From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Marc Zyngier <maz@kernel.org>
Subject: [RFC PATCH 05/27] untangling ep_call_nested(): take pushing cookie into a helper
Date: Sun, 4 Oct 2020 03:39:07 +0100 [thread overview]
Message-ID: <20201004023929.2740074-5-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20201004023929.2740074-1-viro@ZenIV.linux.org.uk>
From: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/eventpoll.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 43aecae0935c..bd2cc78c47c8 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -424,6 +424,21 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi)
#endif /* CONFIG_NET_RX_BUSY_POLL */
+static bool ep_push_nested(void *cookie)
+{
+ int i;
+
+ if (nesting > EP_MAX_NESTS) /* too deep nesting */
+ return false;
+
+ for (i = 0; i < nesting; i++) {
+ if (cookies[i] == cookie) /* loop detected */
+ return false;
+ }
+ cookies[nesting++] = cookie;
+ return true;
+}
+
/**
* ep_call_nested - Perform a bound (possibly) nested call, by checking
* that the recursion limit is not exceeded, and that
@@ -440,17 +455,10 @@ static inline void ep_set_busy_poll_napi_id(struct epitem *epi)
static int ep_call_nested(int (*nproc)(void *, void *, int), void *priv,
void *cookie)
{
- int error, i;
+ int error;
- if (nesting > EP_MAX_NESTS) /* too deep nesting */
+ if (!ep_push_nested(cookie))
return -1;
-
- for (i = 0; i < nesting; i++) {
- if (cookies[i] == cookie) /* loop detected */
- return -1;
- }
- cookies[nesting++] = cookie;
-
/* Call the nested function */
error = (*nproc)(priv, cookie, nesting - 1);
nesting--;
--
2.11.0
next prev parent reply other threads:[~2020-10-04 2:41 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-04 2:36 [RFC][PATCHSET] epoll cleanups Al Viro
2020-10-04 2:39 ` [RFC PATCH 01/27] epoll: switch epitem->pwqlist to single-linked list Al Viro
2020-10-04 2:39 ` [RFC PATCH 02/27] epoll: get rid of epitem->nwait Al Viro
2020-10-04 2:39 ` [RFC PATCH 03/27] untangling ep_call_nested(): get rid of useless arguments Al Viro
2020-10-04 2:39 ` [RFC PATCH 04/27] untangling ep_call_nested(): it's all serialized on epmutex Al Viro
2020-10-04 2:39 ` Al Viro [this message]
2020-10-04 2:39 ` [RFC PATCH 06/27] untangling ep_call_nested(): move push/pop of cookie into the callbacks Al Viro
2020-10-04 2:39 ` [RFC PATCH 07/27] untangling ep_call_nested(): and there was much rejoicing Al Viro
2020-10-04 2:39 ` [RFC PATCH 08/27] reverse_path_check_proc(): sane arguments Al Viro
2020-10-04 2:39 ` [RFC PATCH 09/27] reverse_path_check_proc(): don't bother with cookies Al Viro
2020-10-04 2:39 ` [RFC PATCH 10/27] clean reverse_path_check_proc() a bit Al Viro
2020-10-04 2:39 ` [RFC PATCH 11/27] ep_loop_check_proc(): lift pushing the cookie into callers Al Viro
2020-10-04 2:39 ` [RFC PATCH 12/27] get rid of ep_push_nested() Al Viro
2020-10-04 2:39 ` [RFC PATCH 13/27] ep_loop_check_proc(): saner calling conventions Al Viro
2020-10-04 2:39 ` [RFC PATCH 14/27] ep_scan_ready_list(): prepare to splitup Al Viro
2020-10-04 2:39 ` [RFC PATCH 15/27] lift the calls of ep_read_events_proc() into the callers Al Viro
2020-10-04 2:39 ` [RFC PATCH 16/27] lift the calls of ep_send_events_proc() " Al Viro
2020-10-04 2:39 ` [RFC PATCH 17/27] ep_send_events_proc(): fold into the caller Al Viro
2020-10-04 2:39 ` [RFC PATCH 18/27] lift locking/unlocking ep->mtx out of ep_{start,done}_scan() Al Viro
2020-10-04 2:39 ` [RFC PATCH 19/27] ep_insert(): don't open-code ep_remove() on failure exits Al Viro
2020-10-04 2:39 ` [RFC PATCH 20/27] ep_insert(): we only need tep->mtx around the insertion itself Al Viro
2020-10-04 12:56 ` [ep_insert()] 9ee1cc5666: WARNING:possible_recursive_locking_detected kernel test robot
2020-10-04 14:17 ` Al Viro
2020-10-04 14:27 ` Al Viro
2020-10-04 2:39 ` [RFC PATCH 21/27] take the common part of ep_eventpoll_poll() and ep_item_poll() into helper Al Viro
2020-10-04 2:39 ` [RFC PATCH 22/27] fold ep_read_events_proc() into the only caller Al Viro
2020-10-04 2:39 ` [RFC PATCH 23/27] ep_insert(): move creation of wakeup source past the fl_ep_links insertion Al Viro
2020-10-04 2:39 ` [RFC PATCH 24/27] convert ->f_ep_links/->fllink to hlist Al Viro
2020-10-04 2:39 ` [RFC PATCH 25/27] lift rcu_read_lock() into reverse_path_check() Al Viro
2020-10-04 2:39 ` [RFC PATCH 26/27] epoll: massage the check list insertion Al Viro
2020-10-04 2:39 ` [RFC PATCH 27/27] epoll: take epitem list out of struct file Al Viro
2020-10-05 20:37 ` Qian Cai
2020-10-05 20:49 ` Al Viro
2020-10-04 2:49 ` [RFC][PATCHSET] epoll cleanups Al Viro
2020-10-04 12:13 ` Matthew Wilcox
2020-10-04 14:15 ` Al Viro
2020-10-04 18:08 ` Linus Torvalds
2020-10-04 20:05 ` Al Viro
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