+static void test_vmsplice(int fd, const char *desc) +{ + ssize_t transferred; + struct iovec iov; + int pipefd[2]; + char *mem; + + if (pipe(pipefd)) { + fail("pipe failed: %s\n", strerror(errno)); + return; + } + + mem = mmap(NULL, page_size, prot, mode, fd, 0); + if (mem == MAP_FAILED) { + fail("Unable to mmap secret memory\n"); + goto close_pipe; + } + + /* + * vmsplice() may use GUP-fast, which must also fail. Prefault the + * page table, so GUP-fast could find it. + */ + memset(mem, PATTERN, page_size);Shouldn't the non-prefault case be tested as well?
That's the "easy" case where GUP-fast is never involved, and it should mostly be covered by the ptrace/process_vm_read() tests already.
-- Cheers, David / dhildenb
