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fc4f4be9b5
Patch series "mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings". Trying to reduce the confusion around VM_SHARED and VM_MAYSHARE first requires !CONFIG_MMU to stop using VM_MAYSHARE for MAP_PRIVATE mappings. CONFIG_MMU only sets VM_MAYSHARE for MAP_SHARED mappings. This paves the way for further VM_MAYSHARE and VM_SHARED cleanups: for example, renaming VM_MAYSHARED to VM_MAP_SHARED to make it cleaner what is actually means. Let's first get the weird case out of the way and not use VM_MAYSHARE in MAP_PRIVATE mappings, using a new VM_MAYOVERLAY flag instead. This patch (of 3): We want to stop using VM_MAYSHARE in private mappings to pave the way for clarifying the semantics of VM_MAYSHARE vs. VM_SHARED and reduce the confusion. While CONFIG_MMU uses VM_MAYSHARE to represent MAP_SHARED, !CONFIG_MMU also sets VM_MAYSHARE for selected R/O private file mappings that are an effective overlay of a file mapping. Let's factor out all relevant VM_MAYSHARE checks in !CONFIG_MMU code into is_nommu_shared_mapping() first. Note that whenever VM_SHARED is set, VM_MAYSHARE must be set as well (unless there is a serious BUG). So there is not need to test for VM_SHARED manually. No functional change intended. Link: https://lkml.kernel.org/r/20230102160856.500584-1-david@redhat.com Link: https://lkml.kernel.org/r/20230102160856.500584-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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.. | ||
advise.c | ||
advise.h | ||
alloc_cache.h | ||
cancel.c | ||
cancel.h | ||
epoll.c | ||
epoll.h | ||
fdinfo.c | ||
fdinfo.h | ||
filetable.c | ||
filetable.h | ||
fs.c | ||
fs.h | ||
io_uring.c | ||
io_uring.h | ||
io-wq.c | ||
io-wq.h | ||
kbuf.c | ||
kbuf.h | ||
Makefile | ||
msg_ring.c | ||
msg_ring.h | ||
net.c | ||
net.h | ||
nop.c | ||
nop.h | ||
notif.c | ||
notif.h | ||
opdef.c | ||
opdef.h | ||
openclose.c | ||
openclose.h | ||
poll.c | ||
poll.h | ||
refs.h | ||
rsrc.c | ||
rsrc.h | ||
rw.c | ||
rw.h | ||
slist.h | ||
splice.c | ||
splice.h | ||
sqpoll.c | ||
sqpoll.h | ||
statx.c | ||
statx.h | ||
sync.c | ||
sync.h | ||
tctx.c | ||
tctx.h | ||
timeout.c | ||
timeout.h | ||
uring_cmd.c | ||
uring_cmd.h | ||
xattr.c | ||
xattr.h |