Re: [PATCH v8 3/5] selftests/sgx: Dump enclave memory map

[Shuah Khan]

On 6/11/21 10:27 PM, Jarkko Sakkinen wrote:
> On Fri, Jun 11, 2021 at 04:45:19PM -0600, Shuah Khan wrote:
> > On 6/10/21 2:30 AM, Jarkko Sakkinen wrote:
> > > Often, it's useful to check whether /proc/self/maps looks sane when
> > > dealing with memory mapped objects, especially when they are JIT'ish
> > > dynamically constructed objects. Therefore, dump "/dev/sgx_enclave"
> > > matching lines from the memory map in FIXTURE_SETUP().
> > >
> > > Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> > > ---
> > >    tools/testing/selftests/sgx/main.c | 14 ++++++++++++++
> > >    1 file changed, 14 insertions(+)
> > >
> > > diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
> > > index 6da19b6bf287..14030f8b85ff 100644
> > > --- a/tools/testing/selftests/sgx/main.c
> > > +++ b/tools/testing/selftests/sgx/main.c
> > > @@ -117,6 +117,8 @@ FIXTURE_SETUP(enclave)
> > >    	Elf64_Sym *sgx_enter_enclave_sym = NULL;
> > >    	struct vdso_symtab symtab;
> > >    	struct encl_segment *seg;
> > > +	char maps_line[256];
> > > +	FILE *maps_file;
> > >    	unsigned int i;
> > >    	void *addr;
> > > @@ -167,6 +169,18 @@ FIXTURE_SETUP(enclave)
> > >    	memset(&self->run, 0, sizeof(self->run));
> > >    	self->run.tcs = self->encl.encl_base;
> > > +	maps_file = fopen("/proc/self/maps", "r");
> >
> > I almost applied these. Does this require root access, if so,
> > please add logic to skip the test if non-root user runs it.
> >
> > Same comments for all other paths that might require root access.
>
> As Dave stated, it does not. A process can inspect its own state
> through /proc/self path. E.g. Chrome web browser uses /proc/self/exe
> to initialize multiple instances of itself for browser tabs...

Ah yes. I missed the self part. Thanks for clarifying.

> As far as other things go, this patch set does not bind to any other
> new OS resources.

Thank you. I will apply these for 5.14-rc1.

thanks,
-- Shuah