| Message ID | 20230511125848.78621-2-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/5] mm: vmalloc must set pte via arch code | expand |
My appologies for the noise: A blank line between Cc and Subject has broken the subject and grouping in lore. Please Ignore this, I will resend. On 11/05/2023 13:58, Ryan Roberts wrote: > It is bad practice to directly set pte entries within a pte table. > Instead all modifications must go through arch-provided helpers such as > set_pte_at() to give the arch code visibility and allow it to validate > (and potentially modify) the operation. > > Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function") > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> > --- > mm/vmalloc.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 9683573f1225..d8d2fe797c55 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2899,10 +2899,13 @@ struct vmap_pfn_data { > static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) > { > struct vmap_pfn_data *data = private; > + pte_t ptent; > > if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx]))) > return -EINVAL; > - *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); > + > + ptent = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); > + set_pte_at(&init_mm, addr, pte, ptent); > return 0; > } >
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 9683573f1225..d8d2fe797c55 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2899,10 +2899,13 @@ struct vmap_pfn_data { static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) { struct vmap_pfn_data *data = private; + pte_t ptent; if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx]))) return -EINVAL; - *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); + + ptent = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); + set_pte_at(&init_mm, addr, pte, ptent); return 0; }
It is bad practice to directly set pte entries within a pte table. Instead all modifications must go through arch-provided helpers such as set_pte_at() to give the arch code visibility and allow it to validate (and potentially modify) the operation. Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function") Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- mm/vmalloc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)