Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:
> On Mon, 5 Aug 2024 at 11:55, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> So please consider this a "maybe something like this" patch, but that
>> 'arch_unmap()' really is pretty nasty
>
> Actually, the whole powerpc vdso code confused me. It's not the vvar
> thing that wants this close thing, it's the other ones that have the
> remap thing.
>
> .. and there were two of those error cases that needed to reset the
> vdso pointer.
>
> That all shows just how carefully I was reading this code.
>
> New version - still untested, but now I've read through it one more
> time - attached.
Needs a slight tweak to compile, vvar_close() needs to return void. And
should probably be renamed vdso_close(). Diff below if anyone else wants
to test it.
I'm testing it now, but it should do what we need.
cheers
diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index 6fa041a6690a..431b46976db8 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -81,8 +81,8 @@ static int vdso64_mremap(const struct vm_special_mapping *sm, struct vm_area_str
return vdso_mremap(sm, new_vma, &vdso64_end - &vdso64_start);
}
-static int vvar_close(const struct vm_special_mapping *sm,
- struct vm_area_struct *vma)
+static void vdso_close(const struct vm_special_mapping *sm,
+ struct vm_area_struct *vma)
{
struct mm_struct *mm = vma->vm_mm;
mm->context.vdso = NULL;
@@ -99,13 +99,13 @@ static struct vm_special_mapping vvar_spec __ro_after_init = {
static struct vm_special_mapping vdso32_spec __ro_after_init = {
.name = "[vdso]",
.mremap = vdso32_mremap,
- .close = vvar_close,
+ .close = vdso_close,
};
static struct vm_special_mapping vdso64_spec __ro_after_init = {
.name = "[vdso]",
.mremap = vdso64_mremap,
- .close = vvar_close,
+ .close = vdso_close,
};
#ifdef CONFIG_TIME_NS
