Dave Hansen 4284f7acb7 selftests/sgx: Improve error detection and messages ... 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		2021-03-19 19:23:41 +01:00
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.gitignore
call.S
defines.h
load.c	selftests/sgx: Improve error detection and messages	2021-03-19 19:23:41 +01:00
main.c	selftests/sgx: Improve error detection and messages	2021-03-19 19:23:41 +01:00
main.h
Makefile
sign_key.pem
sign_key.S
sigstruct.c
test_encl.c
test_encl.lds
test_encl_bootstrap.S