Lorenzo Stoakes 567308fe23 mm: perform all memfd seal checks in a single place ... We no longer actually need to perform these checks in the f_op->mmap() hook any longer. We already moved the operation which clears VM_MAYWRITE on a read-only mapping of a write-sealed memfd in order to work around the restrictions imposed by commit 5de195060b ("mm: resolve faulty mmap_region() error path behaviour"). There is no reason for us not to simply go ahead and additionally check to see if any pre-existing seals are in place here rather than defer this to the f_op->mmap() hook. By doing this we remove more logic from shmem_mmap() which doesn't belong there, as well as doing the same for hugetlbfs_file_mmap(). We also remove dubious shared logic in mm.h which simply does not belong there either. It makes sense to do these checks at the earliest opportunity, we know these are shmem (or hugetlbfs) mappings whose relevant VMA flags will not change from the invoking do_mmap() so there is simply no need to wait. This also means the implementation of further memfd seal flags can be done within mm/memfd.c and also have the opportunity to modify VMA flags as necessary early in the mapping logic. Link: https://lkml.kernel.org/r/20241206212846.210835-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Tested-by: Isaac J. Manjarres <isaacmanjarres@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jeff Xu <jeffxu@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>		2024-12-18 19:50:51 -08:00
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inode.c	mm: perform all memfd seal checks in a single place	2024-12-18 19:50:51 -08:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00