lkml.org 
[lkml]   [2002]   [Jan]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] ptrace on stopped processes (2.4)
    From
    Date
    vic <zandy@cs.wisc.edu> writes:

    > From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>:
    > >> --- linux-2.4.16/kernel/ptrace.c Wed Nov 21 16:43:01 2001
    > >> +++ linux-2.4.16.1/kernel/ptrace.c Fri Dec 21 10:42:44 2001
    > >> @@ -89,8 +89,10 @@
    > >> SET_LINKS(task);
    > >> }
    > >> write_unlock_irq(&tasklist_lock);
    > >> -
    > >> - send_sig(SIGSTOP, task, 1);
    > >> + if (task->state != TASK_STOPPED)
    > >> + send_sig(SIGSTOP, task, 1);
    > >> + else
    > >> + task->exit_code = SIGSTOP;
    > >> return 0;
    > >>
    > >> bad:
    > >
    > > It seems that trace is started in the place different from
    > > usual. Then, I think PTRACE_KILL doesn't work.
    >
    > I don't agree, it seems to work for me.

    I tested the following on linux-2.4.16 + your_patch:

    #include <stdio.h>
    #include <signal.h>
    #include <sys/types.h>
    #include <sys/wait.h>
    #include <sys/ptrace.h>
    #include <unistd.h>

    int main(int argc, char *argv[])
    {
    pid_t pid;
    int ret, status;

    pid = fork();
    if (pid == -1)
    exit(1);
    if (pid == 0) {
    raise(SIGSTOP);
    while (1)
    ;
    _exit(1);
    }

    ret = waitpid(pid, &status, WUNTRACED);
    if (ret == -1) {
    perror("waitpid (1)");
    exit(1);
    }

    ret = ptrace(PTRACE_ATTACH, pid, NULL, NULL);
    if (ret == -1) {
    perror("PTRACE_ATTACH");
    exit(1);
    }
    ret = waitpid(pid, &status, 0);
    if (ret == -1) {
    perror("waitpid (2)");
    exit(1);
    }
    ret = ptrace(PTRACE_KILL, pid, NULL, NULL);
    if (ret == -1) {
    perror("PTRACE_KILL");
    exit(1);
    }

    return 0;
    }

    Test result:

    hirofumi@devron (ptrace)[1111]$ ps ax|grep ptrace
    688 tty1 S 0:00 grep ptrace
    hirofumi@devron (ptrace)[1112]$ ls
    ptrace ptrace.c
    hirofumi@devron (ptrace)[1113]$ ./ptrace
    hirofumi@devron (ptrace)[1114]$ ps ax|grep ptrace
    691 tty1 R 0:04 ./ptrace
    693 tty1 S 0:00 grep ptrace
    hirofumi@devron (ptrace)[1115]$

    Do I misunderstand something?
    --
    OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:15    [W:0.025 / U:60.380 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site