[PATCH v2 09/23] mm: unexport vm_brk_flags() and eliminate vm_flags parameter
From: "Lorenzo Stoakes (Oracle)" <ljs@kernel.org>
Date: 2026-03-16 13:09:20
Also in:
linux-mips, linux-mm, linux-riscv, linux-s390, linux-um, linuxppc-dev, lkml, loongarch, selinux
Subsystem:
exec & binfmt api, elf, filesystems (vfs and infrastructure), memory management, memory management - core, memory mapping, the rest · Maintainers:
Kees Cook, Alexander Viro, Christian Brauner, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
This function is only used by elf_load(), and that is a static function that doesn't need an exported symbol to invoke an internal function, so un-EXPORT_SYMBOLS() it. Also, the vm_flags parameter is unnecessary, as we only ever set VM_EXEC, so simply make this parameter a boolean. While we're here, clean up the mm.h definitions for the various vm_xxx() helpers so we actually specify parameter names and elide the redundant extern's. Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> --- fs/binfmt_elf.c | 3 +-- include/linux/mm.h | 12 ++++++------ mm/mmap.c | 8 ++------ 3 files changed, 9 insertions(+), 14 deletions(-)
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index fb857faaf0d6..16a56b6b3f6c 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c@@ -453,14 +453,13 @@ static unsigned long elf_load(struct file *filep, unsigned long addr, zero_end = ELF_PAGEALIGN(zero_end); error = vm_brk_flags(zero_start, zero_end - zero_start, - prot & PROT_EXEC ? VM_EXEC : 0); + prot & PROT_EXEC); if (error) map_addr = error; } return map_addr; } - static unsigned long total_mapping_size(const struct elf_phdr *phdr, int nr) { elf_addr_t min_addr = -1;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0c35423177bf..42d346684678 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -4005,12 +4005,12 @@ static inline void mm_populate(unsigned long addr, unsigned long len) {} #endif /* 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, - unsigned long, unsigned long, - unsigned long, unsigned long); -extern unsigned long __must_check vm_mmap_shadow_stack(unsigned long addr, +int __must_check vm_brk_flags(unsigned long addr, unsigned long request, bool is_exec); +int vm_munmap(unsigned long start, size_t len); +unsigned long __must_check vm_mmap(struct file *file, unsigned long addr, + unsigned long len, unsigned long prot, + unsigned long flag, unsigned long offset); +unsigned long __must_check vm_mmap_shadow_stack(unsigned long addr, unsigned long len, unsigned long flags); struct vm_unmapped_area_info {
diff --git a/mm/mmap.c b/mm/mmap.c
index 79544d893411..2d2b814978bf 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -1201,8 +1201,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, return ret; } -int vm_brk_flags(unsigned long addr, unsigned long request, vm_flags_t vm_flags) +int vm_brk_flags(unsigned long addr, unsigned long request, bool is_exec) { + const vm_flags_t vm_flags = is_exec ? VM_EXEC : 0; struct mm_struct *mm = current->mm; struct vm_area_struct *vma = NULL; unsigned long len;
@@ -1217,10 +1218,6 @@ int vm_brk_flags(unsigned long addr, unsigned long request, vm_flags_t vm_flags) if (!len) return 0; - /* Until we need other flags, refuse anything except VM_EXEC. */ - if ((vm_flags & (~VM_EXEC)) != 0) - return -EINVAL; - if (mmap_write_lock_killable(mm)) return -EINTR;
@@ -1246,7 +1243,6 @@ int vm_brk_flags(unsigned long addr, unsigned long request, vm_flags_t vm_flags) mmap_write_unlock(mm); return ret; } -EXPORT_SYMBOL(vm_brk_flags); static unsigned long tear_down_vmas(struct mm_struct *mm, struct vma_iterator *vmi,
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2.53.0