On 06/17/2016 11:03 AM, Ingo Molnar wrote:
* Dmitry Safonov <[email protected]> wrote:Should print on success: [root@localhost ~]# ./test_mremap_vdso_32 AT_SYSINFO_EHDR is 0xf773f000 [NOTE] Moving vDSO: [f773f000, f7740000] -> [a000000, a001000] [OK] Or segfault if landing was bad (before patches): [root@localhost ~]# ./test_mremap_vdso_32 AT_SYSINFO_EHDR is 0xf774f000 [NOTE] Moving vDSO: [f774f000, f7750000] -> [a000000, a001000] Segmentation fault (core dumped)Yeah, so I changed my mind again, I still don't like that the testcase faults on old kernels: triton:~/tip/tools/testing/selftests/x86> ./test_mremap_vdso_32 AT_SYSINFO_EHDR is 0xf7786000 [NOTE] Moving vDSO: [0xf7786000, 0xf7787000] -> [0xf7781000, 0xf7782000] Segmentation fault How do I know that this testcase is special and that a segmentation fault in this case means that I'm running it on a too old kernel and that it's not some other unexpected failure in the test? At minimum please run it behind fork() and catch the -SIGSEGV child exit: mremap(0xf7747000, 4096, 4096, MREMAP_MAYMOVE|MREMAP_FIXED, 0xf7742000) = 0xf7742000 --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0xf7747be9} --- +++ killed by SIGSEGV +++ and print: [FAIL] mremap() of the vDSO does not work on this kernel! or such. Ok?
Ok, will do. Thanks, Dmitry
