[PATCH 01/16] mm: Add MAP_BELOW_HINT
From: Charlie Jenkins <hidden>
Date: 2024-08-28 05:49:29
Also in:
linux-arch, linux-kselftest, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, lkml, loongarch, sparclinux
Subsystem:
generic include/asm header files, memory mapping - madvise (memory advice), the rest · Maintainers:
Arnd Bergmann, Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, David Hildenbrand, Linus Torvalds
Some applications rely on placing data in free bits addresses allocated by mmap. Various architectures (eg. x86, arm64, powerpc) restrict the address returned by mmap to be less than the maximum address space, unless the hint address is greater than this value. To make this behavior explicit and more versatile across all architectures, define a mmap flag that allows users to define an arbitrary upper limit on addresses returned by mmap. Signed-off-by: Charlie Jenkins <redacted> --- include/uapi/asm-generic/mman-common.h | 1 + tools/include/uapi/asm-generic/mman-common.h | 1 + 2 files changed, 2 insertions(+)
diff --git a/include/uapi/asm-generic/mman-common.h b/include/uapi/asm-generic/mman-common.h
index 6ce1f1ceb432..03ac13d9aa37 100644
--- a/include/uapi/asm-generic/mman-common.h
+++ b/include/uapi/asm-generic/mman-common.h@@ -32,6 +32,7 @@ #define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be * uninitialized */ +#define MAP_BELOW_HINT 0x8000000 /* give out address that is below (inclusive) hint address */ /* * Flags for mlock
diff --git a/tools/include/uapi/asm-generic/mman-common.h b/tools/include/uapi/asm-generic/mman-common.h
index 6ce1f1ceb432..03ac13d9aa37 100644
--- a/tools/include/uapi/asm-generic/mman-common.h
+++ b/tools/include/uapi/asm-generic/mman-common.h@@ -32,6 +32,7 @@ #define MAP_UNINITIALIZED 0x4000000 /* For anonymous mmap, memory could be * uninitialized */ +#define MAP_BELOW_HINT 0x8000000 /* give out address that is below (inclusive) hint address */ /* * Flags for mlock
--
2.45.0