| Message ID | e64fc8cd8e08fac044368aaba27be9fc6f60ff9c.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 10:40 PM <andrey.konovalov@linux.dev> wrote: > > From: Andrey Konovalov <andreyknvl@google.com> > > Currently, kernel_init_free_pages() serves two purposes: either only Nit: "it either" > zeroes memory or zeroes both memory and memory tags via a different > code path. As this function has only two callers, each using only one > code path, this behaviour is confusing. > > This patch pulls the code that zeroes both memory and tags out of > kernel_init_free_pages(). > > As a result of this change, the code in free_pages_prepare() starts to > look complicated, but this is improved in the few following patches. > Those improvements are not integrated into this patch to make diffs > easier to read. > > This patch does no functional changes. > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> > --- > mm/page_alloc.c | 24 +++++++++++++----------- > 1 file changed, 13 insertions(+), 11 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index c99566a3b67e..3589333b5b77 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1269,16 +1269,10 @@ static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) > PageSkipKASanPoison(page); > } > > -static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags) > +static void kernel_init_free_pages(struct page *page, int numpages) > { > int i; > > - if (zero_tags) { > - for (i = 0; i < numpages; i++) > - tag_clear_highpage(page + i); > - return; > - } > - > /* s390's use of memset() could override KASAN redzones. */ > kasan_disable_current(); > for (i = 0; i < numpages; i++) { > @@ -1372,7 +1366,7 @@ static __always_inline bool free_pages_prepare(struct page *page, > bool init = want_init_on_free(); > > if (init) > - kernel_init_free_pages(page, 1 << order, false); > + kernel_init_free_pages(page, 1 << order); > if (!skip_kasan_poison) > kasan_poison_pages(page, order, init); > } > @@ -2415,9 +2409,17 @@ inline void post_alloc_hook(struct page *page, unsigned int order, > bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags); > > kasan_unpoison_pages(page, order, init); > - if (init) > - kernel_init_free_pages(page, 1 << order, > - gfp_flags & __GFP_ZEROTAGS); > + > + if (init) { > + if (gfp_flags & __GFP_ZEROTAGS) { > + int i; > + > + for (i = 0; i < 1 << order; i++) > + tag_clear_highpage(page + i); > + } else { > + kernel_init_free_pages(page, 1 << order); > + } > + } > } > > set_page_owner(page, order, gfp_flags); > -- > 2.25.1 > > -- > You received this message because you are subscribed to the Google Groups "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/e64fc8cd8e08fac044368aaba27be9fc6f60ff9c.1638308023.git.andreyknvl%40google.com.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c99566a3b67e..3589333b5b77 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1269,16 +1269,10 @@ static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) PageSkipKASanPoison(page); } -static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags) +static void kernel_init_free_pages(struct page *page, int numpages) { int i; - if (zero_tags) { - for (i = 0; i < numpages; i++) - tag_clear_highpage(page + i); - return; - } - /* s390's use of memset() could override KASAN redzones. */ kasan_disable_current(); for (i = 0; i < numpages; i++) { @@ -1372,7 +1366,7 @@ static __always_inline bool free_pages_prepare(struct page *page, bool init = want_init_on_free(); if (init) - kernel_init_free_pages(page, 1 << order, false); + kernel_init_free_pages(page, 1 << order); if (!skip_kasan_poison) kasan_poison_pages(page, order, init); } @@ -2415,9 +2409,17 @@ inline void post_alloc_hook(struct page *page, unsigned int order, bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags); kasan_unpoison_pages(page, order, init); - if (init) - kernel_init_free_pages(page, 1 << order, - gfp_flags & __GFP_ZEROTAGS); + + if (init) { + if (gfp_flags & __GFP_ZEROTAGS) { + int i; + + for (i = 0; i < 1 << order; i++) + tag_clear_highpage(page + i); + } else { + kernel_init_free_pages(page, 1 << order); + } + } } set_page_owner(page, order, gfp_flags);