The patch titled
Subject: kasan: separate metadata_fetch_row for each mode
has been added to the -mm tree. Its filename is
kasan-separate-metadata_fetch_row-for-each-mode.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-separate-metadata_fetch_row-for-each-mode.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-separate-metadata_fetch_row-for-each-mode.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: separate metadata_fetch_row for each mode
This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.
Rework print_memory_metadata() to make it agnostic with regard to the way
metadata is stored. Allow providing a separate metadata_fetch_row()
implementation for each KASAN mode. Hardware tag-based KASAN will provide
its own implementation that doesn't use shadow memory.
No functional changes for software modes.
Link: https://lkml.kernel.org/r/5fb1ec0152bb1f521505017800387ec3e36ffe18.1606161801.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>
Tested-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/kasan.h | 8 +++++
mm/kasan/report.c | 56 +++++++++++++++++-------------------
mm/kasan/report_generic.c | 5 +++
mm/kasan/report_sw_tags.c | 5 +++
4 files changed, 45 insertions(+), 29 deletions(-)
--- a/mm/kasan/kasan.h~kasan-separate-metadata_fetch_row-for-each-mode
+++ a/mm/kasan/kasan.h
@@ -58,6 +58,13 @@
#define KASAN_ABI_VERSION 1
#endif
+/* Metadata layout customization. */
+#define META_BYTES_PER_BLOCK 1
+#define META_BLOCKS_PER_ROW 16
+#define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
+#define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
+#define META_ROWS_AROUND_ADDR 2
+
struct kasan_access_info {
const void *access_addr;
const void *first_bad_addr;
@@ -170,6 +177,7 @@ bool check_invalid_free(void *addr);
void *find_first_bad_addr(void *addr, size_t size);
const char *get_bug_type(struct kasan_access_info *info);
+void metadata_fetch_row(char *buffer, void *row);
#if defined(CONFIG_KASAN_GENERIC) && CONFIG_KASAN_STACK
void print_address_stack_frame(const void *addr);
--- a/mm/kasan/report.c~kasan-separate-metadata_fetch_row-for-each-mode
+++ a/mm/kasan/report.c
@@ -33,12 +33,6 @@
#include "kasan.h"
#include "../slab.h"
-/* Metadata layout customization. */
-#define META_BYTES_PER_BLOCK 1
-#define META_BLOCKS_PER_ROW 16
-#define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
-#define META_ROWS_AROUND_ADDR 2
-
static unsigned long kasan_flags;
#define KASAN_BIT_REPORTED 0
@@ -238,55 +232,59 @@ static void print_address_description(vo
print_address_stack_frame(addr);
}
-static bool row_is_guilty(const void *row, const void *guilty)
+static bool meta_row_is_guilty(const void *row, const void *addr)
{
- return (row <= guilty) && (guilty < row + META_BYTES_PER_ROW);
+ return (row <= addr) && (addr < row + META_MEM_BYTES_PER_ROW);
}
-static int shadow_pointer_offset(const void *row, const void *shadow)
+static int meta_pointer_offset(const void *row, const void *addr)
{
- /* The length of ">ff00ff00ff00ff00: " is
- * 3 + (BITS_PER_LONG/8)*2 chars.
+ /*
+ * Memory state around the buggy address:
+ * ff00ff00ff00ff00: 00 00 00 05 fe fe fe fe fe fe fe fe fe fe fe fe
+ * ...
+ *
+ * The length of ">ff00ff00ff00ff00: " is
+ * 3 + (BITS_PER_LONG / 8) * 2 chars.
+ * The length of each granule metadata is 2 bytes
+ * plus 1 byte for space.
*/
- return 3 + (BITS_PER_LONG/8)*2 + (shadow - row)*2 +
- (shadow - row) / META_BYTES_PER_BLOCK + 1;
+ return 3 + (BITS_PER_LONG / 8) * 2 +
+ (addr - row) / KASAN_GRANULE_SIZE * 3 + 1;
}
static void print_memory_metadata(const void *addr)
{
int i;
- const void *shadow = kasan_mem_to_shadow(addr);
- const void *shadow_row;
+ void *row;
- shadow_row = (void *)round_down((unsigned long)shadow,
- META_BYTES_PER_ROW)
- - META_ROWS_AROUND_ADDR * META_BYTES_PER_ROW;
+ row = (void *)round_down((unsigned long)addr, META_MEM_BYTES_PER_ROW)
+ - META_ROWS_AROUND_ADDR * META_MEM_BYTES_PER_ROW;
pr_err("Memory state around the buggy address:\n");
for (i = -META_ROWS_AROUND_ADDR; i <= META_ROWS_AROUND_ADDR; i++) {
- const void *kaddr = kasan_shadow_to_mem(shadow_row);
- char buffer[4 + (BITS_PER_LONG/8)*2];
- char shadow_buf[META_BYTES_PER_ROW];
+ char buffer[4 + (BITS_PER_LONG / 8) * 2];
+ char metadata[META_BYTES_PER_ROW];
snprintf(buffer, sizeof(buffer),
- (i == 0) ? ">%px: " : " %px: ", kaddr);
+ (i == 0) ? ">%px: " : " %px: ", row);
+
/*
* We should not pass a shadow pointer to generic
* function, because generic functions may try to
* access kasan mapping for the passed address.
*/
- memcpy(shadow_buf, shadow_row, META_BYTES_PER_ROW);
+ metadata_fetch_row(&metadata[0], row);
+
print_hex_dump(KERN_ERR, buffer,
DUMP_PREFIX_NONE, META_BYTES_PER_ROW, 1,
- shadow_buf, META_BYTES_PER_ROW, 0);
+ metadata, META_BYTES_PER_ROW, 0);
- if (row_is_guilty(shadow_row, shadow))
- pr_err("%*c\n",
- shadow_pointer_offset(shadow_row, shadow),
- '^');
+ if (meta_row_is_guilty(row, addr))
+ pr_err("%*c\n", meta_pointer_offset(row, addr), '^');
- shadow_row += META_BYTES_PER_ROW;
+ row += META_MEM_BYTES_PER_ROW;
}
}
--- a/mm/kasan/report_generic.c~kasan-separate-metadata_fetch_row-for-each-mode
+++ a/mm/kasan/report_generic.c
@@ -123,6 +123,11 @@ const char *get_bug_type(struct kasan_ac
return get_wild_bug_type(info);
}
+void metadata_fetch_row(char *buffer, void *row)
+{
+ memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
+}
+
#if CONFIG_KASAN_STACK
static bool __must_check tokenize_frame_descr(const char **frame_descr,
char *token, size_t max_tok_len,
--- a/mm/kasan/report_sw_tags.c~kasan-separate-metadata_fetch_row-for-each-mode
+++ a/mm/kasan/report_sw_tags.c
@@ -80,6 +80,11 @@ void *find_first_bad_addr(void *addr, si
return p;
}
+void metadata_fetch_row(char *buffer, void *row)
+{
+ memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
+}
+
void print_tags(u8 addr_tag, const void *addr)
{
u8 *shadow = (u8 *)kasan_mem_to_shadow(addr);
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-drop-unnecessary-gpl-text-from-comment-headers.patch
kasan-kasan_vmalloc-depends-on-kasan_generic.patch
kasan-group-vmalloc-code.patch
kasan-shadow-declarations-only-for-software-modes.patch
kasan-rename-unpoison_shadow-to-unpoison_range.patch
kasan-rename-kasan_shadow_-to-kasan_granule_.patch
kasan-only-build-initc-for-software-modes.patch
kasan-split-out-shadowc-from-commonc.patch
kasan-define-kasan_memory_per_shadow_page.patch
kasan-rename-report-and-tags-files.patch
kasan-dont-duplicate-config-dependencies.patch
kasan-hide-invalid-free-check-implementation.patch
kasan-decode-stack-frame-only-with-kasan_stack_enable.patch
kasan-arm64-only-init-shadow-for-software-modes.patch
kasan-arm64-only-use-kasan_depth-for-software-modes.patch
kasan-arm64-move-initialization-message.patch
kasan-arm64-rename-kasan_init_tags-and-mark-as-__init.patch
kasan-rename-addr_has_shadow-to-addr_has_metadata.patch
kasan-rename-print_shadow_for_address-to-print_memory_metadata.patch
kasan-rename-shadow-layout-macros-to-meta.patch
kasan-separate-metadata_fetch_row-for-each-mode.patch
kasan-arm64-dont-allow-sw_tags-with-arm64_mte.patch
kasan-introduce-config_kasan_hw_tags.patch
arm64-kasan-align-allocations-for-hw_tags.patch
arm64-kasan-add-arch-layer-for-memory-tagging-helpers.patch
kasan-define-kasan_granule_size-for-hw_tags.patch
kasan-x86-s390-update-undef-config_kasan.patch
kasan-arm64-expand-config_kasan-checks.patch
kasan-arm64-implement-hw_tags-runtime.patch
kasan-arm64-print-report-from-tag-fault-handler.patch
kasan-mm-reset-tags-when-accessing-metadata.patch
kasan-arm64-enable-config_kasan_hw_tags.patch
kasan-add-documentation-for-hardware-tag-based-mode.patch
kasan-simplify-quarantine_put-call-site.patch
kasan-rename-get_alloc-free_info.patch
kasan-introduce-set_alloc_info.patch
kasan-arm64-unpoison-stack-only-with-config_kasan_stack.patch
kasan-allow-vmap_stack-for-hw_tags-mode.patch
kasan-remove-__kasan_unpoison_stack.patch
kasan-inline-kasan_reset_tag-for-tag-based-modes.patch
kasan-inline-random_tag-for-hw_tags.patch
kasan-open-code-kasan_unpoison_slab.patch
kasan-inline-unpoison_range-and-check_invalid_free.patch
kasan-add-and-integrate-kasan-boot-parameters.patch
kasan-mm-check-kasan_enabled-in-annotations.patch
kasan-mm-rename-kasan_poison_kfree.patch
kasan-dont-round_up-too-much.patch
kasan-simplify-assign_tag-and-set_tag-calls.patch
kasan-clarify-comment-in-__kasan_kfree_large.patch
kasan-sanitize-objects-when-metadata-doesnt-fit.patch
kasan-mm-allow-cache-merging-with-no-metadata.patch
kasan-update-documentation.patch
