[src/trunk]: src/sys/kern ptrace: Partially undo PT_{READ, WRITE}_{I, D} and un...

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/dc28a6633a0e
branches:  trunk
changeset: 828643:dc28a6633a0e
user:      kamil <kamil%NetBSD.org@localhost>
date:      Fri Dec 22 15:02:57 2017 +0000

description:
ptrace: Partially undo PT_{READ,WRITE}_{I,D} and unbreak these commands

The refactored code did not work and was generating EFAULT.

Sponsored by <The NetBSD Foundation>

diffstat:

 sys/kern/sys_ptrace_common.c |  34 +++++++++++++++++++++++++---------
 1 files changed, 25 insertions(+), 9 deletions(-)

diffs (69 lines):

diff -r 1786f040d962 -r dc28a6633a0e sys/kern/sys_ptrace_common.c
--- a/sys/kern/sys_ptrace_common.c      Fri Dec 22 14:41:55 2017 +0000
+++ b/sys/kern/sys_ptrace_common.c      Fri Dec 22 15:02:57 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_ptrace_common.c,v 1.29 2017/12/17 20:59:27 christos Exp $  */
+/*     $NetBSD: sys_ptrace_common.c,v 1.30 2017/12/22 15:02:57 kamil Exp $     */
 
 /*-
  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -118,7 +118,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_ptrace_common.c,v 1.29 2017/12/17 20:59:27 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_ptrace_common.c,v 1.30 2017/12/22 15:02:57 kamil Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ptrace.h"
@@ -972,6 +972,8 @@
        struct lwp *lt = NULL;
        struct lwp *lt2;
        struct proc *t;                         /* target process */
+       struct uio uio;
+       struct iovec iov;
        struct ptrace_io_desc piod;
        struct vmspace *vm;
        int error, write, tmp, pheld;
@@ -1032,20 +1034,34 @@
 
        case PT_WRITE_I:                /* XXX no separate I and D spaces */
        case PT_WRITE_D:
+#if defined(__HAVE_RAS)
+               /*
+                * Can't write to a RAS
+                */
+               if (ras_lookup(t, addr) != (void *)-1) {
+                       error = EACCES;
+                       break;
+               }
+#endif
                write = 1;
                tmp = data;
                /* FALLTHROUGH */
        case PT_READ_I:                 /* XXX no separate I and D spaces */
        case PT_READ_D:
-               piod.piod_addr = &tmp;
-               piod.piod_len = sizeof(tmp);
-               piod.piod_offs = addr;
-               piod.piod_op = write ? PIOD_WRITE_D : PIOD_READ_D;
-               if ((error = ptrace_doio(l, t, lt, &piod, addr, &vm)) != 0)
-                       break;
+               /* write = 0 done above. */
+               iov.iov_base = (void *)&tmp;
+               iov.iov_len = sizeof(tmp);
+               uio.uio_iov = &iov;
+               uio.uio_iovcnt = 1;
+               uio.uio_offset = (off_t)(unsigned long)addr;
+               uio.uio_resid = sizeof(tmp);
+               uio.uio_rw = write ? UIO_WRITE : UIO_READ;
+               UIO_SETUP_SYSSPACE(&uio);
+
+               error = process_domem(l, lt, &uio);
+
                if (!write)
                        *retval = tmp;
-               uvmspace_free(vm);
                break;
 
        case PT_IO: