mm: Re-introduce vm_flags to do_mmap()

There was no more caller passing vm_flags to do_mmap(), and vm_flags was
removed from the function's input by:

    commit 45e55300f114 ("mm: remove unnecessary wrapper function do_mmap_pgoff()").

There is a new user now.  Shadow stack allocation passes VM_SHADOW_STACK to
do_mmap().  Thus, re-introduce vm_flags to do_mmap().

Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-5-rick.p.edgecombe%40intel.com

diff --git a/fs/aio.c b/fs/aio.c
index 77e3361..c7c8918 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -558,7 +558,7 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 
        ctx->mmap_base = do_mmap(ctx->aio_ring_file, 0, ctx->mmap_size,
                                 PROT_READ | PROT_WRITE,
-                                MAP_SHARED, 0, &unused, NULL);
+                                MAP_SHARED, 0, 0, &unused, NULL);
        mmap_write_unlock(mm);
        if (IS_ERR((void *)ctx->mmap_base)) {
                ctx->mmap_size = 0;

diff --git a/include/linux/mm.h b/include/linux/mm.h
index d40fa0f..f9a627c 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3176,7 +3176,8 @@ extern unsigned long mmap_region(struct file *file, unsigned long addr,
        struct list_head *uf);
 extern unsigned long do_mmap(struct file *file, unsigned long addr,
        unsigned long len, unsigned long prot, unsigned long flags,
-       unsigned long pgoff, unsigned long *populate, struct list_head *uf);
+       vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate,
+       struct list_head *uf);
 extern int do_vmi_munmap(struct vma_iterator *vmi, struct mm_struct *mm,
                         unsigned long start, size_t len, struct list_head *uf,
                         bool unlock);

diff --git a/ipc/shm.c b/ipc/shm.c
index 60e45e7..576a543 100644 (file)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1662,7 +1662,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
                        goto invalid;
        }
 
-       addr = do_mmap(file, addr, size, prot, flags, 0, &populate, NULL);
+       addr = do_mmap(file, addr, size, prot, flags, 0, 0, &populate, NULL);
        *raddr = addr;
        err = 0;
        if (IS_ERR_VALUE(addr))

diff --git a/mm/mmap.c b/mm/mmap.c
index 3eda23c..4900f74 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1189,11 +1189,11 @@ static inline bool file_mmap_ok(struct file *file, struct inode *inode,
  */
 unsigned long do_mmap(struct file *file, unsigned long addr,
                        unsigned long len, unsigned long prot,
-                       unsigned long flags, unsigned long pgoff,
-                       unsigned long *populate, struct list_head *uf)
+                       unsigned long flags, vm_flags_t vm_flags,
+                       unsigned long pgoff, unsigned long *populate,
+                       struct list_head *uf)
 {
        struct mm_struct *mm = current->mm;
-       vm_flags_t vm_flags;
        int pkey = 0;
 
        validate_mm(mm);
@@ -1254,7 +1254,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
         * to. we assume access permissions have been handled by the open
         * of the memory object, so we don't do any here.
         */
-       vm_flags = calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) |
+       vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) |
                        mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
 
        if (flags & MAP_LOCKED)
@@ -2995,7 +2995,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
 
        file = get_file(vma->vm_file);
        ret = do_mmap(vma->vm_file, start, size,
-                       prot, flags, pgoff, &populate, NULL);
+                       prot, flags, 0, pgoff, &populate, NULL);
        fput(file);
 out:
        mmap_write_unlock(mm);

diff --git a/mm/nommu.c b/mm/nommu.c
index c072a66..fe19614 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1015,6 +1015,7 @@ unsigned long do_mmap(struct file *file,
                        unsigned long len,
                        unsigned long prot,
                        unsigned long flags,
+                       vm_flags_t vm_flags,
                        unsigned long pgoff,
                        unsigned long *populate,
                        struct list_head *uf)
@@ -1022,7 +1023,6 @@ unsigned long do_mmap(struct file *file,
        struct vm_area_struct *vma;
        struct vm_region *region;
        struct rb_node *rb;
-       vm_flags_t vm_flags;
        unsigned long capabilities, result;
        int ret;
        VMA_ITERATOR(vmi, current->mm, 0);
@@ -1042,7 +1042,7 @@ unsigned long do_mmap(struct file *file,
 
        /* we've determined that we can make the mapping, now translate what we
         * now know into VMA flags */
-       vm_flags = determine_vm_flags(file, prot, flags, capabilities);
+       vm_flags |= determine_vm_flags(file, prot, flags, capabilities);
 
 
        /* we're going to need to record the mapping */

diff --git a/mm/util.c b/mm/util.c
index dd12b95..8e7fc6c 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -540,7 +540,7 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr,
        if (!ret) {
                if (mmap_write_lock_killable(mm))
                        return -EINTR;
-               ret = do_mmap(file, addr, len, prot, flag, pgoff, &populate,
+               ret = do_mmap(file, addr, len, prot, flag, 0, pgoff, &populate,
                              &uf);
                mmap_write_unlock(mm);
                userfaultfd_unmap_complete(mm, &uf);