diff options
author | Ingo Molnar <mingo@kernel.org> | 2019-09-16 15:04:28 +0300 |
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committer | Ingo Molnar <mingo@kernel.org> | 2019-09-16 15:05:04 +0300 |
commit | 563c4f85f9f0d63b712081d5b4522152cdcb8b6b (patch) | |
tree | 92351ab2d60d5fd7ce5745d21c9a60ce6d46c5dd /kernel/cred.c | |
parent | 4adcdcea717cb2d8436bef00dd689aa5bc76f11b (diff) | |
parent | 09c7e8b21d67c3c78ab9701dbc0fb1e9f14a0ba5 (diff) | |
download | linux-563c4f85f9f0d63b712081d5b4522152cdcb8b6b.tar.xz |
Merge branch 'sched/rt' into sched/core, to pick up -rt changes
Pick up the first couple of patches working towards PREEMPT_RT.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/cred.c')
-rw-r--r-- | kernel/cred.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/kernel/cred.c b/kernel/cred.c index f9a0ce66c9c3..c0a4c12d38b2 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -144,7 +144,10 @@ void __put_cred(struct cred *cred) BUG_ON(cred == current->cred); BUG_ON(cred == current->real_cred); - call_rcu(&cred->rcu, put_cred_rcu); + if (cred->non_rcu) + put_cred_rcu(&cred->rcu); + else + call_rcu(&cred->rcu, put_cred_rcu); } EXPORT_SYMBOL(__put_cred); @@ -261,6 +264,7 @@ struct cred *prepare_creds(void) old = task->cred; memcpy(new, old, sizeof(struct cred)); + new->non_rcu = 0; atomic_set(&new->usage, 1); set_cred_subscribers(new, 0); get_group_info(new->group_info); @@ -544,7 +548,19 @@ const struct cred *override_creds(const struct cred *new) validate_creds(old); validate_creds(new); - get_cred(new); + + /* + * NOTE! This uses 'get_new_cred()' rather than 'get_cred()'. + * + * That means that we do not clear the 'non_rcu' flag, since + * we are only installing the cred into the thread-synchronous + * '->cred' pointer, not the '->real_cred' pointer that is + * visible to other threads under RCU. + * + * Also note that we did validate_creds() manually, not depending + * on the validation in 'get_cred()'. + */ + get_new_cred((struct cred *)new); alter_cred_subscribers(new, 1); rcu_assign_pointer(current->cred, new); alter_cred_subscribers(old, -1); @@ -681,6 +697,7 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon) validate_creds(old); *new = *old; + new->non_rcu = 0; atomic_set(&new->usage, 1); set_cred_subscribers(new, 0); get_uid(new->user); |