linux_dsm_epyc7002/fs
Mike Frysinger 04e4f2b18c FDPIC: Respect PT_GNU_STACK exec protection markings when creating NOMMU stack
The current code will load the stack size and protection markings, but
then only use the markings in the MMU code path.  The NOMMU code path
always passes PROT_EXEC to the mmap() call.  While this doesn't matter
to most people whilst the code is running, it will cause a pointless
icache flush when starting every FDPIC application.  Typically this
icache flush will be of a region on the order of 128KB in size, or may
be the entire icache, depending on the facilities available on the CPU.

In the case where the arch default behaviour seems to be desired
(EXSTACK_DEFAULT), we probe VM_STACK_FLAGS for VM_EXEC to determine
whether we should be setting PROT_EXEC or not.

For arches that support an MPU (Memory Protection Unit - an MMU without
the virtual mapping capability), setting PROT_EXEC or not will make an
important difference.

It should be noted that this change also affects the executability of
the brk region, since ELF-FDPIC has that share with the stack.  However,
this is probably irrelevant as NOMMU programs aren't likely to use the
brk region, preferring instead allocation via mmap().

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-06 18:16:02 -08:00
..
9p
adfs
affs
afs
autofs
autofs4
befs
bfs
btrfs
cachefiles
cifs Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6 2009-12-31 15:17:26 -08:00
coda
configfs
cramfs
debugfs
devpts
dlm
ecryptfs
efs
exofs exofs: simple_write_end does not mark_inode_dirty 2010-01-05 09:14:32 +02:00
exportfs
ext2
ext3
ext4 ext4: Calculate metadata requirements more accurately 2010-01-01 02:41:30 -05:00
fat
freevxfs
fscache
fuse
gfs2
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jbd2
jffs2
jfs
lockd
minix
ncpfs
nfs
nfs_common
nfsd Merge branch 'for-2.6.33' of git://linux-nfs.org/~bfields/linux 2010-01-06 18:10:15 -08:00
nilfs2
nls
notify
ntfs
ocfs2
omfs
openpromfs
partitions
proc
qnx4
quota
ramfs
reiserfs Merge branch 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing 2010-01-02 11:17:05 -08:00
romfs
smbfs
squashfs
sysfs sysfs: Add lockdep annotations for the sysfs active reference 2010-01-04 12:34:46 -08:00
sysv
ubifs
udf
ufs
xfs
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c FDPIC: Respect PT_GNU_STACK exec protection markings when creating NOMMU stack 2010-01-06 18:16:02 -08:00
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c
block_dev.c
buffer.c
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fifo.c
file_table.c
file.c
filesystems.c
fs_struct.c
fs-writeback.c writeback: add missing kernel-doc notation 2010-01-02 10:09:44 -08:00
generic_acl.c
inode.c
internal.h
ioctl.c
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mpage.c
namei.c
namespace.c
nfsctl.c
no-block.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
read_write.c
read_write.h
readdir.c
select.c
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
super.c
sync.c
timerfd.c
utimes.c
xattr_acl.c
xattr.c