| Message ID | b28f30ed5d662439fd2354b7a05e4d58a2889e5f.1638308023.git.andreyknvl@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS | expand |
On Tue, Nov 30, 2021 at 10:39PM +0100, andrey.konovalov@linux.dev wrote: > From: Andrey Konovalov <andreyknvl@google.com> > > Simplify the code around calling kasan_poison_pages() in > free_pages_prepare(). > > Reording kasan_poison_pages() and kernel_init_free_pages() is OK, > since kernel_init_free_pages() can handle poisoned memory. Why did they have to be reordered? > This patch does no functional changes besides reordering the calls. > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > --- > mm/page_alloc.c | 18 +++++------------- > 1 file changed, 5 insertions(+), 13 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 3f3ea41f8c64..0673db27dd12 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1289,6 +1289,7 @@ static __always_inline bool free_pages_prepare(struct page *page, > { > int bad = 0; > bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags); skip_kasan_poison is only used once now, so you could remove the variable -- unless later code will use it in more than once place again. > + bool init = want_init_on_free(); > > VM_BUG_ON_PAGE(PageTail(page), page); > > @@ -1359,19 +1360,10 @@ static __always_inline bool free_pages_prepare(struct page *page, > * With hardware tag-based KASAN, memory tags must be set before the > * page becomes unavailable via debug_pagealloc or arch_free_page. > */ > - if (kasan_has_integrated_init()) { > - bool init = want_init_on_free(); > - > - if (!skip_kasan_poison) > - kasan_poison_pages(page, order, init); > - } else { > - bool init = want_init_on_free(); > - > - if (init) > - kernel_init_free_pages(page, 1 << order); > - if (!skip_kasan_poison) > - kasan_poison_pages(page, order, init); > - } > + if (!skip_kasan_poison) > + kasan_poison_pages(page, order, init); > + if (init && !kasan_has_integrated_init()) > + kernel_init_free_pages(page, 1 << order); > > /* > * arch_free_page() can make the page's contents inaccessible. s390 > -- > 2.25.1
On Wed, Dec 1, 2021 at 3:10 PM Marco Elver <elver@google.com> wrote: > > On Tue, Nov 30, 2021 at 10:39PM +0100, andrey.konovalov@linux.dev wrote: > > From: Andrey Konovalov <andreyknvl@google.com> > > > > Simplify the code around calling kasan_poison_pages() in > > free_pages_prepare(). > > > > Reording kasan_poison_pages() and kernel_init_free_pages() is OK, > > since kernel_init_free_pages() can handle poisoned memory. > > Why did they have to be reordered? It's for the next patch, I'll move the reordering there in v2. > > This patch does no functional changes besides reordering the calls. > > > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> > > --- > > mm/page_alloc.c | 18 +++++------------- > > 1 file changed, 5 insertions(+), 13 deletions(-) > > > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index 3f3ea41f8c64..0673db27dd12 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -1289,6 +1289,7 @@ static __always_inline bool free_pages_prepare(struct page *page, > > { > > int bad = 0; > > bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags); > > skip_kasan_poison is only used once now, so you could remove the > variable -- unless later code will use it in more than once place again. Will do in v2. Thanks!
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3f3ea41f8c64..0673db27dd12 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1289,6 +1289,7 @@ static __always_inline bool free_pages_prepare(struct page *page, { int bad = 0; bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags); + bool init = want_init_on_free(); VM_BUG_ON_PAGE(PageTail(page), page); @@ -1359,19 +1360,10 @@ static __always_inline bool free_pages_prepare(struct page *page, * With hardware tag-based KASAN, memory tags must be set before the * page becomes unavailable via debug_pagealloc or arch_free_page. */ - if (kasan_has_integrated_init()) { - bool init = want_init_on_free(); - - if (!skip_kasan_poison) - kasan_poison_pages(page, order, init); - } else { - bool init = want_init_on_free(); - - if (init) - kernel_init_free_pages(page, 1 << order); - if (!skip_kasan_poison) - kasan_poison_pages(page, order, init); - } + if (!skip_kasan_poison) + kasan_poison_pages(page, order, init); + if (init && !kasan_has_integrated_init()) + kernel_init_free_pages(page, 1 << order); /* * arch_free_page() can make the page's contents inaccessible. s390