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s390/uaccess: fix clear_user_pt()

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The page table walker variant of clear_user() is supposed to copy the
contents of the empty zero page to user space.
However since 238ec4ef "[S390] zero page cache synonyms" empty_zero_page
is not anymore the page itself but contains the pointer to the empty zero
pages. Therefore the page table walker variant of clear_user() copied
the address of the first empty zero page and afterwards more or less
random data to user space instead of clearing the given user space range.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2013-03-21 08:24:11 +01:00 committed by Martin Schwidefsky
parent 94f9852de8
commit b7fef2dd72
1 changed files with 1 additions and 1 deletions
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arch/s390/lib/uaccess_pt.c
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@ -197,7 +197,7 @@ size_t copy_to_user_pt(size_t n, void __user *to, const void *from)
static size_t clear_user_pt(size_t n, void __user *to)
{
void *zpage = &empty_zero_page;
void *zpage = (void *) empty_zero_page;
long done, size, ret;
done = 0;