[tip:core/futexes] arm: Remove bogus comment in futex_atomic_cmpxchg_inatomic()

From: tip-bot for Thomas Gleixner
Date: Mon Mar 14 2011 - 16:17:02 EST


Commit-ID: 07d5ecae2940ddd77746e2fb597dcf57d3c2e277
Gitweb: http://git.kernel.org/tip/07d5ecae2940ddd77746e2fb597dcf57d3c2e277
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Mon, 14 Mar 2011 20:00:30 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 14 Mar 2011 21:10:26 +0100

arm: Remove bogus comment in futex_atomic_cmpxchg_inatomic()

commit 522d7dec(futex: Remove redundant pagefault_disable in
futex_atomic_cmpxchg_inatomic()) added a bogus comment.

/* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic
* call sites. */

Bogus in two aspects:

1) pagefault_disable != preempt_disable even if the mechanism we use
is the same

2) we have a call site which deliberately does not disable pagefaults
as it wants the possible fault to be handled - though that has been
changed for consistency reasons now.

Sigh. I really should have seen that when committing the above. :(

Catched-by-and-rightfully-ranted-at-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
LKML-Reference: <alpine.LFD.2.00.1103141126590.2787@xxxxxxxxxxxxxxxxxxxxxxx>
Cc: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Darren Hart <darren@xxxxxxxxxx>
---
arch/arm/include/asm/futex.h | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index 0e29d8e..199a6b6 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -97,9 +97,6 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;

- /* Note that preemption is disabled by futex_atomic_cmpxchg_inatomic
- * call sites. */
-
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
"1: " T(ldr) " %1, [%4]\n"
" teq %1, %2\n"
--
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