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 the vm_flags and do_mmap_pgoff().
Signed-off-by: Yu-cheng Yu <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: [email protected]
---
fs/aio.c | 6 +++---
fs/hugetlbfs/inode.c | 2 +-
include/linux/fs.h | 2 +-
include/linux/mm.h | 12 +++++++++++-
ipc/shm.c | 2 +-
mm/mmap.c | 16 ++++++++--------
mm/nommu.c | 6 +++---
mm/shmem.c | 2 +-
mm/util.c | 4 ++--
9 files changed, 31 insertions(+), 21 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index d5ec30385566..22d19a4ad586 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -525,9 +525,9 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
return -EINTR;
}
- ctx->mmap_base = do_mmap(ctx->aio_ring_file, 0, ctx->mmap_size,
- PROT_READ | PROT_WRITE,
- MAP_SHARED, 0, &unused, NULL);
+ ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size,
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED, 0, &unused, NULL);
mmap_write_unlock(mm);
if (IS_ERR((void *)ctx->mmap_base)) {
ctx->mmap_size = 0;
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index b5c109703daa..f936bcf02cce 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -140,7 +140,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
* already been checked by prepare_hugepage_range. If you add
* any error returns here, do so after setting VM_HUGETLB, so
* is_vm_hugetlb_page tests below unmap_region go the right
- * way when do_mmap unwinds (may be important on powerpc
+ * way when do_mmap_pgoff unwinds (may be important on powerpc
* and ia64).
*/
vma->vm_flags |= VM_HUGETLB | VM_DONTEXPAND;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7519ae003a08..f7df4558f72c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -538,7 +538,7 @@ static inline int mapping_mapped(struct address_space *mapping)
/*
* Might pages of this file have been modified in userspace?
- * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap
+ * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
* marks vma as VM_SHARED if it is shared, and the file was opened for
* writing i.e. vma may be mprotected writable even if now readonly.
*
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e09d13699bbe..9b6a0f22cd89 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2560,13 +2560,23 @@ 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,
struct list_head *uf);
extern int do_madvise(unsigned long start, size_t len_in, int behavior);
+static inline unsigned long
+do_mmap_pgoff(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)
+{
+ return do_mmap(file, addr, len, prot, flags, 0, pgoff, populate, uf);
+}
+
#ifdef CONFIG_MMU
extern int __mm_populate(unsigned long addr, unsigned long len,
int ignore_errors);
diff --git a/ipc/shm.c b/ipc/shm.c
index e25c7c6106bc..3131c1de6bba 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, &populate, NULL);
+ addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate, NULL);
*raddr = addr;
err = 0;
if (IS_ERR_VALUE(addr))
diff --git a/mm/mmap.c b/mm/mmap.c
index 574b3f273462..81d4a00092da 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1030,7 +1030,7 @@ static inline int is_mergeable_anon_vma(struct anon_vma *anon_vma1,
* anon_vmas, nor if same anon_vma is assigned but offsets incompatible.
*
* We don't check here for the merged mmap wrapping around the end of pagecache
- * indices (16TB on ia32) because do_mmap() does not permit mmap's which
+ * indices (16TB on ia32) because do_mmap_pgoff() does not permit mmap's which
* wrap, nor mmaps which cover the final page at index -1UL.
*/
static int
@@ -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)
@@ -2233,7 +2233,7 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
/*
* mmap_region() will call shmem_zero_setup() to create a file,
* so use shmem's get_unmapped_area in case it can be huge.
- * do_mmap() will clear pgoff, so match alignment.
+ * do_mmap_pgoff() will clear pgoff, so match alignment.
*/
pgoff = 0;
get_area = shmem_get_unmapped_area;
@@ -3006,7 +3006,7 @@ 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,
+ ret = do_mmap_pgoff(vma->vm_file, start, size,
prot, flags, pgoff, &populate, NULL);
fput(file);
out:
@@ -3226,7 +3226,7 @@ int insert_vm_struct(struct mm_struct *mm, struct vm_area_struct *vma)
* By setting it to reflect the virtual start address of the
* vma, merges and splits can happen in a seamless way, just
* using the existing file pgoff checks and manipulations.
- * Similarly in do_mmap and in do_brk.
+ * Similarly in do_mmap_pgoff and in do_brk.
*/
if (vma_is_anonymous(vma)) {
BUG_ON(vma->anon_vma);
diff --git a/mm/nommu.c b/mm/nommu.c
index 75a327149af1..71a4ea828f06 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 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 */
region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
@@ -1763,7 +1763,7 @@ EXPORT_SYMBOL_GPL(access_process_vm);
*
* Check the shared mappings on an inode on behalf of a shrinking truncate to
* make sure that any outstanding VMAs aren't broken and then shrink the
- * vm_regions that extend beyond so that do_mmap() doesn't
+ * vm_regions that extend beyond so that do_mmap_pgoff() doesn't
* automatically grant mappings that are too large.
*/
int nommu_shrink_inode_mappings(struct inode *inode, size_t size,
diff --git a/mm/shmem.c b/mm/shmem.c
index 8e2b35ba93ad..54464c1e7414 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -4248,7 +4248,7 @@ EXPORT_SYMBOL_GPL(shmem_file_setup_with_mnt);
/**
* shmem_zero_setup - setup a shared anonymous mapping
- * @vma: the vma to be mmapped is prepared by do_mmap
+ * @vma: the vma to be mmapped is prepared by do_mmap_pgoff
*/
int shmem_zero_setup(struct vm_area_struct *vma)
{
diff --git a/mm/util.c b/mm/util.c
index 5ef378a2a038..8d6280c05238 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -503,8 +503,8 @@ 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,
- &uf);
+ ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff,
+ &populate, &uf);
mmap_write_unlock(mm);
userfaultfd_unmap_complete(mm, &uf);
if (populate)
--
2.21.0
On Fri, Sep 25, 2020 at 7:57 AM Yu-cheng Yu <[email protected]> wrote:
>
> 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 the vm_flags and do_mmap_pgoff().
I would prefer to change the callers to pass the additional 0 argument
instead of bringing the wrapper function back, but if we're going to
bring it back then we should fix the naming (both functions take a
pgoff argument, so the previous name do_mmap_pgoff() was just plain
confusing).
Peter
On 10/1/2020 7:06 PM, Peter Collingbourne wrote:
> On Fri, Sep 25, 2020 at 7:57 AM Yu-cheng Yu <[email protected]> wrote:
>>
>> 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 the vm_flags and do_mmap_pgoff().
>
> I would prefer to change the callers to pass the additional 0 argument
> instead of bringing the wrapper function back, but if we're going to
> bring it back then we should fix the naming (both functions take a
> pgoff argument, so the previous name do_mmap_pgoff() was just plain
> confusing).
>
> Peter
>
Thanks for your feedback. Here is the updated patch. I will re-send
the whole series later.
Yu-cheng
======
From 6a9f1e6bcdb6e599a44d5f58cf4cebd28c4634a2 Mon Sep 17 00:00:00 2001
From: Yu-cheng Yu <[email protected]>
Date: Wed, 12 Aug 2020 14:01:58 -0700
Subject: [PATCH 19/26] mm: Re-introduce do_mmap_pgoff()
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, fix all callers of the wrapper by passing a zero
vm_flags to do_mmap().
Signed-off-by: Yu-cheng Yu <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: [email protected]
---
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, &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 e09d13699bbe..e020eea33138 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, &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 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, &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 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 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 */
region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
diff --git a/mm/util.c b/mm/util.c
index 5ef378a2a038..beb8b881c080 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -503,7 +503,7 @@ 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);
--
2.21.0
On Fri, Oct 2, 2020 at 8:58 AM Yu, Yu-cheng <[email protected]> wrote:
>
> On 10/1/2020 7:06 PM, Peter Collingbourne wrote:
> > On Fri, Sep 25, 2020 at 7:57 AM Yu-cheng Yu <[email protected]> wrote:
> >>
> >> 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 the vm_flags and do_mmap_pgoff().
> >
> > I would prefer to change the callers to pass the additional 0 argument
> > instead of bringing the wrapper function back, but if we're going to
> > bring it back then we should fix the naming (both functions take a
> > pgoff argument, so the previous name do_mmap_pgoff() was just plain
> > confusing).
> >
> > Peter
> >
>
> Thanks for your feedback. Here is the updated patch. I will re-send
> the whole series later.
>
> Yu-cheng
>
> ======
>
> From 6a9f1e6bcdb6e599a44d5f58cf4cebd28c4634a2 Mon Sep 17 00:00:00 2001
> From: Yu-cheng Yu <[email protected]>
> Date: Wed, 12 Aug 2020 14:01:58 -0700
> Subject: [PATCH 19/26] mm: Re-introduce do_mmap_pgoff()
The subject line of the commit message needs to be updated, but aside from that:
Reviewed-by: Peter Collingbourne <[email protected]>
Peter
>
> 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, fix all callers of the wrapper by passing a zero
> vm_flags to do_mmap().
>
> Signed-off-by: Yu-cheng Yu <[email protected]>
> Cc: Peter Collingbourne <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Oleg Nesterov <[email protected]>
> Cc: [email protected]
> ---
> 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, &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 e09d13699bbe..e020eea33138 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, &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 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, &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 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 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 */
> region = kmem_cache_zalloc(vm_region_jar, GFP_KERNEL);
> diff --git a/mm/util.c b/mm/util.c
> index 5ef378a2a038..beb8b881c080 100644
> --- a/mm/util.c
> +++ b/mm/util.c
> @@ -503,7 +503,7 @@ 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);
> --
> 2.21.0
>
On 10/2/2020 3:52 PM, Peter Collingbourne wrote:
> On Fri, Oct 2, 2020 at 8:58 AM Yu, Yu-cheng <[email protected]> wrote:
>>
>> On 10/1/2020 7:06 PM, Peter Collingbourne wrote:
>>> On Fri, Sep 25, 2020 at 7:57 AM Yu-cheng Yu <[email protected]> wrote:
>>>>
>>>> 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 the vm_flags and do_mmap_pgoff().
>>>
>>> I would prefer to change the callers to pass the additional 0 argument
>>> instead of bringing the wrapper function back, but if we're going to
>>> bring it back then we should fix the naming (both functions take a
>>> pgoff argument, so the previous name do_mmap_pgoff() was just plain
>>> confusing).
>>>
>>> Peter
>>>
>>
>> Thanks for your feedback. Here is the updated patch. I will re-send
>> the whole series later.
>>
>> Yu-cheng
>>
>> ======
>>
>> From 6a9f1e6bcdb6e599a44d5f58cf4cebd28c4634a2 Mon Sep 17 00:00:00 2001
>> From: Yu-cheng Yu <[email protected]>
>> Date: Wed, 12 Aug 2020 14:01:58 -0700
>> Subject: [PATCH 19/26] mm: Re-introduce do_mmap_pgoff()
>
> The subject line of the commit message needs to be updated, but aside from that:
>
> Reviewed-by: Peter Collingbourne <[email protected]>
>
> Peter
Thanks for reviewing. I will fix the subject line.
Yu-cheng