From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@alien8.de>,
linux-kernel@vger.kernel.org
Subject: [tip: x86/iopl] x86/ioperm: Avoid bitmap allocation if no permissions are set
Date: Sat, 16 Nov 2019 11:51:23 -0000 [thread overview]
Message-ID: <157390508369.12247.423990236164065074.tip-bot2@tip-bot2> (raw)
The following commit has been merged into the x86/iopl branch of tip:
Commit-ID: 32f3bf67ee78332f2caec0984cb9d412cd0a3c23
Gitweb: https://git.kernel.org/tip/32f3bf67ee78332f2caec0984cb9d412cd0a3c23
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 12 Nov 2019 19:56:19 +01:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Sat, 16 Nov 2019 11:24:01 +01:00
x86/ioperm: Avoid bitmap allocation if no permissions are set
If ioperm() is invoked the first time and the @turn_on argument is 0, then
there is no point to allocate a bitmap just to clear permissions which are
not set.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/ioport.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
index ca6aa1e..80fa36b 100644
--- a/arch/x86/kernel/ioport.c
+++ b/arch/x86/kernel/ioport.c
@@ -36,6 +36,9 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on)
*/
bitmap = t->io_bitmap_ptr;
if (!bitmap) {
+ /* No point to allocate a bitmap just to clear permissions */
+ if (!turn_on)
+ return 0;
bitmap = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
if (!bitmap)
return -ENOMEM;
next reply other threads:[~2019-11-16 11:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-16 11:51 tip-bot2 for Thomas Gleixner [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-11-13 20:42 [patch V3 07/20] x86/ioperm: Avoid bitmap allocation if no permissions are set Thomas Gleixner
2019-11-15 21:12 ` [tip: x86/iopl] " tip-bot2 for Thomas Gleixner
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