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[[!meta title="glibc: ptrace"]]

[[!tag open_issue_glibc]]

`ptrace` has some issues (`sysdeps/mach/hurd/ptrace.c`).

  * Our implementation (and the generic one in `misc/ptrace.c`) differ
    from the Linux one (`sysdeps/unix/sysv/linux/ptrace.c`)
    w.r.t. handling of...

      * the third argument: `int data` vs. `void *data`;

      * `void *addr2` -- Linux doesn't have this, but we provide some
        additional functionalty using this;

      * function declaration: Linux has **`long`** `int ptrace (enum
        __ptrace_request __request, ...)` **`__THROW`**, we have `int ptrace
        (enum __ptrace_request __request, ...)`;

      * interface do differ, e.g., Linux' `PTRACE_GETREGS` uses `void
        *data`, we use `void *addr` for returning the struct, and in
	Linux this is a `struct user_regs_struct` from `linux/user.h`,
        and for us it is a `struct i386_thread_state` from
        `mach/i386/thread_status.h`;

      * Linux probides some functionality that we don't provide, e.g.,
        `PTRACE_SINGLESTEP`.

  * Some parts are wrongly implemented, e.g., `PTRACE_GETREGS` and
    `PTRACE_SETREGS` both do the same thing.

  * `return` values are wrong, e.g., `return EOPNOTSUPP` should instead
    set `errno = EOPNOTSUPP` and `return -1` in a few places (but not
    with the three `PTRACE_PEEK*` requests.

Also consider the `sysdeps/generic/sys/ptrace.h` and
`sysdeps/unix/sysv/linux/sys/ptrace.h` files.