diff options
author | kib <kib@FreeBSD.org> | 2016-09-03 09:03:40 +0000 |
---|---|---|
committer | kib <kib@FreeBSD.org> | 2016-09-03 09:03:40 +0000 |
commit | d10386210203bc911e09b0465c917418f228e54a (patch) | |
tree | d03b21baad17eac18eb6bfc7a6f3169a669f0c84 /lib/libc/sys | |
parent | 833d85cdfebda1a68898dd0b713a501551739080 (diff) | |
download | FreeBSD-src-d10386210203bc911e09b0465c917418f228e54a.zip FreeBSD-src-d10386210203bc911e09b0465c917418f228e54a.tar.gz |
MFC r304928:
Do not obliterate errno value in the main thread during ptrace(2) call on x86.
MFC r304931:
Follow ABI when calling __error from the ptrace(2) wrapper.
MFC r305012:
Rewrite ptrace(2) wrappers in C.
MFC r305022:
Restore the requirement of setting errno to zero before calling ptrace(2).
Diffstat (limited to 'lib/libc/sys')
-rw-r--r-- | lib/libc/sys/Makefile.inc | 1 | ||||
-rw-r--r-- | lib/libc/sys/ptrace.2 | 20 | ||||
-rw-r--r-- | lib/libc/sys/ptrace.c | 49 |
3 files changed, 68 insertions, 2 deletions
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc index c358e67..2778cad 100644 --- a/lib/libc/sys/Makefile.inc +++ b/lib/libc/sys/Makefile.inc @@ -48,6 +48,7 @@ INTERPOSED = \ poll \ ppoll \ pselect \ + ptrace \ read \ readv \ recvfrom \ diff --git a/lib/libc/sys/ptrace.2 b/lib/libc/sys/ptrace.2 index b15b012..2cd26ee 100644 --- a/lib/libc/sys/ptrace.2 +++ b/lib/libc/sys/ptrace.2 @@ -2,7 +2,7 @@ .\" $NetBSD: ptrace.2,v 1.2 1995/02/27 12:35:37 cgd Exp $ .\" .\" This file is in the public domain. -.Dd July 28, 2016 +.Dd August 29, 2016 .Dt PTRACE 2 .Os .Sh NAME @@ -900,13 +900,29 @@ argument is ignored. .Pp Additionally, other machine-specific requests can exist. .Sh RETURN VALUES +Most requests return 0 on success and \-1 on error. Some requests can cause .Fn ptrace to return \-1 -as a non-error value; to disambiguate, +as a non-error value, among them are +.Dv PT_READ_I +and +.Dv PT_READ_D , +which return the value read from the process memory on success. +To disambiguate, .Va errno can be set to 0 before the call and checked afterwards. +.Pp +The current +.Fn ptrace +implementation always sets +.Va errno +to 0 before calling into the kernel, both for historic reasons and for +consistency with other operating systems. +It is recommended to assign zero to +.Va errno +explicitly for forward compatibility. .Sh ERRORS The .Fn ptrace diff --git a/lib/libc/sys/ptrace.c b/lib/libc/sys/ptrace.c new file mode 100644 index 0000000..2bb615f --- /dev/null +++ b/lib/libc/sys/ptrace.c @@ -0,0 +1,49 @@ +/* + * Copyright (c) 2016 The FreeBSD Foundation. + * All rights reserved. + * + * Portions of this software were developed by Konstantin Belousov + * under sponsorship from the FreeBSD Foundation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice(s), this list of conditions and the following disclaimer as + * the first lines of this file unmodified other than the possible + * addition of one or more copyright notices. + * 2. Redistributions in binary form must reproduce the above copyright + * notice(s), this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE + * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/types.h> +#include <sys/ptrace.h> +#include <errno.h> +#include "libc_private.h" + +__weak_reference(_ptrace, ptrace); + +int +_ptrace(int request, pid_t pid, caddr_t addr, int data) +{ + + errno = 0; + return (__sys_ptrace(request, pid, addr, data)); +} |