Re: [PATCH v5 05/10] mmap locking API: convert mmap_sem call sites missed by coccinelle

[Laurent Dufour]

Le 22/04/2020 à 02:14, Michel Lespinasse a écrit :

Convert the last few remaining mmap_sem rwsem calls to use the new
mmap locking API. These were missed by coccinelle for some reason
(I think coccinelle does not support some of the preprocessor
constructs in these files ?)

Signed-off-by: Michel Lespinasse <wal...@google.com>
Reviewed-by: Daniel Jordan <daniel.m.jor...@oracle.com>

Reviewed-by: Laurent Dufour <lduf...@linux.ibm.com>

---
  arch/mips/mm/fault.c           | 10 +++++-----
  arch/riscv/mm/pageattr.c       |  4 ++--
  arch/x86/kvm/mmu/paging_tmpl.h |  8 ++++----
  drivers/android/binder_alloc.c |  4 ++--
  fs/proc/base.c                 |  6 +++---
  5 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index f8d62cd83b36..9ef2dd39111e 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -97,7 +97,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, 
unsigned long write,
        if (user_mode(regs))
                flags |= FAULT_FLAG_USER;
  retry:
-       down_read(&mm->mmap_sem);
+       mmap_read_lock(mm);
        vma = find_vma(mm, address);
        if (!vma)
                goto bad_area;
@@ -190,7 +190,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, 
unsigned long write,
                }
        }

- up_read(&mm->mmap_sem);

+       mmap_read_unlock(mm);
        return;

/*

@@ -198,7 +198,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, 
unsigned long write,
   * Fix it, but check if it's kernel or user first..
   */
  bad_area:
-       up_read(&mm->mmap_sem);
+       mmap_read_unlock(mm);

bad_area_nosemaphore:

        /* User mode accesses just cause a SIGSEGV */
@@ -250,14 +250,14 @@ static void __kprobes __do_page_fault(struct pt_regs 
*regs, unsigned long write,
         * We ran out of memory, call the OOM killer, and return the userspace
         * (which will retry the fault, or kill us if we got oom-killed).
         */
-       up_read(&mm->mmap_sem);
+       mmap_read_unlock(mm);
        if (!user_mode(regs))
                goto no_context;
        pagefault_out_of_memory();
        return;

do_sigbus:

-       up_read(&mm->mmap_sem);
+       mmap_read_unlock(mm);

/* Kernel mode? Handle exceptions or die */

        if (!user_mode(regs))
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 728759eb530a..b9072c043222 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -117,10 +117,10 @@ static int __set_memory(unsigned long addr, int numpages, 
pgprot_t set_mask,
        if (!numpages)
                return 0;

- down_read(&init_mm.mmap_sem);

+       mmap_read_lock(&init_mm);
        ret =  walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
                                     &masks);
-       up_read(&init_mm.mmap_sem);
+       mmap_read_unlock(&init_mm);

flush_tlb_kernel_range(start, end); diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h

index 9bdf9b7d9a96..40e5bb67cc09 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -165,22 +165,22 @@ static int FNAME(cmpxchg_gpte)(struct kvm_vcpu *vcpu, 
struct kvm_mmu *mmu,
                unsigned long pfn;
                unsigned long paddr;

- down_read(&current->mm->mmap_sem);

+               mmap_read_lock(current->mm);
                vma = find_vma_intersection(current->mm, vaddr, vaddr + 
PAGE_SIZE);
                if (!vma || !(vma->vm_flags & VM_PFNMAP)) {
-                       up_read(&current->mm->mmap_sem);
+                       mmap_read_unlock(current->mm);
                        return -EFAULT;
                }
                pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
                paddr = pfn << PAGE_SHIFT;
                table = memremap(paddr, PAGE_SIZE, MEMREMAP_WB);
                if (!table) {
-                       up_read(&current->mm->mmap_sem);
+                       mmap_read_unlock(current->mm);
                        return -EFAULT;
                }
                ret = CMPXCHG(&table[index], orig_pte, new_pte);
                memunmap(table);
-               up_read(&current->mm->mmap_sem);
+               mmap_read_unlock(current->mm);
        }

return (ret != orig_pte);

diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 5e063739a3a8..cbdc43ed0f9f 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -932,7 +932,7 @@ enum lru_status binder_alloc_free_page(struct list_head 
*item,
        mm = alloc->vma_vm_mm;
        if (!mmget_not_zero(mm))
                goto err_mmget;
-       if (!down_read_trylock(&mm->mmap_sem))
+       if (!mmap_read_trylock(mm))
                goto err_down_read_mmap_sem_failed;
        vma = binder_alloc_get_vma(alloc);

@@ -946,7 +946,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item, trace_binder_unmap_user_end(alloc, index);

        }
-       up_read(&mm->mmap_sem);
+       mmap_read_unlock(mm);
        mmput(mm);

trace_binder_unmap_kernel_start(alloc, index);

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 8fff3c955530..ebb356434652 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2314,7 +2314,7 @@ proc_map_files_readdir(struct file *file, struct 
dir_context *ctx)
        if (!mm)
                goto out_put_task;

- ret = down_read_killable(&mm->mmap_sem);

+       ret = mmap_read_lock_killable(mm);
        if (ret) {
                mmput(mm);
                goto out_put_task;
@@ -2341,7 +2341,7 @@ proc_map_files_readdir(struct file *file, struct 
dir_context *ctx)
                p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
                if (!p) {
                        ret = -ENOMEM;
-                       up_read(&mm->mmap_sem);
+                       mmap_read_unlock(mm);
                        mmput(mm);
                        goto out_put_task;
                }
@@ -2350,7 +2350,7 @@ proc_map_files_readdir(struct file *file, struct 
dir_context *ctx)
                p->end = vma->vm_end;
                p->mode = vma->vm_file->f_mode;
        }
-       up_read(&mm->mmap_sem);
+       mmap_read_unlock(mm);
        mmput(mm);

for (i = 0; i < nr_files; i++) {