From: Vincenzo Frascino <vincenzo.frascino@arm.com> To: Andrey Konovalov <andreyknvl@google.com> Cc: Linux ARM <linux-arm-kernel@lists.infradead.org>, LKML <linux-kernel@vger.kernel.org>, kasan-dev <kasan-dev@googlegroups.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Dmitry Vyukov <dvyukov@google.com>, Andrey Ryabinin <aryabinin@virtuozzo.com>, Alexander Potapenko <glider@google.com>, Marco Elver <elver@google.com>, Evgenii Stepanov <eugenis@google.com>, Branislav Rankov <Branislav.Rankov@arm.com> Subject: Re: [PATCH v5 2/6] kasan: Add KASAN mode kernel parameter Date: Fri, 22 Jan 2021 11:25:49 +0000 [thread overview] Message-ID: <770c1426-3e62-e320-9928-37f6ac580c79@arm.com> (raw) In-Reply-To: <CAAeHK+z3QrZr3OWcvetyChk9GMPuBZVTBjWoqQB45ZSFBOJHwQ@mail.gmail.com> On 1/21/21 5:34 PM, Andrey Konovalov wrote: >> +- ``kasan.mode=sync`` or ``=async`` controls whether KASAN is configured in >> + synchronous or asynchronous mode of execution (default: ``sync``). >> + ``synchronous mode``: an exception is triggered if a tag check fault occurs. > Synchronous mode: a bad access is detected immediately when a tag > check fault occurs. > > (No need for `` here, "synchronous mode" is not an inline snippet.) > Ok will do in v5. >> + ``asynchronous mode``: if a tag check fault occurs, the information is stored >> + asynchronously in hardware (e.g. in the TFSR_EL1 register for arm64). The kernel >> + checks the hardware location and reports an error if the fault is detected. > Asynchronous mode: a bad access detection is delayed. When a tag check > fault occurs, the information is stored in hardware (in the TFSR_EL1 > register for arm64). The kernel periodically checks the hardware and > only reports tag faults during these checks. > Will do in v5. >> + >> - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack >> traces collection (default: ``on`` for ``CONFIG_DEBUG_KERNEL=y``, otherwise >> ``off``). >> diff --git a/lib/test_kasan.c b/lib/test_kasan.c >> index d16ec9e66806..7285dcf9fcc1 100644 >> --- a/lib/test_kasan.c >> +++ b/lib/test_kasan.c >> @@ -97,7 +97,7 @@ static void kasan_test_exit(struct kunit *test) >> READ_ONCE(fail_data.report_found)); \ >> if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) { \ >> if (READ_ONCE(fail_data.report_found)) \ >> - hw_enable_tagging(); \ >> + hw_enable_tagging_sync(); \ >> migrate_enable(); \ >> } \ >> } while (0) >> diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c >> index e529428e7a11..224a2187839c 100644 >> --- a/mm/kasan/hw_tags.c >> +++ b/mm/kasan/hw_tags.c >> @@ -25,6 +25,11 @@ enum kasan_arg { >> KASAN_ARG_ON, >> }; >> >> +enum kasan_arg_mode { >> + KASAN_ARG_MODE_SYNC, >> + KASAN_ARG_MODE_ASYNC, > For other modes I explicitly added a _DEFAULT option first. It makes > sense to do this here as well for consistency. > Will do in v5. >> +}; >> + >> enum kasan_arg_stacktrace { >> KASAN_ARG_STACKTRACE_DEFAULT, >> KASAN_ARG_STACKTRACE_OFF, >> @@ -38,6 +43,7 @@ enum kasan_arg_fault { >> }; >> >> 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 __ro_after_init; >> static enum kasan_arg_fault kasan_arg_fault __ro_after_init; >> >> @@ -68,6 +74,21 @@ static int __init early_kasan_flag(char *arg) >> } >> early_param("kasan", early_kasan_flag); >> >> +/* kasan.mode=sync/async */ >> +static int __init early_kasan_mode(char *arg) >> +{ >> + /* If arg is not set the default mode is sync */ >> + if ((!arg) || !strcmp(arg, "sync")) >> + kasan_arg_mode = KASAN_ARG_MODE_SYNC; >> + else if (!strcmp(arg, "async")) >> + kasan_arg_mode = KASAN_ARG_MODE_ASYNC; >> + else >> + return -EINVAL; >> + >> + return 0; >> +} >> +early_param("kasan.mode", early_kasan_mode); >> + >> /* kasan.stacktrace=off/on */ >> static int __init early_kasan_flag_stacktrace(char *arg) >> { >> @@ -115,7 +136,11 @@ void kasan_init_hw_tags_cpu(void) >> return; >> >> hw_init_tags(KASAN_TAG_MAX); >> - hw_enable_tagging(); >> + > Let's add a comment: > > /* Enable async mode only when explicitly requested through the command line. */ > Will do in v5. -- Regards, Vincenzo
WARNING: multiple messages have this Message-ID (diff)
From: Vincenzo Frascino <vincenzo.frascino@arm.com> To: Andrey Konovalov <andreyknvl@google.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com>, Marco Elver <elver@google.com>, Catalin Marinas <catalin.marinas@arm.com>, Evgenii Stepanov <eugenis@google.com>, LKML <linux-kernel@vger.kernel.org>, kasan-dev <kasan-dev@googlegroups.com>, Alexander Potapenko <glider@google.com>, Linux ARM <linux-arm-kernel@lists.infradead.org>, Andrey Ryabinin <aryabinin@virtuozzo.com>, Will Deacon <will@kernel.org>, Dmitry Vyukov <dvyukov@google.com> Subject: Re: [PATCH v5 2/6] kasan: Add KASAN mode kernel parameter Date: Fri, 22 Jan 2021 11:25:49 +0000 [thread overview] Message-ID: <770c1426-3e62-e320-9928-37f6ac580c79@arm.com> (raw) In-Reply-To: <CAAeHK+z3QrZr3OWcvetyChk9GMPuBZVTBjWoqQB45ZSFBOJHwQ@mail.gmail.com> On 1/21/21 5:34 PM, Andrey Konovalov wrote: >> +- ``kasan.mode=sync`` or ``=async`` controls whether KASAN is configured in >> + synchronous or asynchronous mode of execution (default: ``sync``). >> + ``synchronous mode``: an exception is triggered if a tag check fault occurs. > Synchronous mode: a bad access is detected immediately when a tag > check fault occurs. > > (No need for `` here, "synchronous mode" is not an inline snippet.) > Ok will do in v5. >> + ``asynchronous mode``: if a tag check fault occurs, the information is stored >> + asynchronously in hardware (e.g. in the TFSR_EL1 register for arm64). The kernel >> + checks the hardware location and reports an error if the fault is detected. > Asynchronous mode: a bad access detection is delayed. When a tag check > fault occurs, the information is stored in hardware (in the TFSR_EL1 > register for arm64). The kernel periodically checks the hardware and > only reports tag faults during these checks. > Will do in v5. >> + >> - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack >> traces collection (default: ``on`` for ``CONFIG_DEBUG_KERNEL=y``, otherwise >> ``off``). >> diff --git a/lib/test_kasan.c b/lib/test_kasan.c >> index d16ec9e66806..7285dcf9fcc1 100644 >> --- a/lib/test_kasan.c >> +++ b/lib/test_kasan.c >> @@ -97,7 +97,7 @@ static void kasan_test_exit(struct kunit *test) >> READ_ONCE(fail_data.report_found)); \ >> if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) { \ >> if (READ_ONCE(fail_data.report_found)) \ >> - hw_enable_tagging(); \ >> + hw_enable_tagging_sync(); \ >> migrate_enable(); \ >> } \ >> } while (0) >> diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c >> index e529428e7a11..224a2187839c 100644 >> --- a/mm/kasan/hw_tags.c >> +++ b/mm/kasan/hw_tags.c >> @@ -25,6 +25,11 @@ enum kasan_arg { >> KASAN_ARG_ON, >> }; >> >> +enum kasan_arg_mode { >> + KASAN_ARG_MODE_SYNC, >> + KASAN_ARG_MODE_ASYNC, > For other modes I explicitly added a _DEFAULT option first. It makes > sense to do this here as well for consistency. > Will do in v5. >> +}; >> + >> enum kasan_arg_stacktrace { >> KASAN_ARG_STACKTRACE_DEFAULT, >> KASAN_ARG_STACKTRACE_OFF, >> @@ -38,6 +43,7 @@ enum kasan_arg_fault { >> }; >> >> 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 __ro_after_init; >> static enum kasan_arg_fault kasan_arg_fault __ro_after_init; >> >> @@ -68,6 +74,21 @@ static int __init early_kasan_flag(char *arg) >> } >> early_param("kasan", early_kasan_flag); >> >> +/* kasan.mode=sync/async */ >> +static int __init early_kasan_mode(char *arg) >> +{ >> + /* If arg is not set the default mode is sync */ >> + if ((!arg) || !strcmp(arg, "sync")) >> + kasan_arg_mode = KASAN_ARG_MODE_SYNC; >> + else if (!strcmp(arg, "async")) >> + kasan_arg_mode = KASAN_ARG_MODE_ASYNC; >> + else >> + return -EINVAL; >> + >> + return 0; >> +} >> +early_param("kasan.mode", early_kasan_mode); >> + >> /* kasan.stacktrace=off/on */ >> static int __init early_kasan_flag_stacktrace(char *arg) >> { >> @@ -115,7 +136,11 @@ void kasan_init_hw_tags_cpu(void) >> return; >> >> hw_init_tags(KASAN_TAG_MAX); >> - hw_enable_tagging(); >> + > Let's add a comment: > > /* Enable async mode only when explicitly requested through the command line. */ > Will do in v5. -- Regards, Vincenzo _______________________________________________ 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:[~2021-01-22 11:28 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-21 16:39 [PATCH v5 0/6] arm64: ARMv8.5-A: MTE: Add async mode support Vincenzo Frascino 2021-01-21 16:39 ` Vincenzo Frascino 2021-01-21 16:39 ` [PATCH v5 1/6] arm64: mte: Add asynchronous " Vincenzo Frascino 2021-01-21 16:39 ` Vincenzo Frascino 2021-01-21 16:39 ` [PATCH v5 2/6] kasan: Add KASAN mode kernel parameter Vincenzo Frascino 2021-01-21 16:39 ` Vincenzo Frascino 2021-01-21 17:34 ` Andrey Konovalov 2021-01-21 17:34 ` Andrey Konovalov 2021-01-22 11:25 ` Vincenzo Frascino [this message] 2021-01-22 11:25 ` Vincenzo Frascino 2021-01-21 16:39 ` [PATCH v5 3/6] kasan: Add report for async mode Vincenzo Frascino 2021-01-21 16:39 ` Vincenzo Frascino 2021-01-21 17:36 ` Andrey Konovalov 2021-01-21 17:36 ` Andrey Konovalov 2021-01-22 2:45 ` kernel test robot 2021-01-22 2:45 ` kernel test robot 2021-01-22 2:45 ` kernel test robot 2021-01-22 2:46 ` kernel test robot 2021-01-22 2:46 ` kernel test robot 2021-01-22 2:46 ` kernel test robot 2021-01-22 13:19 ` Catalin Marinas 2021-01-22 13:19 ` Catalin Marinas 2021-01-22 13:27 ` Vincenzo Frascino 2021-01-22 13:27 ` Vincenzo Frascino 2021-01-22 13:38 ` Vincenzo Frascino 2021-01-22 13:38 ` Vincenzo Frascino 2021-01-21 16:39 ` [PATCH v5 4/6] arm64: mte: Enable async tag check fault Vincenzo Frascino 2021-01-21 16:39 ` Vincenzo Frascino 2021-01-21 17:38 ` Andrey Konovalov 2021-01-21 17:38 ` Andrey Konovalov 2021-01-22 11:24 ` Vincenzo Frascino 2021-01-22 11:24 ` Vincenzo Frascino 2021-01-22 11:58 ` Catalin Marinas 2021-01-22 11:58 ` Catalin Marinas 2021-01-21 16:39 ` [PATCH v5 5/6] arm64: mte: Expose execution mode Vincenzo Frascino 2021-01-21 16:39 ` Vincenzo Frascino 2021-01-21 17:41 ` Andrey Konovalov 2021-01-21 17:41 ` Andrey Konovalov 2021-01-21 16:39 ` [PATCH v5 6/6] kasan: Forbid kunit tests when async mode is enabled Vincenzo Frascino 2021-01-21 16:39 ` Vincenzo Frascino 2021-01-21 17:40 ` Andrey Konovalov 2021-01-21 17:40 ` Andrey Konovalov 2021-01-22 11:26 ` Vincenzo Frascino 2021-01-22 11:26 ` Vincenzo Frascino 2021-01-22 12:00 ` Catalin Marinas 2021-01-22 12:00 ` Catalin Marinas 2021-01-22 4:04 ` kernel test robot 2021-01-22 4:04 ` kernel test robot 2021-01-22 4:04 ` kernel test robot
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