From: Rohan McLure <rmclure@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Rohan McLure <rmclure@linux.ibm.com>, npiggin@gmail.com, arnd@arndb.de
Subject: [PATCH 11/12] powerpc: powernv: Annotate asynchronous access to opal tokens
Date: Mon, 8 May 2023 12:01:19 +1000 [thread overview]
Message-ID: <20230508020120.218494-12-rmclure@linux.ibm.com> (raw)
In-Reply-To: <20230508020120.218494-1-rmclure@linux.ibm.com>
The opal-async.c unit contains code for polling event sources, which
implies intentional data races. Ensure that the compiler will atomically
access such variables by means of {READ,WRITE}_ONCE calls, which in turn
inform KCSAN that polling behaviour is intended.
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
---
arch/powerpc/platforms/powernv/opal-async.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/opal-async.c b/arch/powerpc/platforms/powernv/opal-async.c
index c094fdf5825c..282d2ac6fbb0 100644
--- a/arch/powerpc/platforms/powernv/opal-async.c
+++ b/arch/powerpc/platforms/powernv/opal-async.c
@@ -146,7 +146,7 @@ int opal_async_wait_response(uint64_t token, struct opal_msg *msg)
* functional.
*/
opal_wake_poller();
- wait_event(opal_async_wait, opal_async_tokens[token].state
+ wait_event(opal_async_wait, READ_ONCE(opal_async_tokens[token].state)
== ASYNC_TOKEN_COMPLETED);
memcpy(msg, &opal_async_tokens[token].response, sizeof(*msg));
@@ -185,7 +185,7 @@ int opal_async_wait_response_interruptible(uint64_t token, struct opal_msg *msg)
* interruptible version before doing anything else with the
* token.
*/
- if (opal_async_tokens[token].state == ASYNC_TOKEN_ALLOCATED) {
+ if (READ_ONCE(opal_async_tokens[token].state) == ASYNC_TOKEN_ALLOCATED) {
spin_lock_irqsave(&opal_async_comp_lock, flags);
if (opal_async_tokens[token].state == ASYNC_TOKEN_ALLOCATED)
opal_async_tokens[token].state = ASYNC_TOKEN_DISPATCHED;
@@ -199,7 +199,7 @@ int opal_async_wait_response_interruptible(uint64_t token, struct opal_msg *msg)
*/
opal_wake_poller();
ret = wait_event_interruptible(opal_async_wait,
- opal_async_tokens[token].state ==
+ READ_ONCE(opal_async_tokens[token].state) ==
ASYNC_TOKEN_COMPLETED);
if (!ret)
memcpy(msg, &opal_async_tokens[token].response, sizeof(*msg));
--
2.37.2
next prev parent reply other threads:[~2023-05-08 2:10 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-08 2:01 [PATCH 00/12] powerpc: KCSAN fix warnings and mark accesses Rohan McLure
2023-05-08 2:01 ` [PATCH 01/12] powerpc: qspinlock: Fix qnode->locked value interpretation Rohan McLure
2023-05-09 2:01 ` Nicholas Piggin
2023-05-09 4:26 ` Rohan McLure
2023-05-08 2:01 ` [PATCH 02/12] powerpc: qspinlock: Mark accesses to qnode lock checks Rohan McLure
2023-05-09 2:02 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 03/12] powerpc: qspinlock: Enforce qnode writes prior to publishing to queue Rohan McLure
2023-05-09 2:04 ` Nicholas Piggin
2023-05-09 5:26 ` Rohan McLure
2023-05-09 6:45 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 04/12] asm-generic/mmiowb: Mark accesses to fix KCSAN warnings Rohan McLure
2023-05-08 6:30 ` Arnd Bergmann
2023-05-08 15:44 ` [PATCH 4/12] " Gautam Menghani
2023-05-09 2:16 ` [PATCH 04/12] " Nicholas Piggin
2023-05-08 2:01 ` [PATCH 05/12] powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid Rohan McLure
2023-05-09 2:17 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 06/12] powerpc: Mark accesses to power_save callback in arch_cpu_idle Rohan McLure
2023-05-09 2:21 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 07/12] powerpc: powernv: Fix KCSAN datarace warnings on idle_state contention Rohan McLure
2023-05-09 2:26 ` Nicholas Piggin
2023-05-10 2:00 ` Rohan McLure
2023-05-08 2:01 ` [PATCH 08/12] powerpc: Annotate accesses to ipi message flags Rohan McLure
2023-05-09 2:28 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 09/12] powerpc: Mark writes registering ipi to host cpu through kvm Rohan McLure
2023-05-09 2:30 ` Nicholas Piggin
2023-05-08 2:01 ` [PATCH 10/12] powerpc: powernv: Annotate data races in opal events Rohan McLure
2023-05-09 2:31 ` Nicholas Piggin
2023-05-08 2:01 ` Rohan McLure [this message]
2023-05-08 2:01 ` [PATCH 12/12] powerpc: Mark asynchronous accesses to irq_data Rohan McLure
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