From: Davidlohr Bueso <dave@xxxxxxxxxxxx>
coredump_wait() needs mmap_sem such that zap_threads()
is stable. The conversion is trivial as the mmap_sem
is only used in the same function context. No change
in semantics.
In addition, we need an mmrange in exec_mmap() as mmap_sem
is needed for de_thread() or coredump (for core_state and
changing tsk->mm) scenarios. No change in semantics.
Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---
fs/coredump.c | 5 +++--
fs/exec.c | 18 ++++++++++--------
2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/fs/coredump.c b/fs/coredump.c
index 1e2c87acac9b..ad91712498fc 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -412,17 +412,18 @@ static int coredump_wait(int exit_code, struct core_state *core_state)
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
int core_waiters = -EBUSY;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
init_completion(&core_state->startup);
core_state->dumper.task = tsk;
core_state->dumper.next = NULL;
- if (down_write_killable(&mm->mmap_sem))
+ if (mm_write_lock_killable(mm, &mmrange))
return -EINTR;
if (!mm->core_state)
core_waiters = zap_threads(tsk, mm, core_state, exit_code);
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
if (core_waiters > 0) {
struct core_thread *ptr;
diff --git a/fs/exec.c b/fs/exec.c
index e46752874b47..a61ac9e81169 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -294,12 +294,13 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
int err;
struct vm_area_struct *vma = NULL;
struct mm_struct *mm = bprm->mm;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (!vma)
return -ENOMEM;
- if (down_write_killable(&mm->mmap_sem)) {
+ if (mm_write_lock_killable(mm, &mmrange)) {
err = -EINTR;
goto err_free;
}
@@ -324,11 +325,11 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
mm->stack_vm = mm->total_vm = 1;
arch_bprm_mm_init(mm, vma);
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
bprm->p = vma->vm_end - sizeof(void *);
return 0;
err:
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
err_free:
bprm->vma = NULL;
kmem_cache_free(vm_area_cachep, vma);
@@ -739,7 +740,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
bprm->loader -= stack_shift;
bprm->exec -= stack_shift;
- if (down_write_killable(&mm->mmap_sem))
+ if (mm_write_lock_killable(mm, &mmrange))
return -EINTR;
vm_flags = VM_STACK_FLAGS;
@@ -796,7 +797,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
ret = -EFAULT;
out_unlock:
- up_write(&mm->mmap_sem);
+ mm_write_unlock(mm, &mmrange);
return ret;
}
EXPORT_SYMBOL(setup_arg_pages);
@@ -1011,6 +1012,7 @@ static int exec_mmap(struct mm_struct *mm)
{
struct task_struct *tsk;
struct mm_struct *old_mm, *active_mm;
+ DEFINE_RANGE_LOCK_FULL(mmrange);
/* Notify parent that we're no longer interested in the old VM */
tsk = current;
@@ -1025,9 +1027,9 @@ static int exec_mmap(struct mm_struct *mm)
* through with the exec. We must hold mmap_sem around
* checking core_state and changing tsk->mm.
*/
- down_read(&old_mm->mmap_sem);
+ mm_read_lock(old_mm, &mmrange);
if (unlikely(old_mm->core_state)) {
- up_read(&old_mm->mmap_sem);
+ mm_read_unlock(old_mm, &mmrange);
return -EINTR;
}
}
@@ -1040,7 +1042,7 @@ static int exec_mmap(struct mm_struct *mm)
vmacache_flush(tsk);
task_unlock(tsk);
if (old_mm) {
- up_read(&old_mm->mmap_sem);
+ mm_read_unlock(old_mm, &mmrange);
BUG_ON(active_mm != old_mm);
setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm);
mm_update_next_owner(old_mm);
--
2.13.6
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