From: andrey.konovalov@linux.dev To: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Konovalov <andreyknvl@gmail.com>, Marco Elver <elver@google.com>, Alexander Potapenko <glider@google.com>, Dmitry Vyukov <dvyukov@google.com>, Andrey Ryabinin <ryabinin.a.a@gmail.com>, kasan-dev@googlegroups.com, linux-mm@kvack.org, Vincenzo Frascino <vincenzo.frascino@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, linux-arm-kernel@lists.infradead.org, Peter Collingbourne <pcc@google.com>, Evgenii Stepanov <eugenis@google.com>, linux-kernel@vger.kernel.org, Andrey Konovalov <andreyknvl@google.com> Subject: [PATCH mm v5 34/39] kasan: clean up feature flags for HW_TAGS mode Date: Thu, 30 Dec 2021 20:14:59 +0100 [thread overview] Message-ID: <9fefb5cb7639153e50446746fdd3427635bdcda7.1640891329.git.andreyknvl@google.com> (raw) In-Reply-To: <cover.1640891329.git.andreyknvl@google.com> From: Andrey Konovalov <andreyknvl@google.com> - Untie kasan_init_hw_tags() code from the default values of kasan_arg_mode and kasan_arg_stacktrace. - Move static_branch_enable(&kasan_flag_enabled) to the end of kasan_init_hw_tags_cpu(). - Remove excessive comments in kasan_arg_mode switch. - Add new comments. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- Changes v4->v5: - Add this patch. --- mm/kasan/hw_tags.c | 38 +++++++++++++++++++++----------------- mm/kasan/kasan.h | 2 +- 2 files changed, 22 insertions(+), 18 deletions(-) diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 6509809dd5d8..6a3146d1ccc5 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -42,16 +42,22 @@ static enum kasan_arg kasan_arg __ro_after_init; static enum kasan_arg_mode kasan_arg_mode __ro_after_init; static enum kasan_arg_stacktrace kasan_arg_stacktrace __initdata; -/* Whether KASAN is enabled at all. */ +/* + * Whether KASAN is enabled at all. + * The value remains false until KASAN is initialized by kasan_init_hw_tags(). + */ DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled); EXPORT_SYMBOL(kasan_flag_enabled); -/* Whether the selected mode is synchronous/asynchronous/asymmetric.*/ +/* + * Whether the selected mode is synchronous, asynchronous, or asymmetric. + * Defaults to KASAN_MODE_SYNC. + */ enum kasan_mode kasan_mode __ro_after_init; EXPORT_SYMBOL_GPL(kasan_mode); /* Whether to collect alloc/free stack traces. */ -DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace); +DEFINE_STATIC_KEY_TRUE(kasan_flag_stacktrace); /* kasan=off/on */ static int __init early_kasan_flag(char *arg) @@ -127,7 +133,11 @@ void kasan_init_hw_tags_cpu(void) * as this function is only called for MTE-capable hardware. */ - /* If KASAN is disabled via command line, don't initialize it. */ + /* + * If KASAN is disabled via command line, don't initialize it. + * When this function is called, kasan_flag_enabled is not yet + * set by kasan_init_hw_tags(). Thus, check kasan_arg instead. + */ if (kasan_arg == KASAN_ARG_OFF) return; @@ -154,42 +164,36 @@ void __init kasan_init_hw_tags(void) if (kasan_arg == KASAN_ARG_OFF) return; - /* Enable KASAN. */ - static_branch_enable(&kasan_flag_enabled); - switch (kasan_arg_mode) { case KASAN_ARG_MODE_DEFAULT: - /* - * Default to sync mode. - */ - fallthrough; + /* Default is specified by kasan_mode definition. */ + break; case KASAN_ARG_MODE_SYNC: - /* Sync mode enabled. */ kasan_mode = KASAN_MODE_SYNC; break; case KASAN_ARG_MODE_ASYNC: - /* Async mode enabled. */ kasan_mode = KASAN_MODE_ASYNC; break; case KASAN_ARG_MODE_ASYMM: - /* Asymm mode enabled. */ kasan_mode = KASAN_MODE_ASYMM; break; } switch (kasan_arg_stacktrace) { case KASAN_ARG_STACKTRACE_DEFAULT: - /* Default to enabling stack trace collection. */ - static_branch_enable(&kasan_flag_stacktrace); + /* Default is specified by kasan_flag_stacktrace definition. */ break; case KASAN_ARG_STACKTRACE_OFF: - /* Do nothing, kasan_flag_stacktrace keeps its default value. */ + static_branch_disable(&kasan_flag_stacktrace); break; case KASAN_ARG_STACKTRACE_ON: static_branch_enable(&kasan_flag_stacktrace); break; } + /* KASAN is now initialized, enable it. */ + static_branch_enable(&kasan_flag_enabled); + pr_info("KernelAddressSanitizer initialized (hw-tags, mode=%s, stacktrace=%s)\n", kasan_mode_info(), kasan_stack_collection_enabled() ? "on" : "off"); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 020f3e57a03f..efda13a9ce6a 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -12,7 +12,7 @@ #include <linux/static_key.h> #include "../slab.h" -DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace); +DECLARE_STATIC_KEY_TRUE(kasan_flag_stacktrace); enum kasan_mode { KASAN_MODE_SYNC, -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: andrey.konovalov@linux.dev To: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Konovalov <andreyknvl@gmail.com>, Marco Elver <elver@google.com>, Alexander Potapenko <glider@google.com>, Dmitry Vyukov <dvyukov@google.com>, Andrey Ryabinin <ryabinin.a.a@gmail.com>, kasan-dev@googlegroups.com, linux-mm@kvack.org, Vincenzo Frascino <vincenzo.frascino@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, linux-arm-kernel@lists.infradead.org, Peter Collingbourne <pcc@google.com>, Evgenii Stepanov <eugenis@google.com>, linux-kernel@vger.kernel.org, Andrey Konovalov <andreyknvl@google.com> Subject: [PATCH mm v5 34/39] kasan: clean up feature flags for HW_TAGS mode Date: Thu, 30 Dec 2021 20:14:59 +0100 [thread overview] Message-ID: <9fefb5cb7639153e50446746fdd3427635bdcda7.1640891329.git.andreyknvl@google.com> (raw) In-Reply-To: <cover.1640891329.git.andreyknvl@google.com> From: Andrey Konovalov <andreyknvl@google.com> - Untie kasan_init_hw_tags() code from the default values of kasan_arg_mode and kasan_arg_stacktrace. - Move static_branch_enable(&kasan_flag_enabled) to the end of kasan_init_hw_tags_cpu(). - Remove excessive comments in kasan_arg_mode switch. - Add new comments. Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- Changes v4->v5: - Add this patch. --- mm/kasan/hw_tags.c | 38 +++++++++++++++++++++----------------- mm/kasan/kasan.h | 2 +- 2 files changed, 22 insertions(+), 18 deletions(-) diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 6509809dd5d8..6a3146d1ccc5 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -42,16 +42,22 @@ static enum kasan_arg kasan_arg __ro_after_init; static enum kasan_arg_mode kasan_arg_mode __ro_after_init; static enum kasan_arg_stacktrace kasan_arg_stacktrace __initdata; -/* Whether KASAN is enabled at all. */ +/* + * Whether KASAN is enabled at all. + * The value remains false until KASAN is initialized by kasan_init_hw_tags(). + */ DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled); EXPORT_SYMBOL(kasan_flag_enabled); -/* Whether the selected mode is synchronous/asynchronous/asymmetric.*/ +/* + * Whether the selected mode is synchronous, asynchronous, or asymmetric. + * Defaults to KASAN_MODE_SYNC. + */ enum kasan_mode kasan_mode __ro_after_init; EXPORT_SYMBOL_GPL(kasan_mode); /* Whether to collect alloc/free stack traces. */ -DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace); +DEFINE_STATIC_KEY_TRUE(kasan_flag_stacktrace); /* kasan=off/on */ static int __init early_kasan_flag(char *arg) @@ -127,7 +133,11 @@ void kasan_init_hw_tags_cpu(void) * as this function is only called for MTE-capable hardware. */ - /* If KASAN is disabled via command line, don't initialize it. */ + /* + * If KASAN is disabled via command line, don't initialize it. + * When this function is called, kasan_flag_enabled is not yet + * set by kasan_init_hw_tags(). Thus, check kasan_arg instead. + */ if (kasan_arg == KASAN_ARG_OFF) return; @@ -154,42 +164,36 @@ void __init kasan_init_hw_tags(void) if (kasan_arg == KASAN_ARG_OFF) return; - /* Enable KASAN. */ - static_branch_enable(&kasan_flag_enabled); - switch (kasan_arg_mode) { case KASAN_ARG_MODE_DEFAULT: - /* - * Default to sync mode. - */ - fallthrough; + /* Default is specified by kasan_mode definition. */ + break; case KASAN_ARG_MODE_SYNC: - /* Sync mode enabled. */ kasan_mode = KASAN_MODE_SYNC; break; case KASAN_ARG_MODE_ASYNC: - /* Async mode enabled. */ kasan_mode = KASAN_MODE_ASYNC; break; case KASAN_ARG_MODE_ASYMM: - /* Asymm mode enabled. */ kasan_mode = KASAN_MODE_ASYMM; break; } switch (kasan_arg_stacktrace) { case KASAN_ARG_STACKTRACE_DEFAULT: - /* Default to enabling stack trace collection. */ - static_branch_enable(&kasan_flag_stacktrace); + /* Default is specified by kasan_flag_stacktrace definition. */ break; case KASAN_ARG_STACKTRACE_OFF: - /* Do nothing, kasan_flag_stacktrace keeps its default value. */ + static_branch_disable(&kasan_flag_stacktrace); break; case KASAN_ARG_STACKTRACE_ON: static_branch_enable(&kasan_flag_stacktrace); break; } + /* KASAN is now initialized, enable it. */ + static_branch_enable(&kasan_flag_enabled); + pr_info("KernelAddressSanitizer initialized (hw-tags, mode=%s, stacktrace=%s)\n", kasan_mode_info(), kasan_stack_collection_enabled() ? "on" : "off"); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 020f3e57a03f..efda13a9ce6a 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -12,7 +12,7 @@ #include <linux/static_key.h> #include "../slab.h" -DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace); +DECLARE_STATIC_KEY_TRUE(kasan_flag_stacktrace); enum kasan_mode { KASAN_MODE_SYNC, -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-12-30 19:16 UTC|newest] Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-12-30 19:12 [PATCH mm v5 00/39] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 01/39] kasan, page_alloc: deduplicate should_skip_kasan_poison andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 02/39] kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 03/39] kasan, page_alloc: merge kasan_free_pages into free_pages_prepare andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 04/39] kasan, page_alloc: simplify kasan_poison_pages call site andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 05/39] kasan, page_alloc: init memory of skipped pages on free andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 06/39] kasan: drop skip_kasan_poison variable in free_pages_prepare andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 07/39] mm: clarify __GFP_ZEROTAGS comment andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 08/39] kasan: only apply __GFP_ZEROTAGS when memory is zeroed andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 09/39] kasan, page_alloc: refactor init checks in post_alloc_hook andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 10/39] kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 11/39] kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 12/39] kasan, page_alloc: move SetPageSkipKASanPoison " andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 13/39] kasan, page_alloc: move kernel_init_free_pages " andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 14/39] kasan, page_alloc: rework kasan_unpoison_pages call site andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 15/39] kasan: clean up metadata byte definitions andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 16/39] kasan: define KASAN_VMALLOC_INVALID for SW_TAGS andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 17/39] kasan, x86, arm64, s390: rename functions for modules shadow andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:12 ` [PATCH mm v5 18/39] kasan, vmalloc: drop outdated VM_KASAN comment andrey.konovalov 2021-12-30 19:12 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 19/39] kasan: reorder vmalloc hooks andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 20/39] kasan: add wrappers for " andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 21/39] kasan, vmalloc: reset tags in vmalloc functions andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 22/39] kasan, fork: reset pointer tags of vmapped stacks andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 23/39] kasan, arm64: " andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 24/39] kasan, vmalloc: add vmalloc tagging for SW_TAGS andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 25/39] kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 26/39] kasan, vmalloc: unpoison VM_ALLOC pages after mapping andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 27/39] kasan, mm: only define ___GFP_SKIP_KASAN_POISON with HW_TAGS andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 28/39] kasan, page_alloc: allow skipping unpoisoning for HW_TAGS andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 29/39] kasan, page_alloc: allow skipping memory init " andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2022-01-03 2:32 ` Kuan-Ying Lee 2022-01-03 2:32 ` Kuan-Ying Lee 2022-01-04 11:28 ` Andrey Konovalov 2022-01-04 11:28 ` Andrey Konovalov 2021-12-30 19:14 ` [PATCH mm v5 30/39] kasan, vmalloc: add vmalloc tagging " andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 31/39] kasan, vmalloc: only tag normal vmalloc allocations andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2022-01-01 0:25 ` kernel test robot 2021-12-30 19:14 ` [PATCH mm v5 32/39] kasan, arm64: don't tag executable " andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` [PATCH mm v5 33/39] kasan: mark kasan_arg_stacktrace as __initdata andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov 2021-12-30 19:14 ` andrey.konovalov [this message] 2021-12-30 19:14 ` [PATCH mm v5 34/39] kasan: clean up feature flags for HW_TAGS mode andrey.konovalov 2021-12-30 19:15 ` [PATCH mm v5 35/39] kasan: add kasan.vmalloc command line flag andrey.konovalov 2021-12-30 19:15 ` andrey.konovalov 2021-12-30 19:17 ` [PATCH mm v5 36/39] kasan: allow enabling KASAN_VMALLOC and SW/HW_TAGS andrey.konovalov 2021-12-30 19:17 ` andrey.konovalov 2021-12-30 19:17 ` [PATCH mm v5 37/39] arm64: select KASAN_VMALLOC for SW/HW_TAGS modes andrey.konovalov 2021-12-30 19:17 ` andrey.konovalov 2021-12-30 19:17 ` [PATCH mm v5 38/39] kasan: documentation updates andrey.konovalov 2021-12-30 19:17 ` andrey.konovalov 2021-12-30 19:17 ` [PATCH mm v5 39/39] kasan: improve vmalloc tests andrey.konovalov 2021-12-30 19:17 ` andrey.konovalov 2021-12-30 19:19 ` [PATCH mm v5 00/39] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS Andrey Konovalov 2021-12-30 19:19 ` Andrey Konovalov 2021-12-31 2:30 ` Andrew Morton 2021-12-31 2:30 ` Andrew Morton 2022-01-02 2:26 ` Andrey Konovalov 2022-01-02 2:26 ` Andrey Konovalov
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