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Peter Anvin" , Thomas Gleixner , Ingo Molnar , Linux Kernel Mailing List , linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , Weijiang Yang , Pengfei Xu , Andrew Morton Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Oct 2, 2020 at 8:58 AM Yu, Yu-cheng wrote: > > On 10/1/2020 7:06 PM, Peter Collingbourne wrote: > > On Fri, Sep 25, 2020 at 7:57 AM Yu-cheng Yu 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 > 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 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 > Cc: Peter Collingbourne > Cc: Andrew Morton > Cc: Oleg Nesterov > Cc: linux-mm@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, &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 >