[PATCH v14 19/26] mm: Re-introduce vm_flags to do_mmap()

2020-10-12 Thread Yu-cheng Yu
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_SHSTK to
do_mmap().  Re-introduce vm_flags to do_mmap(), but without the old wrapper
do_mmap_pgoff().  Instead, make all callers of the wrapper pass a zero
vm_flags to do_mmap().

Signed-off-by: Yu-cheng Yu 
Reviewed-by: Peter Collingbourne 
Cc: Andrew Morton 
Cc: Oleg Nesterov 
Cc: linux...@kvack.org
---
 fs/aio.c   |  2 +-
 include/linux/mm.h |  3 ++-
 ipc/shm.c  |  2 +-
 mm/mmap.c  | 10 +-
 mm/nommu.c |  4 ++--
 mm/util.c  |  2 +-
 6 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index d5ec30385566..ca8c11665eea 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -527,7 +527,7 @@ 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, , NULL);
+MAP_SHARED, 0, 0, , 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 ce461795fd8b..71677d498300 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2560,7 +2560,8 @@ 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_munmap(struct mm_struct *, unsigned long, size_t,
   struct list_head *uf, bool downgrade);
 extern int do_munmap(struct mm_struct *, unsigned long, size_t,
diff --git a/ipc/shm.c b/ipc/shm.c
index e25c7c6106bc..91474258933d 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1556,7 +1556,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
goto invalid;
}
 
-   addr = do_mmap(file, addr, size, prot, flags, 0, , NULL);
+   addr = do_mmap(file, addr, size, prot, flags, 0, 0, , NULL);
*raddr = addr;
err = 0;
if (IS_ERR_VALUE(addr))
diff --git a/mm/mmap.c b/mm/mmap.c
index 574b3f273462..fc04184d2eae 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1365,11 +1365,11 @@ 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;
 
*populate = 0;
@@ -1431,7 +1431,7 @@ 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)
@@ -3007,7 +3007,7 @@ 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, , NULL);
+   prot, flags, 0, pgoff, , NULL);
fput(file);
 out:
mmap_write_unlock(mm);
diff --git a/mm/nommu.c b/mm/nommu.c
index 75a327149af1..f67d6bcdfc9f 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1078,6 +1078,7 @@ 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)
@@ -1085,7 +1086,6 @@ 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;
 
@@ -1104,7 +1104,7 @@ unsigned long 

[PATCH v14 19/26] mm: Re-introduce vm_flags to do_mmap()

2020-10-09 Thread Yu-cheng Yu
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_SHSTK to
do_mmap().  Re-introduce vm_flags to do_mmap(), but without the old wrapper
do_mmap_pgoff().  Instead, make all callers of the wrapper pass a zero
vm_flags to do_mmap().

Signed-off-by: Yu-cheng Yu 
Reviewed-by: Peter Collingbourne 
Cc: Andrew Morton 
Cc: Oleg Nesterov 
Cc: linux...@kvack.org

v14:
- Remove do_mmap_pgoff() and make all callers of do_mmap() pass vm_flags.
---
 fs/aio.c   |  2 +-
 include/linux/mm.h |  3 ++-
 ipc/shm.c  |  2 +-
 mm/mmap.c  | 10 +-
 mm/nommu.c |  4 ++--
 mm/util.c  |  2 +-
 6 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index d5ec30385566..ca8c11665eea 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -527,7 +527,7 @@ 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, , NULL);
+MAP_SHARED, 0, 0, , 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 ce461795fd8b..71677d498300 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2560,7 +2560,8 @@ 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_munmap(struct mm_struct *, unsigned long, size_t,
   struct list_head *uf, bool downgrade);
 extern int do_munmap(struct mm_struct *, unsigned long, size_t,
diff --git a/ipc/shm.c b/ipc/shm.c
index e25c7c6106bc..91474258933d 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1556,7 +1556,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg,
goto invalid;
}
 
-   addr = do_mmap(file, addr, size, prot, flags, 0, , NULL);
+   addr = do_mmap(file, addr, size, prot, flags, 0, 0, , NULL);
*raddr = addr;
err = 0;
if (IS_ERR_VALUE(addr))
diff --git a/mm/mmap.c b/mm/mmap.c
index 574b3f273462..fc04184d2eae 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1365,11 +1365,11 @@ 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;
 
*populate = 0;
@@ -1431,7 +1431,7 @@ 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)
@@ -3007,7 +3007,7 @@ 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, , NULL);
+   prot, flags, 0, pgoff, , NULL);
fput(file);
 out:
mmap_write_unlock(mm);
diff --git a/mm/nommu.c b/mm/nommu.c
index 75a327149af1..f67d6bcdfc9f 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1078,6 +1078,7 @@ 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)
@@ -1085,7 +1086,6 @@ 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