diff mbox series

[v2,3/4] Demonstrating unit testing via simple-harness

Message ID 20190612153600.13073-4-samcacc@amazon.de (mailing list archive)
State New, archived
Headers show
Series x86 instruction emulator fuzzing | expand

Commit Message

Sam Caccavale June 12, 2019, 3:35 p.m. UTC 
Simple-harness.c uses inline asm support to generate asm and then has the
emulator emulate this code.  This may be useful as a form of testing for
the emulator.

CR: https://code.amazon.com/reviews/CR-8591638
---
 tools/fuzz/x86ie/Makefile         |  7 ++++--
 tools/fuzz/x86ie/simple-harness.c | 42 +++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 tools/fuzz/x86ie/simple-harness.c

--
2.17.1




Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Ralf Herbrich
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879

Comments

Alexander Graf June 21, 2019, 1:43 p.m. UTC | #1 
On 12.06.19 17:35, Sam Caccavale wrote:
> Simple-harness.c uses inline asm support to generate asm and then has the
> emulator emulate this code.  This may be useful as a form of testing for
> the emulator.
> 
> CR: https://code.amazon.com/reviews/CR-8591638
> ---
>   tools/fuzz/x86ie/Makefile         |  7 ++++--
>   tools/fuzz/x86ie/simple-harness.c | 42 +++++++++++++++++++++++++++++++
>   2 files changed, 47 insertions(+), 2 deletions(-)
>   create mode 100644 tools/fuzz/x86ie/simple-harness.c
> 
> diff --git a/tools/fuzz/x86ie/Makefile b/tools/fuzz/x86ie/Makefile
> index d45fe6d266b9..e79d275e1040 100644
> --- a/tools/fuzz/x86ie/Makefile
> +++ b/tools/fuzz/x86ie/Makefile
> @@ -44,8 +44,11 @@ LOCAL_OBJS := emulator_ops.o stubs.o
>   afl-harness: afl-harness.o $(LOCAL_OBJS) $(KERNEL_OBJS)
>   	@$(CC) -v $(KBUILD_CFLAGS) $(LOCAL_OBJS) $(KERNEL_OBJS) $< $(INCLUDES) -Istubs.h -o $@ -no-pie
> 
> -all: afl-harness
> +simple-harness: simple-harness.o $(LOCAL_OBJS) $(KERNEL_OBJS)
> +	@$(CC) -v $(KBUILD_CFLAGS) $(LOCAL_OBJS) $(KERNEL_OBJS) $< $(INCLUDES) -Istubs.h -o $@ -no-pie
> +
> +all: afl-harness simple-harness
> 
>   .PHONY: clean
>   clean:
> -	$(RM) -r *.o afl-harness
> +	$(RM) -r *.o afl-harness simple-harness
> diff --git a/tools/fuzz/x86ie/simple-harness.c b/tools/fuzz/x86ie/simple-harness.c
> new file mode 100644
> index 000000000000..f21fdafe1dd1
> --- /dev/null
> +++ b/tools/fuzz/x86ie/simple-harness.c
> @@ -0,0 +1,42 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <assert.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include "emulator_ops.h"
> +#include <asm/kvm_emulate.h>
> +
> +extern void foo(void)
> +{
> +	asm volatile("__start:"
> +		     ".byte 0x32, 0x05, 0x00, 0x00, 0x00, 0x00;" // xor eax,DWORD PTR [rip+0x0]
> +		     ".byte 0x90;"
> +		     //".byte 0x0f, 0x7f, 0xde;" // movq mm6,mm3

Why?

Alex
diff mbox series

Patch

diff --git a/tools/fuzz/x86ie/Makefile b/tools/fuzz/x86ie/Makefile
index d45fe6d266b9..e79d275e1040 100644
--- a/tools/fuzz/x86ie/Makefile
+++ b/tools/fuzz/x86ie/Makefile
@@ -44,8 +44,11 @@  LOCAL_OBJS := emulator_ops.o stubs.o
 afl-harness: afl-harness.o $(LOCAL_OBJS) $(KERNEL_OBJS)
 	@$(CC) -v $(KBUILD_CFLAGS) $(LOCAL_OBJS) $(KERNEL_OBJS) $< $(INCLUDES) -Istubs.h -o $@ -no-pie

-all: afl-harness
+simple-harness: simple-harness.o $(LOCAL_OBJS) $(KERNEL_OBJS)
+	@$(CC) -v $(KBUILD_CFLAGS) $(LOCAL_OBJS) $(KERNEL_OBJS) $< $(INCLUDES) -Istubs.h -o $@ -no-pie
+
+all: afl-harness simple-harness

 .PHONY: clean
 clean:
-	$(RM) -r *.o afl-harness
+	$(RM) -r *.o afl-harness simple-harness
diff --git a/tools/fuzz/x86ie/simple-harness.c b/tools/fuzz/x86ie/simple-harness.c
new file mode 100644
index 000000000000..f21fdafe1dd1
--- /dev/null
+++ b/tools/fuzz/x86ie/simple-harness.c
@@ -0,0 +1,42 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <assert.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include "emulator_ops.h"
+#include <asm/kvm_emulate.h>
+
+extern void foo(void)
+{
+	asm volatile("__start:"
+		     ".byte 0x32, 0x05, 0x00, 0x00, 0x00, 0x00;" // xor eax,DWORD PTR [rip+0x0]
+		     ".byte 0x90;"
+		     //".byte 0x0f, 0x7f, 0xde;" // movq mm6,mm3
+		     ".byte 0x0f, 0x6f, 0xde;" // same instruction...
+		     ".byte 0x90;"
+		     "__end:");
+}
+
+int main(int argc, char **argv)
+{
+	extern unsigned char __start;
+	extern unsigned char __end;
+	struct state *state = create_emulator();
+	int rc;
+
+	/* Ensures the emulator is in a valid state. */
+	initialize_emulator(state);
+
+	/* Provide the emulator with instructions to emulate. */
+	state->data = &__start;
+	state->data_available = &__end - &__start;
+
+	/* rip addressed instruction */
+	rc = emulate_until_complete(state);
+
+	/* Free the emulator. */
+	free_emulator(state);
+
+	return 0;
+}