cast.exp will fail on s390x with a ERROR: kernel read fault at 0x000000004128dbba (addr) near identifier '@cast' at .../testsuite/systemtap.base/cast.stp:37:17 This is because that line does: cast_data = @cast(get_sockaddr(data), "sockaddr", "<sys/socket.h>")->sa_data[0] make_typequery will see the "<sys/socket.h>" and assume this is a user mode cast and generates a umod, not a kmod. dwarf_cast_query::handle_query_module() sees the umod and installs the uderef for user mode address access. This will then fail (correctly?) fail to access the address as user data. We could fix the test by using "kernel<linux/socket.h>" which will generate a kmod instead of a umod. But the comment in the testcase seems to assume you can use a umod @cast in a begin probe. I think we should not try to provide user space access in begin/end probes through casts and the test should be rewritten if it wants to also test umod casts.
Yes indeed, that test is making an assumption about user memory that doesn't hold. I'll have to refactor that piece to a context with a real user address...
Please test s390x again with commit bc0251a6.
2.6.32-220.el6.s390x Systemtap translator/driver (version 1.7/0.152 commit release-1.6-519-g174c4d7) executing: stap /root/systemtap/testsuite/systemtap.base/cast-user.stp /root/sys temtap/testsuite/cast-user.exe -c /root/systemtap/testsuite/cast-user.exe PASS: cast-user testcase /root/systemtap/testsuite/systemtap.base/cast-user.exp completed in 4 s econds Running /root/systemtap/testsuite/systemtap.base/cast.exp ... executing: stap /root/systemtap/testsuite/systemtap.base/cast.stp PASS: systemtap.base/cast.stp testcase /root/systemtap/testsuite/systemtap.base/cast.exp completed in 4 seconds