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| author | Gerald Schaefer <gerald.schaefer@de.ibm.com> | 2017-09-18 16:51:51 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2017-09-19 08:36:20 +0200 |
| commit | ba385c0594e723d41790ecfb12c610e6f90c7785 (patch) | |
| tree | da82a51857fa5ee45e492b945120889714d78840 /arch/s390/kernel/topology.c | |
| parent | 91c575b335766effa6103eba42a82aea560c365f (diff) | |
| download | op-kernel-dev-ba385c0594e723d41790ecfb12c610e6f90c7785.zip op-kernel-dev-ba385c0594e723d41790ecfb12c610e6f90c7785.tar.gz | |
s390/mm: fix write access check in gup_huge_pmd()
The check for the _SEGMENT_ENTRY_PROTECT bit in gup_huge_pmd() is the
wrong way around. It must not be set for write==1, and not be checked for
write==0. Fix this similar to how it was fixed for ptes long time ago in
commit 25591b070336 ("[S390] fix get_user_pages_fast").
One impact of this bug would be unnecessarily using the gup slow path for
write==0 on r/w mappings. A potentially more severe impact would be that
gup_huge_pmd() will succeed for write==1 on r/o mappings.
Cc: <stable@vger.kernel.org>
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/topology.c')
0 files changed, 0 insertions, 0 deletions
