diff mbox series

[v3,07/11] kselftest: arm64: fake_sigreturn_bad_size_for_magic0

Message ID 20190802170300.20662-8-cristian.marussi@arm.com (mailing list archive)
State New
Headers show
Series Add arm64/signal initial kselftest support | expand

Commit Message

Cristian Marussi Aug. 2, 2019, 5:02 p.m. UTC 
Added a simple fake_sigreturn testcase which builds a ucontext_t
with a badly sized magic0 header and place it onto the stack.
Expects a SIGSEGV on test PASS.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 .../arm64/signal/testcases/.gitignore         |  1 +
 .../fake_sigreturn_bad_size_for_magic0.c      | 57 +++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c

Comments

Dave Martin Aug. 13, 2019, 4:25 p.m. UTC | #1 
On Fri, Aug 02, 2019 at 06:02:56PM +0100, Cristian Marussi wrote:
> Added a simple fake_sigreturn testcase which builds a ucontext_t

Add

> with a badly sized magic0 header and place it onto the stack.

I usually call a record with magic number 0 a "terminator record".

> Expects a SIGSEGV on test PASS.
> 
> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> ---
>  .../arm64/signal/testcases/.gitignore         |  1 +
>  .../fake_sigreturn_bad_size_for_magic0.c      | 57 +++++++++++++++++++
>  2 files changed, 58 insertions(+)
>  create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
> 
> diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> index 0ea6fdc3765c..cf2a73599818 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
> +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
> @@ -5,3 +5,4 @@ mangle_pstate_invalid_mode_el2
>  mangle_pstate_invalid_mode_el3
>  mangle_pstate_ssbs_regs
>  fake_sigreturn_bad_magic
> +fake_sigreturn_bad_size_for_magic0
> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
> new file mode 100644
> index 000000000000..2f53c4740c85
> --- /dev/null
> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
> @@ -0,0 +1,57 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/* Copyright (C) 2019 ARM Limited */
> +

#include <signal.h> ?

> +#include <stdio.h>
> +#include <ucontext.h>
> +
> +#include "test_signals_utils.h"
> +#include "testcases.h"
> +
> +struct fake_sigframe sf;
> +
> +#define MIN_SZ_ALIGN	16
> +
> +static int fake_sigreturn_bad_size_for_magic0_run(struct tdescr *td,
> +						  siginfo_t *si, ucontext_t *uc)
> +{
> +	size_t resv_sz, offset;
> +	struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
> +
> +	/* just to fill the ucontext_t with something real */
> +	if (!get_current_context(td, &sf.uc))
> +		return 1;
> +
> +	resv_sz = GET_SF_RESV_SIZE(sf);
> +	/*
> +	 * find the terminator, preserving existing headers
> +	 * and verify amount of spare room in __reserved area.
> +	 */
> +	head = get_terminator(shead, resv_sz, &offset);
> +	/*
> +	 * try stripping extra_context header when low on space:
> +	 * we need at least HDR_SZ + 16 space for the bad sized terminator.
> +	 */
> +	if (head && resv_sz - offset < HDR_SZ + MIN_SZ_ALIGN) {
> +		fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
> +			resv_sz - offset);
> +		head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset);
> +	}
> +	/* just give up and timeout if still not enough space */
> +	if (head && resv_sz - offset >= HDR_SZ + MIN_SZ_ALIGN) {
> +		head->magic = 0;
> +		head->size = MIN_SZ_ALIGN;

This is different from the amount of space we tested for
(HDR_SZ + MIN_SZ_ALIGN) earlier.

I'm not sure it matters which we use, but we should be consistent.

I suggest sticking with HDR_SZ, unless there's something I've missed.

[...]

Cheers
---Dave
Cristian Marussi Aug. 30, 2019, 2:49 p.m. UTC | #2 
On 13/08/2019 17:25, Dave Martin wrote:
> On Fri, Aug 02, 2019 at 06:02:56PM +0100, Cristian Marussi wrote:
>> Added a simple fake_sigreturn testcase which builds a ucontext_t
> 
> Add

Ok
> 
>> with a badly sized magic0 header and place it onto the stack.
> 
> I usually call a record with magic number 0 a "terminator record".
> 

Ok
>> Expects a SIGSEGV on test PASS.
>>
>> Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
>> ---
>>  .../arm64/signal/testcases/.gitignore         |  1 +
>>  .../fake_sigreturn_bad_size_for_magic0.c      | 57 +++++++++++++++++++
>>  2 files changed, 58 insertions(+)
>>  create mode 100644 tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
>>
>> diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
>> index 0ea6fdc3765c..cf2a73599818 100644
>> --- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
>> +++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
>> @@ -5,3 +5,4 @@ mangle_pstate_invalid_mode_el2
>>  mangle_pstate_invalid_mode_el3
>>  mangle_pstate_ssbs_regs
>>  fake_sigreturn_bad_magic
>> +fake_sigreturn_bad_size_for_magic0
>> diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
>> new file mode 100644
>> index 000000000000..2f53c4740c85
>> --- /dev/null
>> +++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
>> @@ -0,0 +1,57 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Copyright (C) 2019 ARM Limited */
>> +
> 
> #include <signal.h> ?
> 

Ok
>> +#include <stdio.h>
>> +#include <ucontext.h>
>> +
>> +#include "test_signals_utils.h"
>> +#include "testcases.h"
>> +
>> +struct fake_sigframe sf;
>> +
>> +#define MIN_SZ_ALIGN	16
>> +
>> +static int fake_sigreturn_bad_size_for_magic0_run(struct tdescr *td,
>> +						  siginfo_t *si, ucontext_t *uc)
>> +{
>> +	size_t resv_sz, offset;
>> +	struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
>> +
>> +	/* just to fill the ucontext_t with something real */
>> +	if (!get_current_context(td, &sf.uc))
>> +		return 1;
>> +
>> +	resv_sz = GET_SF_RESV_SIZE(sf);
>> +	/*
>> +	 * find the terminator, preserving existing headers
>> +	 * and verify amount of spare room in __reserved area.
>> +	 */
>> +	head = get_terminator(shead, resv_sz, &offset);
>> +	/*
>> +	 * try stripping extra_context header when low on space:
>> +	 * we need at least HDR_SZ + 16 space for the bad sized terminator.
>> +	 */
>> +	if (head && resv_sz - offset < HDR_SZ + MIN_SZ_ALIGN) {
>> +		fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
>> +			resv_sz - offset);
>> +		head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset);
>> +	}
>> +	/* just give up and timeout if still not enough space */
>> +	if (head && resv_sz - offset >= HDR_SZ + MIN_SZ_ALIGN) {
>> +		head->magic = 0;
>> +		head->size = MIN_SZ_ALIGN;
> 
> This is different from the amount of space we tested for
> (HDR_SZ + MIN_SZ_ALIGN) earlier.
> 
> I'm not sure it matters which we use, but we should be consistent.
> 
> I suggest sticking with HDR_SZ, unless there's something I've missed.
> 
I'll stick to HDR_SZ in this case and use the new helper from 06/11
(get_starting_head)

> [...]
> 
> Cheers
> ---Dave
> 

Cheers

Cristian
diff mbox series

Patch

diff --git a/tools/testing/selftests/arm64/signal/testcases/.gitignore b/tools/testing/selftests/arm64/signal/testcases/.gitignore
index 0ea6fdc3765c..cf2a73599818 100644
--- a/tools/testing/selftests/arm64/signal/testcases/.gitignore
+++ b/tools/testing/selftests/arm64/signal/testcases/.gitignore
@@ -5,3 +5,4 @@  mangle_pstate_invalid_mode_el2
 mangle_pstate_invalid_mode_el3
 mangle_pstate_ssbs_regs
 fake_sigreturn_bad_magic
+fake_sigreturn_bad_size_for_magic0
diff --git a/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
new file mode 100644
index 000000000000..2f53c4740c85
--- /dev/null
+++ b/tools/testing/selftests/arm64/signal/testcases/fake_sigreturn_bad_size_for_magic0.c
@@ -0,0 +1,57 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2019 ARM Limited */
+
+#include <stdio.h>
+#include <ucontext.h>
+
+#include "test_signals_utils.h"
+#include "testcases.h"
+
+struct fake_sigframe sf;
+
+#define MIN_SZ_ALIGN	16
+
+static int fake_sigreturn_bad_size_for_magic0_run(struct tdescr *td,
+						  siginfo_t *si, ucontext_t *uc)
+{
+	size_t resv_sz, offset;
+	struct _aarch64_ctx *shead = GET_SF_RESV_HEAD(sf), *head;
+
+	/* just to fill the ucontext_t with something real */
+	if (!get_current_context(td, &sf.uc))
+		return 1;
+
+	resv_sz = GET_SF_RESV_SIZE(sf);
+	/*
+	 * find the terminator, preserving existing headers
+	 * and verify amount of spare room in __reserved area.
+	 */
+	head = get_terminator(shead, resv_sz, &offset);
+	/*
+	 * try stripping extra_context header when low on space:
+	 * we need at least HDR_SZ + 16 space for the bad sized terminator.
+	 */
+	if (head && resv_sz - offset < HDR_SZ + MIN_SZ_ALIGN) {
+		fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
+			resv_sz - offset);
+		head = get_header(shead, EXTRA_MAGIC, resv_sz, &offset);
+	}
+	/* just give up and timeout if still not enough space */
+	if (head && resv_sz - offset >= HDR_SZ + MIN_SZ_ALIGN) {
+		head->magic = 0;
+		head->size = MIN_SZ_ALIGN;
+
+		ASSERT_BAD_CONTEXT(&sf.uc);
+		fake_sigreturn(&sf, sizeof(sf), 16);
+	}
+
+	return 1;
+}
+
+struct tdescr tde = {
+		.name = "FAKE_SIGRETURN_BAD_SIZE_FOR_MAGIC0",
+		.descr = "Triggers a fake sigreturn with a sigframe including a bad non-zero size magic0",
+		.sig_ok = SIGSEGV,
+		.timeout = 3,
+		.run = fake_sigreturn_bad_size_for_magic0_run,
+};