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Commit f90e2d9a authored by Wang Kai's avatar Wang Kai Committed by Ingo Molnar
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x86/mm/pkeys: Fix typo in Documentation/x86/protection-keys.txt 



Replace PKEY_DENY_WRITE with PKEY_DISABLE_WRITE,
to match the source code.

Signed-off-by: default avatarWang Kai <morgan.wang@huawei.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: corbet@lwn.net
Cc: dave.hansen@intel.com
Cc: dave.hansen@linux.intel.com
Cc: linux-doc@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 04b67022

Documentation/x86/protection-keys.txt

+3 −3
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ with a key. In this example WRPKRU is wrapped by a C function 
called pkey_set().



	int real_prot = PROT_READ|PROT_WRITE;

	pkey = pkey_alloc(0, PKEY_DENY_WRITE);

	pkey = pkey_alloc(0, PKEY_DISABLE_WRITE);

	ptr = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);

	ret = pkey_mprotect(ptr, PAGE_SIZE, real_prot, pkey);

	... application runs here
@@ -42,9 +42,9 @@ called pkey_set(). 
Now, if the application needs to update the data at 'ptr', it can

gain access, do the update, then remove its write access:



	pkey_set(pkey, 0); // clear PKEY_DENY_WRITE

	pkey_set(pkey, 0); // clear PKEY_DISABLE_WRITE

	*ptr = foo; // assign something

	pkey_set(pkey, PKEY_DENY_WRITE); // set PKEY_DENY_WRITE again

	pkey_set(pkey, PKEY_DISABLE_WRITE); // set PKEY_DISABLE_WRITE again



Now when it frees the memory, it will also free the pkey since it

is no longer in use: