Re: [PATCH] init_new_context: Use the passed task argument

[Aneesh Kumar]

On 2/28/07, Andrew Morton <[EMAIL PROTECTED]> wrote:

> On Fri, 23 Feb 2007 21:10:36 +0530 "Aneesh Kumar K.V" <[EMAIL PROTECTED]> 
wrote:
> From: Aneesh Kumar K.V <[EMAIL PROTECTED]>
>
> Signed-off-by: Aneesh Kumar K.V <[EMAIL PROTECTED]>
> ---
>  arch/i386/kernel/ldt.c   |    2 +-
>  arch/x86_64/kernel/ldt.c |    2 +-
>  kernel/fork.c            |    2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/i386/kernel/ldt.c b/arch/i386/kernel/ldt.c
> index b410e5f..925354c 100644
> --- a/arch/i386/kernel/ldt.c
> +++ b/arch/i386/kernel/ldt.c
> @@ -97,7 +97,7 @@ int init_new_context(struct task_struct *tsk, struct 
mm_struct *mm)
>
>       init_MUTEX(&mm->context.sem);
>       mm->context.size = 0;
> -     old_mm = current->mm;
> +     old_mm = tsk->mm;
>       if (old_mm && old_mm->context.size > 0) {
>               down(&old_mm->context.sem);
>               retval = copy_ldt(&mm->context, &old_mm->context);
> diff --git a/arch/x86_64/kernel/ldt.c b/arch/x86_64/kernel/ldt.c
> index d7e5d0c..16ae79d 100644
> --- a/arch/x86_64/kernel/ldt.c
> +++ b/arch/x86_64/kernel/ldt.c
> @@ -101,7 +101,7 @@ int init_new_context(struct task_struct *tsk, struct 
mm_struct *mm)
>
>       init_MUTEX(&mm->context.sem);
>       mm->context.size = 0;
> -     old_mm = current->mm;
> +     old_mm = tsk->mm;
>       if (old_mm && old_mm->context.size > 0) {
>               down(&old_mm->context.sem);
>               retval = copy_ldt(&mm->context, &old_mm->context);
> diff --git a/kernel/fork.c b/kernel/fork.c
> index d154cc7..2423d83 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -496,7 +496,7 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
>       if (!mm_init(mm))
>               goto fail_nomem;
>
> -     if (init_new_context(tsk, mm))
> +     if (init_new_context(current, mm))
>               goto fail_nocontext;

This last change makes the comment over dup_mm() wrong.  It also generally
makes dup_mm() less useful, although that migt be OK.  It also makes the
argument to dup_mm() unused and potentially removable.

How about the change as below

diff --git a/kernel/fork.c b/kernel/fork.c
index 2423d83..2184ef5 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -477,7 +477,7 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
  */
 static struct mm_struct *dup_mm(struct task_struct *tsk)
 {
-	struct mm_struct *mm, *oldmm = current->mm;
+	struct mm_struct *mm, *oldmm = tsk->mm;
 	int err;
 
 	if (!oldmm)
@@ -496,7 +496,7 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
 	if (!mm_init(mm))
 		goto fail_nomem;
 
-	if (init_new_context(current, mm))
+	if (init_new_context(tsk, mm))
 		goto fail_nocontext;
 
 	err = dup_mmap(mm, oldmm);
@@ -551,7 +551,7 @@ static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
 	}
 
 	retval = -ENOMEM;
-	mm = dup_mm(tsk);
+	mm = dup_mm(current);
 	if (!mm)
 		goto fail_nomem;