_COMPAT - if (unlikely(tsk->compat_robust_list)) { - compat_exit_robust_list(tsk); - tsk->compat_robust_list = NULL; - } -#endif - if (unlikely(!list_empty(&tsk->pi_state_list))) - exit_pi_state_list(tsk); -#endif - uprobe_free_utask(tsk); /* Get rid of any cached register state */ @@ -1333,6 +1317,18 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm) complete_vfork_done(tsk); } +void exit_mm_release(struct task_struct *tsk, struct mm_struct *mm) +{ + futex_exit_release(tsk); + mm_release(tsk, mm); +} + +void exec_mm_release(struct task_struct *tsk, struct mm_struct *mm) +{ + futex_exec_release(tsk); + mm_release(tsk, mm); +} + /** * dup_mm() - duplicates an existing mm structure * @tsk: the task_struct with which the new mm will be associated. @@ -2124,14 +2120,8 @@ static __latent_entropy struct task_struct *copy_process( #ifdef CONFIG_BLOCK p->plug = NULL; #endif -#ifdef CONFIG_FUTEX - p->robust_list = NULL; -#ifdef CONFIG_COMPAT - p->compat_robust_list = NULL; -#endif - INIT_LIST_HEAD(&p->pi_state_list); - p->pi_state_cache = NULL; -#endif + futex_init_task(p); + /* * sigaltstack should be cleared when sharing the same VM */ |