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[100/192] mm: ignore MAP_EXECUTABLE in ksys_mmap_pgoff()

Message ID 20210629023835.J9ZYGwB5n%akpm@linux-foundation.org (mailing list archive)
State New
Headers show
Series [001/192] mm/gup: fix try_grab_compound_head() race with split_huge_page() | expand

Commit Message

Andrew Morton June 29, 2021, 2:38 a.m. UTC 
From: David Hildenbrand <david@redhat.com>
Subject: mm: ignore MAP_EXECUTABLE in ksys_mmap_pgoff()

Let's also remove masking off MAP_EXECUTABLE from ksys_mmap_pgoff(): the
last in-tree occurrence of MAP_EXECUTABLE 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_EXECUTABLE is ignored.

Link: https://lkml.kernel.org/r/20210421093453.6904-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kevin Brodsky <Kevin.Brodsky@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mman.h |    2 ++
 mm/mmap.c            |    2 +-
 mm/nommu.c           |    2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)
diff mbox series

Patch

--- a/include/linux/mman.h~mm-ignore-map_executable-in-ksys_mmap_pgoff
+++ a/include/linux/mman.h
@@ -31,6 +31,8 @@ 
 /*
  * 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.
  */
 #define LEGACY_MAP_MASK (MAP_SHARED \
 		| MAP_PRIVATE \
--- a/mm/mmap.c~mm-ignore-map_executable-in-ksys_mmap_pgoff
+++ a/mm/mmap.c
@@ -1633,7 +1633,7 @@  unsigned long ksys_mmap_pgoff(unsigned l
 			return PTR_ERR(file);
 	}
 
-	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+	flags &= ~MAP_DENYWRITE;
 
 	retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);
 out_fput:
--- a/mm/nommu.c~mm-ignore-map_executable-in-ksys_mmap_pgoff
+++ a/mm/nommu.c
@@ -1296,7 +1296,7 @@  unsigned long ksys_mmap_pgoff(unsigned l
 			goto out;
 	}
 
-	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+	flags &= ~MAP_DENYWRITE;
 
 	retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);