From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, andreyknvl@google.com,
aryabinin@virtuozzo.com, Branislav.Rankov@arm.com,
catalin.marinas@arm.com, dvyukov@google.com, elver@google.com,
eugenis@google.com, glider@google.com, gor@linux.ibm.com,
kevin.brodsky@arm.com, linux-mm@kvack.org,
mm-commits@vger.kernel.org, torvalds@linux-foundation.org,
vincenzo.frascino@arm.com, will.deacon@arm.com
Subject: [patch 24/60] arm64: mte: add in-kernel MTE helpers
Date: Tue, 22 Dec 2020 12:01:28 -0800 [thread overview]
Message-ID: <20201222200128.a-NXc9wRV%akpm@linux-foundation.org> (raw)
In-Reply-To: <20201222115844.d30aaef7df6f5b120d3e0c3d@linux-foundation.org>
From: Vincenzo Frascino <vincenzo.frascino@arm.com>
Subject: arm64: mte: add in-kernel MTE helpers
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.
Link: https://lkml.kernel.org/r/c31bf759b4411b2d98cdd801eb928e241584fd1f.1606161801.git.andreyknvl@google.com
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>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
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(-)
--- a/arch/arm64/include/asm/esr.h~arm64-mte-add-in-kernel-mte-helpers
+++ a/arch/arm64/include/asm/esr.h
@@ -106,6 +106,7 @@
#define ESR_ELx_FSC_TYPE (0x3C)
#define ESR_ELx_FSC_LEVEL (0x03)
#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)
--- /dev/null
+++ a/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 */
--- a/arch/arm64/include/asm/mte.h~arm64-mte-add-in-kernel-mte-helpers
+++ a/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 *ta
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(s
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 */
--- /dev/null
+++ a/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 */
--- a/arch/arm64/kernel/mte.c~arm64-mte-add-in-kernel-mte-helpers
+++ a/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, str
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 */
--- a/arch/arm64/lib/mte.S~arm64-mte-add-in-kernel-mte-helpers
+++ a/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)
_
next prev parent reply other threads:[~2020-12-22 20:02 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-22 19:58 incoming Andrew Morton
2020-12-22 20:00 ` [patch 01/60] kasan: drop unnecessary GPL text from comment headers Andrew Morton
2020-12-22 20:00 ` [patch 02/60] kasan: KASAN_VMALLOC depends on KASAN_GENERIC Andrew Morton
2020-12-22 20:00 ` [patch 03/60] kasan: group vmalloc code Andrew Morton
2020-12-22 20:00 ` [patch 04/60] kasan: shadow declarations only for software modes Andrew Morton
2020-12-22 20:00 ` [patch 05/60] kasan: rename (un)poison_shadow to (un)poison_range Andrew Morton
2020-12-22 20:00 ` [patch 06/60] kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* Andrew Morton
2020-12-22 20:00 ` [patch 07/60] kasan: only build init.c for software modes Andrew Morton
2020-12-22 20:00 ` [patch 08/60] kasan: split out shadow.c from common.c Andrew Morton
2020-12-22 20:00 ` [patch 09/60] kasan: define KASAN_MEMORY_PER_SHADOW_PAGE Andrew Morton
2020-12-22 20:00 ` [patch 10/60] kasan: rename report and tags files Andrew Morton
2020-12-22 20:00 ` [patch 11/60] kasan: don't duplicate config dependencies Andrew Morton
2020-12-22 20:00 ` [patch 12/60] kasan: hide invalid free check implementation Andrew Morton
2020-12-22 20:00 ` [patch 13/60] kasan: decode stack frame only with KASAN_STACK_ENABLE Andrew Morton
2020-12-22 20:00 ` [patch 14/60] kasan, arm64: only init shadow for software modes Andrew Morton
2020-12-22 20:00 ` [patch 15/60] kasan, arm64: only use kasan_depth " Andrew Morton
2020-12-22 20:01 ` [patch 16/60] kasan, arm64: move initialization message Andrew Morton
2020-12-22 20:01 ` [patch 17/60] kasan, arm64: rename kasan_init_tags and mark as __init Andrew Morton
2020-12-22 20:01 ` [patch 18/60] kasan: rename addr_has_shadow to addr_has_metadata Andrew Morton
2020-12-22 20:01 ` [patch 19/60] kasan: rename print_shadow_for_address to print_memory_metadata Andrew Morton
2020-12-22 20:01 ` [patch 20/60] kasan: rename SHADOW layout macros to META Andrew Morton
2020-12-22 20:01 ` [patch 21/60] kasan: separate metadata_fetch_row for each mode Andrew Morton
2020-12-22 20:01 ` [patch 22/60] kasan: introduce CONFIG_KASAN_HW_TAGS Andrew Morton
2020-12-22 20:01 ` [patch 23/60] arm64: enable armv8.5-a asm-arch option Andrew Morton
2020-12-22 20:01 ` Andrew Morton [this message]
2020-12-22 20:01 ` [patch 25/60] arm64: mte: reset the page tag in page->flags Andrew Morton
2020-12-22 20:01 ` [patch 26/60] arm64: mte: add in-kernel tag fault handler Andrew Morton
2020-12-22 20:01 ` [patch 27/60] arm64: kasan: allow enabling in-kernel MTE Andrew Morton
2020-12-22 20:01 ` [patch 28/60] arm64: mte: convert gcr_user into an exclude mask Andrew Morton
2020-12-22 20:01 ` [patch 29/60] arm64: mte: switch GCR_EL1 in kernel entry and exit Andrew Morton
2020-12-22 20:01 ` [patch 30/60] kasan, mm: untag page address in free_reserved_area Andrew Morton
2020-12-22 20:01 ` [patch 31/60] arm64: kasan: align allocations for HW_TAGS Andrew Morton
2020-12-22 20:01 ` [patch 32/60] arm64: kasan: add arch layer for memory tagging helpers Andrew Morton
2020-12-22 20:01 ` [patch 33/60] kasan: define KASAN_GRANULE_SIZE for HW_TAGS Andrew Morton
2020-12-22 20:02 ` [patch 34/60] kasan, x86, s390: update undef CONFIG_KASAN Andrew Morton
2020-12-22 20:02 ` [patch 35/60] kasan, arm64: expand CONFIG_KASAN checks Andrew Morton
2020-12-22 20:02 ` [patch 36/60] kasan, arm64: implement HW_TAGS runtime Andrew Morton
2020-12-22 20:02 ` [patch 37/60] kasan, arm64: print report from tag fault handler Andrew Morton
2020-12-22 20:02 ` [patch 38/60] kasan, mm: reset tags when accessing metadata Andrew Morton
2020-12-22 20:02 ` [patch 39/60] kasan, arm64: enable CONFIG_KASAN_HW_TAGS Andrew Morton
2020-12-22 20:02 ` [patch 40/60] kasan: add documentation for hardware tag-based mode Andrew Morton
2020-12-22 20:02 ` [patch 41/60] kselftest/arm64: check GCR_EL1 after context switch Andrew Morton
2020-12-22 20:02 ` [patch 42/60] kasan: simplify quarantine_put call site Andrew Morton
2020-12-22 20:02 ` [patch 43/60] kasan: rename get_alloc/free_info Andrew Morton
2020-12-22 20:02 ` [patch 44/60] kasan: introduce set_alloc_info Andrew Morton
2020-12-22 20:02 ` [patch 45/60] kasan, arm64: unpoison stack only with CONFIG_KASAN_STACK Andrew Morton
2020-12-22 20:02 ` [patch 46/60] kasan: allow VMAP_STACK for HW_TAGS mode Andrew Morton
2020-12-22 20:02 ` [patch 47/60] kasan: remove __kasan_unpoison_stack Andrew Morton
2020-12-22 20:02 ` [patch 48/60] kasan: inline kasan_reset_tag for tag-based modes Andrew Morton
2020-12-22 20:02 ` [patch 49/60] kasan: inline random_tag for HW_TAGS Andrew Morton
2020-12-22 20:02 ` [patch 50/60] kasan: open-code kasan_unpoison_slab Andrew Morton
2020-12-22 20:03 ` [patch 51/60] kasan: inline (un)poison_range and check_invalid_free Andrew Morton
2020-12-22 20:03 ` [patch 52/60] kasan: add and integrate kasan boot parameters Andrew Morton
2020-12-22 20:03 ` [patch 53/60] kasan, mm: check kasan_enabled in annotations Andrew Morton
2020-12-22 20:03 ` [patch 54/60] kasan, mm: rename kasan_poison_kfree Andrew Morton
2020-12-22 20:03 ` [patch 55/60] kasan: don't round_up too much Andrew Morton
2020-12-22 20:03 ` [patch 56/60] kasan: simplify assign_tag and set_tag calls Andrew Morton
2020-12-22 20:03 ` [patch 57/60] kasan: clarify comment in __kasan_kfree_large Andrew Morton
2020-12-22 20:03 ` [patch 58/60] kasan: sanitize objects when metadata doesn't fit Andrew Morton
2020-12-22 20:03 ` [patch 59/60] kasan, mm: allow cache merging with no metadata Andrew Morton
2020-12-22 20:03 ` [patch 60/60] kasan: update documentation Andrew Morton
2020-12-22 21:43 ` incoming Linus Torvalds
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