[PATCH v1 6/7] mm: ignore MAP_DENYWRITE in ksys_mmap_pgoff()
From: David Hildenbrand <hidden>
Date: 2021-08-12 08:46:19
Also in:
linux-api, linux-fsdevel, linux-mm, lkml
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
Let's also remove masking off MAP_DENYWROTE from ksys_mmap_pgoff(): the last in-tree occurrence of MAP_DENYWRITE is now in LEGACY_MAP_MASK, which accepts the flag e.g., for MAP_SHARED_VALIDATE; however, the flag is ignored throughout the kernel now. Add a comment to LEGACY_MAP_MASK stating that MAP_DENYWRITE is ignored. Signed-off-by: David Hildenbrand <redacted> --- include/linux/mman.h | 3 ++- mm/mmap.c | 2 -- mm/nommu.c | 2 -- 3 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/include/linux/mman.h b/include/linux/mman.h
index bd9aadda047b..b66e91b8176c 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h@@ -32,7 +32,8 @@ * The historical set of flags that all mmap implementations implicitly * support when a ->mmap_validate() op is not provided in file_operations. * - * MAP_EXECUTABLE is completely ignored throughout the kernel. + * MAP_EXECUTABLE and MAP_DENYWRITE are completely ignored throughout the + * kernel. */ #define LEGACY_MAP_MASK (MAP_SHARED \ | MAP_PRIVATE \
diff --git a/mm/mmap.c b/mm/mmap.c
index 589dc1dc13db..bf11fc6e8311 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -1626,8 +1626,6 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, return PTR_ERR(file); } - flags &= ~MAP_DENYWRITE; - retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); out_fput: if (file)
diff --git a/mm/nommu.c b/mm/nommu.c
index 3a93d4054810..0987d131bdfc 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c@@ -1296,8 +1296,6 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, goto out; } - flags &= ~MAP_DENYWRITE; - retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); if (file)
--
2.31.1