forge/linux-uconsole
1
0
Fork 0
Code Issues 1 Pull requests Projects Releases Packages Wiki Activity Actions

ARM: mm: use pteval_t to represent page protection values

Browse source 
commit 864aa04cd0 upstream.

When updating the page protection map after calculating the user_pgprot
value, the base protection map is temporarily stored in an unsigned long
type, causing truncation of the protection bits when LPAE is enabled.
This effectively means that calls to mprotect() will corrupt the upper
page attributes, clearing the XN bit unconditionally.

This patch uses pteval_t to store the intermediate protection values,
preserving the upper bits for 64-bit descriptors.

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Will Deacon 2012-09-18 19:18:35 +01:00 • committed by Greg Kroah-Hartman
commit f61019b8f7
1 changed files with 1 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

2
arch/arm/mm/mmu.c
View file

@ -467,7 +467,7 @@ static void __init build_mem_type_table(void)
}
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
pteval_t v = pgprot_val(protection_map[i]);
protection_map[i] = __pgprot(v | user_pgprot);
}