From: Alexander Potapenko <glider@google.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Marco Elver <elver@google.com>,
Evgenii Stepanov <eugenis@google.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
kasan-dev <kasan-dev@googlegroups.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Memory Management List <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v9 23/44] kasan: separate metadata_fetch_row for each mode
Date: Wed, 11 Nov 2020 16:22:05 +0100 [thread overview]
Message-ID: <CAG_fn=W-H8nHc_DmBOsnJOUygDJ+wg78K-QSY_wHTSHg-b8vFQ@mail.gmail.com> (raw)
In-Reply-To: <560e04850b62da4fd69caa92b4ce3bebf275ea59.1605046192.git.andreyknvl@google.com>
On Tue, Nov 10, 2020 at 11:12 PM Andrey Konovalov <andreyknvl@google.com> wrote:
>
> 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.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Reviewed-by: Marco Elver <elver@google.com>
> ---
> Change-Id: I5b0ed1d079ea776e620beca6a529a861e7dced95
> ---
> 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(-)
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index f9366dfd94c9..b5b00bff358f 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -57,6 +57,13 @@
> #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;
> @@ -168,6 +175,7 @@ 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);
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 8c588588c88f..8afc1a6ab202 100644
> --- a/mm/kasan/report.c
> +++ b/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(void *addr, u8 tag)
> 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;
> }
> }
>
> diff --git a/mm/kasan/report_generic.c b/mm/kasan/report_generic.c
> index 16ed550850e9..8a9c889872da 100644
> --- a/mm/kasan/report_generic.c
> +++ b/mm/kasan/report_generic.c
> @@ -123,6 +123,11 @@ const char *get_bug_type(struct kasan_access_info *info)
> 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);
I think it is important to use __memcpy() instead of memcpy() in KASAN
runtime to avoid calling instrumented code.
> +}
> +
> #if CONFIG_KASAN_STACK
> static bool __must_check tokenize_frame_descr(const char **frame_descr,
> char *token, size_t max_tok_len,
> diff --git a/mm/kasan/report_sw_tags.c b/mm/kasan/report_sw_tags.c
> index c87d5a343b4e..add2dfe6169c 100644
> --- a/mm/kasan/report_sw_tags.c
> +++ b/mm/kasan/report_sw_tags.c
> @@ -80,6 +80,11 @@ void *find_first_bad_addr(void *addr, size_t size)
> return p;
> }
>
> +void metadata_fetch_row(char *buffer, void *row)
> +{
> + memcpy(buffer, kasan_mem_to_shadow(row), META_BYTES_PER_ROW);
Ditto.
> +}
> +
> void print_tags(u8 addr_tag, const void *addr)
> {
> u8 *shadow = (u8 *)kasan_mem_to_shadow(addr);
> --
> 2.29.2.222.g5d2a92d10f8-goog
>
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg
next prev parent reply other threads:[~2020-11-11 15:22 UTC|newest]
Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 22:09 [PATCH v9 00/44] kasan: add hardware tag-based mode for arm64 Andrey Konovalov
2020-11-10 22:09 ` [PATCH v9 01/44] kasan: drop unnecessary GPL text from comment headers Andrey Konovalov
2020-11-11 13:16 ` Alexander Potapenko
2020-11-10 22:09 ` [PATCH v9 02/44] kasan: KASAN_VMALLOC depends on KASAN_GENERIC Andrey Konovalov
2020-11-11 13:19 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 03/44] kasan: group vmalloc code Andrey Konovalov
2020-11-11 13:21 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 04/44] s390/kasan: include asm/page.h from asm/kasan.h Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 05/44] kasan: shadow declarations only for software modes Andrey Konovalov
2020-11-11 13:25 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 06/44] kasan: rename (un)poison_shadow to (un)poison_memory Andrey Konovalov
2020-11-11 13:26 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 07/44] kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_* Andrey Konovalov
2020-11-11 13:45 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 08/44] kasan: only build init.c for software modes Andrey Konovalov
2020-11-11 13:46 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 09/44] kasan: split out shadow.c from common.c Andrey Konovalov
2020-11-11 14:07 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 10/44] kasan: define KASAN_GRANULE_PAGE Andrey Konovalov
2020-11-11 14:13 ` Alexander Potapenko
2020-11-11 18:47 ` Andrey Konovalov
2020-11-11 19:04 ` Marco Elver
2020-11-12 0:05 ` Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 11/44] kasan: rename report and tags files Andrey Konovalov
2020-11-11 14:15 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 12/44] kasan: don't duplicate config dependencies Andrey Konovalov
2020-11-11 14:20 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 13/44] kasan: hide invalid free check implementation Andrey Konovalov
2020-11-11 14:23 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 14/44] kasan: decode stack frame only with KASAN_STACK_ENABLE Andrey Konovalov
2020-11-11 14:25 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 15/44] kasan, arm64: only init shadow for software modes Andrey Konovalov
2020-11-11 14:30 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 16/44] kasan, arm64: only use kasan_depth " Andrey Konovalov
2020-11-11 14:59 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 17/44] kasan, arm64: move initialization message Andrey Konovalov
2020-11-11 15:03 ` Alexander Potapenko
2020-11-11 18:50 ` Andrey Konovalov
2020-11-12 15:09 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 18/44] kasan, arm64: rename kasan_init_tags and mark as __init Andrey Konovalov
2020-11-11 15:05 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 19/44] kasan: rename addr_has_shadow to addr_has_metadata Andrey Konovalov
2020-11-11 15:06 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 20/44] kasan: rename print_shadow_for_address to print_memory_metadata Andrey Konovalov
2020-11-11 15:07 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 21/44] kasan: kasan_non_canonical_hook only for software modes Andrey Konovalov
2020-11-11 15:08 ` Alexander Potapenko
2020-11-11 18:52 ` Andrey Konovalov
2020-11-12 15:16 ` Alexander Potapenko
2020-11-12 19:27 ` Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 22/44] kasan: rename SHADOW layout macros to META Andrey Konovalov
2020-11-11 15:18 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 23/44] kasan: separate metadata_fetch_row for each mode Andrey Konovalov
2020-11-11 15:22 ` Alexander Potapenko [this message]
2020-11-11 16:19 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 24/44] kasan, arm64: don't allow SW_TAGS with ARM64_MTE Andrey Konovalov
2020-11-11 15:52 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 25/44] kasan: introduce CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-11-11 15:58 ` Alexander Potapenko
2020-11-11 18:53 ` Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 26/44] arm64: Enable armv8.5-a asm-arch option Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 27/44] arm64: mte: Add in-kernel MTE helpers Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 28/44] arm64: mte: Reset the page tag in page->flags Andrey Konovalov
2020-11-12 9:31 ` Catalin Marinas
2020-11-12 9:39 ` Vincenzo Frascino
2020-11-10 22:10 ` [PATCH v9 29/44] arm64: mte: Add in-kernel tag fault handler Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 30/44] arm64: kasan: Allow enabling in-kernel MTE Andrey Konovalov
2020-11-12 9:43 ` Catalin Marinas
2020-11-12 16:46 ` Vincenzo Frascino
2020-11-13 11:17 ` Vincenzo Frascino
2020-11-13 12:00 ` Catalin Marinas
2020-11-13 12:04 ` Vincenzo Frascino
2020-11-10 22:10 ` [PATCH v9 31/44] arm64: mte: Convert gcr_user into an exclude mask Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 32/44] arm64: mte: Switch GCR_EL1 in kernel entry and exit Andrey Konovalov
2020-11-12 9:39 ` Catalin Marinas
2020-11-12 9:45 ` Vincenzo Frascino
2020-11-12 9:45 ` Catalin Marinas
2020-11-12 9:55 ` Vincenzo Frascino
2020-11-10 22:10 ` [PATCH v9 33/44] kasan, mm: untag page address in free_reserved_area Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 34/44] arm64: kasan: Align allocations for HW_TAGS Andrey Konovalov
2020-11-11 16:10 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 35/44] arm64: kasan: Add arch layer for memory tagging helpers Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 36/44] kasan: define KASAN_GRANULE_SIZE for HW_TAGS Andrey Konovalov
2020-11-11 16:13 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 37/44] kasan, x86, s390: update undef CONFIG_KASAN Andrey Konovalov
2020-11-11 16:15 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 38/44] kasan, arm64: expand CONFIG_KASAN checks Andrey Konovalov
2020-11-11 16:22 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 39/44] kasan, arm64: implement HW_TAGS runtime Andrey Konovalov
2020-11-12 17:37 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 40/44] kasan, arm64: print report from tag fault handler Andrey Konovalov
2020-11-11 16:43 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 41/44] kasan, mm: reset tags when accessing metadata Andrey Konovalov
2020-11-12 16:10 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 42/44] kasan, arm64: enable CONFIG_KASAN_HW_TAGS Andrey Konovalov
2020-11-11 16:49 ` Alexander Potapenko
2020-11-10 22:10 ` [PATCH v9 43/44] kasan: add documentation for hardware tag-based mode Andrey Konovalov
2020-11-11 16:57 ` Alexander Potapenko
2020-11-11 18:54 ` Andrey Konovalov
2020-11-10 22:10 ` [PATCH v9 44/44] kselftest/arm64: Check GCR_EL1 after context switch Andrey Konovalov
2020-11-12 9:46 ` Catalin Marinas
2020-11-12 15:59 ` Alexander Potapenko
2020-11-12 16:09 ` Marco Elver
2020-11-12 16:41 ` Alexander Potapenko
2020-11-13 11:47 ` Vincenzo Frascino
2020-11-10 22:54 ` [PATCH v9 00/44] kasan: add hardware tag-based mode for arm64 Andrew Morton
2020-11-11 14:35 ` Andrey Konovalov
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