linux-kernel - [PATCH tip/core/rcu 07/15] uaccess: Cleanup PREEMPT

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Message-Id: <20200928233102.24265-7-paulmck@kernel.org>
Date:   Mon, 28 Sep 2020 16:30:54 -0700
From:   paulmck@...nel.org
To:     rcu@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, kernel-team@...com, mingo@...nel.org,
        jiangshanlai@...il.com, akpm@...ux-foundation.org,
        mathieu.desnoyers@...icios.com, josh@...htriplett.org,
        tglx@...utronix.de, peterz@...radead.org, rostedt@...dmis.org,
        dhowells@...hat.com, edumazet@...gle.com, fweisbec@...il.com,
        oleg@...hat.com, joel@...lfernandes.org, mhocko@...nel.org,
        mgorman@...hsingularity.net, torvalds@...ux-foundation.org,
        "Paul E . McKenney" <paulmck@...nel.org>
Subject: [PATCH tip/core/rcu 07/15] uaccess: Cleanup PREEMPT_COUNT leftovers

From: Thomas Gleixner <tglx@...utronix.de>

CONFIG_PREEMPT_COUNT is now unconditionally enabled and will be
removed. Cleanup the leftovers before doing so.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Paul E. McKenney <paulmck@...nel.org>
---
 include/linux/uaccess.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 94b2854..b79a5a9 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -230,9 +230,9 @@ static inline bool pagefault_disabled(void)
  *
  * This function should only be used by the fault handlers. Other users should
  * stick to pagefault_disabled().
- * Please NEVER use preempt_disable() to disable the fault handler. With
- * !CONFIG_PREEMPT_COUNT, this is like a NOP. So the handler won't be disabled.
- * in_atomic() will report different values based on !CONFIG_PREEMPT_COUNT.
+ *
+ * Please NEVER use preempt_disable() or local_irq_disable() to disable the
+ * fault handler.
  */
 #define faulthandler_disabled() (pagefault_disabled() || in_atomic())
 
-- 
2.9.5