Re: [PATCH 5/6] selftests/sgx: retry the ioctls returned with EAGAIN

Jarkko Sakkinen
2022-08-31T02:32:00Z

On Tue, Aug 30, 2022 at 03:56:29PM -0700, Reinette Chatre wrote:
> Hi Haitao and Jarkko,
>
>
> selftests/sgx: Retry the ioctl()s returned with EAGAIN
>
>
> On 8/29/2022 8:12 PM, Jarkko Sakkinen wrote:
> > From: Haitao Huang <haitao.huang@linux.intel.com>
> >
> > For EMODT and EREMOVE ioctls with a large range, kernel
>
> ioctl()s?

Ioctl is common enough to be considered as noun and is
widely phrased like that in commit messages. I don't
see any added clarity.

>
> > may not finish in one shot and return EAGAIN error code
> > and count of bytes of EPC pages on that operations are
> > finished successfully.
> >
> > Change the unclobbered_vdso_oversubscribed_remove test
> > to rerun the ioctls in a loop, updating offset and length
>
> ioctl()s?
>
> > using the byte count returned in each iteration.
> >
>
> This is a valuable addition, thank you very much.
>
> > Signed-off-by: Haitao Huang <haitao.huang@linux.intel.com>
> > Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
> > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
> > ---
> > tools/testing/selftests/sgx/main.c | 39 +++++++++++++++++++++++-------
> > 1 file changed, 30 insertions(+), 9 deletions(-)
> >
> > diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
> > index 867e98502120..3268d8b01b0b 100644
> > --- a/tools/testing/selftests/sgx/main.c
> > +++ b/tools/testing/selftests/sgx/main.c
> > @@ -399,7 +399,7 @@ TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900)
> > unsigned long total_mem;
> > int ret, errno_save;
> > unsigned long addr;
> > - unsigned long i;
> > + unsigned long i, count;
>
> Reverse fir tree?

+1

>
> >
> > /*
> > * Create enclave with additional heap that is as big as all
> > @@ -461,16 +461,27 @@ TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900)
> > modt_ioc.offset = heap->offset;
> > modt_ioc.length = heap->size;
> > modt_ioc.page_type = SGX_PAGE_TYPE_TRIM;
> > -
> > + count = 0;
> > TH_LOG("Changing type of %zd bytes to trimmed may take a while ...",
> > heap->size);
> > - ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc);
> > - errno_save = ret == -1 ? errno : 0;
> > + do {
> > + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPES, &modt_ioc);
> > + errno_save = ret == -1 ? errno : 0;
> > + if (errno_save == EAGAIN) {
> > + count += modt_ioc.count;
> > + modt_ioc.offset += modt_ioc.count;
> > + modt_ioc.length -= modt_ioc.count;
> > + modt_ioc.result = 0;
>
> As part of the test I think it would be helpful to know if there was a result code
> in here. What do you think of failing the test if it is not zero?

I would not mind doing that.

>
> > + modt_ioc.count = 0;
> > + } else
> > + break;
>
> Watch out for unbalanced braces (also later in patch). This causes
> checkpatch.pl noise.

Again. I did run checkpatch to all of these. Will revisit.

>
> > + } while (modt_ioc.length != 0);
> >
> > EXPECT_EQ(ret, 0);
> > EXPECT_EQ(errno_save, 0);
> > EXPECT_EQ(modt_ioc.result, 0);
> > - EXPECT_EQ(modt_ioc.count, heap->size);
> > + count += modt_ioc.count;
> > + EXPECT_EQ(count, heap->size);
> >
> > /* EACCEPT all removed pages. */
> > addr = self->encl.encl_base + heap->offset;
> > @@ -498,15 +509,25 @@ TEST_F_TIMEOUT(enclave, unclobbered_vdso_oversubscribed_remove, 900)
> >
> > remove_ioc.offset = heap->offset;
> > remove_ioc.length = heap->size;
> > -
> > + count = 0;
> > TH_LOG("Removing %zd bytes from enclave may take a while ...",
> > heap->size);
> > - ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc);
> > - errno_save = ret == -1 ? errno : 0;
> > + do {
> > + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_REMOVE_PAGES, &remove_ioc);
> > + errno_save = ret == -1 ? errno : 0;
> > + if (errno_save == EAGAIN) {
> > + count += remove_ioc.count;
> > + remove_ioc.offset += remove_ioc.count;
> > + remove_ioc.length -= remove_ioc.count;
> > + remove_ioc.count = 0;
> > + } else
> > + break;
> > + } while (remove_ioc.length != 0);
> >
> > EXPECT_EQ(ret, 0);
> > EXPECT_EQ(errno_save, 0);
> > - EXPECT_EQ(remove_ioc.count, heap->size);
> > + count += remove_ioc.count;
> > + EXPECT_EQ(count, heap->size);
> > }
> >
> > TEST_F(enclave, clobbered_vdso)
>
> Reinette

BR, Jarkko