diff options
Diffstat (limited to 'user/grind.c')
| -rw-r--r-- | user/grind.c | 333 |
1 files changed, 333 insertions, 0 deletions
diff --git a/user/grind.c b/user/grind.c new file mode 100644 index 0000000..14e2aae --- /dev/null +++ b/user/grind.c @@ -0,0 +1,333 @@ +// +// run random system calls in parallel forever. +// + +#include "kernel/param.h" +#include "kernel/types.h" +#include "kernel/stat.h" +#include "user/user.h" +#include "kernel/fs.h" +#include "kernel/fcntl.h" +#include "kernel/syscall.h" +#include "kernel/memlayout.h" +#include "kernel/riscv.h" + +// from FreeBSD. +int +do_rand(unsigned long *ctx) +{ +/* + * Compute x = (7^5 * x) mod (2^31 - 1) + * without overflowing 31 bits: + * (2^31 - 1) = 127773 * (7^5) + 2836 + * From "Random number generators: good ones are hard to find", + * Park and Miller, Communications of the ACM, vol. 31, no. 10, + * October 1988, p. 1195. + */ + long hi, lo, x; + + /* Transform to [1, 0x7ffffffe] range. */ + x = (*ctx % 0x7ffffffe) + 1; + hi = x / 127773; + lo = x % 127773; + x = 16807 * lo - 2836 * hi; + if (x < 0) + x += 0x7fffffff; + /* Transform to [0, 0x7ffffffd] range. */ + x--; + *ctx = x; + return (x); +} + +unsigned long rand_next = 1; + +int +rand(void) +{ + return (do_rand(&rand_next)); +} + +void +go(int which_child) +{ + int fd = -1; + static char buf[999]; + char *break0 = sbrk(0); + uint64 iters = 0; + + mkdir("grindir"); + if(chdir("grindir") != 0){ + printf("chdir grindir failed\n"); + exit(1); + } + chdir("/"); + + while(1){ + iters++; + if((iters % 500) == 0) + write(1, which_child?"B":"A", 1); + int what = rand() % 23; + if(what == 1){ + close(open("grindir/../a", O_CREATE|O_RDWR)); + } else if(what == 2){ + close(open("grindir/../grindir/../b", O_CREATE|O_RDWR)); + } else if(what == 3){ + unlink("grindir/../a"); + } else if(what == 4){ + if(chdir("grindir") != 0){ + printf("chdir grindir failed\n"); + exit(1); + } + unlink("../b"); + chdir("/"); + } else if(what == 5){ + close(fd); + fd = open("/grindir/../a", O_CREATE|O_RDWR); + } else if(what == 6){ + close(fd); + fd = open("/./grindir/./../b", O_CREATE|O_RDWR); + } else if(what == 7){ + write(fd, buf, sizeof(buf)); + } else if(what == 8){ + read(fd, buf, sizeof(buf)); + } else if(what == 9){ + mkdir("grindir/../a"); + close(open("a/../a/./a", O_CREATE|O_RDWR)); + unlink("a/a"); + } else if(what == 10){ + mkdir("/../b"); + close(open("grindir/../b/b", O_CREATE|O_RDWR)); + unlink("b/b"); + } else if(what == 11){ + unlink("b"); + link("../grindir/./../a", "../b"); + } else if(what == 12){ + unlink("../grindir/../a"); + link(".././b", "/grindir/../a"); + } else if(what == 13){ + int pid = fork(); + if(pid == 0){ + exit(0); + } else if(pid < 0){ + printf("grind: fork failed\n"); + exit(1); + } + wait(0); + } else if(what == 14){ + int pid = fork(); + if(pid == 0){ + fork(); + fork(); + exit(0); + } else if(pid < 0){ + printf("grind: fork failed\n"); + exit(1); + } + wait(0); + } else if(what == 15){ + sbrk(6011); + } else if(what == 16){ + if(sbrk(0) > break0) + sbrk(-(sbrk(0) - break0)); + } else if(what == 17){ + int pid = fork(); + if(pid == 0){ + close(open("a", O_CREATE|O_RDWR)); + exit(0); + } else if(pid < 0){ + printf("grind: fork failed\n"); + exit(1); + } + if(chdir("../grindir/..") != 0){ + printf("chdir failed\n"); + exit(1); + } + kill(pid); + wait(0); + } else if(what == 18){ + int pid = fork(); + if(pid == 0){ + kill(getpid()); + exit(0); + } else if(pid < 0){ + printf("grind: fork failed\n"); + exit(1); + } + wait(0); + } else if(what == 19){ + int fds[2]; + if(pipe(fds) < 0){ + printf("grind: pipe failed\n"); + exit(1); + } + int pid = fork(); + if(pid == 0){ + fork(); + fork(); + if(write(fds[1], "x", 1) != 1) + printf("grind: pipe write failed\n"); + char c; + if(read(fds[0], &c, 1) != 1) + printf("grind: pipe read failed\n"); + exit(0); + } else if(pid < 0){ + printf("grind: fork failed\n"); + exit(1); + } + close(fds[0]); + close(fds[1]); + wait(0); + } else if(what == 20){ + int pid = fork(); + if(pid == 0){ + unlink("a"); + mkdir("a"); + chdir("a"); + unlink("../a"); + fd = open("x", O_CREATE|O_RDWR); + unlink("x"); + exit(0); + } else if(pid < 0){ + printf("fork failed\n"); + exit(1); + } + wait(0); + } else if(what == 21){ + unlink("c"); + // should always succeed. check that there are free i-nodes, + // file descriptors, blocks. + int fd1 = open("c", O_CREATE|O_RDWR); + if(fd1 < 0){ + printf("create c failed\n"); + exit(1); + } + if(write(fd1, "x", 1) != 1){ + printf("write c failed\n"); + exit(1); + } + struct stat st; + if(fstat(fd1, &st) != 0){ + printf("fstat failed\n"); + exit(1); + } + if(st.size != 1){ + printf("fstat reports wrong size %d\n", (int)st.size); + exit(1); + } + if(st.ino > 200){ + printf("fstat reports crazy i-number %d\n", st.ino); + exit(1); + } + close(fd1); + unlink("c"); + } else if(what == 22){ + // echo hi | cat + int aa[2], bb[2]; + if(pipe(aa) < 0){ + fprintf(2, "pipe failed\n"); + exit(1); + } + if(pipe(bb) < 0){ + fprintf(2, "pipe failed\n"); + exit(1); + } + int pid1 = fork(); + if(pid1 == 0){ + close(bb[0]); + close(bb[1]); + close(aa[0]); + close(1); + if(dup(aa[1]) != 1){ + fprintf(2, "dup failed\n"); + exit(1); + } + close(aa[1]); + char *args[3] = { "echo", "hi", 0 }; + exec("grindir/../echo", args); + fprintf(2, "echo: not found\n"); + exit(2); + } else if(pid1 < 0){ + fprintf(2, "fork failed\n"); + exit(3); + } + int pid2 = fork(); + if(pid2 == 0){ + close(aa[1]); + close(bb[0]); + close(0); + if(dup(aa[0]) != 0){ + fprintf(2, "dup failed\n"); + exit(4); + } + close(aa[0]); + close(1); + if(dup(bb[1]) != 1){ + fprintf(2, "dup failed\n"); + exit(5); + } + close(bb[1]); + char *args[2] = { "cat", 0 }; + exec("/cat", args); + fprintf(2, "cat: not found\n"); + exit(6); + } else if(pid2 < 0){ + fprintf(2, "fork failed\n"); + exit(7); + } + close(aa[0]); + close(aa[1]); + close(bb[1]); + char buf[3] = { 0, 0, 0 }; + read(bb[0], buf+0, 1); + read(bb[0], buf+1, 1); + close(bb[0]); + int st1, st2; + wait(&st1); + wait(&st2); + if(st1 != 0 || st2 != 0 || strcmp(buf, "hi") != 0){ + printf("exec pipeline failed %d %d \"%s\"\n", st1, st2, buf); + exit(1); + } + } + } +} + +int +main() +{ + unlink("a"); + unlink("b"); + + int pid1 = fork(); + if(pid1 < 0){ + printf("grind: fork failed\n"); + exit(1); + } + if(pid1 == 0){ + rand_next = 31; + go(0); + exit(0); + } + + int pid2 = fork(); + if(pid2 < 0){ + printf("grind: fork failed\n"); + exit(1); + } + if(pid2 == 0){ + rand_next = 7177; + go(1); + exit(0); + } + + int st1 = -1; + wait(&st1); + if(st1 != 0){ + kill(pid1); + kill(pid2); + } + int st2 = -1; + wait(&st2); + + exit(0); +} |