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| author |   Thomas Gleixner <tglx@linutronix.de> | 2019-11-12 19:56:19 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-11-16 11:24:01 +0100 |
| commit | 32f3bf67ee78332f2caec0984cb9d412cd0a3c23 (patch) | |
| tree | 47bf912535016ecb14a1d2f14db0bb8e05256a6e /arch/x86/kernel/ioport.c | |
| parent | x86/ioperm: Simplify first ioperm() invocation logic (diff) | |
| download | linux-dev-32f3bf67ee78332f2caec0984cb9d412cd0a3c23.tar.xz linux-dev-32f3bf67ee78332f2caec0984cb9d412cd0a3c23.zip | |
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>
Diffstat (limited to 'arch/x86/kernel/ioport.c')
| -rw-r--r-- | arch/x86/kernel/ioport.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index ca6aa1e33c97..80fa36be2670 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; |