From: Andrey Konovalov <andreyknvl@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-kernel@lists.infradead.org,
Marco Elver <elver@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Will Deacon <will.deacon@arm.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Alexander Potapenko <glider@google.com>,
Evgenii Stepanov <eugenis@google.com>,
Andrey Konovalov <andreyknvl@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Dmitry Vyukov <dvyukov@google.com>
Subject: [PATCH mm v11 25/42] arm64: mte: Add in-kernel MTE helpers
Date: Mon, 23 Nov 2020 21:07:49 +0100 [thread overview]
Message-ID: <c31bf759b4411b2d98cdd801eb928e241584fd1f.1606161801.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1606161801.git.andreyknvl@google.com>
From: Vincenzo Frascino <vincenzo.frascino@arm.com>
Provide helper functions to manipulate allocation and pointer tags for
kernel addresses.
Low-level helper functions (mte_assign_*, written in assembly) operate
tag values from the [0x0, 0xF] range. High-level helper functions
(mte_get/set_*) use the [0xF0, 0xFF] range to preserve compatibility
with normal kernel pointers that have 0xFF in their top byte.
MTE_GRANULE_SIZE and related definitions are moved to mte-def.h header
that doesn't have any dependencies and is safe to include into any
low-level header.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
---
Change-Id: I1b5230254f90dc21a913447cb17f07fea7944ece
---
arch/arm64/include/asm/esr.h | 1 +
arch/arm64/include/asm/mte-def.h | 15 ++++++++
arch/arm64/include/asm/mte-kasan.h | 56 ++++++++++++++++++++++++++++++
arch/arm64/include/asm/mte.h | 20 +++++++----
arch/arm64/kernel/mte.c | 48 +++++++++++++++++++++++++
arch/arm64/lib/mte.S | 16 +++++++++
6 files changed, 150 insertions(+), 6 deletions(-)
create mode 100644 arch/arm64/include/asm/mte-def.h
create mode 100644 arch/arm64/include/asm/mte-kasan.h
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 22c81f1edda2..971c20ddfed4 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -105,6 +105,7 @@
#define ESR_ELx_FSC (0x3F)
#define ESR_ELx_FSC_TYPE (0x3C)
#define ESR_ELx_FSC_EXTABT (0x10)
+#define ESR_ELx_FSC_MTE (0x11)
#define ESR_ELx_FSC_SERROR (0x11)
#define ESR_ELx_FSC_ACCESS (0x08)
#define ESR_ELx_FSC_FAULT (0x04)
diff --git a/arch/arm64/include/asm/mte-def.h b/arch/arm64/include/asm/mte-def.h
new file mode 100644
index 000000000000..8401ac5840c7
--- /dev/null
+++ b/arch/arm64/include/asm/mte-def.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#ifndef __ASM_MTE_DEF_H
+#define __ASM_MTE_DEF_H
+
+#define MTE_GRANULE_SIZE UL(16)
+#define MTE_GRANULE_MASK (~(MTE_GRANULE_SIZE - 1))
+#define MTE_TAG_SHIFT 56
+#define MTE_TAG_SIZE 4
+#define MTE_TAG_MASK GENMASK((MTE_TAG_SHIFT + (MTE_TAG_SIZE - 1)), MTE_TAG_SHIFT)
+#define MTE_TAG_MAX (MTE_TAG_MASK >> MTE_TAG_SHIFT)
+
+#endif /* __ASM_MTE_DEF_H */
diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mte-kasan.h
new file mode 100644
index 000000000000..3a70fb1807fd
--- /dev/null
+++ b/arch/arm64/include/asm/mte-kasan.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#ifndef __ASM_MTE_KASAN_H
+#define __ASM_MTE_KASAN_H
+
+#include <asm/mte-def.h>
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+/*
+ * The functions below are meant to be used only for the
+ * KASAN_HW_TAGS interface defined in asm/memory.h.
+ */
+#ifdef CONFIG_ARM64_MTE
+
+static inline u8 mte_get_ptr_tag(void *ptr)
+{
+ /* Note: The format of KASAN tags is 0xF<x> */
+ u8 tag = 0xF0 | (u8)(((u64)(ptr)) >> MTE_TAG_SHIFT);
+
+ return tag;
+}
+
+u8 mte_get_mem_tag(void *addr);
+u8 mte_get_random_tag(void);
+void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag);
+
+#else /* CONFIG_ARM64_MTE */
+
+static inline u8 mte_get_ptr_tag(void *ptr)
+{
+ return 0xFF;
+}
+
+static inline u8 mte_get_mem_tag(void *addr)
+{
+ return 0xFF;
+}
+static inline u8 mte_get_random_tag(void)
+{
+ return 0xFF;
+}
+static inline void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag)
+{
+ return addr;
+}
+
+#endif /* CONFIG_ARM64_MTE */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_MTE_KASAN_H */
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
index 1c99fcadb58c..cf1cd181dcb2 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -5,14 +5,16 @@
#ifndef __ASM_MTE_H
#define __ASM_MTE_H
-#define MTE_GRANULE_SIZE UL(16)
-#define MTE_GRANULE_MASK (~(MTE_GRANULE_SIZE - 1))
-#define MTE_TAG_SHIFT 56
-#define MTE_TAG_SIZE 4
+#include <asm/compiler.h>
+#include <asm/mte-def.h>
+
+#define __MTE_PREAMBLE ARM64_ASM_PREAMBLE ".arch_extension memtag\n"
#ifndef __ASSEMBLY__
+#include <linux/bitfield.h>
#include <linux/page-flags.h>
+#include <linux/types.h>
#include <asm/pgtable-types.h>
@@ -45,7 +47,9 @@ long get_mte_ctrl(struct task_struct *task);
int mte_ptrace_copy_tags(struct task_struct *child, long request,
unsigned long addr, unsigned long data);
-#else
+void mte_assign_mem_tag_range(void *addr, size_t size);
+
+#else /* CONFIG_ARM64_MTE */
/* unused if !CONFIG_ARM64_MTE, silence the compiler */
#define PG_mte_tagged 0
@@ -80,7 +84,11 @@ static inline int mte_ptrace_copy_tags(struct task_struct *child,
return -EIO;
}
-#endif
+static inline void mte_assign_mem_tag_range(void *addr, size_t size)
+{
+}
+
+#endif /* CONFIG_ARM64_MTE */
#endif /* __ASSEMBLY__ */
#endif /* __ASM_MTE_H */
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index 52a0638ed967..8f99c65837fd 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -13,10 +13,13 @@
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/thread_info.h>
+#include <linux/types.h>
#include <linux/uio.h>
+#include <asm/barrier.h>
#include <asm/cpufeature.h>
#include <asm/mte.h>
+#include <asm/mte-kasan.h>
#include <asm/ptrace.h>
#include <asm/sysreg.h>
@@ -72,6 +75,51 @@ int memcmp_pages(struct page *page1, struct page *page2)
return ret;
}
+u8 mte_get_mem_tag(void *addr)
+{
+ if (!system_supports_mte())
+ return 0xFF;
+
+ asm(__MTE_PREAMBLE "ldg %0, [%0]"
+ : "+r" (addr));
+
+ return mte_get_ptr_tag(addr);
+}
+
+u8 mte_get_random_tag(void)
+{
+ void *addr;
+
+ if (!system_supports_mte())
+ return 0xFF;
+
+ asm(__MTE_PREAMBLE "irg %0, %0"
+ : "+r" (addr));
+
+ return mte_get_ptr_tag(addr);
+}
+
+void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag)
+{
+ void *ptr = addr;
+
+ if ((!system_supports_mte()) || (size == 0))
+ return addr;
+
+ /* Make sure that size is MTE granule aligned. */
+ WARN_ON(size & (MTE_GRANULE_SIZE - 1));
+
+ /* Make sure that the address is MTE granule aligned. */
+ WARN_ON((u64)addr & (MTE_GRANULE_SIZE - 1));
+
+ tag = 0xF0 | tag;
+ ptr = (void *)__tag_set(ptr, tag);
+
+ mte_assign_mem_tag_range(ptr, size);
+
+ return ptr;
+}
+
static void update_sctlr_el1_tcf0(u64 tcf0)
{
/* ISB required for the kernel uaccess routines */
diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S
index cceed41bba15..e63890292bc1 100644
--- a/arch/arm64/lib/mte.S
+++ b/arch/arm64/lib/mte.S
@@ -149,3 +149,19 @@ SYM_FUNC_START(mte_restore_page_tags)
ret
SYM_FUNC_END(mte_restore_page_tags)
+
+/*
+ * Assign allocation tags for a region of memory based on the pointer tag
+ * x0 - source pointer
+ * x1 - size
+ *
+ * Note: The address must be non-NULL and MTE_GRANULE_SIZE aligned and
+ * size must be non-zero and MTE_GRANULE_SIZE aligned.
+ */
+SYM_FUNC_START(mte_assign_mem_tag_range)
+1: stg x0, [x0]
+ add x0, x0, #MTE_GRANULE_SIZE
+ subs x1, x1, #MTE_GRANULE_SIZE
+ b.gt 1b
+ ret
+SYM_FUNC_END(mte_assign_mem_tag_range)
--
2.29.2.454.gaff20da3a2-goog
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next prev parent reply other threads:[~2020-11-23 20:19 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-23 20:07 [PATCH mm v11 00/42] kasan: add hardware tag-based mode for arm64 Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 01/42] kasan: drop unnecessary GPL text from comment headers Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 02/42] kasan: KASAN_VMALLOC depends on KASAN_GENERIC Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 03/42] kasan: group vmalloc code Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 04/42] kasan: shadow declarations only for software modes Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 05/42] kasan: rename (un)poison_shadow to (un)poison_range Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 06/42] kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 07/42] kasan: only build init.c for software modes Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 08/42] kasan: split out shadow.c from common.c Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 09/42] kasan: define KASAN_MEMORY_PER_SHADOW_PAGE Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 10/42] kasan: rename report and tags files Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 11/42] kasan: don't duplicate config dependencies Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 12/42] kasan: hide invalid free check implementation Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 13/42] kasan: decode stack frame only with KASAN_STACK_ENABLE Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 14/42] kasan, arm64: only init shadow for software modes Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 15/42] kasan, arm64: only use kasan_depth " Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 16/42] kasan, arm64: move initialization message Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 17/42] kasan, arm64: rename kasan_init_tags and mark as __init Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 18/42] kasan: rename addr_has_shadow to addr_has_metadata Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 19/42] kasan: rename print_shadow_for_address to print_memory_metadata Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 20/42] kasan: rename SHADOW layout macros to META Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 21/42] kasan: separate metadata_fetch_row for each mode Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 22/42] kasan, arm64: don't allow SW_TAGS with ARM64_MTE Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 23/42] kasan: introduce CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 24/42] arm64: Enable armv8.5-a asm-arch option Andrey Konovalov
2020-11-23 20:07 ` Andrey Konovalov [this message]
2020-11-23 20:07 ` [PATCH mm v11 26/42] arm64: mte: Reset the page tag in page->flags Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 27/42] arm64: mte: Add in-kernel tag fault handler Andrey Konovalov
2020-12-03 10:26 ` Catalin Marinas
2020-12-03 10:39 ` Vincenzo Frascino
2020-11-23 20:07 ` [PATCH mm v11 28/42] arm64: kasan: Allow enabling in-kernel MTE Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 29/42] arm64: mte: Convert gcr_user into an exclude mask Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 30/42] arm64: mte: Switch GCR_EL1 in kernel entry and exit Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 31/42] kasan, mm: untag page address in free_reserved_area Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 32/42] arm64: kasan: Align allocations for HW_TAGS Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 33/42] arm64: kasan: Add arch layer for memory tagging helpers Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 34/42] kasan: define KASAN_GRANULE_SIZE for HW_TAGS Andrey Konovalov
2020-11-23 20:07 ` [PATCH mm v11 35/42] kasan, x86, s390: update undef CONFIG_KASAN Andrey Konovalov
2020-11-23 20:08 ` [PATCH mm v11 36/42] kasan, arm64: expand CONFIG_KASAN checks Andrey Konovalov
2020-11-23 20:08 ` [PATCH mm v11 37/42] kasan, arm64: implement HW_TAGS runtime Andrey Konovalov
2020-11-23 20:08 ` [PATCH mm v11 38/42] kasan, arm64: print report from tag fault handler Andrey Konovalov
2020-11-23 20:08 ` [PATCH mm v11 39/42] kasan, mm: reset tags when accessing metadata Andrey Konovalov
2020-11-23 20:08 ` [PATCH mm v11 40/42] kasan, arm64: enable CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-11-23 20:08 ` [PATCH mm v11 41/42] kasan: add documentation for hardware tag-based mode Andrey Konovalov
2020-11-23 20:08 ` [PATCH mm v11 42/42] kselftest/arm64: Check GCR_EL1 after context switch Andrey Konovalov
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