The SGX selftests can fail for a bunch of non-obvious reasons
like 'noexec' permissions on /dev (which is the default *EVERYWHERE*
it seems).
A new test mistakenly also looked for +x permission on the
/dev/sgx_enclave. File execute permissions really only apply to
the ability of execve() to work on a file, *NOT* on the ability
for an application to map the file with PROT_EXEC. SGX needs to
mmap(PROT_EXEC), but doesn't need to execve() the device file.
Remove the check.
Fixes: 4284f7acb7 ("selftests/sgx: Improve error detection and messages")
Reported-by: Tim Gardner <tim.gardner@canonical.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-sgx@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Extend the enclave to have two operations: ENCL_OP_PUT and ENCL_OP_GET.
ENCL_OP_PUT stores value inside the enclave address space and
ENCL_OP_GET reads it. The internal buffer can be later extended to be
variable size, and allow reclaimer tests.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Add EXPECT_EEXIT() macro, which will conditionally print the exception
information, in addition to
EXPECT_EQ(self->run.function, EEXIT);
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
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@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Migrate to kselftest harness. Use a fixture test with enclave initialized
and de-initialized for each of the existing three tests, in other words:
1. One FIXTURE() for managing the enclave life-cycle.
2. Three TEST_F()'s, one for each test case.
Dump lines of /proc/self/maps matching "sgx" in FIXTURE_SETUP() as this
can be very useful debugging information later on.
Amended commit log:
This migration changes the output of this test. Instead of skipping
the tests if open /dev/sgx_enclave fails, it will run all the tests
and report failures on all of them.
Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Rename symbols for better clarity:
* 'eenter' might be confused for directly calling ENCLU[EENTER]. It does
not. It calls into the VDSO, which actually has the EENTER instruction.
* 'sgx_call_vdso' is *only* used for entering the enclave. It's not some
generic SGX call into the VDSO.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Expose SGX architectural structures, as KVM will use many of the
architectural constants and structs to virtualize SGX.
Name the new header file as asm/sgx.h, rather than asm/sgx_arch.h, to
have single header to provide SGX facilities to share with other kernel
componments. Also update MAINTAINERS to include asm/sgx.h.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Link: https://lkml.kernel.org/r/6bf47acd91ab4d709e66ad1692c7803e4c9063a0.1616136308.git.kai.huang@intel.com
Use the library function getauxval() instead of a custom function to get
the base address of the vDSO.
[ bp: Massage commit message. ]
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lkml.kernel.org/r/20210314111621.68428-1-tianjia.zhang@linux.alibaba.com
The SGX device file (/dev/sgx_enclave) is unusual in that it requires
execute permissions. It has to be both "chmod +x" *and* be on a
filesystem without 'noexec'.
In the future, udev and systemd should get updates to set up systems
automatically. But, for now, nobody's systems do this automatically,
and everybody gets error messages like this when running ./test_sgx:
0x0000000000000000 0x0000000000002000 0x03
0x0000000000002000 0x0000000000001000 0x05
0x0000000000003000 0x0000000000003000 0x03
mmap() failed, errno=1.
That isn't very user friendly, even for forgetful kernel developers.
Further, the test case is rather haphazard about its use of fprintf()
versus perror().
Improve the error messages. Use perror() where possible. Lastly,
do some sanity checks on opening and mmap()ing the device file so
that we can get a decent error message out to the user.
Now, if your user doesn't have permission, you'll get the following:
$ ls -l /dev/sgx_enclave
crw------- 1 root root 10, 126 Mar 18 11:29 /dev/sgx_enclave
$ ./test_sgx
Unable to open /dev/sgx_enclave: Permission denied
If you then 'chown dave:dave /dev/sgx_enclave' (or whatever), but
you leave execute permissions off, you'll get:
$ ls -l /dev/sgx_enclave
crw------- 1 dave dave 10, 126 Mar 18 11:29 /dev/sgx_enclave
$ ./test_sgx
no execute permissions on device file
If you fix that with "chmod ug+x /dev/sgx" but you leave /dev as
noexec, you'll get this:
$ mount | grep "/dev .*noexec"
udev on /dev type devtmpfs (rw,nosuid,noexec,...)
$ ./test_sgx
ERROR: mmap for exec: Operation not permitted
mmap() succeeded for PROT_READ, but failed for PROT_EXEC
check that user has execute permissions on /dev/sgx_enclave and
that /dev does not have noexec set: 'mount | grep "/dev .*noexec"'
That can be fixed with:
mount -o remount,noexec /devESC
Hopefully, the combination of better error messages and the search
engines indexing this message will help people fix their systems
until we do this properly.
[ bp: Improve error messages more. ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lore.kernel.org/r/20210318194301.11D9A984@viggo.jf.intel.com
Use a statically generated key for signing the enclave, because
generating keys on the fly can eat the kernel entropy pool. Another
good reason for doing this is predictable builds. The RSA has been
arbitrarily selected. It's contents do not matter.
This also makes the selftest execute a lot quicker instead of the delay
that it had before (because of slow key generation).
[ bp: Disambiguate "static key" which means something else in the
kernel, fix typos. ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: linux-kselftest@vger.kernel.org
Link: https://lkml.kernel.org/r/20201118170640.39629-1-jarkko@kernel.org
Add a selftest for SGX. It is a trivial test where a simple enclave
copies one 64-bit word of memory between two memory locations,
but ensures that all SGX hardware and software infrastructure is
functioning.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Cc: linux-kselftest@vger.kernel.org
Link: https://lkml.kernel.org/r/20201112220135.165028-21-jarkko@kernel.org
