[PATCH v4 6/6] mm: Remove unused vm_brk()

From: Kees Cook
Date: Thu Sep 28 2023 - 23:25:12 EST


With fs/binfmt_elf.c fully refactored to use the new elf_load() helper,
there are no more users of vm_brk(), so remove it.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Suggested-by: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
include/linux/mm.h | 3 +--
mm/mmap.c | 6 ------
mm/nommu.c | 5 -----
3 files changed, 1 insertion(+), 13 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index bf5d0b1b16f4..216dd0c6dcf8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3308,8 +3308,7 @@ static inline void mm_populate(unsigned long addr, unsigned long len)
static inline void mm_populate(unsigned long addr, unsigned long len) {}
#endif

-/* These take the mm semaphore themselves */
-extern int __must_check vm_brk(unsigned long, unsigned long);
+/* This takes the mm semaphore itself */
extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
extern int vm_munmap(unsigned long, size_t);
extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
diff --git a/mm/mmap.c b/mm/mmap.c
index b56a7f0c9f85..34d2337ace59 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -3174,12 +3174,6 @@ int vm_brk_flags(unsigned long addr, unsigned long request, unsigned long flags)
}
EXPORT_SYMBOL(vm_brk_flags);

-int vm_brk(unsigned long addr, unsigned long len)
-{
- return vm_brk_flags(addr, len, 0);
-}
-EXPORT_SYMBOL(vm_brk);
-
/* Release all mmaps. */
void exit_mmap(struct mm_struct *mm)
{
diff --git a/mm/nommu.c b/mm/nommu.c
index 7f9e9e5a0e12..23c43c208f2b 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1531,11 +1531,6 @@ void exit_mmap(struct mm_struct *mm)
mmap_write_unlock(mm);
}

-int vm_brk(unsigned long addr, unsigned long len)
-{
- return -ENOMEM;
-}
-
/*
* expand (or shrink) an existing mapping, potentially moving it at the same
* time (controlled by the MREMAP_MAYMOVE flag and available VM space)
--
2.34.1