[PATCH V2 00/15] selftests/sgx: Oversubscription, page permission, thread entry

[PATCH V2 00/15] selftests/sgx: Oversubscription, page permission, thread entry

[Reinette Chatre]

V1 available at:
https://lore.kernel.org/lkml/cover.1631731214.git.reinette.chatre@intel.com/

Changes since V1:

- Biggest change: The non-kselftest placeholder patches included in this series
  that the kselftest work depends on are still being discussed elsewhere
  (link below) but has changed significantly since the first submission,
  warranting an update to the kselftest patches that depend on it.
  Jarkko: I made significant modifications to your
  "selftests/sgx: Add a new kselftest: unclobbered_vdso_oversubscribed"
  that you may want to look at.
- Improve cover letter and changelogs (Dave).
- Add Jarkko and Dave's signatures where obtained (Jarkko and Dave).
- Fix Cedric's signature in patch 1 (Jarkko and Cedric).
- Improve the loop locating the data segment (Jarkko).
- Update placeholder patches that makes the amount of SGX memory available to
  latest version (v8). Previously this dependency consisted out of one
  patch, now it spans two.

Hi Everybody,

This series consists out of outstanding SGX selftests changes, rebased
and gathered in a single series that can easily be merged for testing
and development, and a few more changes added to expand the existing tests.

The outstanding SGX selftest changes included in this series that have already
been submitted separately are:

* A more than two year old patch fixing a benign linker warning that is still
  present today:
  https://lore.kernel.org/linux-sgx/20191017030340.18301-2-sean.j.christopherson@intel.com/
  The original patch is added intact and not all email addresses
  within are valid.

* Latest (v4) of Jarkko Sakkinen's series to add an oversubscription test:
  https://lore.kernel.org/linux-sgx/20210809093127.76264-1-jarkko@kernel.org/

* Latest (v2) of Jarkko Sakkinen's patch that provides per-op
  parameter structs for the test enclave:
  https://lore.kernel.org/linux-sgx/20210812224645.90280-1-jarkko@kernel.org/

The reason why most of these patches are outstanding is that they depend
on a kernel change that is still under discussion. Decision to wait in:
https://lore.kernel.org/linux-sgx/f8674dac5579a8a424de1565f7ffa2b5bf2f8e36.camel@kernel.org/
The latest patches (v8) for this dependency is included in
this series as a placeholder until the ongoing discussions are concluded:
https://lore.kernel.org/lkml/20211018135744.45527-1-jarkko@kernel.org/
https://lore.kernel.org/lkml/20211018135744.45527-2-jarkko@kernel.org/

The new changes introduced in this series builds on Jarkko's outstanding
SGX selftest changes and adds new tests for page permissions, exception
handling, and thread entry.

Building and running enclaves is painful and traditionally requires a
big software stack. This adds features like threads to the SGX selftests
which are traditionally implemented in that big software stack. This
helps test SGX kernel support with only code from the kernel tree.

Reinette

Jarkko Sakkinen (10):
  x86/sgx: Rename fallback labels in sgx_init()
  x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node
  selftests/sgx: Assign source for each segment
  selftests/sgx: Make data measurement for an enclave segment optional
  selftests/sgx: Create a heap for the test enclave
  selftests/sgx: Dump segments and /proc/self/maps only on failure
  selftests/sgx: Encpsulate the test enclave creation
  selftests/sgx: Move setup_test_encl() to each TEST_F()
  selftests/sgx: Add a new kselftest: unclobbered_vdso_oversubscribed
  selftests/sgx: Provide per-op parameter structs for the test enclave

Reinette Chatre (4):
  selftests/sgx: Rename test properties in preparation for more enclave
    tests
  selftests/sgx: Add page permission and exception test
  selftests/sgx: Enable multiple thread support
  selftests/sgx: Add test for multiple TCS entry

Sean Christopherson (1):
  selftests/x86/sgx: Fix a benign linker warning

 Documentation/ABI/stable/sysfs-devices-node   |   7 +
 arch/x86/kernel/cpu/sgx/main.c                |  97 ++++-
 arch/x86/kernel/cpu/sgx/sgx.h                 |   2 +
 tools/testing/selftests/sgx/Makefile          |   2 +-
 tools/testing/selftests/sgx/defines.h         |  33 +-
 tools/testing/selftests/sgx/load.c            |  40 +-
 tools/testing/selftests/sgx/main.c            | 396 ++++++++++++++++--
 tools/testing/selftests/sgx/main.h            |   7 +-
 tools/testing/selftests/sgx/sigstruct.c       |  12 +-
 tools/testing/selftests/sgx/test_encl.c       |  60 ++-
 .../selftests/sgx/test_encl_bootstrap.S       |  21 +-
 11 files changed, 585 insertions(+), 92 deletions(-)

base-commit: 7d2a07b769330c34b4deabeed939325c77a7ec2f

-- 
2.25.1

[PATCH V2 01/15] selftests/x86/sgx: Fix a benign linker warning

[Reinette Chatre]

From: Sean Christopherson <sean.j.christopherson@intel.com>

Pass a build id of "none" to the linker to suppress a warning about the
build id being ignored:

  /usr/bin/ld: warning: .note.gnu.build-id section discarded, --build-id
  ignored.

Link: https://lore.kernel.org/linux-sgx/20191017030340.18301-2-sean.j.christopherson@intel.com/
Suggested-by: Cedric Xing <cedric.xing@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Change Cedric's signature to a "Suggested-by" (Jarkko and Cedric).
- Add signatures from Jarkko and Dave.

 tools/testing/selftests/sgx/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/sgx/Makefile b/tools/testing/selftests/sgx/Makefile
index 7f12d55b97f8..2956584e1e37 100644
--- a/tools/testing/selftests/sgx/Makefile
+++ b/tools/testing/selftests/sgx/Makefile
@@ -45,7 +45,7 @@ $(OUTPUT)/sign_key.o: sign_key.S
 	$(CC) $(HOST_CFLAGS) -c $< -o $@
 
 $(OUTPUT)/test_encl.elf: test_encl.lds test_encl.c test_encl_bootstrap.S
-	$(CC) $(ENCL_CFLAGS) -T $^ -o $@
+	$(CC) $(ENCL_CFLAGS) -T $^ -o $@ -Wl,--build-id=none
 
 EXTRA_CLEAN := \
 	$(OUTPUT)/test_encl.elf \
-- 
2.25.1

Re: [PATCH V2 01/15] selftests/x86/sgx: Fix a benign linker warning

[Dave Hansen]

On 10/28/21 1:37 PM, Reinette Chatre wrote:
> From: Sean Christopherson <sean.j.christopherson@intel.com>
> 
> Pass a build id of "none" to the linker to suppress a warning about the
> build id being ignored:
> 
>   /usr/bin/ld: warning: .note.gnu.build-id section discarded, --build-id
>   ignored.

Do we have a good grasp on why this is producing a warning in the first
place?  This seems like something that could get merged quickly with one
more sentence in the changelog.

Re: [PATCH V2 01/15] selftests/x86/sgx: Fix a benign linker warning

[Sean Christopherson]

On Thu, Oct 28, 2021, Dave Hansen wrote:
> On 10/28/21 1:37 PM, Reinette Chatre wrote:
> > From: Sean Christopherson <sean.j.christopherson@intel.com>
> > 
> > Pass a build id of "none" to the linker to suppress a warning about the
> > build id being ignored:
> > 
> >   /usr/bin/ld: warning: .note.gnu.build-id section discarded, --build-id
> >   ignored.
> 
> Do we have a good grasp on why this is producing a warning in the first
> place?  This seems like something that could get merged quickly with one
> more sentence in the changelog.

The SGX selftests use a custom linker script, tools/testing/selftests/sgx/test_encl.lds,
to configure the resulting enclave binary so that it's loadable as an enclave
more or less as-is.  One of the things the script does is drop sections the
selftests doesn't want, .note* sections being in that category.  I don't recall
exactly why the script drops sections; I assume it's to simply the loading process.
Anyways, .note.gnu.build-id is collateral damage and the linker complains.

Re: [PATCH V2 01/15] selftests/x86/sgx: Fix a benign linker warning

[Reinette Chatre]

Hi Dave,

On 10/28/2021 5:26 PM, Dave Hansen wrote:
> On 10/28/21 1:37 PM, Reinette Chatre wrote:
>> From: Sean Christopherson <sean.j.christopherson@intel.com>
>>
>> Pass a build id of "none" to the linker to suppress a warning about the
>> build id being ignored:
>>
>>    /usr/bin/ld: warning: .note.gnu.build-id section discarded, --build-id
>>    ignored.
> 
> Do we have a good grasp on why this is producing a warning in the first
> place?  This seems like something that could get merged quickly with one
> more sentence in the changelog.
> 

How about a new changelog as below:

The enclave binary (test_encl.elf) is built with only three sections 
(tcs, text, and data) as controlled by its custom linker script.

If gcc is built with "--enable-linker-build-id" (this appears to be a 
common configuration even if it is by default off) then gcc will pass 
"--build-id" to the linker that will prompt it (the linker) to to write 
unique bits identifying the linked file to a ".note.gnu.build-id" section.

The section ".note.gnu.build-id" does not exist in the test enclave 
resulting in the following warning emitted by the linker:

/usr/bin/ld: warning: .note.gnu.build-id section discarded, --build-id 
ignored

The test enclave does not use the build id within the binary so fix the 
warning by passing a build id of "none" to the linker that will disable 
the setting from any earlier "--build-id" options and thus disable the 
attempt to write the build id to a ".note.gnu.build-id" section that 
does not exist.

Reinette

Re: [PATCH V2 01/15] selftests/x86/sgx: Fix a benign linker warning

[Dave Hansen]

On 10/29/21 10:09 AM, Reinette Chatre wrote:
> On 10/28/2021 5:26 PM, Dave Hansen wrote:
>> On 10/28/21 1:37 PM, Reinette Chatre wrote:
>>> From: Sean Christopherson <sean.j.christopherson@intel.com>
>>>
>>> Pass a build id of "none" to the linker to suppress a warning about the
>>> build id being ignored:
>>>
>>>    /usr/bin/ld: warning: .note.gnu.build-id section discarded,
>>> --build-id
>>>    ignored.
>>
>> Do we have a good grasp on why this is producing a warning in the first
>> place?  This seems like something that could get merged quickly with one
>> more sentence in the changelog.
>>
> 
> How about a new changelog as below:
> 
> The enclave binary (test_encl.elf) is built with only three sections
> (tcs, text, and data) as controlled by its custom linker script.
> 
> If gcc is built with "--enable-linker-build-id" (this appears to be a
> common configuration even if it is by default off) then gcc will pass
> "--build-id" to the linker that will prompt it (the linker) to to write
> unique bits identifying the linked file to a ".note.gnu.build-id" section.
> 
> The section ".note.gnu.build-id" does not exist in the test enclave
> resulting in the following warning emitted by the linker:
> 
> /usr/bin/ld: warning: .note.gnu.build-id section discarded, --build-id
> ignored
> 
> The test enclave does not use the build id within the binary so fix the
> warning by passing a build id of "none" to the linker that will disable
> the setting from any earlier "--build-id" options and thus disable the
> attempt to write the build id to a ".note.gnu.build-id" section that
> does not exist.

Looks great, thanks for putting that together!

[PATCH V2 02/15] x86/sgx: Rename fallback labels in sgx_init()

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

It's hard to add new content to this function because it is time
consuming to match fallback and its cause. Rename labels in a way
that the name of error label refers to the site where failure
happened. This way it is easier to keep on track what is going
on.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
[reinette: Placeholder patch - submitted separately upstream
https://lore.kernel.org/lkml/20211018135744.45527-1-jarkko@kernel.org/
]
---
 arch/x86/kernel/cpu/sgx/main.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 63d3de02bbcc..a6e313f1a82d 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -803,12 +803,12 @@ static int __init sgx_init(void)
 
 	if (!sgx_page_reclaimer_init()) {
 		ret = -ENOMEM;
-		goto err_page_cache;
+		goto err_reclaimer;
 	}
 
 	ret = misc_register(&sgx_dev_provision);
 	if (ret)
-		goto err_kthread;
+		goto err_provision;
 
 	/*
 	 * Always try to initialize the native *and* KVM drivers.
@@ -821,17 +821,17 @@ static int __init sgx_init(void)
 	ret = sgx_drv_init();
 
 	if (sgx_vepc_init() && ret)
-		goto err_provision;
+		goto err_driver;
 
 	return 0;
 
-err_provision:
+err_driver:
 	misc_deregister(&sgx_dev_provision);
 
-err_kthread:
+err_provision:
 	kthread_stop(ksgxd_tsk);
 
-err_page_cache:
+err_reclaimer:
 	for (i = 0; i < sgx_nr_epc_sections; i++) {
 		vfree(sgx_epc_sections[i].pages);
 		memunmap(sgx_epc_sections[i].virt_addr);
-- 
2.25.1

Re: [PATCH V2 02/15] x86/sgx: Rename fallback labels in sgx_init()

[Dave Hansen]

On 10/28/21 1:37 PM, Reinette Chatre wrote:
> -err_provision:
> +err_driver:
>  	misc_deregister(&sgx_dev_provision);
>  
> -err_kthread:
> +err_provision:
>  	kthread_stop(ksgxd_tsk);
>  
> -err_page_cache:
> +err_reclaimer:
>  	for (i = 0; i < sgx_nr_epc_sections; i++) {
>  		vfree(sgx_epc_sections[i].pages);
>  		memunmap(sgx_epc_sections[i].virt_addr);

This isn't the normal pattern we use in the kernel.

Usually, we say what is being *DONE* at the label, almost like we are
calling a function.  Here's a random example from one of the most
prolific users of gotos in arch/x86:

        ret = kernfs_get_tree(fc);
        if (ret < 0)
                goto out_psl;
...
out_psl:
        rdt_pseudo_lock_release();

See?  The "psl" is doing a "pseudo lock release".

I don't particularly like the labels as-is, but this patch makes them
less clear, IMNHO.  Let's just drop this patch for now, please.

[PATCH V2 03/15] x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

The amount of SGX memory on the system is determined by the BIOS and it
varies wildly between systems.  It can be from dozens of MB's on desktops
or VM's, up to many GB's on servers.  Just like for regular memory, it is
sometimes useful to know the amount of usable SGX memory in the system.

Add an attribute for the amount of SGX memory in bytes to each NUMA
node. The path is /sys/devices/system/node/node[0-9]*/sgx/size.
Calculate these values by summing up EPC section sizes for each node
during the driver initalization.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
[reinette: Placeholder patch - submitted separately upstream
https://lore.kernel.org/lkml/20211018135744.45527-2-jarkko@kernel.org/
]
---
 Documentation/ABI/stable/sysfs-devices-node |  7 ++
 arch/x86/kernel/cpu/sgx/main.c              | 85 +++++++++++++++++++++
 arch/x86/kernel/cpu/sgx/sgx.h               |  2 +
 3 files changed, 94 insertions(+)

diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node
index 484fc04bcc25..12dc2149e8e0 100644
--- a/Documentation/ABI/stable/sysfs-devices-node
+++ b/Documentation/ABI/stable/sysfs-devices-node
@@ -176,3 +176,10 @@ Contact:	Keith Busch <keith.busch@intel.com>
 Description:
 		The cache write policy: 0 for write-back, 1 for write-through,
 		other or unknown.
+
+What:		/sys/devices/system/node/nodeX/sgx/size
+Date:		October 2021
+Contact:	Jarkko Sakkinen <jarkko@kernel.org>
+Description:
+		Total available physical SGX memory, also known as Enclave Page
+		Cache (EPC), in bytes.
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index a6e313f1a82d..dc1d46c51323 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -714,9 +714,11 @@ static bool __init sgx_page_cache_init(void)
 			spin_lock_init(&sgx_numa_nodes[nid].lock);
 			INIT_LIST_HEAD(&sgx_numa_nodes[nid].free_page_list);
 			node_set(nid, sgx_numa_mask);
+			sgx_numa_nodes[nid].size = 0;
 		}
 
 		sgx_epc_sections[i].node =  &sgx_numa_nodes[nid];
+		sgx_numa_nodes[nid].size += size;
 
 		sgx_nr_epc_sections++;
 	}
@@ -790,6 +792,81 @@ int sgx_set_attribute(unsigned long *allowed_attributes,
 }
 EXPORT_SYMBOL_GPL(sgx_set_attribute);
 
+#ifdef CONFIG_NUMA
+static ssize_t size_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	unsigned long size = 0;
+	int nid;
+
+	for (nid = 0; nid < num_possible_nodes(); nid++) {
+		if (dev == sgx_numa_nodes[nid].dev) {
+			size = sgx_numa_nodes[nid].size;
+			break;
+		}
+	}
+
+	return sysfs_emit(buf, "%lu\n", size);
+}
+DEVICE_ATTR_RO(size);
+
+static struct attribute *sgx_node_attrs[] = {
+	&dev_attr_size.attr,
+	NULL,
+};
+
+static const struct attribute_group sgx_node_attr_group = {
+	.name = "sgx",
+	.attrs = sgx_node_attrs,
+};
+
+static void sgx_numa_exit(void)
+{
+	struct device *dev;
+	int nid;
+
+	for (nid = 0; nid < num_possible_nodes(); nid++) {
+		dev = &node_devices[nid]->dev;
+		if (dev)
+			sysfs_remove_group(&dev->kobj, &sgx_node_attr_group);
+	}
+}
+
+static bool sgx_numa_init(void)
+{
+	struct sgx_numa_node *node;
+	struct device *dev;
+	int nid;
+	int ret;
+
+	for (nid = 0; nid < num_possible_nodes(); nid++) {
+		if (!sgx_numa_nodes[nid].size)
+			continue;
+
+		node = &sgx_numa_nodes[nid];
+		dev = &node_devices[nid]->dev;
+
+		ret = sysfs_create_group(&dev->kobj, &sgx_node_attr_group);
+		if (ret) {
+			sgx_numa_exit();
+			return false;
+		}
+
+		node->dev = dev;
+	}
+
+	return true;
+}
+#else
+static inline void sgx_numa_exit(void)
+{
+}
+
+static inline bool sgx_numa_init(void)
+{
+	return true;
+}
+#endif /* CONFIG_NUMA */
+
 static int __init sgx_init(void)
 {
 	int ret;
@@ -806,6 +883,11 @@ static int __init sgx_init(void)
 		goto err_reclaimer;
 	}
 
+	if (!sgx_numa_init()) {
+		ret = -ENOMEM;
+		goto err_numa_nodes;
+	}
+
 	ret = misc_register(&sgx_dev_provision);
 	if (ret)
 		goto err_provision;
@@ -829,6 +911,9 @@ static int __init sgx_init(void)
 	misc_deregister(&sgx_dev_provision);
 
 err_provision:
+	sgx_numa_exit();
+
+err_numa_nodes:
 	kthread_stop(ksgxd_tsk);
 
 err_reclaimer:
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index 4628acec0009..1de8c627a286 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -39,6 +39,8 @@ struct sgx_epc_page {
  */
 struct sgx_numa_node {
 	struct list_head free_page_list;
+	struct device *dev;
+	unsigned long size;
 	spinlock_t lock;
 };
 
-- 
2.25.1

Re: [PATCH V2 03/15] x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node

[Dave Hansen]

On 10/28/21 1:37 PM, Reinette Chatre wrote:
> The amount of SGX memory on the system is determined by the BIOS and it
> varies wildly between systems.  It can be from dozens of MB's on desktops
> or VM's, up to many GB's on servers.  Just like for regular memory, it is
> sometimes useful to know the amount of usable SGX memory in the system.
> 
> Add an attribute for the amount of SGX memory in bytes to each NUMA
> node. The path is /sys/devices/system/node/node[0-9]*/sgx/size.
> Calculate these values by summing up EPC section sizes for each node
> during the driver initalization.

For now, can we just make the selftests read the SGX CPUID section
leaves?  It's not as precise as knowing how much the kernel actually
decided to use, but it's good enough for a selftest.  It also means we
can merge something without having to worry about long-term ABI.

This is also why I once suggested that we first make the selftests
depend on some debugfs file that would be short-lived.  But, if we use
CPUID, we don't even need to mess with debugfs.

You can even just steal the code from sgx_page_cache_init() to do it.

Would that work, or am I missing something?

Re: [PATCH V2 03/15] x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node

[Reinette Chatre]

Hi Dave,

On 10/29/2021 11:06 AM, Dave Hansen wrote:
> On 10/28/21 1:37 PM, Reinette Chatre wrote:
>> The amount of SGX memory on the system is determined by the BIOS and it
>> varies wildly between systems.  It can be from dozens of MB's on desktops
>> or VM's, up to many GB's on servers.  Just like for regular memory, it is
>> sometimes useful to know the amount of usable SGX memory in the system.
>>
>> Add an attribute for the amount of SGX memory in bytes to each NUMA
>> node. The path is /sys/devices/system/node/node[0-9]*/sgx/size.
>> Calculate these values by summing up EPC section sizes for each node
>> during the driver initalization.
> 
> For now, can we just make the selftests read the SGX CPUID section
> leaves?  It's not as precise as knowing how much the kernel actually
> decided to use, but it's good enough for a selftest.  It also means we
> can merge something without having to worry about long-term ABI.

Yes, we can do that.

> 
> This is also why I once suggested that we first make the selftests
> depend on some debugfs file that would be short-lived.  But, if we use
> CPUID, we don't even need to mess with debugfs.

My apologies, this was not intended to avoid your suggestion. V1 did use 
the debugfs solution as you suggested as placeholder but after the 
debufs solution evolved the tests were adapted to follow those changes 
instead of sticking with the debugfs solution as proposed in
https://lore.kernel.org/lkml/6f3cc681e10877e639b882eaabf1a5e21bd2fc94.camel@kernel.org/

> You can even just steal the code from sgx_page_cache_init() to do it.
> 
> Would that work, or am I missing something?
> 

I do think that will work. The selftests are only interested in the 
total SGX memory (as opposed to memory per numa node as exposed with the 
current interface) and that can be obtained via CPUID. I will adapt the 
oversubscription test case to obtain its needed info via CPUID.

Thank you very much

Reinette

[PATCH V2 04/15] selftests/sgx: Assign source for each segment

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

Define source per segment so that enclave pages can be added from different
sources, e.g. anonymous VMA for zero pages. In other words, add 'src' field
to struct encl_segment, and assign it to 'encl->src' for pages inherited
from the enclave binary.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.

 tools/testing/selftests/sgx/load.c      | 5 +++--
 tools/testing/selftests/sgx/main.h      | 1 +
 tools/testing/selftests/sgx/sigstruct.c | 8 ++++----
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c
index 3ebe5d1fe337..5605474aab73 100644
--- a/tools/testing/selftests/sgx/load.c
+++ b/tools/testing/selftests/sgx/load.c
@@ -107,7 +107,7 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
 	memset(&secinfo, 0, sizeof(secinfo));
 	secinfo.flags = seg->flags;
 
-	ioc.src = (uint64_t)encl->src + seg->offset;
+	ioc.src = (uint64_t)seg->src;
 	ioc.offset = seg->offset;
 	ioc.length = seg->size;
 	ioc.secinfo = (unsigned long)&secinfo;
@@ -216,6 +216,7 @@ bool encl_load(const char *path, struct encl *encl)
 
 		if (j == 0) {
 			src_offset = phdr->p_offset & PAGE_MASK;
+			encl->src = encl->bin + src_offset;
 
 			seg->prot = PROT_READ | PROT_WRITE;
 			seg->flags = SGX_PAGE_TYPE_TCS << 8;
@@ -228,13 +229,13 @@ bool encl_load(const char *path, struct encl *encl)
 
 		seg->offset = (phdr->p_offset & PAGE_MASK) - src_offset;
 		seg->size = (phdr->p_filesz + PAGE_SIZE - 1) & PAGE_MASK;
+		seg->src = encl->src + seg->offset;
 
 		j++;
 	}
 
 	assert(j == encl->nr_segments);
 
-	encl->src = encl->bin + src_offset;
 	encl->src_size = encl->segment_tbl[j - 1].offset +
 			 encl->segment_tbl[j - 1].size;
 
diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h
index 68672fd86cf9..452d11dc4889 100644
--- a/tools/testing/selftests/sgx/main.h
+++ b/tools/testing/selftests/sgx/main.h
@@ -7,6 +7,7 @@
 #define MAIN_H
 
 struct encl_segment {
+	void *src;
 	off_t offset;
 	size_t size;
 	unsigned int prot;
diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c
index 92bbc5a15c39..202a96fd81bf 100644
--- a/tools/testing/selftests/sgx/sigstruct.c
+++ b/tools/testing/selftests/sgx/sigstruct.c
@@ -289,14 +289,14 @@ static bool mrenclave_eextend(EVP_MD_CTX *ctx, uint64_t offset,
 static bool mrenclave_segment(EVP_MD_CTX *ctx, struct encl *encl,
 			      struct encl_segment *seg)
 {
-	uint64_t end = seg->offset + seg->size;
+	uint64_t end = seg->size;
 	uint64_t offset;
 
-	for (offset = seg->offset; offset < end; offset += PAGE_SIZE) {
-		if (!mrenclave_eadd(ctx, offset, seg->flags))
+	for (offset = 0; offset < end; offset += PAGE_SIZE) {
+		if (!mrenclave_eadd(ctx, seg->offset + offset, seg->flags))
 			return false;
 
-		if (!mrenclave_eextend(ctx, offset, encl->src + offset))
+		if (!mrenclave_eextend(ctx, seg->offset + offset, seg->src + offset))
 			return false;
 	}
 
-- 
2.25.1

[PATCH V2 05/15] selftests/sgx: Make data measurement for an enclave segment optional

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

For a heap makes sense to leave its contents "unmeasured" in the SGX
enclave build process, meaning that they won't contribute to the
cryptographic signature (a RSA-3072 signed SHA56 hash) of the enclave.

Enclaves are signed blobs where the signature is calculated both from
page data and also from "structural properties" of the pages.  For
instance a page offset of *every* page added to the enclave is hashed.

For data, this is optional, not least because hashing a page has a
significant contribution to the enclave load time. Thus, where there is
no reason to hash, do not. The SGX ioctl interface supports this with
SGX_PAGE_MEASURE flag. Only when the flag is *set*, data is measured.

Add seg->measure boolean flag to struct encl_segment. Only when the
flag is set, include the segment data to the signature (represented
by SIGSTRUCT architectural structure).

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.

 tools/testing/selftests/sgx/load.c      | 6 +++++-
 tools/testing/selftests/sgx/main.h      | 1 +
 tools/testing/selftests/sgx/sigstruct.c | 6 ++++--
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c
index 5605474aab73..f1be78984c50 100644
--- a/tools/testing/selftests/sgx/load.c
+++ b/tools/testing/selftests/sgx/load.c
@@ -111,7 +111,10 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
 	ioc.offset = seg->offset;
 	ioc.length = seg->size;
 	ioc.secinfo = (unsigned long)&secinfo;
-	ioc.flags = SGX_PAGE_MEASURE;
+	if (seg->measure)
+		ioc.flags = SGX_PAGE_MEASURE;
+	else
+		ioc.flags = 0;
 
 	rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_ADD_PAGES, &ioc);
 	if (rc < 0) {
@@ -230,6 +233,7 @@ bool encl_load(const char *path, struct encl *encl)
 		seg->offset = (phdr->p_offset & PAGE_MASK) - src_offset;
 		seg->size = (phdr->p_filesz + PAGE_SIZE - 1) & PAGE_MASK;
 		seg->src = encl->src + seg->offset;
+		seg->measure = true;
 
 		j++;
 	}
diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h
index 452d11dc4889..aebc69e7cdc8 100644
--- a/tools/testing/selftests/sgx/main.h
+++ b/tools/testing/selftests/sgx/main.h
@@ -12,6 +12,7 @@ struct encl_segment {
 	size_t size;
 	unsigned int prot;
 	unsigned int flags;
+	bool measure;
 };
 
 struct encl {
diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c
index 202a96fd81bf..50c5ab1aa6fa 100644
--- a/tools/testing/selftests/sgx/sigstruct.c
+++ b/tools/testing/selftests/sgx/sigstruct.c
@@ -296,8 +296,10 @@ static bool mrenclave_segment(EVP_MD_CTX *ctx, struct encl *encl,
 		if (!mrenclave_eadd(ctx, seg->offset + offset, seg->flags))
 			return false;
 
-		if (!mrenclave_eextend(ctx, seg->offset + offset, seg->src + offset))
-			return false;
+		if (seg->measure) {
+			if (!mrenclave_eextend(ctx, seg->offset + offset, seg->src + offset))
+				return false;
+		}
 	}
 
 	return true;
-- 
2.25.1

[PATCH V2 06/15] selftests/sgx: Create a heap for the test enclave

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

Create a heap for the test enclave, which is allocated from /dev/null,
and left unmeasured. This is beneficial by its own because it verifies
that an enclave built from multiple choices, works properly. If LSM
hooks are added for SGX some day, a multi source enclave has higher
probability to trigger bugs on access control checks.

The immediate need comes from the need to implement page reclaim tests.
In order to trigger the page reclaimer, one can just set the size of
the heap to high enough.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.

 tools/testing/selftests/sgx/load.c | 29 ++++++++++++++++++++++-------
 tools/testing/selftests/sgx/main.c |  2 +-
 tools/testing/selftests/sgx/main.h |  4 +++-
 3 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c
index f1be78984c50..9d4322c946e2 100644
--- a/tools/testing/selftests/sgx/load.c
+++ b/tools/testing/selftests/sgx/load.c
@@ -21,6 +21,8 @@
 
 void encl_delete(struct encl *encl)
 {
+	struct encl_segment *heap_seg = &encl->segment_tbl[encl->nr_segments - 1];
+
 	if (encl->encl_base)
 		munmap((void *)encl->encl_base, encl->encl_size);
 
@@ -30,6 +32,8 @@ void encl_delete(struct encl *encl)
 	if (encl->fd)
 		close(encl->fd);
 
+	munmap(heap_seg->src, heap_seg->size);
+
 	if (encl->segment_tbl)
 		free(encl->segment_tbl);
 
@@ -125,11 +129,10 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
 	return true;
 }
 
-
-
-bool encl_load(const char *path, struct encl *encl)
+bool encl_load(const char *path, struct encl *encl, unsigned long heap_size)
 {
 	const char device_path[] = "/dev/sgx_enclave";
+	struct encl_segment *seg;
 	Elf64_Phdr *phdr_tbl;
 	off_t src_offset;
 	Elf64_Ehdr *ehdr;
@@ -181,6 +184,8 @@ bool encl_load(const char *path, struct encl *encl)
 	ehdr = encl->bin;
 	phdr_tbl = encl->bin + ehdr->e_phoff;
 
+	encl->nr_segments = 1; /* one for the heap */
+
 	for (i = 0; i < ehdr->e_phnum; i++) {
 		Elf64_Phdr *phdr = &phdr_tbl[i];
 
@@ -196,7 +201,6 @@ bool encl_load(const char *path, struct encl *encl)
 	for (i = 0, j = 0; i < ehdr->e_phnum; i++) {
 		Elf64_Phdr *phdr = &phdr_tbl[i];
 		unsigned int flags = phdr->p_flags;
-		struct encl_segment *seg;
 
 		if (phdr->p_type != PT_LOAD)
 			continue;
@@ -238,10 +242,21 @@ bool encl_load(const char *path, struct encl *encl)
 		j++;
 	}
 
-	assert(j == encl->nr_segments);
+	assert(j == encl->nr_segments - 1);
+
+	seg = &encl->segment_tbl[j];
+	seg->offset =  encl->segment_tbl[j - 1].offset + encl->segment_tbl[j - 1].size;
+	seg->size = heap_size;
+	seg->src = mmap(NULL, heap_size, PROT_READ | PROT_WRITE,
+			MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+	seg->prot = PROT_READ | PROT_WRITE;
+	seg->flags = (SGX_PAGE_TYPE_REG << 8) | seg->prot;
+	seg->measure = false;
+
+	if (seg->src == MAP_FAILED)
+		goto err;
 
-	encl->src_size = encl->segment_tbl[j - 1].offset +
-			 encl->segment_tbl[j - 1].size;
+	encl->src_size = encl->segment_tbl[j].offset + encl->segment_tbl[j].size;
 
 	for (encl->encl_size = 4096; encl->encl_size < encl->src_size; )
 		encl->encl_size <<= 1;
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index e252015e0c15..6858a35fed20 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -122,7 +122,7 @@ FIXTURE_SETUP(enclave)
 	unsigned int i;
 	void *addr;
 
-	if (!encl_load("test_encl.elf", &self->encl)) {
+	if (!encl_load("test_encl.elf", &self->encl, ENCL_HEAP_SIZE_DEFAULT)) {
 		encl_delete(&self->encl);
 		ksft_exit_skip("cannot load enclaves\n");
 	}
diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h
index aebc69e7cdc8..b45c52ec7ab3 100644
--- a/tools/testing/selftests/sgx/main.h
+++ b/tools/testing/selftests/sgx/main.h
@@ -6,6 +6,8 @@
 #ifndef MAIN_H
 #define MAIN_H
 
+#define ENCL_HEAP_SIZE_DEFAULT	4096
+
 struct encl_segment {
 	void *src;
 	off_t offset;
@@ -33,7 +35,7 @@ extern unsigned char sign_key[];
 extern unsigned char sign_key_end[];
 
 void encl_delete(struct encl *ctx);
-bool encl_load(const char *path, struct encl *encl);
+bool encl_load(const char *path, struct encl *encl, unsigned long heap_size);
 bool encl_measure(struct encl *encl);
 bool encl_build(struct encl *encl);
 
-- 
2.25.1

[PATCH V2 07/15] selftests/sgx: Dump segments and /proc/self/maps only on failure

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

Logging is always a compromise between clarity and detail. The main use
case for dumping VMA's is when FIXTURE_SETUP() fails, and is less important
for enclaves that do initialize correctly. Therefore, print the segments
and /proc/self/maps only in the error case.

Finally, if a single test ever creates multiple enclaves, the amount of
log lines would become enormous.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.

 tools/testing/selftests/sgx/main.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 6858a35fed20..deab02f2f3ce 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -127,12 +127,6 @@ FIXTURE_SETUP(enclave)
 		ksft_exit_skip("cannot load enclaves\n");
 	}
 
-	for (i = 0; i < self->encl.nr_segments; i++) {
-		seg = &self->encl.segment_tbl[i];
-
-		TH_LOG("0x%016lx 0x%016lx 0x%02x", seg->offset, seg->size, seg->prot);
-	}
-
 	if (!encl_measure(&self->encl))
 		goto err;
 
@@ -169,6 +163,17 @@ FIXTURE_SETUP(enclave)
 	memset(&self->run, 0, sizeof(self->run));
 	self->run.tcs = self->encl.encl_base;
 
+	return;
+
+err:
+	encl_delete(&self->encl);
+
+	for (i = 0; i < self->encl.nr_segments; i++) {
+		seg = &self->encl.segment_tbl[i];
+
+		TH_LOG("0x%016lx 0x%016lx 0x%02x", seg->offset, seg->size, seg->prot);
+	}
+
 	maps_file = fopen("/proc/self/maps", "r");
 	if (maps_file != NULL)  {
 		while (fgets(maps_line, sizeof(maps_line), maps_file) != NULL) {
@@ -181,11 +186,7 @@ FIXTURE_SETUP(enclave)
 		fclose(maps_file);
 	}
 
-err:
-	if (!sgx_enter_enclave_sym)
-		encl_delete(&self->encl);
-
-	ASSERT_NE(sgx_enter_enclave_sym, NULL);
+	ASSERT_TRUE(false);
 }
 
 FIXTURE_TEARDOWN(enclave)
-- 
2.25.1

[PATCH V2 08/15] selftests/sgx: Encpsulate the test enclave creation

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

Introduce setup_test_encl() so that the enclave creation can be moved to
TEST_F()'s. This is required for a reclaimer test where the heap size needs
to be set large enough to triger the page reclaimer.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.

 tools/testing/selftests/sgx/main.c | 44 ++++++++++++++++++------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index deab02f2f3ce..5b3e49a36344 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -112,7 +112,8 @@ FIXTURE(enclave) {
 	struct sgx_enclave_run run;
 };
 
-FIXTURE_SETUP(enclave)
+static bool setup_test_encl(unsigned long heap_size, struct encl *encl,
+			    struct __test_metadata *_metadata)
 {
 	Elf64_Sym *sgx_enter_enclave_sym = NULL;
 	struct vdso_symtab symtab;
@@ -122,25 +123,25 @@ FIXTURE_SETUP(enclave)
 	unsigned int i;
 	void *addr;
 
-	if (!encl_load("test_encl.elf", &self->encl, ENCL_HEAP_SIZE_DEFAULT)) {
-		encl_delete(&self->encl);
-		ksft_exit_skip("cannot load enclaves\n");
+	if (!encl_load("test_encl.elf", encl, heap_size)) {
+		encl_delete(encl);
+		TH_LOG("Failed to load the test enclave.\n");
 	}
 
-	if (!encl_measure(&self->encl))
+	if (!encl_measure(encl))
 		goto err;
 
-	if (!encl_build(&self->encl))
+	if (!encl_build(encl))
 		goto err;
 
 	/*
 	 * An enclave consumer only must do this.
 	 */
-	for (i = 0; i < self->encl.nr_segments; i++) {
-		struct encl_segment *seg = &self->encl.segment_tbl[i];
+	for (i = 0; i < encl->nr_segments; i++) {
+		struct encl_segment *seg = &encl->segment_tbl[i];
 
-		addr = mmap((void *)self->encl.encl_base + seg->offset, seg->size,
-			    seg->prot, MAP_SHARED | MAP_FIXED, self->encl.fd, 0);
+		addr = mmap((void *)encl->encl_base + seg->offset, seg->size,
+			    seg->prot, MAP_SHARED | MAP_FIXED, encl->fd, 0);
 		EXPECT_NE(addr, MAP_FAILED);
 		if (addr == MAP_FAILED)
 			goto err;
@@ -160,16 +161,13 @@ FIXTURE_SETUP(enclave)
 
 	vdso_sgx_enter_enclave = addr + sgx_enter_enclave_sym->st_value;
 
-	memset(&self->run, 0, sizeof(self->run));
-	self->run.tcs = self->encl.encl_base;
-
-	return;
+	return true;
 
 err:
-	encl_delete(&self->encl);
+	encl_delete(encl);
 
-	for (i = 0; i < self->encl.nr_segments; i++) {
-		seg = &self->encl.segment_tbl[i];
+	for (i = 0; i < encl->nr_segments; i++) {
+		seg = &encl->segment_tbl[i];
 
 		TH_LOG("0x%016lx 0x%016lx 0x%02x", seg->offset, seg->size, seg->prot);
 	}
@@ -186,7 +184,17 @@ FIXTURE_SETUP(enclave)
 		fclose(maps_file);
 	}
 
-	ASSERT_TRUE(false);
+	TH_LOG("Failed to initialize the test enclave.\n");
+
+	return false;
+}
+
+FIXTURE_SETUP(enclave)
+{
+	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
+
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
 }
 
 FIXTURE_TEARDOWN(enclave)
-- 
2.25.1

[PATCH V2 09/15] selftests/sgx: Move setup_test_encl() to each TEST_F()

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

Create the test enclave inside each TEST_F(), instead of FIXTURE_SETUP(),
so that the heap size can be defined per test.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.

 tools/testing/selftests/sgx/main.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 5b3e49a36344..f41fba919d06 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -191,10 +191,6 @@ static bool setup_test_encl(unsigned long heap_size, struct encl *encl,
 
 FIXTURE_SETUP(enclave)
 {
-	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
-
-	memset(&self->run, 0, sizeof(self->run));
-	self->run.tcs = self->encl.encl_base;
 }
 
 FIXTURE_TEARDOWN(enclave)
@@ -226,6 +222,11 @@ TEST_F(enclave, unclobbered_vdso)
 {
 	struct encl_op op;
 
+	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
+
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
+
 	op.type = ENCL_OP_PUT;
 	op.buffer = MAGIC;
 
@@ -248,6 +249,11 @@ TEST_F(enclave, clobbered_vdso)
 {
 	struct encl_op op;
 
+	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
+
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
+
 	op.type = ENCL_OP_PUT;
 	op.buffer = MAGIC;
 
@@ -278,6 +284,11 @@ TEST_F(enclave, clobbered_vdso_and_user_function)
 {
 	struct encl_op op;
 
+	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
+
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
+
 	self->run.user_handler = (__u64)test_handler;
 	self->run.user_data = 0xdeadbeef;
 
-- 
2.25.1

[PATCH V2 10/15] selftests/sgx: Add a new kselftest: unclobbered_vdso_oversubscribed

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

Add a variation of the unclobbered_vdso test.

In the new test, create a heap for the test enclave, which has the same
size as all available Enclave Page Cache (EPC) pages in the system. This
will guarantee that all test_encl.elf pages *and* SGX Enclave Control
Structure (SECS) have been swapped out by the page reclaimer during the
load time.

This test will trigger both the page reclaimer and the page fault handler.
The page reclaimer triggered, while the heap is being created during the
load time. The page fault handler is triggered for all the required pages,
while the test case is executing.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
[reinette: rework code obtaining SGX physical memory based on most recent
upstream solution]
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.
- Add support to obtain SGX physical memory from v8 of Jarkko's patches.

 tools/testing/selftests/sgx/main.c | 114 +++++++++++++++++++++++++++++
 tools/testing/selftests/sgx/main.h |   1 +
 2 files changed, 115 insertions(+)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index f41fba919d06..541862c15901 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 /*  Copyright(c) 2016-20 Intel Corporation. */
 
+#define _GNU_SOURCE
+#include <dirent.h>
 #include <elf.h>
 #include <errno.h>
 #include <fcntl.h>
@@ -245,6 +247,118 @@ TEST_F(enclave, unclobbered_vdso)
 	EXPECT_EQ(self->run.user_data, 0);
 }
 
+static bool sysfs_get_ulong(const char *path, unsigned long *value)
+{
+	struct stat sbuf;
+	char buf[128];
+	ssize_t ret;
+	int fd;
+
+	ret = stat(path, &sbuf);
+	if (ret)
+		return false;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return false;
+
+	ret = read(fd, buf, sizeof(buf));
+	if (ret < 0) {
+		close(fd);
+		return false;
+	}
+
+	errno = 0;
+	*value = strtoul(buf, NULL, 0);
+
+	close(fd);
+
+	return errno ? false : true;
+}
+
+/*
+ * Sum total available physical SGX memory across all NUMA nodes
+ *
+ * Return: total available physical SGX memory available on system or 0 if a
+ * failure is encountered.
+ */
+static unsigned long get_total_epc_mem(void)
+{
+	char *node, *path = NULL;
+	unsigned long total = 0;
+	unsigned long size = 0;
+	struct dirent *entry;
+	struct stat statbuf;
+	DIR *dp;
+	int ret;
+
+	dp = opendir(SGX_TOTAL_MEM_PATH);
+	if (!dp)
+		return 0;
+
+	while ((entry = readdir(dp))) {
+		node = strstr(entry->d_name, "node");
+		if (!node)
+			continue;
+
+		ret = asprintf(&path, "%s/%s/sgx/size",
+				SGX_TOTAL_MEM_PATH, entry->d_name);
+		if (ret == -1) {
+			total = 0;
+			goto out;
+		}
+
+		ret = stat(path, &statbuf);
+		if (ret == -1) {
+			free(path);
+			continue;
+		}
+
+		if (S_ISREG(statbuf.st_mode) && statbuf.st_size > 0) {
+			if (sysfs_get_ulong(path, &size))
+				total += size;
+		}
+
+		free(path);
+	}
+
+out:
+	closedir(dp);
+
+	return total;
+}
+
+TEST_F(enclave, unclobbered_vdso_oversubscribed)
+{
+	unsigned long total_mem;
+	struct encl_op op;
+
+	total_mem = get_total_epc_mem();
+	ASSERT_NE(total_mem, 0);
+	ASSERT_TRUE(setup_test_encl(total_mem, &self->encl, _metadata));
+
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
+
+	op.type = ENCL_OP_PUT;
+	op.buffer = MAGIC;
+
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.user_data, 0);
+
+	op.type = ENCL_OP_GET;
+	op.buffer = 0;
+
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+
+	EXPECT_EQ(op.buffer, MAGIC);
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.user_data, 0);
+
+}
+
 TEST_F(enclave, clobbered_vdso)
 {
 	struct encl_op op;
diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h
index b45c52ec7ab3..59027df32a6a 100644
--- a/tools/testing/selftests/sgx/main.h
+++ b/tools/testing/selftests/sgx/main.h
@@ -7,6 +7,7 @@
 #define MAIN_H
 
 #define ENCL_HEAP_SIZE_DEFAULT	4096
+#define SGX_TOTAL_MEM_PATH	"/sys/devices/system/node"
 
 struct encl_segment {
 	void *src;
-- 
2.25.1

[PATCH V2 11/15] selftests/sgx: Provide per-op parameter structs for the test enclave

[Reinette Chatre]

From: Jarkko Sakkinen <jarkko@kernel.org>

To add more operations to the test enclave, the protocol needs to allow
to have operations with varying parameters. Create a separate parameter
struct for each existing operation, with the shared parameters in struct
encl_op_header.

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
[reinette: rebased to apply on top of oversubscription test series]
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add signature from Dave.

 tools/testing/selftests/sgx/defines.h   | 14 ++++-
 tools/testing/selftests/sgx/main.c      | 68 +++++++++++++------------
 tools/testing/selftests/sgx/test_encl.c | 33 +++++++-----
 3 files changed, 69 insertions(+), 46 deletions(-)

diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index f88562afcaa0..6ff95a766287 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -21,11 +21,21 @@
 enum encl_op_type {
 	ENCL_OP_PUT,
 	ENCL_OP_GET,
+	ENCL_OP_MAX,
 };
 
-struct encl_op {
+struct encl_op_header {
 	uint64_t type;
-	uint64_t buffer;
+};
+
+struct encl_op_put {
+	struct encl_op_header header;
+	uint64_t value;
+};
+
+struct encl_op_get {
+	struct encl_op_header header;
+	uint64_t value;
 };
 
 #endif /* DEFINES_H */
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 541862c15901..2ac5c3300df2 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -222,27 +222,28 @@ FIXTURE_TEARDOWN(enclave)
 
 TEST_F(enclave, unclobbered_vdso)
 {
-	struct encl_op op;
+	struct encl_op_put put_op;
+	struct encl_op_get get_op;
 
 	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
 
 	memset(&self->run, 0, sizeof(self->run));
 	self->run.tcs = self->encl.encl_base;
 
-	op.type = ENCL_OP_PUT;
-	op.buffer = MAGIC;
+	put_op.header.type = ENCL_OP_PUT;
+	put_op.value = MAGIC;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, false), 0);
 
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	op.type = ENCL_OP_GET;
-	op.buffer = 0;
+	get_op.header.type = ENCL_OP_GET;
+	get_op.value = 0;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, false), 0);
 
-	EXPECT_EQ(op.buffer, MAGIC);
+	EXPECT_EQ(get_op.value, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 }
@@ -331,7 +332,8 @@ static unsigned long get_total_epc_mem(void)
 TEST_F(enclave, unclobbered_vdso_oversubscribed)
 {
 	unsigned long total_mem;
-	struct encl_op op;
+	struct encl_op_put put_op;
+	struct encl_op_get get_op;
 
 	total_mem = get_total_epc_mem();
 	ASSERT_NE(total_mem, 0);
@@ -340,20 +342,20 @@ TEST_F(enclave, unclobbered_vdso_oversubscribed)
 	memset(&self->run, 0, sizeof(self->run));
 	self->run.tcs = self->encl.encl_base;
 
-	op.type = ENCL_OP_PUT;
-	op.buffer = MAGIC;
+	put_op.header.type = ENCL_OP_PUT;
+	put_op.value = MAGIC;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, false), 0);
 
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	op.type = ENCL_OP_GET;
-	op.buffer = 0;
+	get_op.header.type = ENCL_OP_GET;
+	get_op.value = 0;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, false), 0);
 
-	EXPECT_EQ(op.buffer, MAGIC);
+	EXPECT_EQ(get_op.value, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
@@ -361,27 +363,28 @@ TEST_F(enclave, unclobbered_vdso_oversubscribed)
 
 TEST_F(enclave, clobbered_vdso)
 {
-	struct encl_op op;
+	struct encl_op_put put_op;
+	struct encl_op_get get_op;
 
 	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
 
 	memset(&self->run, 0, sizeof(self->run));
 	self->run.tcs = self->encl.encl_base;
 
-	op.type = ENCL_OP_PUT;
-	op.buffer = MAGIC;
+	put_op.header.type = ENCL_OP_PUT;
+	put_op.value = MAGIC;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, true), 0);
 
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	op.type = ENCL_OP_GET;
-	op.buffer = 0;
+	get_op.header.type = ENCL_OP_GET;
+	get_op.value = 0;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, true), 0);
 
-	EXPECT_EQ(op.buffer, MAGIC);
+	EXPECT_EQ(get_op.value, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 }
@@ -396,7 +399,8 @@ static int test_handler(long rdi, long rsi, long rdx, long ursp, long r8, long r
 
 TEST_F(enclave, clobbered_vdso_and_user_function)
 {
-	struct encl_op op;
+	struct encl_op_put put_op;
+	struct encl_op_get get_op;
 
 	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
 
@@ -406,20 +410,20 @@ TEST_F(enclave, clobbered_vdso_and_user_function)
 	self->run.user_handler = (__u64)test_handler;
 	self->run.user_data = 0xdeadbeef;
 
-	op.type = ENCL_OP_PUT;
-	op.buffer = MAGIC;
+	put_op.header.type = ENCL_OP_PUT;
+	put_op.value = MAGIC;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, true), 0);
 
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	op.type = ENCL_OP_GET;
-	op.buffer = 0;
+	get_op.header.type = ENCL_OP_GET;
+	get_op.value = 0;
 
-	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, true), 0);
 
-	EXPECT_EQ(op.buffer, MAGIC);
+	EXPECT_EQ(get_op.value, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 }
diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c
index 734ea52f9924..f11eb8315704 100644
--- a/tools/testing/selftests/sgx/test_encl.c
+++ b/tools/testing/selftests/sgx/test_encl.c
@@ -16,20 +16,29 @@ static void *memcpy(void *dest, const void *src, size_t n)
 	return dest;
 }
 
-void encl_body(void *rdi,  void *rsi)
+static void do_encl_op_put(void *op)
+{
+	struct encl_op_put *op2 = op;
+
+	memcpy(&encl_buffer[0], &op2->value, 8);
+}
+
+static void do_encl_op_get(void *op)
 {
-	struct encl_op *op = (struct encl_op *)rdi;
+	struct encl_op_get *op2 = op;
 
-	switch (op->type) {
-	case ENCL_OP_PUT:
-		memcpy(&encl_buffer[0], &op->buffer, 8);
-		break;
+	memcpy(&op2->value, &encl_buffer[0], 8);
+}
+
+void encl_body(void *rdi,  void *rsi)
+{
+	const void (*encl_op_array[ENCL_OP_MAX])(void *) = {
+		do_encl_op_put,
+		do_encl_op_get,
+	};
 
-	case ENCL_OP_GET:
-		memcpy(&op->buffer, &encl_buffer[0], 8);
-		break;
+	struct encl_op_header *op = (struct encl_op_header *)rdi;
 
-	default:
-		break;
-	}
+	if (op->type < ENCL_OP_MAX)
+		(*encl_op_array[op->type])(op);
 }
-- 
2.25.1

[PATCH V2 12/15] selftests/sgx: Rename test properties in preparation for more enclave tests

[Reinette Chatre]

SGX selftests prepares a data structure outside of the enclave with
the type of and data for the operation that needs to be run within
the enclave. At this time only two complementary operations are supported
by the enclave: copying a value from outside the enclave into a default
buffer within the enclave and reading a value from the enclave's default
buffer into a variable accessible outside the enclave.

In preparation for more operations supported by the enclave the names of the
current enclave operations are changed to more accurately reflect the
operations and more easily distinguish it from future operations:

* The enums ENCL_OP_PUT and ENCL_OP_GET are renamed to ENCL_OP_PUT_TO_BUFFER
  and ENCL_OP_GET_FROM_BUFFER respectively.
* The structs encl_op_put and encl_op_get are renamed to encl_op_put_to_buf
  and encl_op_get_from_buf respectively.
* The enclave functions do_encl_op_put and do_encl_op_get are renamed to
  do_encl_op_put_to_buf and do_encl_op_get_from_buf respectively.

No functional changes.

Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add Jarkko and Dave's signatures.

 tools/testing/selftests/sgx/defines.h   |  8 +++----
 tools/testing/selftests/sgx/main.c      | 32 ++++++++++++-------------
 tools/testing/selftests/sgx/test_encl.c | 12 +++++-----
 3 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index 6ff95a766287..9ea0c7882dfb 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -19,8 +19,8 @@
 #include "../../../../arch/x86/include/uapi/asm/sgx.h"
 
 enum encl_op_type {
-	ENCL_OP_PUT,
-	ENCL_OP_GET,
+	ENCL_OP_PUT_TO_BUFFER,
+	ENCL_OP_GET_FROM_BUFFER,
 	ENCL_OP_MAX,
 };
 
@@ -28,12 +28,12 @@ struct encl_op_header {
 	uint64_t type;
 };
 
-struct encl_op_put {
+struct encl_op_put_to_buf {
 	struct encl_op_header header;
 	uint64_t value;
 };
 
-struct encl_op_get {
+struct encl_op_get_from_buf {
 	struct encl_op_header header;
 	uint64_t value;
 };
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 2ac5c3300df2..f1802faed78e 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -222,15 +222,15 @@ FIXTURE_TEARDOWN(enclave)
 
 TEST_F(enclave, unclobbered_vdso)
 {
-	struct encl_op_put put_op;
-	struct encl_op_get get_op;
+	struct encl_op_get_from_buf get_op;
+	struct encl_op_put_to_buf put_op;
 
 	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
 
 	memset(&self->run, 0, sizeof(self->run));
 	self->run.tcs = self->encl.encl_base;
 
-	put_op.header.type = ENCL_OP_PUT;
+	put_op.header.type = ENCL_OP_PUT_TO_BUFFER;
 	put_op.value = MAGIC;
 
 	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, false), 0);
@@ -238,7 +238,7 @@ TEST_F(enclave, unclobbered_vdso)
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	get_op.header.type = ENCL_OP_GET;
+	get_op.header.type = ENCL_OP_GET_FROM_BUFFER;
 	get_op.value = 0;
 
 	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, false), 0);
@@ -331,9 +331,9 @@ static unsigned long get_total_epc_mem(void)
 
 TEST_F(enclave, unclobbered_vdso_oversubscribed)
 {
+	struct encl_op_get_from_buf get_op;
+	struct encl_op_put_to_buf put_op;
 	unsigned long total_mem;
-	struct encl_op_put put_op;
-	struct encl_op_get get_op;
 
 	total_mem = get_total_epc_mem();
 	ASSERT_NE(total_mem, 0);
@@ -342,7 +342,7 @@ TEST_F(enclave, unclobbered_vdso_oversubscribed)
 	memset(&self->run, 0, sizeof(self->run));
 	self->run.tcs = self->encl.encl_base;
 
-	put_op.header.type = ENCL_OP_PUT;
+	put_op.header.type = ENCL_OP_PUT_TO_BUFFER;
 	put_op.value = MAGIC;
 
 	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, false), 0);
@@ -350,7 +350,7 @@ TEST_F(enclave, unclobbered_vdso_oversubscribed)
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	get_op.header.type = ENCL_OP_GET;
+	get_op.header.type = ENCL_OP_GET_FROM_BUFFER;
 	get_op.value = 0;
 
 	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, false), 0);
@@ -363,15 +363,15 @@ TEST_F(enclave, unclobbered_vdso_oversubscribed)
 
 TEST_F(enclave, clobbered_vdso)
 {
-	struct encl_op_put put_op;
-	struct encl_op_get get_op;
+	struct encl_op_get_from_buf get_op;
+	struct encl_op_put_to_buf put_op;
 
 	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
 
 	memset(&self->run, 0, sizeof(self->run));
 	self->run.tcs = self->encl.encl_base;
 
-	put_op.header.type = ENCL_OP_PUT;
+	put_op.header.type = ENCL_OP_PUT_TO_BUFFER;
 	put_op.value = MAGIC;
 
 	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, true), 0);
@@ -379,7 +379,7 @@ TEST_F(enclave, clobbered_vdso)
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	get_op.header.type = ENCL_OP_GET;
+	get_op.header.type = ENCL_OP_GET_FROM_BUFFER;
 	get_op.value = 0;
 
 	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, true), 0);
@@ -399,8 +399,8 @@ static int test_handler(long rdi, long rsi, long rdx, long ursp, long r8, long r
 
 TEST_F(enclave, clobbered_vdso_and_user_function)
 {
-	struct encl_op_put put_op;
-	struct encl_op_get get_op;
+	struct encl_op_get_from_buf get_op;
+	struct encl_op_put_to_buf put_op;
 
 	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
 
@@ -410,7 +410,7 @@ TEST_F(enclave, clobbered_vdso_and_user_function)
 	self->run.user_handler = (__u64)test_handler;
 	self->run.user_data = 0xdeadbeef;
 
-	put_op.header.type = ENCL_OP_PUT;
+	put_op.header.type = ENCL_OP_PUT_TO_BUFFER;
 	put_op.value = MAGIC;
 
 	EXPECT_EQ(ENCL_CALL(&put_op, &self->run, true), 0);
@@ -418,7 +418,7 @@ TEST_F(enclave, clobbered_vdso_and_user_function)
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 
-	get_op.header.type = ENCL_OP_GET;
+	get_op.header.type = ENCL_OP_GET_FROM_BUFFER;
 	get_op.value = 0;
 
 	EXPECT_EQ(ENCL_CALL(&get_op, &self->run, true), 0);
diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c
index f11eb8315704..4e8da738173f 100644
--- a/tools/testing/selftests/sgx/test_encl.c
+++ b/tools/testing/selftests/sgx/test_encl.c
@@ -16,16 +16,16 @@ static void *memcpy(void *dest, const void *src, size_t n)
 	return dest;
 }
 
-static void do_encl_op_put(void *op)
+static void do_encl_op_put_to_buf(void *op)
 {
-	struct encl_op_put *op2 = op;
+	struct encl_op_put_to_buf *op2 = op;
 
 	memcpy(&encl_buffer[0], &op2->value, 8);
 }
 
-static void do_encl_op_get(void *op)
+static void do_encl_op_get_from_buf(void *op)
 {
-	struct encl_op_get *op2 = op;
+	struct encl_op_get_from_buf *op2 = op;
 
 	memcpy(&op2->value, &encl_buffer[0], 8);
 }
@@ -33,8 +33,8 @@ static void do_encl_op_get(void *op)
 void encl_body(void *rdi,  void *rsi)
 {
 	const void (*encl_op_array[ENCL_OP_MAX])(void *) = {
-		do_encl_op_put,
-		do_encl_op_get,
+		do_encl_op_put_to_buf,
+		do_encl_op_get_from_buf,
 	};
 
 	struct encl_op_header *op = (struct encl_op_header *)rdi;
-- 
2.25.1

[PATCH V2 13/15] selftests/sgx: Add page permission and exception test

[Reinette Chatre]

The Enclave Page Cache Map (EPCM) is a secure structure used by the
processor to track the contents of the enclave page cache. The EPCM
contains permissions with which enclave pages can be accessed. SGX
support allows EPCM and PTE page permissions to differ - as long as
the PTE permissions do not exceed the EPCM permissions.

Add a test that:
(1) Creates an SGX enclave page with writable EPCM permission.
(2) Changes the PTE permission on the page to read-only. This should
    be permitted because the permission does not exceed the EPCM
    permission.
(3) Attempts a write to the page. This should generate a page fault
    (#PF) because of the read-only PTE even though the EPCM
    permissions allow the page to be written to.

This introduces the first test of SGX exception handling. In this test
the issue that caused the exception (PTE page permissions) can be fixed
from outside the enclave and after doing so it is possible to re-enter
enclave at original entrypoint with ERESUME.

Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Make changelog more readable (Dave).
- Add signature from Dave.
- Improve loop locating data segment (Jarkko).

 tools/testing/selftests/sgx/defines.h   |  14 +++
 tools/testing/selftests/sgx/main.c      | 134 ++++++++++++++++++++++++
 tools/testing/selftests/sgx/test_encl.c |  21 ++++
 3 files changed, 169 insertions(+)

diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index 9ea0c7882dfb..0bbda6f0c7d3 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -21,6 +21,8 @@
 enum encl_op_type {
 	ENCL_OP_PUT_TO_BUFFER,
 	ENCL_OP_GET_FROM_BUFFER,
+	ENCL_OP_PUT_TO_ADDRESS,
+	ENCL_OP_GET_FROM_ADDRESS,
 	ENCL_OP_MAX,
 };
 
@@ -38,4 +40,16 @@ struct encl_op_get_from_buf {
 	uint64_t value;
 };
 
+struct encl_op_put_to_addr {
+	struct encl_op_header header;
+	uint64_t value;
+	uint64_t addr;
+};
+
+struct encl_op_get_from_addr {
+	struct encl_op_header header;
+	uint64_t value;
+	uint64_t addr;
+};
+
 #endif /* DEFINES_H */
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index f1802faed78e..9efb619e0393 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -23,6 +23,7 @@
 #include "main.h"
 
 static const uint64_t MAGIC = 0x1122334455667788ULL;
+static const uint64_t MAGIC2 = 0x8877665544332211ULL;
 vdso_sgx_enter_enclave_t vdso_sgx_enter_enclave;
 
 struct vdso_symtab {
@@ -109,6 +110,25 @@ static Elf64_Sym *vdso_symtab_get(struct vdso_symtab *symtab, const char *name)
 	return NULL;
 }
 
+/*
+ * Return the offset in the enclave where the data segment can be found.
+ * The first RW segment loaded is the TCS, skip that to get info on the
+ * data segment.
+ */
+static off_t encl_get_data_offset(struct encl *encl)
+{
+	int i;
+
+	for (i = 1; i < encl->nr_segments; i++) {
+		struct encl_segment *seg = &encl->segment_tbl[i];
+
+		if (seg->prot == (PROT_READ | PROT_WRITE))
+			return seg->offset;
+	}
+
+	return -1;
+}
+
 FIXTURE(enclave) {
 	struct encl encl;
 	struct sgx_enclave_run run;
@@ -428,4 +448,118 @@ TEST_F(enclave, clobbered_vdso_and_user_function)
 	EXPECT_EQ(self->run.user_data, 0);
 }
 
+/*
+ * Second page of .data segment is used to test changing PTE permissions.
+ * This spans the local encl_buffer within the test enclave.
+ *
+ * 1) Start with a sanity check: a value is written to the target page within
+ *    the enclave and read back to ensure target page can be written to.
+ * 2) Change PTE permissions (RW -> RO) of target page within enclave.
+ * 3) Repeat (1) - this time expecting a regular #PF communicated via the
+ *    vDSO.
+ * 4) Change PTE permissions of target page within enclave back to be RW.
+ * 5) Repeat (1) by resuming enclave, now expected to be possible to write to
+ *    and read from target page within enclave.
+ */
+TEST_F(enclave, pte_permissions)
+{
+	struct encl_op_get_from_addr get_addr_op;
+	struct encl_op_put_to_addr put_addr_op;
+	unsigned long data_start;
+	int ret;
+
+	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
+
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
+
+	data_start = self->encl.encl_base +
+		     encl_get_data_offset(&self->encl) +
+		     PAGE_SIZE;
+
+	/*
+	 * Sanity check to ensure it is possible to write to page that will
+	 * have its permissions manipulated.
+	 */
+
+	/* Write MAGIC to page */
+	put_addr_op.value = MAGIC;
+	put_addr_op.addr = data_start;
+	put_addr_op.header.type = ENCL_OP_PUT_TO_ADDRESS;
+
+	EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.exception_vector, 0);
+	EXPECT_EQ(self->run.exception_error_code, 0);
+	EXPECT_EQ(self->run.exception_addr, 0);
+
+	/*
+	 * Read memory that was just written to, confirming that it is the
+	 * value previously written (MAGIC).
+	 */
+	get_addr_op.value = 0;
+	get_addr_op.addr = data_start;
+	get_addr_op.header.type = ENCL_OP_GET_FROM_ADDRESS;
+
+	EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0);
+
+	EXPECT_EQ(get_addr_op.value, MAGIC);
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.exception_vector, 0);
+	EXPECT_EQ(self->run.exception_error_code, 0);
+	EXPECT_EQ(self->run.exception_addr, 0);
+
+	/* Change PTE permissions of target page within the enclave */
+	ret = mprotect((void *)data_start, PAGE_SIZE, PROT_READ);
+	if (ret)
+		perror("mprotect");
+
+	/*
+	 * PTE permissions of target page changed to read-only, EPCM
+	 * permissions unchanged (EPCM permissions are RW), attempt to
+	 * write to the page, expecting a regular #PF.
+	 */
+
+	put_addr_op.value = MAGIC2;
+
+	EXPECT_EQ(ENCL_CALL(&put_addr_op, &self->run, true), 0);
+
+	EXPECT_EQ(self->run.exception_vector, 14);
+	EXPECT_EQ(self->run.exception_error_code, 0x7);
+	EXPECT_EQ(self->run.exception_addr, data_start);
+
+	self->run.exception_vector = 0;
+	self->run.exception_error_code = 0;
+	self->run.exception_addr = 0;
+
+	/*
+	 * Change PTE permissions back to enable enclave to write to the
+	 * target page and resume enclave - do not expect any exceptions this
+	 * time.
+	 */
+	ret = mprotect((void *)data_start, PAGE_SIZE, PROT_READ | PROT_WRITE);
+	if (ret)
+		perror("mprotect");
+
+	EXPECT_EQ(vdso_sgx_enter_enclave((unsigned long)&put_addr_op, 0,
+					 0, ERESUME, 0, 0, &self->run),
+		 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.exception_vector, 0);
+	EXPECT_EQ(self->run.exception_error_code, 0);
+	EXPECT_EQ(self->run.exception_addr, 0);
+
+	get_addr_op.value = 0;
+
+	EXPECT_EQ(ENCL_CALL(&get_addr_op, &self->run, true), 0);
+
+	EXPECT_EQ(get_addr_op.value, MAGIC2);
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.exception_vector, 0);
+	EXPECT_EQ(self->run.exception_error_code, 0);
+	EXPECT_EQ(self->run.exception_addr, 0);
+}
+
 TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c
index 4e8da738173f..5d86e3e6456a 100644
--- a/tools/testing/selftests/sgx/test_encl.c
+++ b/tools/testing/selftests/sgx/test_encl.c
@@ -4,6 +4,11 @@
 #include <stddef.h>
 #include "defines.h"
 
+/*
+ * Data buffer spanning two pages that will be placed first in .data
+ * segment. Even if not used internally the second page is needed by
+ * external test manipulating page permissions.
+ */
 static uint8_t encl_buffer[8192] = { 1 };
 
 static void *memcpy(void *dest, const void *src, size_t n)
@@ -30,11 +35,27 @@ static void do_encl_op_get_from_buf(void *op)
 	memcpy(&op2->value, &encl_buffer[0], 8);
 }
 
+static void do_encl_op_put_to_addr(void *_op)
+{
+	struct encl_op_put_to_addr *op = _op;
+
+	memcpy((void *)op->addr, &op->value, 8);
+}
+
+static void do_encl_op_get_from_addr(void *_op)
+{
+	struct encl_op_get_from_addr *op = _op;
+
+	memcpy(&op->value, (void *)op->addr, 8);
+}
+
 void encl_body(void *rdi,  void *rsi)
 {
 	const void (*encl_op_array[ENCL_OP_MAX])(void *) = {
 		do_encl_op_put_to_buf,
 		do_encl_op_get_from_buf,
+		do_encl_op_put_to_addr,
+		do_encl_op_get_from_addr,
 	};
 
 	struct encl_op_header *op = (struct encl_op_header *)rdi;
-- 
2.25.1

Re: [PATCH V2 13/15] selftests/sgx: Add page permission and exception test

[Jarkko Sakkinen]

On Thu, Oct 28, 2021 at 01:37:38PM -0700, Reinette Chatre wrote:
> The Enclave Page Cache Map (EPCM) is a secure structure used by the
> processor to track the contents of the enclave page cache. The EPCM
> contains permissions with which enclave pages can be accessed. SGX
> support allows EPCM and PTE page permissions to differ - as long as
> the PTE permissions do not exceed the EPCM permissions.
> 
> Add a test that:
> (1) Creates an SGX enclave page with writable EPCM permission.
> (2) Changes the PTE permission on the page to read-only. This should
>     be permitted because the permission does not exceed the EPCM
>     permission.
> (3) Attempts a write to the page. This should generate a page fault
>     (#PF) because of the read-only PTE even though the EPCM
>     permissions allow the page to be written to.
> 
> This introduces the first test of SGX exception handling. In this test
> the issue that caused the exception (PTE page permissions) can be fixed
> from outside the enclave and after doing so it is possible to re-enter
> enclave at original entrypoint with ERESUME.
> 
> Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

/Jarkko

[PATCH V2 14/15] selftests/sgx: Enable multiple thread support

[Reinette Chatre]

Each thread executing in an enclave is associated with a Thread Control
Structure (TCS). The test enclave contains two hardcoded TCS. Each TCS
contains meta-data used by the hardware to save and restore thread specific
information when entering/exiting the enclave.

The two TCS structures within the test enclave share their SSA (State Save
Area) resulting in the threads clobbering each other's data. Fix this by
providing each TCS their own SSA area.

Additionally, there is an 8K stack space and its address is
computed from the enclave entry point which is correctly done for
TCS #1 that starts on the first address inside the enclave but
results in out of bounds memory when entering as TCS #2. Split 8K
stack space into two separate pages with offset symbol between to ensure
the current enclave entry calculation can continue to be used for both threads.

While using the enclave with multiple threads requires these fixes the
impact is not apparent because every test up to this point enters the
enclave from the first TCS.

More detail about the stack fix:
-------------------------------
Before this change the test enclave (test_encl) looks as follows:

.tcs (2 pages):
(page 1) TCS #1
(page 2) TCS #2

.text (1 page)
One page of code

.data (5 pages)
(page 1) encl_buffer
(page 2) encl_buffer
(page 3) SSA
(page 4 and 5) STACK
encl_stack:

As shown above there is a symbol, encl_stack, that points to the end of the
.data segment (pointing to the end of page 5 in .data) which is also the end
of the enclave.

The enclave entry code computes the stack address by adding encl_stack to the
pointer to the TCS that entered the enclave. When entering at TCS #1 the
stack is computed correctly but when entering at TCS #2 the stack pointer
would point to one page beyond the end of the enclave and a #PF would
result when TCS #2 attempts to enter the enclave.

The fix involves moving the encl_stack symbol between the two stack pages.
Doing so enables the stack address computation in the entry code to compute
the correct stack address for each TCS.

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add Jarkko and Dave's signatures.

 .../selftests/sgx/test_encl_bootstrap.S       | 21 ++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/sgx/test_encl_bootstrap.S b/tools/testing/selftests/sgx/test_encl_bootstrap.S
index 5d5680d4ea39..82fb0dfcbd23 100644
--- a/tools/testing/selftests/sgx/test_encl_bootstrap.S
+++ b/tools/testing/selftests/sgx/test_encl_bootstrap.S
@@ -12,7 +12,7 @@
 
 	.fill	1, 8, 0			# STATE (set by CPU)
 	.fill	1, 8, 0			# FLAGS
-	.quad	encl_ssa		# OSSA
+	.quad	encl_ssa_tcs1		# OSSA
 	.fill	1, 4, 0			# CSSA (set by CPU)
 	.fill	1, 4, 1			# NSSA
 	.quad	encl_entry		# OENTRY
@@ -23,10 +23,10 @@
 	.fill	1, 4, 0xFFFFFFFF	# GSLIMIT
 	.fill	4024, 1, 0		# Reserved
 
-	# Identical to the previous TCS.
+	# TCS2
 	.fill	1, 8, 0			# STATE (set by CPU)
 	.fill	1, 8, 0			# FLAGS
-	.quad	encl_ssa		# OSSA
+	.quad	encl_ssa_tcs2		# OSSA
 	.fill	1, 4, 0			# CSSA (set by CPU)
 	.fill	1, 4, 1			# NSSA
 	.quad	encl_entry		# OENTRY
@@ -40,8 +40,9 @@
 	.text
 
 encl_entry:
-	# RBX contains the base address for TCS, which is also the first address
-	# inside the enclave. By adding the value of le_stack_end to it, we get
+	# RBX contains the base address for TCS, which is the first address
+	# inside the enclave for TCS #1 and one page into the enclave for
+	# TCS #2. By adding the value of encl_stack to it, we get
 	# the absolute address for the stack.
 	lea	(encl_stack)(%rbx), %rax
 	xchg	%rsp, %rax
@@ -81,9 +82,15 @@ encl_entry:
 
 	.section ".data", "aw"
 
-encl_ssa:
+encl_ssa_tcs1:
+	.space 4096
+encl_ssa_tcs2:
 	.space 4096
 
 	.balign 4096
-	.space 8192
+	# Stack of TCS #1
+	.space 4096
 encl_stack:
+	.balign 4096
+	# Stack of TCS #2
+	.space 4096
-- 
2.25.1

[PATCH V2 15/15] selftests/sgx: Add test for multiple TCS entry

[Reinette Chatre]

Each thread executing in an enclave is associated with a Thread Control
Structure (TCS). The SGX test enclave contains two hardcoded TCS, thus
supporting two threads in the enclave.

Add a test to ensure it is possible to enter enclave at both entrypoints.

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
---
Changes since V1:
- Add Jarkko and Dave's signatures.

 tools/testing/selftests/sgx/defines.h   |  1 +
 tools/testing/selftests/sgx/main.c      | 32 +++++++++++++++++++++++++
 tools/testing/selftests/sgx/test_encl.c |  6 +++++
 3 files changed, 39 insertions(+)

diff --git a/tools/testing/selftests/sgx/defines.h b/tools/testing/selftests/sgx/defines.h
index 0bbda6f0c7d3..02d775789ea7 100644
--- a/tools/testing/selftests/sgx/defines.h
+++ b/tools/testing/selftests/sgx/defines.h
@@ -23,6 +23,7 @@ enum encl_op_type {
 	ENCL_OP_GET_FROM_BUFFER,
 	ENCL_OP_PUT_TO_ADDRESS,
 	ENCL_OP_GET_FROM_ADDRESS,
+	ENCL_OP_NOP,
 	ENCL_OP_MAX,
 };
 
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 9efb619e0393..a86796d70a7b 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -448,6 +448,38 @@ TEST_F(enclave, clobbered_vdso_and_user_function)
 	EXPECT_EQ(self->run.user_data, 0);
 }
 
+/*
+ * Sanity check that it is possible to enter either of the two hardcoded TCS
+ */
+TEST_F(enclave, tcs_entry)
+{
+	struct encl_op_header op;
+
+	ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
+
+	memset(&self->run, 0, sizeof(self->run));
+	self->run.tcs = self->encl.encl_base;
+
+	op.type = ENCL_OP_NOP;
+
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.exception_vector, 0);
+	EXPECT_EQ(self->run.exception_error_code, 0);
+	EXPECT_EQ(self->run.exception_addr, 0);
+
+	/* Move to the next TCS. */
+	self->run.tcs = self->encl.encl_base + PAGE_SIZE;
+
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.exception_vector, 0);
+	EXPECT_EQ(self->run.exception_error_code, 0);
+	EXPECT_EQ(self->run.exception_addr, 0);
+}
+
 /*
  * Second page of .data segment is used to test changing PTE permissions.
  * This spans the local encl_buffer within the test enclave.
diff --git a/tools/testing/selftests/sgx/test_encl.c b/tools/testing/selftests/sgx/test_encl.c
index 5d86e3e6456a..4fca01cfd898 100644
--- a/tools/testing/selftests/sgx/test_encl.c
+++ b/tools/testing/selftests/sgx/test_encl.c
@@ -49,6 +49,11 @@ static void do_encl_op_get_from_addr(void *_op)
 	memcpy(&op->value, (void *)op->addr, 8);
 }
 
+static void do_encl_op_nop(void *_op)
+{
+
+}
+
 void encl_body(void *rdi,  void *rsi)
 {
 	const void (*encl_op_array[ENCL_OP_MAX])(void *) = {
@@ -56,6 +61,7 @@ void encl_body(void *rdi,  void *rsi)
 		do_encl_op_get_from_buf,
 		do_encl_op_put_to_addr,
 		do_encl_op_get_from_addr,
+		do_encl_op_nop,
 	};
 
 	struct encl_op_header *op = (struct encl_op_header *)rdi;
-- 
2.25.1