From: Alexandru Elisei <alexandru.elisei@arm.com> To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC 34/37] arm64: mte: Handle fatal signal in reserve_metadata_storage() Date: Wed, 23 Aug 2023 14:13:47 +0100 [thread overview] Message-ID: <20230823131350.114942-35-alexandru.elisei@arm.com> (raw) In-Reply-To: <20230823131350.114942-1-alexandru.elisei@arm.com> As long as a fatal signal is pending, alloc_contig_range() will fail with -EINTR. This makes it impossible for tag storage allocation to succeed, and the page allocator will print an OOM splat. The process is going to be killed, so return 0 (success) from reserve_metadata_storage() to allow the page allocator to make progress. set_pte_at() will map it with PAGE_METADATA_NONE and subsequent accesses from different threads will trap until the signal is delivered. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> --- arch/arm64/kernel/mte_tag_storage.c | 17 +++++++++++++++++ arch/arm64/mm/fault.c | 23 +++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c index ce378f45f866..1ccbcc144979 100644 --- a/arch/arm64/kernel/mte_tag_storage.c +++ b/arch/arm64/kernel/mte_tag_storage.c @@ -556,6 +556,23 @@ int reserve_metadata_storage(struct page *page, int order, gfp_t gfp) break; } + /* + * alloc_contig_range() returns -EINTR from + * __alloc_contig_migrate_range() if a fatal signal is pending. + * As long as the signal hasn't been handled, it is impossible + * to reserve tag storage for any page. Treat it as an error, + * but return 0 so the page allocator can make forward progress, + * instead of printing an OOM splat. + * + * The tagged page with missing tag storage will be mapped with + * PAGE_METADATA_NONE in set_pte_at(), and accesses until the + * signal is delivered will cause a fault. + */ + if (ret == -EINTR) { + ret = 0; + goto out_error; + } + if (ret) goto out_error; diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 7e2dcf5e3baf..64c5d77664c8 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -37,7 +37,9 @@ #include <asm/debug-monitors.h> #include <asm/esr.h> #include <asm/kprobes.h> +#include <asm/memory_metadata.h> #include <asm/mte.h> +#include <asm/mte_tag_storage.h> #include <asm/processor.h> #include <asm/sysreg.h> #include <asm/system_misc.h> @@ -936,10 +938,31 @@ void do_debug_exception(unsigned long addr_if_watchpoint, unsigned long esr, } NOKPROBE_SYMBOL(do_debug_exception); +static void save_zero_page_tags(struct page *page) +{ + void *tags; + + clear_page(page_address(page)); + + tags = kmalloc(MTE_PAGE_TAG_STORAGE_SIZE, GFP_KERNEL | __GFP_ZERO); + if (WARN_ON(!tags)) + return; + + if (WARN_ON(mte_save_page_tags_by_pfn(page, tags))) + mte_free_tags_mem(tags); +} + void tag_clear_highpage(struct page *page) { /* Tag storage pages cannot be tagged. */ WARN_ON_ONCE(is_migrate_metadata_page(page)); + + if (metadata_storage_enabled() && + unlikely(!page_tag_storage_reserved(page))) { + save_zero_page_tags(page); + return; + } + /* Newly allocated page, shouldn't have been tagged yet */ WARN_ON_ONCE(!try_page_mte_tagging(page)); mte_zero_clear_page_tags(page_address(page)); -- 2.41.0
WARNING: multiple messages have this Message-ID (diff)
From: Alexandru Elisei <alexandru.elisei@arm.com> To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC 34/37] arm64: mte: Handle fatal signal in reserve_metadata_storage() Date: Wed, 23 Aug 2023 14:13:47 +0100 [thread overview] Message-ID: <20230823131350.114942-35-alexandru.elisei@arm.com> (raw) In-Reply-To: <20230823131350.114942-1-alexandru.elisei@arm.com> As long as a fatal signal is pending, alloc_contig_range() will fail with -EINTR. This makes it impossible for tag storage allocation to succeed, and the page allocator will print an OOM splat. The process is going to be killed, so return 0 (success) from reserve_metadata_storage() to allow the page allocator to make progress. set_pte_at() will map it with PAGE_METADATA_NONE and subsequent accesses from different threads will trap until the signal is delivered. Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com> --- arch/arm64/kernel/mte_tag_storage.c | 17 +++++++++++++++++ arch/arm64/mm/fault.c | 23 +++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c index ce378f45f866..1ccbcc144979 100644 --- a/arch/arm64/kernel/mte_tag_storage.c +++ b/arch/arm64/kernel/mte_tag_storage.c @@ -556,6 +556,23 @@ int reserve_metadata_storage(struct page *page, int order, gfp_t gfp) break; } + /* + * alloc_contig_range() returns -EINTR from + * __alloc_contig_migrate_range() if a fatal signal is pending. + * As long as the signal hasn't been handled, it is impossible + * to reserve tag storage for any page. Treat it as an error, + * but return 0 so the page allocator can make forward progress, + * instead of printing an OOM splat. + * + * The tagged page with missing tag storage will be mapped with + * PAGE_METADATA_NONE in set_pte_at(), and accesses until the + * signal is delivered will cause a fault. + */ + if (ret == -EINTR) { + ret = 0; + goto out_error; + } + if (ret) goto out_error; diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 7e2dcf5e3baf..64c5d77664c8 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -37,7 +37,9 @@ #include <asm/debug-monitors.h> #include <asm/esr.h> #include <asm/kprobes.h> +#include <asm/memory_metadata.h> #include <asm/mte.h> +#include <asm/mte_tag_storage.h> #include <asm/processor.h> #include <asm/sysreg.h> #include <asm/system_misc.h> @@ -936,10 +938,31 @@ void do_debug_exception(unsigned long addr_if_watchpoint, unsigned long esr, } NOKPROBE_SYMBOL(do_debug_exception); +static void save_zero_page_tags(struct page *page) +{ + void *tags; + + clear_page(page_address(page)); + + tags = kmalloc(MTE_PAGE_TAG_STORAGE_SIZE, GFP_KERNEL | __GFP_ZERO); + if (WARN_ON(!tags)) + return; + + if (WARN_ON(mte_save_page_tags_by_pfn(page, tags))) + mte_free_tags_mem(tags); +} + void tag_clear_highpage(struct page *page) { /* Tag storage pages cannot be tagged. */ WARN_ON_ONCE(is_migrate_metadata_page(page)); + + if (metadata_storage_enabled() && + unlikely(!page_tag_storage_reserved(page))) { + save_zero_page_tags(page); + return; + } + /* Newly allocated page, shouldn't have been tagged yet */ WARN_ON_ONCE(!try_page_mte_tagging(page)); mte_zero_clear_page_tags(page_address(page)); -- 2.41.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-08-23 13:19 UTC|newest] Thread overview: 136+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-08-23 13:13 [PATCH RFC 00/37] Add support for arm64 MTE dynamic tag storage reuse Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 01/37] mm: page_alloc: Rename gfp_to_alloc_flags_cma -> gfp_to_alloc_flags_fast Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 02/37] arm64: mte: Rework naming for tag manipulation functions Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 03/37] arm64: mte: Rename __GFP_ZEROTAGS to __GFP_TAGGED Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 04/37] mm: Add MIGRATE_METADATA allocation policy Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei [not found] ` <CGME20231012013834epcas2p28ff3162673294077caef3b0794b69e72@epcas2p2.samsung.com> 2023-10-12 1:28 ` Hyesoo Yu 2023-10-12 1:28 ` Hyesoo Yu 2023-10-16 12:40 ` Alexandru Elisei 2023-10-16 12:40 ` Alexandru Elisei 2023-10-23 7:52 ` Hyesoo Yu 2023-10-23 7:52 ` Hyesoo Yu 2023-08-23 13:13 ` [PATCH RFC 05/37] mm: Add memory statistics for the " Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 06/37] mm: page_alloc: Allocate from movable pcp lists only if ALLOC_FROM_METADATA Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei [not found] ` <CGME20231012013524epcas2p4b50f306e3e4d0b937b31f978022844e5@epcas2p4.samsung.com> 2023-10-12 1:25 ` Hyesoo Yu 2023-10-12 1:25 ` Hyesoo Yu 2023-10-16 12:41 ` Alexandru Elisei 2023-10-16 12:41 ` Alexandru Elisei 2023-10-17 10:26 ` Catalin Marinas 2023-10-17 10:26 ` Catalin Marinas 2023-10-23 7:16 ` Hyesoo Yu 2023-10-23 7:16 ` Hyesoo Yu 2023-10-23 10:50 ` Catalin Marinas 2023-10-23 10:50 ` Catalin Marinas 2023-10-23 11:55 ` David Hildenbrand 2023-10-23 11:55 ` David Hildenbrand 2023-10-23 17:08 ` Catalin Marinas 2023-10-23 17:08 ` Catalin Marinas 2023-10-23 17:22 ` David Hildenbrand 2023-10-23 17:22 ` David Hildenbrand 2023-08-23 13:13 ` [PATCH RFC 07/37] mm: page_alloc: Bypass pcp when freeing MIGRATE_METADATA pages Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 08/37] mm: compaction: Account for free metadata pages in __compact_finished() Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 09/37] mm: compaction: Handle metadata pages as source for direct compaction Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 10/37] mm: compaction: Do not use MIGRATE_METADATA to replace pages with metadata Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 11/37] mm: migrate/mempolicy: Allocate metadata-enabled destination page Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 12/37] mm: gup: Don't allow longterm pinning of MIGRATE_METADATA pages Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 13/37] arm64: mte: Reserve tag storage memory Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 14/37] arm64: mte: Expose tag storage pages to the MIGRATE_METADATA freelist Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 15/37] arm64: mte: Make tag storage depend on ARCH_KEEP_MEMBLOCK Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 16/37] arm64: mte: Move tag storage to MIGRATE_MOVABLE when MTE is disabled Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 17/37] arm64: mte: Disable dynamic tag storage management if HW KASAN is enabled Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei [not found] ` <CGME20231012014514epcas2p3ca99a067f3044c5753309a08cd0b05c4@epcas2p3.samsung.com> 2023-10-12 1:35 ` Hyesoo Yu 2023-10-12 1:35 ` Hyesoo Yu 2023-10-16 12:42 ` Alexandru Elisei 2023-10-16 12:42 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 18/37] arm64: mte: Check that tag storage blocks are in the same zone Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 19/37] mm: page_alloc: Manage metadata storage on page allocation Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 20/37] mm: compaction: Reserve metadata storage in compaction_alloc() Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-11-21 4:49 ` Peter Collingbourne 2023-11-21 4:49 ` Peter Collingbourne 2023-11-21 11:54 ` Alexandru Elisei 2023-11-21 11:54 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 21/37] mm: khugepaged: Handle metadata-enabled VMAs Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 22/37] mm: shmem: Allocate metadata storage for in-memory filesystems Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 23/37] mm: Teach vma_alloc_folio() about metadata-enabled VMAs Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 24/37] mm: page_alloc: Teach alloc_contig_range() about MIGRATE_METADATA Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 25/37] arm64: mte: Manage tag storage on page allocation Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 26/37] arm64: mte: Perform CMOs for tag blocks on tagged page allocation/free Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 27/37] arm64: mte: Reserve tag block for the zero page Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 28/37] mm: sched: Introduce PF_MEMALLOC_ISOLATE Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 29/37] mm: arm64: Define the PAGE_METADATA_NONE page protection Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 30/37] mm: mprotect: arm64: Set PAGE_METADATA_NONE for mprotect(PROT_MTE) Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 31/37] mm: arm64: Set PAGE_METADATA_NONE in set_pte_at() if missing metadata storage Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 32/37] mm: Call arch_swap_prepare_to_restore() before arch_swap_restore() Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 33/37] arm64: mte: swap/copypage: Handle tag restoring when missing tag storage Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei [this message] 2023-08-23 13:13 ` [PATCH RFC 34/37] arm64: mte: Handle fatal signal in reserve_metadata_storage() Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 35/37] mm: hugepage: Handle PAGE_METADATA_NONE faults for huge pages Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 36/37] KVM: arm64: Disable MTE is tag storage is enabled Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-23 13:13 ` [PATCH RFC 37/37] arm64: mte: Enable tag storage management Alexandru Elisei 2023-08-23 13:13 ` Alexandru Elisei 2023-08-24 7:50 ` [PATCH RFC 00/37] Add support for arm64 MTE dynamic tag storage reuse David Hildenbrand 2023-08-24 7:50 ` David Hildenbrand 2023-08-24 10:44 ` Catalin Marinas 2023-08-24 10:44 ` Catalin Marinas 2023-08-24 11:06 ` David Hildenbrand 2023-08-24 11:06 ` David Hildenbrand 2023-08-24 11:25 ` David Hildenbrand 2023-08-24 11:25 ` David Hildenbrand 2023-08-24 15:24 ` Catalin Marinas 2023-08-24 15:24 ` Catalin Marinas 2023-09-06 11:23 ` Alexandru Elisei 2023-09-06 11:23 ` Alexandru Elisei 2023-09-11 11:52 ` Catalin Marinas 2023-09-11 11:52 ` Catalin Marinas 2023-09-11 12:29 ` David Hildenbrand 2023-09-11 12:29 ` David Hildenbrand 2023-09-13 15:29 ` Catalin Marinas 2023-09-13 15:29 ` Catalin Marinas [not found] ` <CGME20231025031004epcas2p485a0b7a9247bc61d54064d7f7bdd1e89@epcas2p4.samsung.com> 2023-10-25 2:59 ` Hyesoo Yu 2023-10-25 2:59 ` Hyesoo Yu 2023-10-25 8:47 ` Alexandru Elisei 2023-10-25 8:47 ` Alexandru Elisei 2023-10-25 8:52 ` Hyesoo Yu 2023-10-25 8:52 ` Hyesoo Yu 2023-10-27 11:04 ` Catalin Marinas 2023-10-27 11:04 ` Catalin Marinas 2023-09-13 8:11 ` Kuan-Ying Lee (李冠穎) 2023-09-13 8:11 ` Kuan-Ying Lee (李冠穎) 2023-09-14 17:37 ` Catalin Marinas 2023-09-14 17:37 ` Catalin Marinas
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