Commit graph

4 commits

Author SHA1 Message Date
Martin Schwidefsky
043d07084b [S390] Remove data execution protection
The noexec support on s390 does not rely on a bit in the page table
entry but utilizes the secondary space mode to distinguish between
memory accesses for instructions vs. data. The noexec code relies
on the assumption that the cpu will always use the secondary space
page table for data accesses while it is running in the secondary
space mode. Up to the z9-109 class machines this has been the case.
Unfortunately this is not true anymore with z10 and later machines.
The load-relative-long instructions lrl, lgrl and lgfrl access the
memory operand using the same addressing-space mode that has been
used to fetch the instruction.
This breaks the noexec mode for all user space binaries compiled
with march=z10 or later. The only option is to remove the current
noexec support.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-23 10:24:28 +02:00
Heiko Carstens
84afdcee62 [S390] pgtable: move pte_mkhuge() from hugetlb.h to pgtable.h
All architectures besides s390 have pte_mkhuge() defined in pgtable.h.
So move the function to pgtable.h on s390 as well.
Fixes a compile error introduced with "hugetlb: hugepage migration core"
in linux-next which only happens on s390.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25 16:10:19 +02:00
Martin Schwidefsky
050eef364a [S390] fix tlb flushing vs. concurrent /proc accesses
The tlb flushing code uses the mm_users field of the mm_struct to
decide if each page table entry needs to be flushed individually with
IPTE or if a global flush for the mm_struct is sufficient after all page
table updates have been done. The comment for mm_users says "How many
users with user space?" but the /proc code increases mm_users after it
found the process structure by pid without creating a new user process.
Which makes mm_users useless for the decision between the two tlb
flusing methods. The current code can be confused to not flush tlb
entries by a concurrent access to /proc files if e.g. a fork is in
progres. The solution for this problem is to make the tlb flushing
logic independent from the mm_users field.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-08-24 09:26:34 +02:00
Martin Schwidefsky
c6557e7f2b [S390] move include/asm-s390 to arch/s390/include/asm
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-08-01 20:42:05 +02:00
Renamed from include/asm-s390/hugetlb.h (Browse further)