From: Andrey Konovalov <andreyknvl@google.com>
To: Dmitry Vyukov <dvyukov@google.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
kasan-dev@googlegroups.com
Cc: Marco Elver <elver@google.com>,
Elena Petrova <lenaptr@google.com>,
Andrey Konovalov <andreyknvl@google.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Will Deacon <will.deacon@arm.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Alexander Potapenko <glider@google.com>,
linux-arm-kernel@lists.infradead.org,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Andrew Morton <akpm@linux-foundation.org>,
Evgenii Stepanov <eugenis@google.com>
Subject: [PATCH 20/35] arm64: mte: Add in-kernel MTE helpers
Date: Fri, 14 Aug 2020 19:27:02 +0200 [thread overview]
Message-ID: <2cf260bdc20793419e32240d2a3e692b0adf1f80.1597425745.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1597425745.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 definition is moved to mte_asm.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>
---
arch/arm64/include/asm/esr.h | 1 +
arch/arm64/include/asm/mte.h | 46 +++++++++++++++++++++++++++++---
arch/arm64/include/asm/mte_asm.h | 10 +++++++
arch/arm64/kernel/mte.c | 43 +++++++++++++++++++++++++++++
arch/arm64/lib/mte.S | 41 ++++++++++++++++++++++++++++
5 files changed, 138 insertions(+), 3 deletions(-)
create mode 100644 arch/arm64/include/asm/mte_asm.h
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 035003acfa87..bc0dc66a6a27 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -103,6 +103,7 @@
#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.h b/arch/arm64/include/asm/mte.h
index 1c99fcadb58c..733be1cb5c95 100644
--- a/arch/arm64/include/asm/mte.h
+++ b/arch/arm64/include/asm/mte.h
@@ -5,14 +5,19 @@
#ifndef __ASM_MTE_H
#define __ASM_MTE_H
-#define MTE_GRANULE_SIZE UL(16)
+#include <asm/mte_asm.h>
+
#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)
#ifndef __ASSEMBLY__
+#include <linux/bitfield.h>
#include <linux/page-flags.h>
+#include <linux/types.h>
#include <asm/pgtable-types.h>
@@ -45,7 +50,16 @@ 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_valid_ptr_tag(void *ptr);
+void *mte_assign_random_ptr_tag(void *ptr);
+void mte_assign_mem_tag_range(void *addr, size_t size);
+
+#define mte_get_ptr_tag(ptr) ((u8)(((u64)(ptr)) >> MTE_TAG_SHIFT))
+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 */
/* unused if !CONFIG_ARM64_MTE, silence the compiler */
#define PG_mte_tagged 0
@@ -80,7 +94,33 @@ static inline int mte_ptrace_copy_tags(struct task_struct *child,
return -EIO;
}
-#endif
+static inline void *mte_assign_valid_ptr_tag(void *ptr)
+{
+ return ptr;
+}
+static inline void *mte_assign_random_ptr_tag(void *ptr)
+{
+ return ptr;
+}
+static inline void mte_assign_mem_tag_range(void *addr, size_t size)
+{
+}
+
+#define mte_get_ptr_tag(ptr) 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_H */
diff --git a/arch/arm64/include/asm/mte_asm.h b/arch/arm64/include/asm/mte_asm.h
new file mode 100644
index 000000000000..aa532c1851e1
--- /dev/null
+++ b/arch/arm64/include/asm/mte_asm.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#ifndef __ASM_MTE_ASM_H
+#define __ASM_MTE_ASM_H
+
+#define MTE_GRANULE_SIZE UL(16)
+
+#endif /* __ASM_MTE_ASM_H */
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index eb39504e390a..e2d708b4583d 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -13,8 +13,10 @@
#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/ptrace.h>
@@ -72,6 +74,47 @@ int memcmp_pages(struct page *page1, struct page *page2)
return ret;
}
+u8 mte_get_mem_tag(void *addr)
+{
+ if (system_supports_mte())
+ addr = mte_assign_valid_ptr_tag(addr);
+
+ return 0xF0 | mte_get_ptr_tag(addr);
+}
+
+u8 mte_get_random_tag(void)
+{
+ u8 tag = 0xF;
+
+ if (system_supports_mte())
+ tag = mte_get_ptr_tag(mte_assign_random_ptr_tag(NULL));
+
+ return 0xF0 | tag;
+}
+
+void * __must_check mte_set_mem_tag_range(void *addr, size_t size, u8 tag)
+{
+ void *ptr = addr;
+
+ if ((!system_supports_mte()) || (size == 0))
+ return addr;
+
+ tag = 0xF0 | (tag & 0xF);
+ ptr = (void *)__tag_set(ptr, tag);
+ size = ALIGN(size, MTE_GRANULE_SIZE);
+
+ mte_assign_mem_tag_range(ptr, size);
+
+ /*
+ * mte_assign_mem_tag_range() can be invoked in a multi-threaded
+ * context, ensure that tags are written in memory before the
+ * reference is used.
+ */
+ smp_wmb();
+
+ 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 03ca6d8b8670..8c743540e32c 100644
--- a/arch/arm64/lib/mte.S
+++ b/arch/arm64/lib/mte.S
@@ -149,3 +149,44 @@ SYM_FUNC_START(mte_restore_page_tags)
ret
SYM_FUNC_END(mte_restore_page_tags)
+
+/*
+ * Assign pointer tag based on the allocation tag
+ * x0 - source pointer
+ * Returns:
+ * x0 - pointer with the correct tag to access memory
+ */
+SYM_FUNC_START(mte_assign_valid_ptr_tag)
+ ldg x0, [x0]
+ ret
+SYM_FUNC_END(mte_assign_valid_ptr_tag)
+
+/*
+ * Assign random pointer tag
+ * x0 - source pointer
+ * Returns:
+ * x0 - pointer with a random tag
+ */
+SYM_FUNC_START(mte_assign_random_ptr_tag)
+ irg x0, x0
+ ret
+SYM_FUNC_END(mte_assign_random_ptr_tag)
+
+/*
+ * Assign allocation tags for a region of memory based on the pointer tag
+ * x0 - source pointer
+ * x1 - size
+ *
+ * Note: size is expected to be MTE_GRANULE_SIZE aligned
+ */
+SYM_FUNC_START(mte_assign_mem_tag_range)
+ /* if (src == NULL) return; */
+ cbz x0, 2f
+ /* if (size == 0) return; */
+ cbz x1, 2f
+1: stg x0, [x0]
+ add x0, x0, #MTE_GRANULE_SIZE
+ sub x1, x1, #MTE_GRANULE_SIZE
+ cbnz x1, 1b
+2: ret
+SYM_FUNC_END(mte_assign_mem_tag_range)
--
2.28.0.220.ged08abb693-goog
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next prev parent reply other threads:[~2020-08-14 17:34 UTC|newest]
Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-14 17:26 [PATCH 00/35] kasan: add hardware tag-based mode for arm64 Andrey Konovalov
2020-08-14 17:26 ` [PATCH 01/35] kasan: KASAN_VMALLOC depends on KASAN_GENERIC Andrey Konovalov
2020-08-14 17:26 ` [PATCH 02/35] kasan: group vmalloc code Andrey Konovalov
2020-08-14 17:26 ` [PATCH 03/35] kasan: shadow declarations only for software modes Andrey Konovalov
2020-09-18 14:55 ` Marco Elver
2020-09-18 14:56 ` Andrey Konovalov
2020-08-14 17:26 ` [PATCH 04/35] kasan: rename (un)poison_shadow to (un)poison_memory Andrey Konovalov
2020-08-14 17:26 ` [PATCH 05/35] kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* Andrey Konovalov
2020-08-14 17:26 ` [PATCH 06/35] kasan: only build init.c for software modes Andrey Konovalov
2020-08-14 17:26 ` [PATCH 07/35] kasan: split out shadow.c from common.c Andrey Konovalov
2020-08-14 17:26 ` [PATCH 08/35] kasan: rename generic/tags_report.c files Andrey Konovalov
2020-08-14 17:26 ` [PATCH 09/35] kasan: don't duplicate config dependencies Andrey Konovalov
2020-08-14 17:26 ` [PATCH 10/35] kasan: hide invalid free check implementation Andrey Konovalov
2020-08-14 17:26 ` [PATCH 11/35] kasan: decode stack frame only with KASAN_STACK_ENABLE Andrey Konovalov
2020-08-14 17:26 ` [PATCH 12/35] kasan, arm64: only init shadow for software modes Andrey Konovalov
2020-08-14 17:26 ` [PATCH 13/35] kasan, arm64: only use kasan_depth " Andrey Konovalov
2020-08-14 17:26 ` [PATCH 14/35] kasan: rename addr_has_shadow to addr_has_metadata Andrey Konovalov
2020-08-14 17:26 ` [PATCH 15/35] kasan: rename print_shadow_for_address to print_memory_metadata Andrey Konovalov
2020-08-14 17:26 ` [PATCH 16/35] kasan: kasan_non_canonical_hook only for software modes Andrey Konovalov
2020-08-14 17:26 ` [PATCH 17/35] kasan: rename SHADOW layout macros to META Andrey Konovalov
2020-08-14 17:27 ` [PATCH 18/35] kasan: separate metadata_fetch_row for each mode Andrey Konovalov
2020-08-14 17:27 ` [PATCH 19/35] kasan: don't allow SW_TAGS with ARM64_MTE Andrey Konovalov
2020-08-27 8:04 ` Catalin Marinas
2020-08-27 9:54 ` Vincenzo Frascino
2020-08-27 12:02 ` Andrey Konovalov
2020-08-14 17:27 ` Andrey Konovalov [this message]
2020-08-27 9:38 ` [PATCH 20/35] arm64: mte: Add in-kernel MTE helpers Catalin Marinas
2020-08-27 10:31 ` Vincenzo Frascino
2020-08-27 11:10 ` Catalin Marinas
2020-08-27 11:24 ` Vincenzo Frascino
2020-08-27 12:46 ` Andrey Konovalov
2020-09-08 13:23 ` Andrey Konovalov
2020-09-08 14:50 ` Catalin Marinas
2020-08-14 17:27 ` [PATCH 21/35] arm64: mte: Add in-kernel tag fault handler Andrey Konovalov
2020-08-27 9:54 ` Catalin Marinas
2020-08-27 10:44 ` Vincenzo Frascino
2020-08-27 12:31 ` Andrey Konovalov
2020-08-27 13:10 ` Catalin Marinas
2020-08-27 13:34 ` Andrey Konovalov
2020-08-27 14:56 ` Catalin Marinas
2020-08-27 19:14 ` Evgenii Stepanov
2020-08-28 9:56 ` Catalin Marinas
2020-08-14 17:27 ` [PATCH 22/35] arm64: mte: Enable in-kernel MTE Andrey Konovalov
2020-08-27 10:01 ` Catalin Marinas
2020-08-27 10:46 ` Vincenzo Frascino
2020-09-08 14:39 ` Andrey Konovalov
2020-09-08 14:52 ` Catalin Marinas
2020-08-14 17:27 ` [PATCH 23/35] arm64: mte: Convert gcr_user into an exclude mask Andrey Konovalov
2020-08-14 17:27 ` [PATCH 24/35] arm64: mte: Switch GCR_EL1 in kernel entry and exit Andrey Konovalov
2020-08-27 10:38 ` Catalin Marinas
2020-08-27 10:56 ` Vincenzo Frascino
2020-08-27 12:16 ` Catalin Marinas
2020-09-08 14:02 ` Andrey Konovalov
2020-09-08 14:53 ` Andrey Konovalov
2020-09-08 15:39 ` Catalin Marinas
2020-09-08 19:41 ` Derrick McKee
2020-09-08 13:58 ` Andrey Konovalov
2020-09-08 15:16 ` Catalin Marinas
2020-08-14 17:27 ` [PATCH 25/35] kasan: introduce CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-08-27 11:33 ` Vincenzo Frascino
2020-08-27 12:22 ` Andrey Konovalov
2020-08-14 17:27 ` [PATCH 26/35] kasan, arm64: Enable TBI EL1 Andrey Konovalov
2020-08-27 10:40 ` Catalin Marinas
2020-08-27 11:05 ` Vincenzo Frascino
2020-08-27 11:13 ` Catalin Marinas
2020-08-27 11:17 ` Vincenzo Frascino
2020-08-27 12:43 ` Andrey Konovalov
2020-08-27 13:45 ` Vincenzo Frascino
2020-08-27 14:36 ` Andrey Konovalov
2020-09-08 13:18 ` Andrey Konovalov
2020-09-08 14:06 ` Catalin Marinas
2020-09-08 14:12 ` Andrey Konovalov
2020-09-08 14:41 ` Catalin Marinas
2020-08-14 17:27 ` [PATCH 27/35] kasan, arm64: align allocations for HW_TAGS Andrey Konovalov
2020-08-14 17:27 ` [PATCH 28/35] kasan: define KASAN_GRANULE_SIZE " Andrey Konovalov
2020-08-27 10:41 ` Catalin Marinas
2020-08-27 11:07 ` Vincenzo Frascino
2020-08-27 12:05 ` Andrey Konovalov
2020-08-14 17:27 ` [PATCH 29/35] kasan, x86, s390: update undef CONFIG_KASAN Andrey Konovalov
2020-08-14 17:27 ` [PATCH 30/35] kasan, arm64: expand CONFIG_KASAN checks Andrey Konovalov
2020-08-14 17:27 ` [PATCH 31/35] kasan, arm64: implement HW_TAGS runtime Andrey Konovalov
2020-08-27 10:45 ` Catalin Marinas
2020-08-27 11:35 ` Vincenzo Frascino
2020-08-27 12:37 ` Andrey Konovalov
2020-08-14 17:27 ` [PATCH 32/35] kasan, arm64: print report from tag fault handler Andrey Konovalov
2020-08-27 10:48 ` Catalin Marinas
2020-08-27 12:11 ` Vincenzo Frascino
2020-08-27 12:34 ` Andrey Konovalov
2020-08-27 14:21 ` Catalin Marinas
2020-08-14 17:27 ` [PATCH 33/35] kasan, slub: reset tags when accessing metadata Andrey Konovalov
2020-08-14 17:27 ` [PATCH 34/35] kasan, arm64: enable CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-08-14 17:27 ` [PATCH 35/35] kasan: add documentation for hardware tag-based mode Andrey Konovalov
2020-08-28 11:12 ` Marco Elver
2020-08-28 12:28 ` Andrey Konovalov
2020-09-14 19:06 ` [PATCH 00/35] kasan: add hardware tag-based mode for arm64 Derrick McKee
2020-09-14 20:04 ` Andrey Konovalov
2020-09-14 21:36 ` Derrick McKee
2020-09-14 22:41 ` Derrick McKee
2020-09-14 22:50 ` Andrey Konovalov
2020-09-15 9:46 ` Derrick McKee
2020-09-15 17:51 ` Derrick McKee
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