From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4369 invoked by alias); 27 Dec 2011 21:39:14 -0000 Received: (qmail 4356 invoked by uid 22791); 27 Dec 2011 21:39:12 -0000 X-SWARE-Spam-Status: No, hits=-2.7 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from sibelius.xs4all.nl (HELO glazunov.sibelius.xs4all.nl) (83.163.83.176) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 27 Dec 2011 21:38:59 +0000 Received: from glazunov.sibelius.xs4all.nl (kettenis@localhost [127.0.0.1]) by glazunov.sibelius.xs4all.nl (8.14.5/8.14.3) with ESMTP id pBRLcrvd001969; Tue, 27 Dec 2011 22:38:53 +0100 (CET) Received: (from kettenis@localhost) by glazunov.sibelius.xs4all.nl (8.14.5/8.14.3/Submit) id pBRLcpI1006890; Tue, 27 Dec 2011 22:38:51 +0100 (CET) Date: Tue, 27 Dec 2011 22:03:00 -0000 Message-Id: <201112272138.pBRLcpI1006890@glazunov.sibelius.xs4all.nl> From: Mark Kettenis To: stanshebs@earthlink.net CC: gdb-patches@sourceware.org In-reply-to: <4EF3841C.2050603@earthlink.net> (message from Stan Shebs on Thu, 22 Dec 2011 11:25:16 -0800) Subject: Re: [PATCH] PIE support for OpenBSD References: <201112172108.pBHL8Th2032226@glazunov.sibelius.xs4all.nl> <20111221171315.GA18194@host2.jankratochvil.net> <201112212126.pBLLQ2Fl013069@glazunov.sibelius.xs4all.nl> <4EF26E18.3030401@earthlink.net> <201112221020.pBMAKaL0007007@glazunov.sibelius.xs4all.nl> <4EF3841C.2050603@earthlink.net> Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2011-12/txt/msg00851.txt.bz2 > Date: Thu, 22 Dec 2011 11:25:16 -0800 > From: Stan Shebs > > Looks fine to me. It would be helpful to mention somewhere in the > vicinity of the #if's that the code is BSD-specific or BSDish, so as to > forestall people hunting around in other OS headers wondering if those > macros are defined or not. Fair enough. The diff below is what I committed. 2011-12-27 Mark Kettenis * inf-ptrace.c [PT_IO && PIOD_READ_AUXV] (inf_ptrace_xfer_partial): Implement TARGET_OBJECT_AUXV. (inf_ptrace_auxv_parse): New function. (inf_ptrace_target): Initialize to_auxv_parse field. Index: inf-ptrace.c =================================================================== RCS file: /cvs/src/src/gdb/inf-ptrace.c,v retrieving revision 1.75 diff -u -p -r1.75 inf-ptrace.c --- inf-ptrace.c 22 Sep 2011 10:22:28 -0000 1.75 +++ inf-ptrace.c 27 Dec 2011 21:35:05 -0000 @@ -582,6 +582,26 @@ inf_ptrace_xfer_partial (struct target_o return -1; case TARGET_OBJECT_AUXV: +#if defined (PT_IO) && defined (PIOD_READ_AUXV) + /* OpenBSD 4.5 has a new PIOD_READ_AUXV operation for the PT_IO + request that allows us to read the auxilliary vector. Other + BSD's may follow if they feel the need to support PIE. */ + { + struct ptrace_io_desc piod; + + if (writebuf) + return -1; + piod.piod_op = PIOD_READ_AUXV; + piod.piod_addr = readbuf; + piod.piod_offs = (void *) (long) offset; + piod.piod_len = len; + + errno = 0; + if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0) + /* Return the actual number of bytes read or written. */ + return piod.piod_len; + } +#endif return -1; case TARGET_OBJECT_WCOOKIE: @@ -619,6 +639,41 @@ inf_ptrace_pid_to_str (struct target_ops return normal_pid_to_str (ptid); } +#if defined (PT_IO) && defined (PIOD_READ_AUXV) + +/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR. + Return 0 if *READPTR is already at the end of the buffer. + Return -1 if there is insufficient buffer for a whole entry. + Return 1 if an entry was read into *TYPEP and *VALP. */ + +static int +inf_ptrace_auxv_parse (struct target_ops *ops, gdb_byte **readptr, + gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp) +{ + struct type *int_type = builtin_type (target_gdbarch)->builtin_int; + struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr; + const int sizeof_auxv_type = TYPE_LENGTH (int_type); + const int sizeof_auxv_val = TYPE_LENGTH (ptr_type); + enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); + gdb_byte *ptr = *readptr; + + if (endptr == ptr) + return 0; + + if (endptr - ptr < 2 * sizeof_auxv_val) + return -1; + + *typep = extract_unsigned_integer (ptr, sizeof_auxv_type, byte_order); + ptr += sizeof_auxv_val; /* Alignment. */ + *valp = extract_unsigned_integer (ptr, sizeof_auxv_val, byte_order); + ptr += sizeof_auxv_val; + + *readptr = ptr; + return 1; +} + +#endif + /* Create a prototype ptrace target. The client can override it with local methods. */ @@ -644,6 +699,9 @@ inf_ptrace_target (void) t->to_pid_to_str = inf_ptrace_pid_to_str; t->to_stop = inf_ptrace_stop; t->to_xfer_partial = inf_ptrace_xfer_partial; +#if defined (PT_IO) && defined (PIOD_READ_AUXV) + t->to_auxv_parse = inf_ptrace_auxv_parse; +#endif return t; }