]> git.baikalelectronics.ru Git - kernel.git/commit
x86: fix NX bit handling in change_page_attr()
authorHuang, Ying <ying.huang@intel.com>
Wed, 30 Jan 2008 12:34:04 +0000 (13:34 +0100)
committerIngo Molnar <mingo@elte.hu>
Wed, 30 Jan 2008 12:34:04 +0000 (13:34 +0100)
commit68049ee0157bf6783190580b815b27faf21a1c4c
tree0181936dae49d098e98f629344ace9ad1daa15c9
parent87e5ee1f070a52e6c4fc29ed7b4f1e91ba5d00a5
x86: fix NX bit handling in change_page_attr()

This patch fixes a bug of change_page_attr/change_page_attr_addr on
Intel i386/x86_64 CPUs.  After changing page attribute to be
executable with these functions, the page remains un-executable on
Intel i386/x86_64 CPU.  Because on Intel i386/x86_64 CPU, only if the
"NX" bits of all three level page tables are cleared (PAE is enabled),
the corresponding page is executable (refer to section 4.13.2 of Intel
64 and IA-32 Architectures Software Developer's Manual).  So, the bug
is fixed through clearing the "NX" bit of PMD when splitting the huge
PMD.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/mm/pageattr.c