[src/trunk]: src/sys/kern Merge the code back; the problem was that since we ...

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

details:   https://anonhg.NetBSD.org/src/rev/aacf8360ea7b
branches:  trunk
changeset: 828653:aacf8360ea7b
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Dec 23 22:12:19 2017 +0000

description:
Merge the code back; the problem was that since we are reading/writing
to a kernel address for PT_{READ,WRITE}_{I,D} we need the kernel vmspace.

diffstat:

 sys/kern/sys_ptrace_common.c |  57 ++++++++++++++++---------------------------
 1 files changed, 21 insertions(+), 36 deletions(-)

diffs (120 lines):

diff -r 8da116174369 -r aacf8360ea7b sys/kern/sys_ptrace_common.c
--- a/sys/kern/sys_ptrace_common.c      Sat Dec 23 22:07:57 2017 +0000
+++ b/sys/kern/sys_ptrace_common.c      Sat Dec 23 22:12:19 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_ptrace_common.c,v 1.30 2017/12/22 15:02:57 kamil Exp $     */
+/*     $NetBSD: sys_ptrace_common.c,v 1.31 2017/12/23 22:12:19 christos 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 1.30 2017/12/22 15:02:57 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_ptrace_common.c,v 1.31 2017/12/23 22:12:19 christos Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ptrace.h"
@@ -904,7 +904,7 @@
 
 static int
 ptrace_doio(struct lwp *l, struct proc *t, struct lwp *lt,
-    struct ptrace_io_desc *piod, void *addr, struct vmspace **vm)
+    struct ptrace_io_desc *piod, void *addr, bool sysspace)
 {
        struct uio uio;
        struct iovec iov;
@@ -947,19 +947,23 @@
                error = EINVAL;
                break;
        }
-       if (error)
-               return error;
-       error = proc_vmspace_getref(l->l_proc, vm);
+
        if (error)
                return error;
 
-       uio.uio_vmspace = *vm;
+       if (sysspace) {
+               uio.uio_vmspace = vmspace_kernel();
+       } else {
+               error = proc_vmspace_getref(l->l_proc, &uio.uio_vmspace);
+               if (error)
+                       return error;
+       }
 
        error = process_domem(l, lt, &uio);
-       if (error) {
-               uvmspace_free(*vm);
+       if (!sysspace)
+               uvmspace_free(uio.uio_vmspace);
+       if (error)
                return error;
-       }
        piod->piod_len -= uio.uio_resid;
        return 0;
 }
@@ -972,10 +976,7 @@
        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;
        int signo = 0;
        int resume_all;
@@ -1034,32 +1035,17 @@
 
        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:
-               /* 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);
-
+               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, true)) != 0)
+                       break;
                if (!write)
                        *retval = tmp;
                break;
@@ -1067,10 +1053,9 @@
        case PT_IO:
                if ((error = ptm->ptm_copyin_piod(&piod, addr, data)) != 0)
                        break;
-               if ((error = ptrace_doio(l, t, lt, &piod, addr, &vm)) != 0)
+               if ((error = ptrace_doio(l, t, lt, &piod, addr, false)) != 0)
                        break;
                (void) ptm->ptm_copyout_piod(&piod, addr, data);
-               uvmspace_free(vm);
                break;
 
        case PT_DUMPCORE: