Date: Mon, 25 Mar 2002 11:45:23 -0800 From: Bakul Shah <bakul@bitblocks.com> To: callum.gibson@db.com Cc: hackers@FreeBSD.ORG, Peter Wemm <peter@wemm.org> Subject: Re: Missing PT_READ_U Message-ID: <200203251945.OAA08115@renown.cnchost.com> In-Reply-To: Your message of "Mon, 25 Mar 2002 13:28:08 %2B1100." <20020325022808.11749.qmail@merton.aus.deuba.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> }> As the culprit behind PT_READ_U's demise, I'm willing to dive in
> }> and help here if needed.
> }Thanks but Julian sent me a patch for 4.5 that seems to work
> }with no changes in ups. Would be nice if PT_READ_U is put
> }back in 4.x.
>
> As a followup to this old thread (and as the poster of the original
> question on the ups mailing list in late Feb) I note there has still
> been no change on the RELENG_4 branch to fix this. Could we have the
> patch posted here at least so other people can use ups again (with
> signals)? I'd just apply a reverse patch from kern/sys_process.c 1.51.2.2
> to 1.51.2.1 except that I don't know if other files (apart from sys/ptrace.h)
> have been affected.
Julain Elischer's diff as applied to the 4.5-RELEASE included
below. With this change ups-3.37-beta4 compiled unchanged.
But note that you still can't change any registers. If
PT_WRITE_U is added back to the FreeBSD-4.x branch, no change
is necessary to ups. So how about it, Peter Wemm?
The other alternative is to change ups to understand
PT_{SET,GET}{REGS,FPREGS} -- this would be needed for
FreeBSD-5 in any case. But this is not a quick change as ups
uses PTRACE_{PEEK,POKE}USER for dealing with registers and
signals and these need to be replaced something more
discriminating. I took a quick look at it but then got
distracted. Also, not every arch. has separate FP regs and I
didn't look deep enough in ups to figure out how to add
machine dependent code like this.
-- bakul
Index: sys/ptrace.h
===================================================================
RCS file: /home/ncvs/src/sys/sys/ptrace.h,v
retrieving revision 1.10.2.1
diff -u -r1.10.2.1 ptrace.h
--- sys/ptrace.h 3 Oct 2001 06:55:43 -0000 1.10.2.1
+++ sys/ptrace.h 1 Mar 2002 21:52:57 -0000
@@ -40,7 +40,7 @@
#define PT_TRACE_ME 0 /* child declares it's being traced */
#define PT_READ_I 1 /* read word in child's I space */
#define PT_READ_D 2 /* read word in child's D space */
-/* was PT_READ_U 3 * read word in child's user structure */
+#define PT_READ_U 3 /* read word in child's user structure */
#define PT_WRITE_I 4 /* write word in child's I space */
#define PT_WRITE_D 5 /* write word in child's D space */
/* was PT_WRITE_U 6 * write word in child's user structure */
Index: kern/sys_process.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/sys_process.c,v
retrieving revision 1.51.2.3
diff -u -r1.51.2.3 sys_process.c
--- kern/sys_process.c 22 Jan 2002 17:22:59 -0000 1.51.2.3
+++ kern/sys_process.c 1 Mar 2002 23:45:18 -0000
@@ -257,6 +257,7 @@
case PT_READ_I:
case PT_READ_D:
+ case PT_READ_U:
case PT_WRITE_I:
case PT_WRITE_D:
case PT_CONTINUE:
@@ -413,6 +417,33 @@
}
return (error);
+ case PT_READ_U:
+ if ((uintptr_t)uap->addr > UPAGES * PAGE_SIZE -
+ sizeof(int)) {
+ return EFAULT;
+ }
+ if ((uintptr_t)uap->addr & (sizeof(int) - 1)) {
+ return EFAULT;
+ }
+ if (ptrace_read_u_check(p,(vm_offset_t) uap->addr,
+ sizeof(int))) {
+ return EFAULT;
+ }
+ error = 0;
+ PHOLD(p); /* user had damn well better be incore!*/
+ if (p->p_flag & P_INMEM) {
+ p->p_addr->u_kproc.kp_proc = *p;
+ fill_eproc (p, &p->p_addr->u_kproc.kp_eproc);
+ curp->p_retval[0] = *(int *)
+ ((uintptr_t)p->p_addr +
+ (uintptr_t)uap->addr);
+ } else {
+ curp->p_retval[0] = 0;
+ error = EFAULT;
+ }
+ PRELE(p);
+ return error;
+
case PT_KILL:
uap->data = SIGKILL;
goto sendsig; /* in PT_CONTINUE above */
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200203251945.OAA08115>