| Message ID | 20241204175004.906754-1-catalin.marinas@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: mte: Fix copy_highpage() warning on hugetlb folios | expand |
On 12/4/24 9:50 AM, Catalin Marinas wrote: > Commit 25c17c4b55de ("hugetlb: arm64: add mte support") improved the > copy_highpage() function to update the tags in the destination hugetlb > folio. However, when the source folio isn't tagged, the code takes the > non-hugetlb path where try_page_mte_tagging() warns as the destination > is a hugetlb folio: > > WARNING: CPU: 0 PID: 363 at arch/arm64/include/asm/mte.h:58 copy_highpage+0x1d4/0x2d8 > [...] > pc : copy_highpage+0x1d4/0x2d8 > lr : copy_highpage+0x78/0x2d8 > [...] > Call trace: > copy_highpage+0x1d4/0x2d8 (P) > copy_highpage+0x78/0x2d8 (L) > copy_user_highpage+0x20/0x48 > copy_user_large_folio+0x1bc/0x268 > hugetlb_wp+0x190/0x860 > hugetlb_fault+0xa28/0xc10 > handle_mm_fault+0x2a0/0x2c0 > do_page_fault+0x12c/0x578 > do_mem_abort+0x4c/0xa8 > el0_da+0x44/0xb0 > el0t_64_sync_handler+0xc4/0x138 > el0t_64_sync+0x198/0x1a0 > > Change the check for the tagged status of the source folio so that it > does not fall through the non-hugetlb case. In addition, only perform > the copy (for the full folio) if the source page is the folio head and > warn if the destination folio is already tagged, for symmetry with the > non-hugetlb case. > > Fixes: 25c17c4b55de ("hugetlb: arm64: add mte support") > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > Reported-by: Sasha Levin <sashal@kernel.org> > Cc: Yang Shi <yang@os.amperecomputing.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Will Deacon <will@kernel.org> > Link: https://lore.kernel.org/r/Z0STR6VLt2MCalnY@sashalap Thanks for fixing this. Reviewed-by: Yang Shi <yang@os.amperecomputing.com> > --- > arch/arm64/mm/copypage.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c > index 87b3f1a25535..a86c897017df 100644 > --- a/arch/arm64/mm/copypage.c > +++ b/arch/arm64/mm/copypage.c > @@ -30,11 +30,13 @@ void copy_highpage(struct page *to, struct page *from) > if (!system_supports_mte()) > return; > > - if (folio_test_hugetlb(src) && > - folio_test_hugetlb_mte_tagged(src)) { > - if (!folio_try_hugetlb_mte_tagging(dst)) > + if (folio_test_hugetlb(src)) { > + if (!folio_test_hugetlb_mte_tagged(src) || > + from != folio_page(src, 0)) > return; > > + WARN_ON_ONCE(!folio_try_hugetlb_mte_tagging(dst)); > + > /* > * Populate tags for all subpages. > *
On Wed, 04 Dec 2024 17:50:04 +0000, Catalin Marinas wrote: > Commit 25c17c4b55de ("hugetlb: arm64: add mte support") improved the > copy_highpage() function to update the tags in the destination hugetlb > folio. However, when the source folio isn't tagged, the code takes the > non-hugetlb path where try_page_mte_tagging() warns as the destination > is a hugetlb folio: > > WARNING: CPU: 0 PID: 363 at arch/arm64/include/asm/mte.h:58 copy_highpage+0x1d4/0x2d8 > [...] > pc : copy_highpage+0x1d4/0x2d8 > lr : copy_highpage+0x78/0x2d8 > [...] > Call trace: > copy_highpage+0x1d4/0x2d8 (P) > copy_highpage+0x78/0x2d8 (L) > copy_user_highpage+0x20/0x48 > copy_user_large_folio+0x1bc/0x268 > hugetlb_wp+0x190/0x860 > hugetlb_fault+0xa28/0xc10 > handle_mm_fault+0x2a0/0x2c0 > do_page_fault+0x12c/0x578 > do_mem_abort+0x4c/0xa8 > el0_da+0x44/0xb0 > el0t_64_sync_handler+0xc4/0x138 > el0t_64_sync+0x198/0x1a0 > > [...] Applied to arm64 (for-next/fixes), thanks! [1/1] arm64: mte: Fix copy_highpage() warning on hugetlb folios https://git.kernel.org/arm64/c/cf3b16dae4ca
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c index 87b3f1a25535..a86c897017df 100644 --- a/arch/arm64/mm/copypage.c +++ b/arch/arm64/mm/copypage.c @@ -30,11 +30,13 @@ void copy_highpage(struct page *to, struct page *from) if (!system_supports_mte()) return; - if (folio_test_hugetlb(src) && - folio_test_hugetlb_mte_tagged(src)) { - if (!folio_try_hugetlb_mte_tagging(dst)) + if (folio_test_hugetlb(src)) { + if (!folio_test_hugetlb_mte_tagged(src) || + from != folio_page(src, 0)) return; + WARN_ON_ONCE(!folio_try_hugetlb_mte_tagging(dst)); + /* * Populate tags for all subpages. *
Commit 25c17c4b55de ("hugetlb: arm64: add mte support") improved the copy_highpage() function to update the tags in the destination hugetlb folio. However, when the source folio isn't tagged, the code takes the non-hugetlb path where try_page_mte_tagging() warns as the destination is a hugetlb folio: WARNING: CPU: 0 PID: 363 at arch/arm64/include/asm/mte.h:58 copy_highpage+0x1d4/0x2d8 [...] pc : copy_highpage+0x1d4/0x2d8 lr : copy_highpage+0x78/0x2d8 [...] Call trace: copy_highpage+0x1d4/0x2d8 (P) copy_highpage+0x78/0x2d8 (L) copy_user_highpage+0x20/0x48 copy_user_large_folio+0x1bc/0x268 hugetlb_wp+0x190/0x860 hugetlb_fault+0xa28/0xc10 handle_mm_fault+0x2a0/0x2c0 do_page_fault+0x12c/0x578 do_mem_abort+0x4c/0xa8 el0_da+0x44/0xb0 el0t_64_sync_handler+0xc4/0x138 el0t_64_sync+0x198/0x1a0 Change the check for the tagged status of the source folio so that it does not fall through the non-hugetlb case. In addition, only perform the copy (for the full folio) if the source page is the folio head and warn if the destination folio is already tagged, for symmetry with the non-hugetlb case. Fixes: 25c17c4b55de ("hugetlb: arm64: add mte support") Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Sasha Levin <sashal@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: David Hildenbrand <david@redhat.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/Z0STR6VLt2MCalnY@sashalap --- arch/arm64/mm/copypage.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)