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* [PATCH v2] mm/kasan: move kasan.fault to mm/kasan/report.c
@ 2021-07-13  1:05 ` Woody Lin
  0 siblings, 0 replies; 6+ messages in thread
From: Woody Lin @ 2021-07-13  1:05 UTC (permalink / raw)
  To: Marco Elver, Andrey Ryabinin, Dmitry Vyukov
  Cc: Alexander Potapenko, Andrey Konovalov, Jonathan Corbet,
	Andrew Morton, kasan-dev, linux-doc, linux-kernel, linux-mm,
	Woody Lin

Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it
can support all KASAN modes - generic, and both tag-based.

Signed-off-by: Woody Lin <woodylin@google.com>
---
 Documentation/dev-tools/kasan.rst | 13 ++++++----
 mm/kasan/hw_tags.c                | 43 -------------------------------
 mm/kasan/kasan.h                  |  1 -
 mm/kasan/report.c                 | 29 ++++++++++++++++++---
 4 files changed, 34 insertions(+), 52 deletions(-)

diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 83ec4a556c19..21dc03bc10a4 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -181,9 +181,16 @@ By default, KASAN prints a bug report only for the first invalid memory access.
 With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
 effectively disables ``panic_on_warn`` for KASAN reports.
 
+Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot
+parameter can be used to control panic and reporting behaviour:
+
+- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
+  report or also panic the kernel (default: ``report``). The panic happens even
+  if ``kasan_multi_shot`` is enabled.
+
 Hardware tag-based KASAN mode (see the section about various modes below) is
 intended for use in production as a security mitigation. Therefore, it supports
-boot parameters that allow disabling KASAN or controlling its features.
+additional boot parameters that allow disabling KASAN or controlling features:
 
 - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
 
@@ -199,10 +206,6 @@ boot parameters that allow disabling KASAN or controlling its features.
 - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
   traces collection (default: ``on``).
 
-- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
-  report or also panic the kernel (default: ``report``). The panic happens even
-  if ``kasan_multi_shot`` is enabled.
-
 Implementation details
 ----------------------
 
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 4ea8c368b5b8..51903639e55f 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -37,16 +37,9 @@ enum kasan_arg_stacktrace {
 	KASAN_ARG_STACKTRACE_ON,
 };
 
-enum kasan_arg_fault {
-	KASAN_ARG_FAULT_DEFAULT,
-	KASAN_ARG_FAULT_REPORT,
-	KASAN_ARG_FAULT_PANIC,
-};
-
 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;
 
 /* Whether KASAN is enabled at all. */
 DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
@@ -59,9 +52,6 @@ EXPORT_SYMBOL_GPL(kasan_flag_async);
 /* Whether to collect alloc/free stack traces. */
 DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
 
-/* Whether to panic or print a report and disable tag checking on fault. */
-bool kasan_flag_panic __ro_after_init;
-
 /* kasan=off/on */
 static int __init early_kasan_flag(char *arg)
 {
@@ -113,23 +103,6 @@ static int __init early_kasan_flag_stacktrace(char *arg)
 }
 early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
 
-/* kasan.fault=report/panic */
-static int __init early_kasan_fault(char *arg)
-{
-	if (!arg)
-		return -EINVAL;
-
-	if (!strcmp(arg, "report"))
-		kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
-	else if (!strcmp(arg, "panic"))
-		kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
-	else
-		return -EINVAL;
-
-	return 0;
-}
-early_param("kasan.fault", early_kasan_fault);
-
 /* kasan_init_hw_tags_cpu() is called for each CPU. */
 void kasan_init_hw_tags_cpu(void)
 {
@@ -197,22 +170,6 @@ void __init kasan_init_hw_tags(void)
 		break;
 	}
 
-	switch (kasan_arg_fault) {
-	case KASAN_ARG_FAULT_DEFAULT:
-		/*
-		 * Default to no panic on report.
-		 * Do nothing, kasan_flag_panic keeps its default value.
-		 */
-		break;
-	case KASAN_ARG_FAULT_REPORT:
-		/* Do nothing, kasan_flag_panic keeps its default value. */
-		break;
-	case KASAN_ARG_FAULT_PANIC:
-		/* Enable panic on report. */
-		kasan_flag_panic = true;
-		break;
-	}
-
 	pr_info("KernelAddressSanitizer initialized\n");
 }
 
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 98e3059bfea4..9d57383ce1fa 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -36,7 +36,6 @@ static inline bool kasan_async_mode_enabled(void)
 
 #endif
 
-extern bool kasan_flag_panic __ro_after_init;
 extern bool kasan_flag_async __ro_after_init;
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 8fff1825b22c..884a950c7026 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -39,6 +39,31 @@ static unsigned long kasan_flags;
 #define KASAN_BIT_REPORTED	0
 #define KASAN_BIT_MULTI_SHOT	1
 
+enum kasan_arg_fault {
+	KASAN_ARG_FAULT_DEFAULT,
+	KASAN_ARG_FAULT_REPORT,
+	KASAN_ARG_FAULT_PANIC,
+};
+
+static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
+
+/* kasan.fault=report/panic */
+static int __init early_kasan_fault(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	if (!strcmp(arg, "report"))
+		kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
+	else if (!strcmp(arg, "panic"))
+		kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+early_param("kasan.fault", early_kasan_fault);
+
 bool kasan_save_enable_multi_shot(void)
 {
 	return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
@@ -102,10 +127,8 @@ static void end_report(unsigned long *flags, unsigned long addr)
 		panic_on_warn = 0;
 		panic("panic_on_warn set ...\n");
 	}
-#ifdef CONFIG_KASAN_HW_TAGS
-	if (kasan_flag_panic)
+	if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
 		panic("kasan.fault=panic set ...\n");
-#endif
 	kasan_enable_current();
 }
 
-- 
2.32.0.93.g670b81a890-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH v2] mm/kasan: move kasan.fault to mm/kasan/report.c
@ 2021-07-13  1:05 ` Woody Lin
  0 siblings, 0 replies; 6+ messages in thread
From: Woody Lin @ 2021-07-13  1:05 UTC (permalink / raw)
  To: Marco Elver, Andrey Ryabinin, Dmitry Vyukov
  Cc: Alexander Potapenko, Andrey Konovalov, Jonathan Corbet,
	Andrew Morton, kasan-dev, linux-doc, linux-kernel, linux-mm,
	Woody Lin

Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it
can support all KASAN modes - generic, and both tag-based.

Signed-off-by: Woody Lin <woodylin@google.com>
---
 Documentation/dev-tools/kasan.rst | 13 ++++++----
 mm/kasan/hw_tags.c                | 43 -------------------------------
 mm/kasan/kasan.h                  |  1 -
 mm/kasan/report.c                 | 29 ++++++++++++++++++---
 4 files changed, 34 insertions(+), 52 deletions(-)

diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 83ec4a556c19..21dc03bc10a4 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -181,9 +181,16 @@ By default, KASAN prints a bug report only for the first invalid memory access.
 With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
 effectively disables ``panic_on_warn`` for KASAN reports.
 
+Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot
+parameter can be used to control panic and reporting behaviour:
+
+- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
+  report or also panic the kernel (default: ``report``). The panic happens even
+  if ``kasan_multi_shot`` is enabled.
+
 Hardware tag-based KASAN mode (see the section about various modes below) is
 intended for use in production as a security mitigation. Therefore, it supports
-boot parameters that allow disabling KASAN or controlling its features.
+additional boot parameters that allow disabling KASAN or controlling features:
 
 - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
 
@@ -199,10 +206,6 @@ boot parameters that allow disabling KASAN or controlling its features.
 - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
   traces collection (default: ``on``).
 
-- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
-  report or also panic the kernel (default: ``report``). The panic happens even
-  if ``kasan_multi_shot`` is enabled.
-
 Implementation details
 ----------------------
 
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 4ea8c368b5b8..51903639e55f 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -37,16 +37,9 @@ enum kasan_arg_stacktrace {
 	KASAN_ARG_STACKTRACE_ON,
 };
 
-enum kasan_arg_fault {
-	KASAN_ARG_FAULT_DEFAULT,
-	KASAN_ARG_FAULT_REPORT,
-	KASAN_ARG_FAULT_PANIC,
-};
-
 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;
 
 /* Whether KASAN is enabled at all. */
 DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
@@ -59,9 +52,6 @@ EXPORT_SYMBOL_GPL(kasan_flag_async);
 /* Whether to collect alloc/free stack traces. */
 DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
 
-/* Whether to panic or print a report and disable tag checking on fault. */
-bool kasan_flag_panic __ro_after_init;
-
 /* kasan=off/on */
 static int __init early_kasan_flag(char *arg)
 {
@@ -113,23 +103,6 @@ static int __init early_kasan_flag_stacktrace(char *arg)
 }
 early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
 
-/* kasan.fault=report/panic */
-static int __init early_kasan_fault(char *arg)
-{
-	if (!arg)
-		return -EINVAL;
-
-	if (!strcmp(arg, "report"))
-		kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
-	else if (!strcmp(arg, "panic"))
-		kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
-	else
-		return -EINVAL;
-
-	return 0;
-}
-early_param("kasan.fault", early_kasan_fault);
-
 /* kasan_init_hw_tags_cpu() is called for each CPU. */
 void kasan_init_hw_tags_cpu(void)
 {
@@ -197,22 +170,6 @@ void __init kasan_init_hw_tags(void)
 		break;
 	}
 
-	switch (kasan_arg_fault) {
-	case KASAN_ARG_FAULT_DEFAULT:
-		/*
-		 * Default to no panic on report.
-		 * Do nothing, kasan_flag_panic keeps its default value.
-		 */
-		break;
-	case KASAN_ARG_FAULT_REPORT:
-		/* Do nothing, kasan_flag_panic keeps its default value. */
-		break;
-	case KASAN_ARG_FAULT_PANIC:
-		/* Enable panic on report. */
-		kasan_flag_panic = true;
-		break;
-	}
-
 	pr_info("KernelAddressSanitizer initialized\n");
 }
 
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 98e3059bfea4..9d57383ce1fa 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -36,7 +36,6 @@ static inline bool kasan_async_mode_enabled(void)
 
 #endif
 
-extern bool kasan_flag_panic __ro_after_init;
 extern bool kasan_flag_async __ro_after_init;
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 8fff1825b22c..884a950c7026 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -39,6 +39,31 @@ static unsigned long kasan_flags;
 #define KASAN_BIT_REPORTED	0
 #define KASAN_BIT_MULTI_SHOT	1
 
+enum kasan_arg_fault {
+	KASAN_ARG_FAULT_DEFAULT,
+	KASAN_ARG_FAULT_REPORT,
+	KASAN_ARG_FAULT_PANIC,
+};
+
+static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
+
+/* kasan.fault=report/panic */
+static int __init early_kasan_fault(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	if (!strcmp(arg, "report"))
+		kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
+	else if (!strcmp(arg, "panic"))
+		kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+early_param("kasan.fault", early_kasan_fault);
+
 bool kasan_save_enable_multi_shot(void)
 {
 	return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
@@ -102,10 +127,8 @@ static void end_report(unsigned long *flags, unsigned long addr)
 		panic_on_warn = 0;
 		panic("panic_on_warn set ...\n");
 	}
-#ifdef CONFIG_KASAN_HW_TAGS
-	if (kasan_flag_panic)
+	if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
 		panic("kasan.fault=panic set ...\n");
-#endif
 	kasan_enable_current();
 }
 
-- 
2.32.0.93.g670b81a890-goog



^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/kasan: move kasan.fault to mm/kasan/report.c
  2021-07-13  1:05 ` Woody Lin
@ 2021-07-13  7:19   ` Marco Elver
  -1 siblings, 0 replies; 6+ messages in thread
From: Marco Elver @ 2021-07-13  7:19 UTC (permalink / raw)
  To: Woody Lin
  Cc: Andrey Ryabinin, Dmitry Vyukov, Alexander Potapenko,
	Andrey Konovalov, Jonathan Corbet, Andrew Morton, kasan-dev,
	linux-doc, linux-kernel, linux-mm

On Tue, 13 Jul 2021 at 03:07, Woody Lin <woodylin@google.com> wrote:
> Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it
> can support all KASAN modes - generic, and both tag-based.
>
> Signed-off-by: Woody Lin <woodylin@google.com>

Reviewed-by: Marco Elver <elver@google.com>

Thank you.

> ---
>  Documentation/dev-tools/kasan.rst | 13 ++++++----
>  mm/kasan/hw_tags.c                | 43 -------------------------------
>  mm/kasan/kasan.h                  |  1 -
>  mm/kasan/report.c                 | 29 ++++++++++++++++++---
>  4 files changed, 34 insertions(+), 52 deletions(-)
>
> diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
> index 83ec4a556c19..21dc03bc10a4 100644
> --- a/Documentation/dev-tools/kasan.rst
> +++ b/Documentation/dev-tools/kasan.rst
> @@ -181,9 +181,16 @@ By default, KASAN prints a bug report only for the first invalid memory access.
>  With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
>  effectively disables ``panic_on_warn`` for KASAN reports.
>
> +Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot
> +parameter can be used to control panic and reporting behaviour:
> +
> +- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> +  report or also panic the kernel (default: ``report``). The panic happens even
> +  if ``kasan_multi_shot`` is enabled.
> +
>  Hardware tag-based KASAN mode (see the section about various modes below) is
>  intended for use in production as a security mitigation. Therefore, it supports
> -boot parameters that allow disabling KASAN or controlling its features.
> +additional boot parameters that allow disabling KASAN or controlling features:
>
>  - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
>
> @@ -199,10 +206,6 @@ boot parameters that allow disabling KASAN or controlling its features.
>  - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
>    traces collection (default: ``on``).
>
> -- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> -  report or also panic the kernel (default: ``report``). The panic happens even
> -  if ``kasan_multi_shot`` is enabled.
> -
>  Implementation details
>  ----------------------
>
> diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
> index 4ea8c368b5b8..51903639e55f 100644
> --- a/mm/kasan/hw_tags.c
> +++ b/mm/kasan/hw_tags.c
> @@ -37,16 +37,9 @@ enum kasan_arg_stacktrace {
>         KASAN_ARG_STACKTRACE_ON,
>  };
>
> -enum kasan_arg_fault {
> -       KASAN_ARG_FAULT_DEFAULT,
> -       KASAN_ARG_FAULT_REPORT,
> -       KASAN_ARG_FAULT_PANIC,
> -};
> -
>  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;
>
>  /* Whether KASAN is enabled at all. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
> @@ -59,9 +52,6 @@ EXPORT_SYMBOL_GPL(kasan_flag_async);
>  /* Whether to collect alloc/free stack traces. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
>
> -/* Whether to panic or print a report and disable tag checking on fault. */
> -bool kasan_flag_panic __ro_after_init;
> -
>  /* kasan=off/on */
>  static int __init early_kasan_flag(char *arg)
>  {
> @@ -113,23 +103,6 @@ static int __init early_kasan_flag_stacktrace(char *arg)
>  }
>  early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
>
> -/* kasan.fault=report/panic */
> -static int __init early_kasan_fault(char *arg)
> -{
> -       if (!arg)
> -               return -EINVAL;
> -
> -       if (!strcmp(arg, "report"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> -       else if (!strcmp(arg, "panic"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> -       else
> -               return -EINVAL;
> -
> -       return 0;
> -}
> -early_param("kasan.fault", early_kasan_fault);
> -
>  /* kasan_init_hw_tags_cpu() is called for each CPU. */
>  void kasan_init_hw_tags_cpu(void)
>  {
> @@ -197,22 +170,6 @@ void __init kasan_init_hw_tags(void)
>                 break;
>         }
>
> -       switch (kasan_arg_fault) {
> -       case KASAN_ARG_FAULT_DEFAULT:
> -               /*
> -                * Default to no panic on report.
> -                * Do nothing, kasan_flag_panic keeps its default value.
> -                */
> -               break;
> -       case KASAN_ARG_FAULT_REPORT:
> -               /* Do nothing, kasan_flag_panic keeps its default value. */
> -               break;
> -       case KASAN_ARG_FAULT_PANIC:
> -               /* Enable panic on report. */
> -               kasan_flag_panic = true;
> -               break;
> -       }
> -
>         pr_info("KernelAddressSanitizer initialized\n");
>  }
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 98e3059bfea4..9d57383ce1fa 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -36,7 +36,6 @@ static inline bool kasan_async_mode_enabled(void)
>
>  #endif
>
> -extern bool kasan_flag_panic __ro_after_init;
>  extern bool kasan_flag_async __ro_after_init;
>
>  #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 8fff1825b22c..884a950c7026 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -39,6 +39,31 @@ static unsigned long kasan_flags;
>  #define KASAN_BIT_REPORTED     0
>  #define KASAN_BIT_MULTI_SHOT   1
>
> +enum kasan_arg_fault {
> +       KASAN_ARG_FAULT_DEFAULT,
> +       KASAN_ARG_FAULT_REPORT,
> +       KASAN_ARG_FAULT_PANIC,
> +};
> +
> +static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
> +
> +/* kasan.fault=report/panic */
> +static int __init early_kasan_fault(char *arg)
> +{
> +       if (!arg)
> +               return -EINVAL;
> +
> +       if (!strcmp(arg, "report"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> +       else if (!strcmp(arg, "panic"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> +       else
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +early_param("kasan.fault", early_kasan_fault);
> +
>  bool kasan_save_enable_multi_shot(void)
>  {
>         return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
> @@ -102,10 +127,8 @@ static void end_report(unsigned long *flags, unsigned long addr)
>                 panic_on_warn = 0;
>                 panic("panic_on_warn set ...\n");
>         }
> -#ifdef CONFIG_KASAN_HW_TAGS
> -       if (kasan_flag_panic)
> +       if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
>                 panic("kasan.fault=panic set ...\n");
> -#endif
>         kasan_enable_current();
>  }
>
> --
> 2.32.0.93.g670b81a890-goog
>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/kasan: move kasan.fault to mm/kasan/report.c
@ 2021-07-13  7:19   ` Marco Elver
  0 siblings, 0 replies; 6+ messages in thread
From: Marco Elver @ 2021-07-13  7:19 UTC (permalink / raw)
  To: Woody Lin
  Cc: Andrey Ryabinin, Dmitry Vyukov, Alexander Potapenko,
	Andrey Konovalov, Jonathan Corbet, Andrew Morton, kasan-dev,
	linux-doc, linux-kernel, linux-mm

On Tue, 13 Jul 2021 at 03:07, Woody Lin <woodylin@google.com> wrote:
> Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it
> can support all KASAN modes - generic, and both tag-based.
>
> Signed-off-by: Woody Lin <woodylin@google.com>

Reviewed-by: Marco Elver <elver@google.com>

Thank you.

> ---
>  Documentation/dev-tools/kasan.rst | 13 ++++++----
>  mm/kasan/hw_tags.c                | 43 -------------------------------
>  mm/kasan/kasan.h                  |  1 -
>  mm/kasan/report.c                 | 29 ++++++++++++++++++---
>  4 files changed, 34 insertions(+), 52 deletions(-)
>
> diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
> index 83ec4a556c19..21dc03bc10a4 100644
> --- a/Documentation/dev-tools/kasan.rst
> +++ b/Documentation/dev-tools/kasan.rst
> @@ -181,9 +181,16 @@ By default, KASAN prints a bug report only for the first invalid memory access.
>  With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
>  effectively disables ``panic_on_warn`` for KASAN reports.
>
> +Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot
> +parameter can be used to control panic and reporting behaviour:
> +
> +- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> +  report or also panic the kernel (default: ``report``). The panic happens even
> +  if ``kasan_multi_shot`` is enabled.
> +
>  Hardware tag-based KASAN mode (see the section about various modes below) is
>  intended for use in production as a security mitigation. Therefore, it supports
> -boot parameters that allow disabling KASAN or controlling its features.
> +additional boot parameters that allow disabling KASAN or controlling features:
>
>  - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
>
> @@ -199,10 +206,6 @@ boot parameters that allow disabling KASAN or controlling its features.
>  - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
>    traces collection (default: ``on``).
>
> -- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> -  report or also panic the kernel (default: ``report``). The panic happens even
> -  if ``kasan_multi_shot`` is enabled.
> -
>  Implementation details
>  ----------------------
>
> diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
> index 4ea8c368b5b8..51903639e55f 100644
> --- a/mm/kasan/hw_tags.c
> +++ b/mm/kasan/hw_tags.c
> @@ -37,16 +37,9 @@ enum kasan_arg_stacktrace {
>         KASAN_ARG_STACKTRACE_ON,
>  };
>
> -enum kasan_arg_fault {
> -       KASAN_ARG_FAULT_DEFAULT,
> -       KASAN_ARG_FAULT_REPORT,
> -       KASAN_ARG_FAULT_PANIC,
> -};
> -
>  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;
>
>  /* Whether KASAN is enabled at all. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
> @@ -59,9 +52,6 @@ EXPORT_SYMBOL_GPL(kasan_flag_async);
>  /* Whether to collect alloc/free stack traces. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
>
> -/* Whether to panic or print a report and disable tag checking on fault. */
> -bool kasan_flag_panic __ro_after_init;
> -
>  /* kasan=off/on */
>  static int __init early_kasan_flag(char *arg)
>  {
> @@ -113,23 +103,6 @@ static int __init early_kasan_flag_stacktrace(char *arg)
>  }
>  early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
>
> -/* kasan.fault=report/panic */
> -static int __init early_kasan_fault(char *arg)
> -{
> -       if (!arg)
> -               return -EINVAL;
> -
> -       if (!strcmp(arg, "report"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> -       else if (!strcmp(arg, "panic"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> -       else
> -               return -EINVAL;
> -
> -       return 0;
> -}
> -early_param("kasan.fault", early_kasan_fault);
> -
>  /* kasan_init_hw_tags_cpu() is called for each CPU. */
>  void kasan_init_hw_tags_cpu(void)
>  {
> @@ -197,22 +170,6 @@ void __init kasan_init_hw_tags(void)
>                 break;
>         }
>
> -       switch (kasan_arg_fault) {
> -       case KASAN_ARG_FAULT_DEFAULT:
> -               /*
> -                * Default to no panic on report.
> -                * Do nothing, kasan_flag_panic keeps its default value.
> -                */
> -               break;
> -       case KASAN_ARG_FAULT_REPORT:
> -               /* Do nothing, kasan_flag_panic keeps its default value. */
> -               break;
> -       case KASAN_ARG_FAULT_PANIC:
> -               /* Enable panic on report. */
> -               kasan_flag_panic = true;
> -               break;
> -       }
> -
>         pr_info("KernelAddressSanitizer initialized\n");
>  }
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 98e3059bfea4..9d57383ce1fa 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -36,7 +36,6 @@ static inline bool kasan_async_mode_enabled(void)
>
>  #endif
>
> -extern bool kasan_flag_panic __ro_after_init;
>  extern bool kasan_flag_async __ro_after_init;
>
>  #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 8fff1825b22c..884a950c7026 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -39,6 +39,31 @@ static unsigned long kasan_flags;
>  #define KASAN_BIT_REPORTED     0
>  #define KASAN_BIT_MULTI_SHOT   1
>
> +enum kasan_arg_fault {
> +       KASAN_ARG_FAULT_DEFAULT,
> +       KASAN_ARG_FAULT_REPORT,
> +       KASAN_ARG_FAULT_PANIC,
> +};
> +
> +static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
> +
> +/* kasan.fault=report/panic */
> +static int __init early_kasan_fault(char *arg)
> +{
> +       if (!arg)
> +               return -EINVAL;
> +
> +       if (!strcmp(arg, "report"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> +       else if (!strcmp(arg, "panic"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> +       else
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +early_param("kasan.fault", early_kasan_fault);
> +
>  bool kasan_save_enable_multi_shot(void)
>  {
>         return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
> @@ -102,10 +127,8 @@ static void end_report(unsigned long *flags, unsigned long addr)
>                 panic_on_warn = 0;
>                 panic("panic_on_warn set ...\n");
>         }
> -#ifdef CONFIG_KASAN_HW_TAGS
> -       if (kasan_flag_panic)
> +       if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
>                 panic("kasan.fault=panic set ...\n");
> -#endif
>         kasan_enable_current();
>  }
>
> --
> 2.32.0.93.g670b81a890-goog
>


^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/kasan: move kasan.fault to mm/kasan/report.c
  2021-07-13  1:05 ` Woody Lin
@ 2021-07-13 18:40   ` Andrey Konovalov
  -1 siblings, 0 replies; 6+ messages in thread
From: Andrey Konovalov @ 2021-07-13 18:40 UTC (permalink / raw)
  To: Woody Lin
  Cc: Marco Elver, Andrey Ryabinin, Dmitry Vyukov, Alexander Potapenko,
	Jonathan Corbet, Andrew Morton, kasan-dev,
	open list:DOCUMENTATION, LKML, Linux Memory Management List

On Tue, Jul 13, 2021 at 3:07 AM Woody Lin <woodylin@google.com> wrote:
>
> Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it
> can support all KASAN modes - generic, and both tag-based.
>
> Signed-off-by: Woody Lin <woodylin@google.com>
> ---
>  Documentation/dev-tools/kasan.rst | 13 ++++++----
>  mm/kasan/hw_tags.c                | 43 -------------------------------
>  mm/kasan/kasan.h                  |  1 -
>  mm/kasan/report.c                 | 29 ++++++++++++++++++---
>  4 files changed, 34 insertions(+), 52 deletions(-)
>
> diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
> index 83ec4a556c19..21dc03bc10a4 100644
> --- a/Documentation/dev-tools/kasan.rst
> +++ b/Documentation/dev-tools/kasan.rst
> @@ -181,9 +181,16 @@ By default, KASAN prints a bug report only for the first invalid memory access.
>  With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
>  effectively disables ``panic_on_warn`` for KASAN reports.
>
> +Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot
> +parameter can be used to control panic and reporting behaviour:
> +
> +- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> +  report or also panic the kernel (default: ``report``). The panic happens even
> +  if ``kasan_multi_shot`` is enabled.
> +
>  Hardware tag-based KASAN mode (see the section about various modes below) is
>  intended for use in production as a security mitigation. Therefore, it supports
> -boot parameters that allow disabling KASAN or controlling its features.
> +additional boot parameters that allow disabling KASAN or controlling features:
>
>  - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
>
> @@ -199,10 +206,6 @@ boot parameters that allow disabling KASAN or controlling its features.
>  - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
>    traces collection (default: ``on``).
>
> -- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> -  report or also panic the kernel (default: ``report``). The panic happens even
> -  if ``kasan_multi_shot`` is enabled.
> -
>  Implementation details
>  ----------------------
>
> diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
> index 4ea8c368b5b8..51903639e55f 100644
> --- a/mm/kasan/hw_tags.c
> +++ b/mm/kasan/hw_tags.c
> @@ -37,16 +37,9 @@ enum kasan_arg_stacktrace {
>         KASAN_ARG_STACKTRACE_ON,
>  };
>
> -enum kasan_arg_fault {
> -       KASAN_ARG_FAULT_DEFAULT,
> -       KASAN_ARG_FAULT_REPORT,
> -       KASAN_ARG_FAULT_PANIC,
> -};
> -
>  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;
>
>  /* Whether KASAN is enabled at all. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
> @@ -59,9 +52,6 @@ EXPORT_SYMBOL_GPL(kasan_flag_async);
>  /* Whether to collect alloc/free stack traces. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
>
> -/* Whether to panic or print a report and disable tag checking on fault. */
> -bool kasan_flag_panic __ro_after_init;
> -
>  /* kasan=off/on */
>  static int __init early_kasan_flag(char *arg)
>  {
> @@ -113,23 +103,6 @@ static int __init early_kasan_flag_stacktrace(char *arg)
>  }
>  early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
>
> -/* kasan.fault=report/panic */
> -static int __init early_kasan_fault(char *arg)
> -{
> -       if (!arg)
> -               return -EINVAL;
> -
> -       if (!strcmp(arg, "report"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> -       else if (!strcmp(arg, "panic"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> -       else
> -               return -EINVAL;
> -
> -       return 0;
> -}
> -early_param("kasan.fault", early_kasan_fault);
> -
>  /* kasan_init_hw_tags_cpu() is called for each CPU. */
>  void kasan_init_hw_tags_cpu(void)
>  {
> @@ -197,22 +170,6 @@ void __init kasan_init_hw_tags(void)
>                 break;
>         }
>
> -       switch (kasan_arg_fault) {
> -       case KASAN_ARG_FAULT_DEFAULT:
> -               /*
> -                * Default to no panic on report.
> -                * Do nothing, kasan_flag_panic keeps its default value.
> -                */
> -               break;
> -       case KASAN_ARG_FAULT_REPORT:
> -               /* Do nothing, kasan_flag_panic keeps its default value. */
> -               break;
> -       case KASAN_ARG_FAULT_PANIC:
> -               /* Enable panic on report. */
> -               kasan_flag_panic = true;
> -               break;
> -       }
> -
>         pr_info("KernelAddressSanitizer initialized\n");
>  }
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 98e3059bfea4..9d57383ce1fa 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -36,7 +36,6 @@ static inline bool kasan_async_mode_enabled(void)
>
>  #endif
>
> -extern bool kasan_flag_panic __ro_after_init;
>  extern bool kasan_flag_async __ro_after_init;
>
>  #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 8fff1825b22c..884a950c7026 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -39,6 +39,31 @@ static unsigned long kasan_flags;
>  #define KASAN_BIT_REPORTED     0
>  #define KASAN_BIT_MULTI_SHOT   1
>
> +enum kasan_arg_fault {
> +       KASAN_ARG_FAULT_DEFAULT,
> +       KASAN_ARG_FAULT_REPORT,
> +       KASAN_ARG_FAULT_PANIC,
> +};
> +
> +static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
> +
> +/* kasan.fault=report/panic */
> +static int __init early_kasan_fault(char *arg)
> +{
> +       if (!arg)
> +               return -EINVAL;
> +
> +       if (!strcmp(arg, "report"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> +       else if (!strcmp(arg, "panic"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> +       else
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +early_param("kasan.fault", early_kasan_fault);
> +
>  bool kasan_save_enable_multi_shot(void)
>  {
>         return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
> @@ -102,10 +127,8 @@ static void end_report(unsigned long *flags, unsigned long addr)
>                 panic_on_warn = 0;
>                 panic("panic_on_warn set ...\n");
>         }
> -#ifdef CONFIG_KASAN_HW_TAGS
> -       if (kasan_flag_panic)
> +       if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
>                 panic("kasan.fault=panic set ...\n");
> -#endif
>         kasan_enable_current();
>  }
>
> --
> 2.32.0.93.g670b81a890-goog
>

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [PATCH v2] mm/kasan: move kasan.fault to mm/kasan/report.c
@ 2021-07-13 18:40   ` Andrey Konovalov
  0 siblings, 0 replies; 6+ messages in thread
From: Andrey Konovalov @ 2021-07-13 18:40 UTC (permalink / raw)
  To: Woody Lin
  Cc: Marco Elver, Andrey Ryabinin, Dmitry Vyukov, Alexander Potapenko,
	Jonathan Corbet, Andrew Morton, kasan-dev,
	open list:DOCUMENTATION, LKML, Linux Memory Management List

On Tue, Jul 13, 2021 at 3:07 AM Woody Lin <woodylin@google.com> wrote:
>
> Move the boot parameter 'kasan.fault' from hw_tags.c to report.c, so it
> can support all KASAN modes - generic, and both tag-based.
>
> Signed-off-by: Woody Lin <woodylin@google.com>
> ---
>  Documentation/dev-tools/kasan.rst | 13 ++++++----
>  mm/kasan/hw_tags.c                | 43 -------------------------------
>  mm/kasan/kasan.h                  |  1 -
>  mm/kasan/report.c                 | 29 ++++++++++++++++++---
>  4 files changed, 34 insertions(+), 52 deletions(-)
>
> diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
> index 83ec4a556c19..21dc03bc10a4 100644
> --- a/Documentation/dev-tools/kasan.rst
> +++ b/Documentation/dev-tools/kasan.rst
> @@ -181,9 +181,16 @@ By default, KASAN prints a bug report only for the first invalid memory access.
>  With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
>  effectively disables ``panic_on_warn`` for KASAN reports.
>
> +Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot
> +parameter can be used to control panic and reporting behaviour:
> +
> +- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> +  report or also panic the kernel (default: ``report``). The panic happens even
> +  if ``kasan_multi_shot`` is enabled.
> +
>  Hardware tag-based KASAN mode (see the section about various modes below) is
>  intended for use in production as a security mitigation. Therefore, it supports
> -boot parameters that allow disabling KASAN or controlling its features.
> +additional boot parameters that allow disabling KASAN or controlling features:
>
>  - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
>
> @@ -199,10 +206,6 @@ boot parameters that allow disabling KASAN or controlling its features.
>  - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
>    traces collection (default: ``on``).
>
> -- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
> -  report or also panic the kernel (default: ``report``). The panic happens even
> -  if ``kasan_multi_shot`` is enabled.
> -
>  Implementation details
>  ----------------------
>
> diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
> index 4ea8c368b5b8..51903639e55f 100644
> --- a/mm/kasan/hw_tags.c
> +++ b/mm/kasan/hw_tags.c
> @@ -37,16 +37,9 @@ enum kasan_arg_stacktrace {
>         KASAN_ARG_STACKTRACE_ON,
>  };
>
> -enum kasan_arg_fault {
> -       KASAN_ARG_FAULT_DEFAULT,
> -       KASAN_ARG_FAULT_REPORT,
> -       KASAN_ARG_FAULT_PANIC,
> -};
> -
>  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;
>
>  /* Whether KASAN is enabled at all. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
> @@ -59,9 +52,6 @@ EXPORT_SYMBOL_GPL(kasan_flag_async);
>  /* Whether to collect alloc/free stack traces. */
>  DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
>
> -/* Whether to panic or print a report and disable tag checking on fault. */
> -bool kasan_flag_panic __ro_after_init;
> -
>  /* kasan=off/on */
>  static int __init early_kasan_flag(char *arg)
>  {
> @@ -113,23 +103,6 @@ static int __init early_kasan_flag_stacktrace(char *arg)
>  }
>  early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
>
> -/* kasan.fault=report/panic */
> -static int __init early_kasan_fault(char *arg)
> -{
> -       if (!arg)
> -               return -EINVAL;
> -
> -       if (!strcmp(arg, "report"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> -       else if (!strcmp(arg, "panic"))
> -               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> -       else
> -               return -EINVAL;
> -
> -       return 0;
> -}
> -early_param("kasan.fault", early_kasan_fault);
> -
>  /* kasan_init_hw_tags_cpu() is called for each CPU. */
>  void kasan_init_hw_tags_cpu(void)
>  {
> @@ -197,22 +170,6 @@ void __init kasan_init_hw_tags(void)
>                 break;
>         }
>
> -       switch (kasan_arg_fault) {
> -       case KASAN_ARG_FAULT_DEFAULT:
> -               /*
> -                * Default to no panic on report.
> -                * Do nothing, kasan_flag_panic keeps its default value.
> -                */
> -               break;
> -       case KASAN_ARG_FAULT_REPORT:
> -               /* Do nothing, kasan_flag_panic keeps its default value. */
> -               break;
> -       case KASAN_ARG_FAULT_PANIC:
> -               /* Enable panic on report. */
> -               kasan_flag_panic = true;
> -               break;
> -       }
> -
>         pr_info("KernelAddressSanitizer initialized\n");
>  }
>
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index 98e3059bfea4..9d57383ce1fa 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -36,7 +36,6 @@ static inline bool kasan_async_mode_enabled(void)
>
>  #endif
>
> -extern bool kasan_flag_panic __ro_after_init;
>  extern bool kasan_flag_async __ro_after_init;
>
>  #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 8fff1825b22c..884a950c7026 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -39,6 +39,31 @@ static unsigned long kasan_flags;
>  #define KASAN_BIT_REPORTED     0
>  #define KASAN_BIT_MULTI_SHOT   1
>
> +enum kasan_arg_fault {
> +       KASAN_ARG_FAULT_DEFAULT,
> +       KASAN_ARG_FAULT_REPORT,
> +       KASAN_ARG_FAULT_PANIC,
> +};
> +
> +static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
> +
> +/* kasan.fault=report/panic */
> +static int __init early_kasan_fault(char *arg)
> +{
> +       if (!arg)
> +               return -EINVAL;
> +
> +       if (!strcmp(arg, "report"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
> +       else if (!strcmp(arg, "panic"))
> +               kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
> +       else
> +               return -EINVAL;
> +
> +       return 0;
> +}
> +early_param("kasan.fault", early_kasan_fault);
> +
>  bool kasan_save_enable_multi_shot(void)
>  {
>         return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
> @@ -102,10 +127,8 @@ static void end_report(unsigned long *flags, unsigned long addr)
>                 panic_on_warn = 0;
>                 panic("panic_on_warn set ...\n");
>         }
> -#ifdef CONFIG_KASAN_HW_TAGS
> -       if (kasan_flag_panic)
> +       if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
>                 panic("kasan.fault=panic set ...\n");
> -#endif
>         kasan_enable_current();
>  }
>
> --
> 2.32.0.93.g670b81a890-goog
>

Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>


^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-07-13 18:41 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-13  1:05 [PATCH v2] mm/kasan: move kasan.fault to mm/kasan/report.c Woody Lin
2021-07-13  1:05 ` Woody Lin
2021-07-13  7:19 ` Marco Elver
2021-07-13  7:19   ` Marco Elver
2021-07-13 18:40 ` Andrey Konovalov
2021-07-13 18:40   ` Andrey Konovalov

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