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* + kfence-allow-re-enabling-kfence-after-system-startup.patch added to -mm tree
@ 2022-03-06 23:44 Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2022-03-06 23:44 UTC (permalink / raw)
  To: mm-commits, glider, elver, dvyukov, dtcccc, akpm


The patch titled
     Subject: kfence: allow re-enabling KFENCE after system startup
has been added to the -mm tree.  Its filename is
     kfence-allow-re-enabling-kfence-after-system-startup.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/kfence-allow-re-enabling-kfence-after-system-startup.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kfence-allow-re-enabling-kfence-after-system-startup.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Tianchen Ding <dtcccc@linux.alibaba.com>
Subject: kfence: allow re-enabling KFENCE after system startup

Patch series "provide the flexibility to enable KFENCE", v2.


This patch (of 2):

If once KFENCE is disabled by:
echo 0 > /sys/module/kfence/parameters/sample_interval
KFENCE could never be re-enabled until next rebooting.

Allow re-enabling it by writing a positive num to sample_interval.

Link: https://lkml.kernel.org/r/20220305144858.17040-1-dtcccc@linux.alibaba.com
Link: https://lkml.kernel.org/r/20220305144858.17040-2-dtcccc@linux.alibaba.com
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kfence/core.c |   21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

--- a/mm/kfence/core.c~kfence-allow-re-enabling-kfence-after-system-startup
+++ a/mm/kfence/core.c
@@ -38,14 +38,17 @@
 #define KFENCE_WARN_ON(cond)                                                   \
 	({                                                                     \
 		const bool __cond = WARN_ON(cond);                             \
-		if (unlikely(__cond))                                          \
+		if (unlikely(__cond)) {                                        \
 			WRITE_ONCE(kfence_enabled, false);                     \
+			disabled_by_warn = true;                               \
+		}                                                              \
 		__cond;                                                        \
 	})
 
 /* === Data ================================================================= */
 
 static bool kfence_enabled __read_mostly;
+static bool disabled_by_warn __read_mostly;
 
 unsigned long kfence_sample_interval __read_mostly = CONFIG_KFENCE_SAMPLE_INTERVAL;
 EXPORT_SYMBOL_GPL(kfence_sample_interval); /* Export for test modules. */
@@ -55,6 +58,7 @@ EXPORT_SYMBOL_GPL(kfence_sample_interval
 #endif
 #define MODULE_PARAM_PREFIX "kfence."
 
+static int kfence_enable_late(void);
 static int param_set_sample_interval(const char *val, const struct kernel_param *kp)
 {
 	unsigned long num;
@@ -65,10 +69,11 @@ static int param_set_sample_interval(con
 
 	if (!num) /* Using 0 to indicate KFENCE is disabled. */
 		WRITE_ONCE(kfence_enabled, false);
-	else if (!READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING)
-		return -EINVAL; /* Cannot (re-)enable KFENCE on-the-fly. */
 
 	*((unsigned long *)kp->arg) = num;
+
+	if (num && !READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING)
+		return disabled_by_warn ? -EINVAL : kfence_enable_late();
 	return 0;
 }
 
@@ -787,6 +792,16 @@ void __init kfence_init(void)
 		(void *)(__kfence_pool + KFENCE_POOL_SIZE));
 }
 
+static int kfence_enable_late(void)
+{
+	if (!__kfence_pool)
+		return -EINVAL;
+
+	WRITE_ONCE(kfence_enabled, true);
+	queue_delayed_work(system_unbound_wq, &kfence_timer, 0);
+	return 0;
+}
+
 void kfence_shutdown_cache(struct kmem_cache *s)
 {
 	unsigned long flags;
_

Patches currently in -mm which might be from dtcccc@linux.alibaba.com are

kfence-allow-re-enabling-kfence-after-system-startup.patch
kfence-alloc-kfence_pool-after-system-startup.patch


^ permalink raw reply	[flat|nested] 3+ messages in thread

* + kfence-allow-re-enabling-kfence-after-system-startup.patch added to -mm tree
@ 2022-03-07 23:50 Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2022-03-07 23:50 UTC (permalink / raw)
  To: mm-commits, glider, elver, dvyukov, dtcccc, akpm


The patch titled
     Subject: kfence: allow re-enabling KFENCE after system startup
has been added to the -mm tree.  Its filename is
     kfence-allow-re-enabling-kfence-after-system-startup.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/kfence-allow-re-enabling-kfence-after-system-startup.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kfence-allow-re-enabling-kfence-after-system-startup.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Tianchen Ding <dtcccc@linux.alibaba.com>
Subject: kfence: allow re-enabling KFENCE after system startup

Patch series "provide the flexibility to enable KFENCE", v3.

If CONFIG_CONTIG_ALLOC is not supported, we fallback to try
alloc_pages_exact().  Allocating pages in this way has limits about
MAX_ORDER (default 11).  So we will not support allocating kfence pool
after system startup with a large KFENCE_NUM_OBJECTS.

When handling failures in kfence_init_pool_late(), we pair
free_pages_exact() to alloc_pages_exact() for compatibility consideration,
though it actually does the same as free_contig_range().


This patch (of 2):

If once KFENCE is disabled by:
echo 0 > /sys/module/kfence/parameters/sample_interval
KFENCE could never be re-enabled until next rebooting.

Allow re-enabling it by writing a positive num to sample_interval.

Link: https://lkml.kernel.org/r/20220307074516.6920-1-dtcccc@linux.alibaba.com
Link: https://lkml.kernel.org/r/20220307074516.6920-2-dtcccc@linux.alibaba.com
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kfence/core.c |   21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

--- a/mm/kfence/core.c~kfence-allow-re-enabling-kfence-after-system-startup
+++ a/mm/kfence/core.c
@@ -38,14 +38,17 @@
 #define KFENCE_WARN_ON(cond)                                                   \
 	({                                                                     \
 		const bool __cond = WARN_ON(cond);                             \
-		if (unlikely(__cond))                                          \
+		if (unlikely(__cond)) {                                        \
 			WRITE_ONCE(kfence_enabled, false);                     \
+			disabled_by_warn = true;                               \
+		}                                                              \
 		__cond;                                                        \
 	})
 
 /* === Data ================================================================= */
 
 static bool kfence_enabled __read_mostly;
+static bool disabled_by_warn __read_mostly;
 
 unsigned long kfence_sample_interval __read_mostly = CONFIG_KFENCE_SAMPLE_INTERVAL;
 EXPORT_SYMBOL_GPL(kfence_sample_interval); /* Export for test modules. */
@@ -55,6 +58,7 @@ EXPORT_SYMBOL_GPL(kfence_sample_interval
 #endif
 #define MODULE_PARAM_PREFIX "kfence."
 
+static int kfence_enable_late(void);
 static int param_set_sample_interval(const char *val, const struct kernel_param *kp)
 {
 	unsigned long num;
@@ -65,10 +69,11 @@ static int param_set_sample_interval(con
 
 	if (!num) /* Using 0 to indicate KFENCE is disabled. */
 		WRITE_ONCE(kfence_enabled, false);
-	else if (!READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING)
-		return -EINVAL; /* Cannot (re-)enable KFENCE on-the-fly. */
 
 	*((unsigned long *)kp->arg) = num;
+
+	if (num && !READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING)
+		return disabled_by_warn ? -EINVAL : kfence_enable_late();
 	return 0;
 }
 
@@ -787,6 +792,16 @@ void __init kfence_init(void)
 		(void *)(__kfence_pool + KFENCE_POOL_SIZE));
 }
 
+static int kfence_enable_late(void)
+{
+	if (!__kfence_pool)
+		return -EINVAL;
+
+	WRITE_ONCE(kfence_enabled, true);
+	queue_delayed_work(system_unbound_wq, &kfence_timer, 0);
+	return 0;
+}
+
 void kfence_shutdown_cache(struct kmem_cache *s)
 {
 	unsigned long flags;
_

Patches currently in -mm which might be from dtcccc@linux.alibaba.com are

kfence-allow-re-enabling-kfence-after-system-startup.patch
kfence-alloc-kfence_pool-after-system-startup.patch


^ permalink raw reply	[flat|nested] 3+ messages in thread

* + kfence-allow-re-enabling-kfence-after-system-startup.patch added to -mm tree
@ 2022-03-06 23:40 Andrew Morton
  0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2022-03-06 23:40 UTC (permalink / raw)
  To: mm-commits, glider, elver, dvyukov, dtcccc, akpm


The patch titled
     Subject: kfence: allow re-enabling KFENCE after system startup
has been added to the -mm tree.  Its filename is
     kfence-allow-re-enabling-kfence-after-system-startup.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/kfence-allow-re-enabling-kfence-after-system-startup.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kfence-allow-re-enabling-kfence-after-system-startup.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Tianchen Ding <dtcccc@linux.alibaba.com>
Subject: kfence: allow re-enabling KFENCE after system startup

Patch series "provide the flexibility to enable KFENCE", v2.


This patch (of 2):

If once KFENCE is disabled by:
echo 0 > /sys/module/kfence/parameters/sample_interval
KFENCE could never be re-enabled until next rebooting.

Allow re-enabling it by writing a positive num to sample_interval.

Link: https://lkml.kernel.org/r/20220305144858.17040-2-dtcccc@linux.alibaba.com
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kfence/core.c |   21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

--- a/mm/kfence/core.c~kfence-allow-re-enabling-kfence-after-system-startup
+++ a/mm/kfence/core.c
@@ -38,14 +38,17 @@
 #define KFENCE_WARN_ON(cond)                                                   \
 	({                                                                     \
 		const bool __cond = WARN_ON(cond);                             \
-		if (unlikely(__cond))                                          \
+		if (unlikely(__cond)) {                                        \
 			WRITE_ONCE(kfence_enabled, false);                     \
+			disabled_by_warn = true;                               \
+		}                                                              \
 		__cond;                                                        \
 	})
 
 /* === Data ================================================================= */
 
 static bool kfence_enabled __read_mostly;
+static bool disabled_by_warn __read_mostly;
 
 unsigned long kfence_sample_interval __read_mostly = CONFIG_KFENCE_SAMPLE_INTERVAL;
 EXPORT_SYMBOL_GPL(kfence_sample_interval); /* Export for test modules. */
@@ -55,6 +58,7 @@ EXPORT_SYMBOL_GPL(kfence_sample_interval
 #endif
 #define MODULE_PARAM_PREFIX "kfence."
 
+static int kfence_enable_late(void);
 static int param_set_sample_interval(const char *val, const struct kernel_param *kp)
 {
 	unsigned long num;
@@ -65,10 +69,11 @@ static int param_set_sample_interval(con
 
 	if (!num) /* Using 0 to indicate KFENCE is disabled. */
 		WRITE_ONCE(kfence_enabled, false);
-	else if (!READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING)
-		return -EINVAL; /* Cannot (re-)enable KFENCE on-the-fly. */
 
 	*((unsigned long *)kp->arg) = num;
+
+	if (num && !READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING)
+		return disabled_by_warn ? -EINVAL : kfence_enable_late();
 	return 0;
 }
 
@@ -787,6 +792,16 @@ void __init kfence_init(void)
 		(void *)(__kfence_pool + KFENCE_POOL_SIZE));
 }
 
+static int kfence_enable_late(void)
+{
+	if (!__kfence_pool)
+		return -EINVAL;
+
+	WRITE_ONCE(kfence_enabled, true);
+	queue_delayed_work(system_unbound_wq, &kfence_timer, 0);
+	return 0;
+}
+
 void kfence_shutdown_cache(struct kmem_cache *s)
 {
 	unsigned long flags;
_

Patches currently in -mm which might be from dtcccc@linux.alibaba.com are

kfence-allow-re-enabling-kfence-after-system-startup.patch
kfence-alloc-kfence_pool-after-system-startup.patch


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2022-03-07 23:51 UTC | newest]

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