* [PATCH v2 1/5] kasan: support alloca() poisoning
2017-11-29 21:50 [PATCH v2 0/5] kasan: support alloca, LLVM Paul Lawrence
@ 2017-11-29 21:50 ` Paul Lawrence
2017-11-30 8:26 ` Dmitry Vyukov
2017-11-29 21:50 ` [PATCH v2 2/5] kasan: Add tests for alloca poisonong Paul Lawrence
` (3 subsequent siblings)
4 siblings, 1 reply; 14+ messages in thread
From: Paul Lawrence @ 2017-11-29 21:50 UTC (permalink / raw)
To: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Masahiro Yamada, Michal Marek
Cc: linux-kernel, kasan-dev, linux-mm, linux-kbuild,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann,
Paul Lawrence
clang's AddressSanitizer implementation adds redzones on either side of
alloca()ed buffers. These redzones are 32-byte aligned and at least 32
bytes long.
__asan_alloca_poison() is passed the size and address of the allocated
buffer, *excluding* the redzones on either side. The left redzone will
always be to the immediate left of this buffer; but AddressSanitizer may
need to add padding between the end of the buffer and the right redzone.
If there are any 8-byte chunks inside this padding, we should poison
those too.
__asan_allocas_unpoison() is just passed the top and bottom of the
dynamic stack area, so unpoisoning is simpler.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
mm/kasan/kasan.c | 32 ++++++++++++++++++++++++++++++++
mm/kasan/kasan.h | 8 ++++++++
mm/kasan/report.c | 4 ++++
3 files changed, 44 insertions(+)
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 405bba487df5..f86f862f41f8 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -736,6 +736,38 @@ void __asan_unpoison_stack_memory(const void *addr, size_t size)
}
EXPORT_SYMBOL(__asan_unpoison_stack_memory);
+/* Emitted by compiler to poison alloca()ed objects. */
+void __asan_alloca_poison(unsigned long addr, size_t size)
+{
+ size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
+ size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) -
+ rounded_up_size;
+
+ const void *left_redzone = (const void *)(addr -
+ KASAN_ALLOCA_REDZONE_SIZE);
+ const void *right_redzone = (const void *)(addr + rounded_up_size);
+
+ WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
+
+ kasan_unpoison_shadow((const void *)addr, size);
+ kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
+ KASAN_ALLOCA_LEFT);
+ kasan_poison_shadow(right_redzone,
+ padding_size + KASAN_ALLOCA_REDZONE_SIZE,
+ KASAN_ALLOCA_RIGHT);
+}
+EXPORT_SYMBOL(__asan_alloca_poison);
+
+/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */
+void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
+{
+ if (unlikely(!stack_top || stack_top > stack_bottom))
+ return;
+
+ kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
+}
+EXPORT_SYMBOL(__asan_allocas_unpoison);
+
#ifdef CONFIG_MEMORY_HOTPLUG
static int __meminit kasan_mem_notifier(struct notifier_block *nb,
unsigned long action, void *data)
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index c70851a9a6a4..7c0bcd1f4c0d 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -24,6 +24,14 @@
#define KASAN_STACK_PARTIAL 0xF4
#define KASAN_USE_AFTER_SCOPE 0xF8
+/*
+ * alloca redzone shadow values
+ */
+#define KASAN_ALLOCA_LEFT 0xCA
+#define KASAN_ALLOCA_RIGHT 0xCB
+
+#define KASAN_ALLOCA_REDZONE_SIZE 32
+
/* Don't break randconfig/all*config builds */
#ifndef KASAN_ABI_VERSION
#define KASAN_ABI_VERSION 1
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 6bcfb01ba038..25419d426426 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -102,6 +102,10 @@ static const char *get_shadow_bug_type(struct kasan_access_info *info)
case KASAN_USE_AFTER_SCOPE:
bug_type = "use-after-scope";
break;
+ case KASAN_ALLOCA_LEFT:
+ case KASAN_ALLOCA_RIGHT:
+ bug_type = "alloca-out-of-bounds";
+ break;
}
return bug_type;
--
2.15.0.531.g2ccb3012c9-goog
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^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v2 1/5] kasan: support alloca() poisoning
2017-11-29 21:50 ` [PATCH v2 1/5] kasan: support alloca() poisoning Paul Lawrence
@ 2017-11-30 8:26 ` Dmitry Vyukov
2017-11-30 8:29 ` Dmitry Vyukov
0 siblings, 1 reply; 14+ messages in thread
From: Dmitry Vyukov @ 2017-11-30 8:26 UTC (permalink / raw)
To: Paul Lawrence
Cc: Andrey Ryabinin, Alexander Potapenko, Masahiro Yamada,
Michal Marek, LKML, kasan-dev, Linux-MM,
open list:KERNEL BUILD + fi...,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
/\/\/\/\/\/\On Wed, Nov 29, 2017 at 10:50 PM, Paul Lawrence
<paullawrence@google.com> wrote:
> clang's AddressSanitizer implementation adds redzones on either side of
> alloca()ed buffers. These redzones are 32-byte aligned and at least 32
> bytes long.
>
> __asan_alloca_poison() is passed the size and address of the allocated
> buffer, *excluding* the redzones on either side. The left redzone will
> always be to the immediate left of this buffer; but AddressSanitizer may
> need to add padding between the end of the buffer and the right redzone.
> If there are any 8-byte chunks inside this padding, we should poison
> those too.
>
> __asan_allocas_unpoison() is just passed the top and bottom of the
> dynamic stack area, so unpoisoning is simpler.
>
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>
> mm/kasan/kasan.c | 32 ++++++++++++++++++++++++++++++++
> mm/kasan/kasan.h | 8 ++++++++
> mm/kasan/report.c | 4 ++++
> 3 files changed, 44 insertions(+)
>
> diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
> index 405bba487df5..f86f862f41f8 100644
> --- a/mm/kasan/kasan.c
> +++ b/mm/kasan/kasan.c
> @@ -736,6 +736,38 @@ void __asan_unpoison_stack_memory(const void *addr, size_t size)
> }
> EXPORT_SYMBOL(__asan_unpoison_stack_memory);
>
> +/* Emitted by compiler to poison alloca()ed objects. */
> +void __asan_alloca_poison(unsigned long addr, size_t size)
> +{
> + size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
> + size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) -
> + rounded_up_size;
> +
> + const void *left_redzone = (const void *)(addr -
> + KASAN_ALLOCA_REDZONE_SIZE);
> + const void *right_redzone = (const void *)(addr + rounded_up_size);
> +
> + WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
> +
> + kasan_unpoison_shadow((const void *)addr, size);
/\/\/\/\/\/\
Why do we need this? Stack must be clean. Compiler instrumentation
does not clear shadow for objects in function prologue, if stack is
dirty KASAN would explode.
> + kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
> + KASAN_ALLOCA_LEFT);
> + kasan_poison_shadow(right_redzone,
> + padding_size + KASAN_ALLOCA_REDZONE_SIZE,
> + KASAN_ALLOCA_RIGHT);
We also need to poison [size, rounded_up_size) with partial value if
the range is not empty. I.e. we can poison exactly, say, 3 bytes
there.
> +}
> +EXPORT_SYMBOL(__asan_alloca_poison);
> +
> +/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */
> +void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
> +{
> + if (unlikely(!stack_top || stack_top > stack_bottom))
> + return;
> +
> + kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
> +}
> +EXPORT_SYMBOL(__asan_allocas_unpoison);
> +
> #ifdef CONFIG_MEMORY_HOTPLUG
> static int __meminit kasan_mem_notifier(struct notifier_block *nb,
> unsigned long action, void *data)
> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
> index c70851a9a6a4..7c0bcd1f4c0d 100644
> --- a/mm/kasan/kasan.h
> +++ b/mm/kasan/kasan.h
> @@ -24,6 +24,14 @@
> #define KASAN_STACK_PARTIAL 0xF4
> #define KASAN_USE_AFTER_SCOPE 0xF8
>
> +/*
> + * alloca redzone shadow values
> + */
> +#define KASAN_ALLOCA_LEFT 0xCA
> +#define KASAN_ALLOCA_RIGHT 0xCB
> +
> +#define KASAN_ALLOCA_REDZONE_SIZE 32
> +
> /* Don't break randconfig/all*config builds */
> #ifndef KASAN_ABI_VERSION
> #define KASAN_ABI_VERSION 1
> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
> index 6bcfb01ba038..25419d426426 100644
> --- a/mm/kasan/report.c
> +++ b/mm/kasan/report.c
> @@ -102,6 +102,10 @@ static const char *get_shadow_bug_type(struct kasan_access_info *info)
> case KASAN_USE_AFTER_SCOPE:
> bug_type = "use-after-scope";
> break;
> + case KASAN_ALLOCA_LEFT:
> + case KASAN_ALLOCA_RIGHT:
> + bug_type = "alloca-out-of-bounds";
> + break;
> }
>
> return bug_type;
> --
> 2.15.0.531.g2ccb3012c9-goog
>
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^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 1/5] kasan: support alloca() poisoning
2017-11-30 8:26 ` Dmitry Vyukov
@ 2017-11-30 8:29 ` Dmitry Vyukov
0 siblings, 0 replies; 14+ messages in thread
From: Dmitry Vyukov @ 2017-11-30 8:29 UTC (permalink / raw)
To: Paul Lawrence
Cc: Andrey Ryabinin, Alexander Potapenko, Masahiro Yamada,
Michal Marek, LKML, kasan-dev, Linux-MM,
open list:KERNEL BUILD + fi...,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
On Thu, Nov 30, 2017 at 9:26 AM, Dmitry Vyukov <dvyukov@google.com> wrote:
> /\/\/\/\/\/\On Wed, Nov 29, 2017 at 10:50 PM, Paul Lawrence
> <paullawrence@google.com> wrote:
>> clang's AddressSanitizer implementation adds redzones on either side of
>> alloca()ed buffers. These redzones are 32-byte aligned and at least 32
>> bytes long.
>>
>> __asan_alloca_poison() is passed the size and address of the allocated
>> buffer, *excluding* the redzones on either side. The left redzone will
>> always be to the immediate left of this buffer; but AddressSanitizer may
>> need to add padding between the end of the buffer and the right redzone.
>> If there are any 8-byte chunks inside this padding, we should poison
>> those too.
>>
>> __asan_allocas_unpoison() is just passed the top and bottom of the
>> dynamic stack area, so unpoisoning is simpler.
>>
>> Signed-off-by: Greg Hackmann <ghackmann@google.com>
>> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>>
>> mm/kasan/kasan.c | 32 ++++++++++++++++++++++++++++++++
>> mm/kasan/kasan.h | 8 ++++++++
>> mm/kasan/report.c | 4 ++++
>> 3 files changed, 44 insertions(+)
>>
>> diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
>> index 405bba487df5..f86f862f41f8 100644
>> --- a/mm/kasan/kasan.c
>> +++ b/mm/kasan/kasan.c
>> @@ -736,6 +736,38 @@ void __asan_unpoison_stack_memory(const void *addr, size_t size)
>> }
>> EXPORT_SYMBOL(__asan_unpoison_stack_memory);
>>
>> +/* Emitted by compiler to poison alloca()ed objects. */
>> +void __asan_alloca_poison(unsigned long addr, size_t size)
>> +{
>> + size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE);
>> + size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) -
>> + rounded_up_size;
>> +
>> + const void *left_redzone = (const void *)(addr -
>> + KASAN_ALLOCA_REDZONE_SIZE);
>> + const void *right_redzone = (const void *)(addr + rounded_up_size);
>> +
>> + WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE));
>> +
>> + kasan_unpoison_shadow((const void *)addr, size);
>
> /\/\/\/\/\/\
>
> Why do we need this? Stack must be clean. Compiler instrumentation
> does not clear shadow for objects in function prologue, if stack is
> dirty KASAN would explode.
>
>
>> + kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE,
>> + KASAN_ALLOCA_LEFT);
>> + kasan_poison_shadow(right_redzone,
>> + padding_size + KASAN_ALLOCA_REDZONE_SIZE,
>> + KASAN_ALLOCA_RIGHT);
>
> We also need to poison [size, rounded_up_size) with partial value if
> the range is not empty. I.e. we can poison exactly, say, 3 bytes
> there.
Wait, kasan_unpoison_shadow does this, right?
Somewhat counter-intuitive and more expensive than needed. Let's
poison only the last byte.
>> +}
>> +EXPORT_SYMBOL(__asan_alloca_poison);
>> +
>> +/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */
>> +void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
>> +{
>> + if (unlikely(!stack_top || stack_top > stack_bottom))
>> + return;
>> +
>> + kasan_unpoison_shadow(stack_top, stack_bottom - stack_top);
>> +}
>> +EXPORT_SYMBOL(__asan_allocas_unpoison);
>> +
>> #ifdef CONFIG_MEMORY_HOTPLUG
>> static int __meminit kasan_mem_notifier(struct notifier_block *nb,
>> unsigned long action, void *data)
>> diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
>> index c70851a9a6a4..7c0bcd1f4c0d 100644
>> --- a/mm/kasan/kasan.h
>> +++ b/mm/kasan/kasan.h
>> @@ -24,6 +24,14 @@
>> #define KASAN_STACK_PARTIAL 0xF4
>> #define KASAN_USE_AFTER_SCOPE 0xF8
>>
>> +/*
>> + * alloca redzone shadow values
>> + */
>> +#define KASAN_ALLOCA_LEFT 0xCA
>> +#define KASAN_ALLOCA_RIGHT 0xCB
>> +
>> +#define KASAN_ALLOCA_REDZONE_SIZE 32
>> +
>> /* Don't break randconfig/all*config builds */
>> #ifndef KASAN_ABI_VERSION
>> #define KASAN_ABI_VERSION 1
>> diff --git a/mm/kasan/report.c b/mm/kasan/report.c
>> index 6bcfb01ba038..25419d426426 100644
>> --- a/mm/kasan/report.c
>> +++ b/mm/kasan/report.c
>> @@ -102,6 +102,10 @@ static const char *get_shadow_bug_type(struct kasan_access_info *info)
>> case KASAN_USE_AFTER_SCOPE:
>> bug_type = "use-after-scope";
>> break;
>> + case KASAN_ALLOCA_LEFT:
>> + case KASAN_ALLOCA_RIGHT:
>> + bug_type = "alloca-out-of-bounds";
>> + break;
>> }
>>
>> return bug_type;
>> --
>> 2.15.0.531.g2ccb3012c9-goog
>>
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^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2 2/5] kasan: Add tests for alloca poisonong
2017-11-29 21:50 [PATCH v2 0/5] kasan: support alloca, LLVM Paul Lawrence
2017-11-29 21:50 ` [PATCH v2 1/5] kasan: support alloca() poisoning Paul Lawrence
@ 2017-11-29 21:50 ` Paul Lawrence
2017-11-30 8:30 ` Dmitry Vyukov
2017-11-29 21:50 ` [PATCH v2 3/5] kasan: added functions for unpoisoning stack variables Paul Lawrence
` (2 subsequent siblings)
4 siblings, 1 reply; 14+ messages in thread
From: Paul Lawrence @ 2017-11-29 21:50 UTC (permalink / raw)
To: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Masahiro Yamada, Michal Marek
Cc: linux-kernel, kasan-dev, linux-mm, linux-kbuild,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann,
Paul Lawrence
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
lib/test_kasan.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index ef1a3ac1397e..2724f86c4cef 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -472,6 +472,26 @@ static noinline void __init use_after_scope_test(void)
p[1023] = 1;
}
+static noinline void __init kasan_alloca_oob_left(void)
+{
+ volatile int i = 10;
+ char alloca_array[i];
+ char *p = alloca_array - 1;
+
+ pr_info("out-of-bounds to left on alloca\n");
+ *(volatile char *)p;
+}
+
+static noinline void __init kasan_alloca_oob_right(void)
+{
+ volatile int i = 10;
+ char alloca_array[i];
+ char *p = alloca_array + i;
+
+ pr_info("out-of-bounds to right on alloca\n");
+ *(volatile char *)p;
+}
+
static int __init kmalloc_tests_init(void)
{
/*
@@ -502,6 +522,8 @@ static int __init kmalloc_tests_init(void)
memcg_accounted_kmem_cache();
kasan_stack_oob();
kasan_global_oob();
+ kasan_alloca_oob_left();
+ kasan_alloca_oob_right();
ksize_unpoisons_memory();
copy_user_test();
use_after_scope_test();
--
2.15.0.531.g2ccb3012c9-goog
--
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^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v2 2/5] kasan: Add tests for alloca poisonong
2017-11-29 21:50 ` [PATCH v2 2/5] kasan: Add tests for alloca poisonong Paul Lawrence
@ 2017-11-30 8:30 ` Dmitry Vyukov
0 siblings, 0 replies; 14+ messages in thread
From: Dmitry Vyukov @ 2017-11-30 8:30 UTC (permalink / raw)
To: Paul Lawrence
Cc: Andrey Ryabinin, Alexander Potapenko, Masahiro Yamada,
Michal Marek, LKML, kasan-dev, Linux-MM,
open list:KERNEL BUILD + fi...,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
On Wed, Nov 29, 2017 at 10:50 PM, 'Paul Lawrence' via kasan-dev
<kasan-dev@googlegroups.com> wrote:
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>
> lib/test_kasan.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> index ef1a3ac1397e..2724f86c4cef 100644
> --- a/lib/test_kasan.c
> +++ b/lib/test_kasan.c
> @@ -472,6 +472,26 @@ static noinline void __init use_after_scope_test(void)
> p[1023] = 1;
> }
>
> +static noinline void __init kasan_alloca_oob_left(void)
> +{
> + volatile int i = 10;
> + char alloca_array[i];
> + char *p = alloca_array - 1;
> +
> + pr_info("out-of-bounds to left on alloca\n");
> + *(volatile char *)p;
> +}
> +
> +static noinline void __init kasan_alloca_oob_right(void)
> +{
> + volatile int i = 10;
> + char alloca_array[i];
> + char *p = alloca_array + i;
> +
> + pr_info("out-of-bounds to right on alloca\n");
> + *(volatile char *)p;
> +}
> +
> static int __init kmalloc_tests_init(void)
> {
> /*
> @@ -502,6 +522,8 @@ static int __init kmalloc_tests_init(void)
> memcg_accounted_kmem_cache();
> kasan_stack_oob();
> kasan_global_oob();
> + kasan_alloca_oob_left();
> + kasan_alloca_oob_right();
> ksize_unpoisons_memory();
> copy_user_test();
> use_after_scope_test();
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
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^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2 3/5] kasan: added functions for unpoisoning stack variables
2017-11-29 21:50 [PATCH v2 0/5] kasan: support alloca, LLVM Paul Lawrence
2017-11-29 21:50 ` [PATCH v2 1/5] kasan: support alloca() poisoning Paul Lawrence
2017-11-29 21:50 ` [PATCH v2 2/5] kasan: Add tests for alloca poisonong Paul Lawrence
@ 2017-11-29 21:50 ` Paul Lawrence
2017-11-30 8:31 ` Dmitry Vyukov
2017-11-29 21:50 ` [PATCH v2 4/5] kasan: support LLVM-style asan parameters Paul Lawrence
2017-11-29 21:50 ` [PATCH v2 5/5] kasan: add compiler support for clang Paul Lawrence
4 siblings, 1 reply; 14+ messages in thread
From: Paul Lawrence @ 2017-11-29 21:50 UTC (permalink / raw)
To: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Masahiro Yamada, Michal Marek
Cc: linux-kernel, kasan-dev, linux-mm, linux-kbuild,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann,
Paul Lawrence
From: Alexander Potapenko <glider@google.com>
As a code-size optimization, LLVM builds since r279383 may
bulk-manipulate the shadow region when (un)poisoning large memory
blocks. This requires new callbacks that simply do an uninstrumented
memset().
This fixes linking the Clang-built kernel when using KASAN.
Signed-off-by: Alexander Potapenko <glider@google.com>
[ghackmann@google.com: fix memset() parameters, and tweak
commit message to describe new callbacks]
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
---
mm/kasan/kasan.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index f86f862f41f8..89565a1ec417 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -768,6 +768,21 @@ void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
}
EXPORT_SYMBOL(__asan_allocas_unpoison);
+/* Emitted by the compiler to [un]poison local variables. */
+#define DEFINE_ASAN_SET_SHADOW(byte) \
+ void __asan_set_shadow_##byte(const void *addr, size_t size) \
+ { \
+ __memset((void *)addr, 0x##byte, size); \
+ } \
+ EXPORT_SYMBOL(__asan_set_shadow_##byte)
+
+DEFINE_ASAN_SET_SHADOW(00);
+DEFINE_ASAN_SET_SHADOW(f1);
+DEFINE_ASAN_SET_SHADOW(f2);
+DEFINE_ASAN_SET_SHADOW(f3);
+DEFINE_ASAN_SET_SHADOW(f5);
+DEFINE_ASAN_SET_SHADOW(f8);
+
#ifdef CONFIG_MEMORY_HOTPLUG
static int __meminit kasan_mem_notifier(struct notifier_block *nb,
unsigned long action, void *data)
--
2.15.0.531.g2ccb3012c9-goog
--
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* Re: [PATCH v2 3/5] kasan: added functions for unpoisoning stack variables
2017-11-29 21:50 ` [PATCH v2 3/5] kasan: added functions for unpoisoning stack variables Paul Lawrence
@ 2017-11-30 8:31 ` Dmitry Vyukov
0 siblings, 0 replies; 14+ messages in thread
From: Dmitry Vyukov @ 2017-11-30 8:31 UTC (permalink / raw)
To: Paul Lawrence
Cc: Andrey Ryabinin, Alexander Potapenko, Masahiro Yamada,
Michal Marek, LKML, kasan-dev, Linux-MM,
open list:KERNEL BUILD + fi...,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
On Wed, Nov 29, 2017 at 10:50 PM, 'Paul Lawrence' via kasan-dev
<kasan-dev@googlegroups.com> wrote:
> From: Alexander Potapenko <glider@google.com>
>
> As a code-size optimization, LLVM builds since r279383 may
> bulk-manipulate the shadow region when (un)poisoning large memory
> blocks. This requires new callbacks that simply do an uninstrumented
> memset().
>
> This fixes linking the Clang-built kernel when using KASAN.
>
> Signed-off-by: Alexander Potapenko <glider@google.com>
> [ghackmann@google.com: fix memset() parameters, and tweak
> commit message to describe new callbacks]
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>
> ---
> mm/kasan/kasan.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
> index f86f862f41f8..89565a1ec417 100644
> --- a/mm/kasan/kasan.c
> +++ b/mm/kasan/kasan.c
> @@ -768,6 +768,21 @@ void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom)
> }
> EXPORT_SYMBOL(__asan_allocas_unpoison);
>
> +/* Emitted by the compiler to [un]poison local variables. */
> +#define DEFINE_ASAN_SET_SHADOW(byte) \
> + void __asan_set_shadow_##byte(const void *addr, size_t size) \
> + { \
> + __memset((void *)addr, 0x##byte, size); \
> + } \
> + EXPORT_SYMBOL(__asan_set_shadow_##byte)
> +
> +DEFINE_ASAN_SET_SHADOW(00);
> +DEFINE_ASAN_SET_SHADOW(f1);
> +DEFINE_ASAN_SET_SHADOW(f2);
> +DEFINE_ASAN_SET_SHADOW(f3);
> +DEFINE_ASAN_SET_SHADOW(f5);
> +DEFINE_ASAN_SET_SHADOW(f8);
> +
> #ifdef CONFIG_MEMORY_HOTPLUG
> static int __meminit kasan_mem_notifier(struct notifier_block *nb,
> unsigned long action, void *data)
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
--
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^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v2 4/5] kasan: support LLVM-style asan parameters
2017-11-29 21:50 [PATCH v2 0/5] kasan: support alloca, LLVM Paul Lawrence
` (2 preceding siblings ...)
2017-11-29 21:50 ` [PATCH v2 3/5] kasan: added functions for unpoisoning stack variables Paul Lawrence
@ 2017-11-29 21:50 ` Paul Lawrence
2017-11-30 8:33 ` Dmitry Vyukov
2017-11-30 16:36 ` Andrey Ryabinin
2017-11-29 21:50 ` [PATCH v2 5/5] kasan: add compiler support for clang Paul Lawrence
4 siblings, 2 replies; 14+ messages in thread
From: Paul Lawrence @ 2017-11-29 21:50 UTC (permalink / raw)
To: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Masahiro Yamada, Michal Marek
Cc: linux-kernel, kasan-dev, linux-mm, linux-kbuild,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann,
Paul Lawrence
Use cc-option to figure out whether the compiler's sanitizer uses
LLVM-style parameters ("-mllvm -asan-foo=bar") or GCC-style parameters
("--param asan-foo=bar").
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
---
scripts/Makefile.kasan | 39 +++++++++++++++++++++++++++------------
1 file changed, 27 insertions(+), 12 deletions(-)
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 1ce7115aa499..89c5b166adec 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -10,24 +10,39 @@ KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
-CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
- -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET) \
- --param asan-stack=1 --param asan-globals=1 \
- --param asan-instrumentation-with-call-threshold=$(call_threshold))
-
ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
ifneq ($(CONFIG_COMPILE_TEST),y)
$(warning Cannot use CONFIG_KASAN: \
-fsanitize=kernel-address is not supported by compiler)
endif
else
- ifeq ($(CFLAGS_KASAN),)
- ifneq ($(CONFIG_COMPILE_TEST),y)
- $(warning CONFIG_KASAN: compiler does not support all options.\
- Trying minimal configuration)
- endif
- CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
- endif
+ # -fasan-shadow-offset fails without -fsanitize
+ CFLAGS_KASAN_SHADOW := \
+ $(call cc-option, -fsanitize=kernel-address \
+ -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET))
+ ifeq ($(CFLAGS_KASAN_SHADOW),)
+ CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
+ else
+ CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW)
+ endif
+
+ # Now add all the compiler specific options that are valid standalone
+ CFLAGS_KASAN := $(CFLAGS_KASAN) \
+ $(call cc-option, --param asan-globals=1) \
+ $(call cc-option, --param asan-instrument-allocas=1) \
+ $(call cc-option, --param asan-instrumentation-with-call-threshold=$(call_threshold)) \
+ $(call cc-option, -mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)) \
+ $(call cc-option, -mllvm -asan-stack=1) \
+ $(call cc-option, -mllvm -asan-globals=1) \
+ $(call cc-option, -mllvm -asan-use-after-scope=1) \
+ $(call cc-option, -mllvm -asan-instrumentation-with-call-threshold=$(call_threshold))
+
+
+ # This option crashes on gcc 4.9, and is not available on clang
+ ifeq ($(call cc-ifversion, -ge, 0500, y), y)
+ CFLAGS_KASAN := $(CFLAGS_KASAN) $(call cc-option, --param asan-stack=1)
+ endif
+
endif
CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)
--
2.15.0.531.g2ccb3012c9-goog
--
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^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v2 4/5] kasan: support LLVM-style asan parameters
2017-11-29 21:50 ` [PATCH v2 4/5] kasan: support LLVM-style asan parameters Paul Lawrence
@ 2017-11-30 8:33 ` Dmitry Vyukov
2017-11-30 16:36 ` Andrey Ryabinin
1 sibling, 0 replies; 14+ messages in thread
From: Dmitry Vyukov @ 2017-11-30 8:33 UTC (permalink / raw)
To: Paul Lawrence
Cc: Andrey Ryabinin, Alexander Potapenko, Masahiro Yamada,
Michal Marek, LKML, kasan-dev, Linux-MM,
open list:KERNEL BUILD + fi...,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
On Wed, Nov 29, 2017 at 10:50 PM, 'Paul Lawrence' via kasan-dev
<kasan-dev@googlegroups.com> wrote:
> Use cc-option to figure out whether the compiler's sanitizer uses
> LLVM-style parameters ("-mllvm -asan-foo=bar") or GCC-style parameters
> ("--param asan-foo=bar").
>
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>
> ---
> scripts/Makefile.kasan | 39 +++++++++++++++++++++++++++------------
> 1 file changed, 27 insertions(+), 12 deletions(-)
>
> diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
> index 1ce7115aa499..89c5b166adec 100644
> --- a/scripts/Makefile.kasan
> +++ b/scripts/Makefile.kasan
> @@ -10,24 +10,39 @@ KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
>
> CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
>
> -CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
> - -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET) \
> - --param asan-stack=1 --param asan-globals=1 \
> - --param asan-instrumentation-with-call-threshold=$(call_threshold))
> -
> ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
> ifneq ($(CONFIG_COMPILE_TEST),y)
> $(warning Cannot use CONFIG_KASAN: \
> -fsanitize=kernel-address is not supported by compiler)
> endif
> else
> - ifeq ($(CFLAGS_KASAN),)
> - ifneq ($(CONFIG_COMPILE_TEST),y)
> - $(warning CONFIG_KASAN: compiler does not support all options.\
> - Trying minimal configuration)
> - endif
> - CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
> - endif
> + # -fasan-shadow-offset fails without -fsanitize
> + CFLAGS_KASAN_SHADOW := \
> + $(call cc-option, -fsanitize=kernel-address \
> + -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET))
> + ifeq ($(CFLAGS_KASAN_SHADOW),)
> + CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
> + else
> + CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW)
> + endif
> +
> + # Now add all the compiler specific options that are valid standalone
> + CFLAGS_KASAN := $(CFLAGS_KASAN) \
> + $(call cc-option, --param asan-globals=1) \
> + $(call cc-option, --param asan-instrument-allocas=1) \
> + $(call cc-option, --param asan-instrumentation-with-call-threshold=$(call_threshold)) \
> + $(call cc-option, -mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)) \
> + $(call cc-option, -mllvm -asan-stack=1) \
> + $(call cc-option, -mllvm -asan-globals=1) \
> + $(call cc-option, -mllvm -asan-use-after-scope=1) \
> + $(call cc-option, -mllvm -asan-instrumentation-with-call-threshold=$(call_threshold))
> +
> +
> + # This option crashes on gcc 4.9, and is not available on clang
> + ifeq ($(call cc-ifversion, -ge, 0500, y), y)
> + CFLAGS_KASAN := $(CFLAGS_KASAN) $(call cc-option, --param asan-stack=1)
> + endif
> +
> endif
>
> CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)
Acked-by: Dmitry Vyukov <dvyukov@google.com>
--
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^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 4/5] kasan: support LLVM-style asan parameters
2017-11-29 21:50 ` [PATCH v2 4/5] kasan: support LLVM-style asan parameters Paul Lawrence
2017-11-30 8:33 ` Dmitry Vyukov
@ 2017-11-30 16:36 ` Andrey Ryabinin
1 sibling, 0 replies; 14+ messages in thread
From: Andrey Ryabinin @ 2017-11-30 16:36 UTC (permalink / raw)
To: Paul Lawrence, Alexander Potapenko, Dmitry Vyukov,
Masahiro Yamada, Michal Marek
Cc: linux-kernel, kasan-dev, linux-mm, linux-kbuild,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
On 11/30/2017 12:50 AM, Paul Lawrence wrote:
> Use cc-option to figure out whether the compiler's sanitizer uses
> LLVM-style parameters ("-mllvm -asan-foo=bar") or GCC-style parameters
> ("--param asan-foo=bar").
>
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>
> ---
> scripts/Makefile.kasan | 39 +++++++++++++++++++++++++++------------
> 1 file changed, 27 insertions(+), 12 deletions(-)
>
It looks rather messy. Try the following patch.
Note, that I didn't add asan-instrument-allocas=1 because it has nothing to do
with LLVM-style params support.
asan-instrument-allocas should probably be in the patch that adds alloca() support.
From: Andrey Ryabinin <aryabinin@virtuozzo.com>
Subject: [PATCH] kasan/Makefile: Support LLVM style asan parameters.
LLVM doesn't understand GCC-style paramters ("--param asan-foo=bar"),
thus we currently we don't use inline/globals/stack instrumentation
when building the kernel with clang.
Add support for LLVM-style parameters ("-mllvm -asan-foo=bar") to
enable all KASAN features.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
---
scripts/Makefile.kasan | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 1ce7115aa499..2af5977c394d 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -10,10 +10,7 @@ KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
-CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
- -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET) \
- --param asan-stack=1 --param asan-globals=1 \
- --param asan-instrumentation-with-call-threshold=$(call_threshold))
+cc-param = $(call cc-option, --param $(1)) $(call cc-option, -mllvm -$(1))
ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
ifneq ($(CONFIG_COMPILE_TEST),y)
@@ -21,13 +18,23 @@ ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
-fsanitize=kernel-address is not supported by compiler)
endif
else
- ifeq ($(CFLAGS_KASAN),)
- ifneq ($(CONFIG_COMPILE_TEST),y)
- $(warning CONFIG_KASAN: compiler does not support all options.\
- Trying minimal configuration)
- endif
- CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
- endif
+ # -fasan-shadow-offset fails without -fsanitize
+ CFLAGS_KASAN_SHADOW := $(call cc-option, -fsanitize=kernel-address \
+ -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET), \
+ $(call cc-option, -fsanitize=kernel-address \
+ -mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)))
+
+ ifeq ($(CFLAGS_KASAN_SHADOW),)
+ CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
+ else
+ # Now add all the compiler specific options that are valid standalone
+ CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \
+ $(call cc-param,asan-globals=1) \
+ $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
+ $(call cc-param,asan-stack=1) \
+ $(call cc-param,asan-use-after-scope=1)
+ endif
+
endif
CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)
--
2.13.6
--
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^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH v2 5/5] kasan: add compiler support for clang
2017-11-29 21:50 [PATCH v2 0/5] kasan: support alloca, LLVM Paul Lawrence
` (3 preceding siblings ...)
2017-11-29 21:50 ` [PATCH v2 4/5] kasan: support LLVM-style asan parameters Paul Lawrence
@ 2017-11-29 21:50 ` Paul Lawrence
2017-11-30 8:34 ` Dmitry Vyukov
2017-11-30 16:45 ` Andrey Ryabinin
4 siblings, 2 replies; 14+ messages in thread
From: Paul Lawrence @ 2017-11-29 21:50 UTC (permalink / raw)
To: Andrey Ryabinin, Alexander Potapenko, Dmitry Vyukov,
Masahiro Yamada, Michal Marek
Cc: linux-kernel, kasan-dev, linux-mm, linux-kbuild,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann,
Paul Lawrence
For now we can hard-code ASAN ABI level 5, since historical clang builds
can't build the kernel anyway. We also need to emulate gcc's
__SANITIZE_ADDRESS__ flag, or memset() calls won't be instrumented.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Paul Lawrence <paullawrence@google.com>
---
include/linux/compiler-clang.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
index 3b609edffa8f..d02a4df3f473 100644
--- a/include/linux/compiler-clang.h
+++ b/include/linux/compiler-clang.h
@@ -19,3 +19,11 @@
#define randomized_struct_fields_start struct {
#define randomized_struct_fields_end };
+
+/* all clang versions usable with the kernel support KASAN ABI version 5 */
+#define KASAN_ABI_VERSION 5
+
+/* emulate gcc's __SANITIZE_ADDRESS__ flag */
+#if __has_feature(address_sanitizer)
+#define __SANITIZE_ADDRESS__
+#endif
--
2.15.0.531.g2ccb3012c9-goog
--
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^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH v2 5/5] kasan: add compiler support for clang
2017-11-29 21:50 ` [PATCH v2 5/5] kasan: add compiler support for clang Paul Lawrence
@ 2017-11-30 8:34 ` Dmitry Vyukov
2017-11-30 16:45 ` Andrey Ryabinin
1 sibling, 0 replies; 14+ messages in thread
From: Dmitry Vyukov @ 2017-11-30 8:34 UTC (permalink / raw)
To: Paul Lawrence
Cc: Andrey Ryabinin, Alexander Potapenko, Masahiro Yamada,
Michal Marek, LKML, kasan-dev, Linux-MM,
open list:KERNEL BUILD + fi...,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
On Wed, Nov 29, 2017 at 10:50 PM, 'Paul Lawrence' via kasan-dev
<kasan-dev@googlegroups.com> wrote:
> For now we can hard-code ASAN ABI level 5, since historical clang builds
> can't build the kernel anyway. We also need to emulate gcc's
> __SANITIZE_ADDRESS__ flag, or memset() calls won't be instrumented.
>
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>
> ---
> include/linux/compiler-clang.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
> index 3b609edffa8f..d02a4df3f473 100644
> --- a/include/linux/compiler-clang.h
> +++ b/include/linux/compiler-clang.h
> @@ -19,3 +19,11 @@
>
> #define randomized_struct_fields_start struct {
> #define randomized_struct_fields_end };
> +
> +/* all clang versions usable with the kernel support KASAN ABI version 5 */
> +#define KASAN_ABI_VERSION 5
> +
> +/* emulate gcc's __SANITIZE_ADDRESS__ flag */
> +#if __has_feature(address_sanitizer)
> +#define __SANITIZE_ADDRESS__
> +#endif
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
--
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^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH v2 5/5] kasan: add compiler support for clang
2017-11-29 21:50 ` [PATCH v2 5/5] kasan: add compiler support for clang Paul Lawrence
2017-11-30 8:34 ` Dmitry Vyukov
@ 2017-11-30 16:45 ` Andrey Ryabinin
1 sibling, 0 replies; 14+ messages in thread
From: Andrey Ryabinin @ 2017-11-30 16:45 UTC (permalink / raw)
To: Paul Lawrence, Alexander Potapenko, Dmitry Vyukov,
Masahiro Yamada, Michal Marek
Cc: linux-kernel, kasan-dev, linux-mm, linux-kbuild,
Matthias Kaehlcke, Michael Davidson, Greg Hackmann
On 11/30/2017 12:50 AM, Paul Lawrence wrote:
> For now we can hard-code ASAN ABI level 5, since historical clang builds
> can't build the kernel anyway. We also need to emulate gcc's
> __SANITIZE_ADDRESS__ flag, or memset() calls won't be instrumented.
>
> Signed-off-by: Greg Hackmann <ghackmann@google.com>
> Signed-off-by: Paul Lawrence <paullawrence@google.com>
>
> ---
> include/linux/compiler-clang.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
> index 3b609edffa8f..d02a4df3f473 100644
> --- a/include/linux/compiler-clang.h
> +++ b/include/linux/compiler-clang.h
> @@ -19,3 +19,11 @@
>
> #define randomized_struct_fields_start struct {
> #define randomized_struct_fields_end };
> +
> +/* all clang versions usable with the kernel support KASAN ABI version 5 */
> +#define KASAN_ABI_VERSION 5
> +
This patch should be earlier in this series. Patch 4/5 breaks clang-built kernel, because
we start using globals instrumentation with wrong KASAN_ABI_VERSION.
> +/* emulate gcc's __SANITIZE_ADDRESS__ flag */
> +#if __has_feature(address_sanitizer)
> +#define __SANITIZE_ADDRESS__
> +#endif
>
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^ permalink raw reply [flat|nested] 14+ messages in thread