From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25652 invoked by alias); 11 Jul 2011 17:01:09 -0000 Received: (qmail 25629 invoked by uid 22791); 11 Jul 2011 17:01:06 -0000 X-SWARE-Spam-Status: No, hits=-2.0 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,TVD_RCVD_SPACE_BRACKET,TW_BJ,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from smtp.nokia.com (HELO mgw-da01.nokia.com) (147.243.128.24) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 11 Jul 2011 17:00:51 +0000 Received: from nokia.com (localhost [127.0.0.1]) by mgw-da01.nokia.com (Switch-3.4.4/Switch-3.4.3) with ESMTP id p6BH0Y0o012070; Mon, 11 Jul 2011 20:00:34 +0300 Received: from bettdhcp167184.europe.nokia.com ([bettdhcp167184.europe.nokia.com [172.25.167.184]]) by mgw-da01.nokia.com with RELAY id p6BH04E7011548 ; Mon, 11 Jul 2011 20:00:08 +0300 Subject: Re: [PATCH,gdb,Update6]: ensures that cie ptr of an fda is a cie Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii From: Fawzi Mohamed In-Reply-To: Date: Mon, 11 Jul 2011 17:19:00 -0000 Cc: ext Jan Kratochvil , , ext Tristan Gingold , =?iso-8859-1?Q?Andr=E9_P=F6nitz?= Content-Transfer-Encoding: quoted-printable Message-Id: <870E5F11-1670-4333-B66E-83C297D00182@nokia.com> References: <0FC98010-6811-4715-BD3B-AE8B9221C7BF@nokia.com> <20110706170323.GA28535@host1.jankratochvil.net> <4A77D598-9262-4A47-813D-0CD977E9DA68@nokia.com> To: ext Tom Tromey X-Nokia-AV: Clean 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: 2011-07/txt/msg00274.txt.bz2 On Jul 7, 2011, at 9:37 PM, ext Tom Tromey wrote: > [...] Tom, thanks for the comments, I did the changes. > I think it is weird not to use the result of the xrealloc call, even > though we know it is just shrinking the buffer. I added a comment about that. Fawzi 2011-07-07 Fawzi Mohamed * dwarf2-frame.c (decode_frame_entry, decode_frame_entry_1): Ensure that CIE pointer of an FDE really points to a CIE . diff --git a/gdb/dwarf2-frame.c b/gdb/dwarf2-frame.c index b68a773..18d74b4 100644 --- a/gdb/dwarf2-frame.c +++ b/gdb/dwarf2-frame.c @@ -1801,17 +1801,30 @@ add_fde (struct dwarf2_fde_table *fde_table, struct= dwarf2_fde *fde) #define DW64_CIE_ID ~0 #endif =20 +/* Defines the type of eh_frames that are expected to be decoded: CIE, FDE + or any of them. */ + +enum eh_frame_type +{ + EH_CIE_TYPE_ID =3D 1 << 0, + EH_FDE_TYPE_ID =3D 1 << 1, + EH_CIE_OR_FDE_TYPE_ID =3D EH_CIE_TYPE_ID | EH_FDE_TYPE_ID +}; + static gdb_byte *decode_frame_entry (struct comp_unit *unit, gdb_byte *sta= rt, int eh_frame_p, struct dwarf2_cie_table *cie_table, - struct dwarf2_fde_table *fde_table); + struct dwarf2_fde_table *fde_table, + enum eh_frame_type entry_type); + +/* Decode the next CIE or FDE, entry_type specifies the expected type. + Return NULL if invalid input, otherwise the next byte to be processed. = */ =20 -/* Decode the next CIE or FDE. Return NULL if invalid input, otherwise - the next byte to be processed. */ static gdb_byte * decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_fram= e_p, struct dwarf2_cie_table *cie_table, - struct dwarf2_fde_table *fde_table) + struct dwarf2_fde_table *fde_table, + enum eh_frame_type entry_type) { struct gdbarch *gdbarch =3D get_objfile_arch (unit->objfile); gdb_byte *buf, *end; @@ -1862,6 +1875,10 @@ decode_frame_entry_1 (struct comp_unit *unit, gdb_by= te *start, int eh_frame_p, char *augmentation; unsigned int cie_version; =20 + /* Check that a CIE was expected. */ + if ((entry_type & EH_CIE_TYPE_ID) =3D=3D 0) + error (_("Found a CIE when not expecting it.")); + /* Record the offset into the .debug_frame section of this CIE. */ cie_pointer =3D start - unit->dwarf_frame_buffer; =20 @@ -2027,6 +2044,10 @@ decode_frame_entry_1 (struct comp_unit *unit, gdb_by= te *start, int eh_frame_p, /* This is a FDE. */ struct dwarf2_fde *fde; =20 + /* Check that an FDE was expected. */ + if ((entry_type & EH_FDE_TYPE_ID) =3D=3D 0) + error (_("Found an FDE when not expecting it.")); + /* In an .eh_frame section, the CIE pointer is the delta between the address within the FDE where the CIE pointer is stored and the address of the CIE. Convert it to an offset into the .eh_frame @@ -2048,7 +2069,8 @@ decode_frame_entry_1 (struct comp_unit *unit, gdb_byt= e *start, int eh_frame_p, if (fde->cie =3D=3D NULL) { decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer, - eh_frame_p, cie_table, fde_table); + eh_frame_p, cie_table, fde_table, + EH_CIE_TYPE_ID); fde->cie =3D find_cie (cie_table, cie_pointer); } =20 @@ -2089,11 +2111,14 @@ decode_frame_entry_1 (struct comp_unit *unit, gdb_b= yte *start, int eh_frame_p, return end; } =20 -/* Read a CIE or FDE in BUF and decode it. */ +/* Read a CIE or FDE in BUF and decode it. Entry_type specifies whether we + expect an FDE or a CIE. */ + static gdb_byte * decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_= p, struct dwarf2_cie_table *cie_table, - struct dwarf2_fde_table *fde_table) + struct dwarf2_fde_table *fde_table, + enum eh_frame_type entry_type) { enum { NONE, ALIGN4, ALIGN8, FAIL } workaround =3D NONE; gdb_byte *ret; @@ -2102,7 +2127,7 @@ decode_frame_entry (struct comp_unit *unit, gdb_byte = *start, int eh_frame_p, while (1) { ret =3D decode_frame_entry_1 (unit, start, eh_frame_p, - cie_table, fde_table); + cie_table, fde_table, entry_type); if (ret !=3D NULL) break; =20 @@ -2212,6 +2237,7 @@ dwarf2_build_frame_info (struct objfile *objfile) struct dwarf2_cie_table cie_table; struct dwarf2_fde_table fde_table; struct dwarf2_fde_table *fde_table2; + volatile struct gdb_exception e; =20 cie_table.num_entries =3D 0; cie_table.entries =3D NULL; @@ -2253,10 +2279,28 @@ dwarf2_build_frame_info (struct objfile *objfile) if (txt) unit->tbase =3D txt->vma; =20 - frame_ptr =3D unit->dwarf_frame_buffer; - while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_= size) - frame_ptr =3D decode_frame_entry (unit, frame_ptr, 1, - &cie_table, &fde_table); + TRY_CATCH (e, RETURN_MASK_ERROR) + { + frame_ptr =3D unit->dwarf_frame_buffer; + while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_siz= e) + frame_ptr =3D decode_frame_entry (unit, frame_ptr, 1, + &cie_table, &fde_table, + EH_CIE_OR_FDE_TYPE_ID); + } + + if (e.reason < 0) + { + warning (_("skipping .eh_frame info of %s: %s"), + objfile->name, e.message); + + if (fde_table.num_entries !=3D 0) + { + xfree(fde_table.entries); + fde_table.entries =3D NULL; + fde_table.num_entries =3D 0; + } + /* The cie_table is discarded by the next if. */ + } =20 if (cie_table.num_entries !=3D 0) { @@ -2274,10 +2318,39 @@ dwarf2_build_frame_info (struct objfile *objfile) &unit->dwarf_frame_size); if (unit->dwarf_frame_size) { - frame_ptr =3D unit->dwarf_frame_buffer; - while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) - frame_ptr =3D decode_frame_entry (unit, frame_ptr, 0, - &cie_table, &fde_table); + int num_old_fde_entries =3D fde_table.num_entries; + + TRY_CATCH (e, RETURN_MASK_ERROR) + { + frame_ptr =3D unit->dwarf_frame_buffer; + while (frame_ptr < unit->dwarf_frame_buffer + unit->dwarf_frame_size) + frame_ptr =3D decode_frame_entry (unit, frame_ptr, 0, + &cie_table, &fde_table, + EH_CIE_OR_FDE_TYPE_ID); + } + if (e.reason < 0) + { + warning (_("skipping .debug_frame info of %s: %s"), + objfile->name, e.message); + + if (fde_table.num_entries !=3D 0) + { + fde_table.num_entries =3D num_old_fde_entries; + if (num_old_fde_entries =3D=3D 0) + { + xfree (fde_table.entries); + fde_table.entries =3D NULL; + } + else + { + /* just shrinks, could be skipped */ + xrealloc (fde_table.entries,fde_table.num_entries * + sizeof (fde_table.entries[0])); + } + } + fde_table.num_entries =3D num_old_fde_entries; + /* The cie_table is discarded by the next if. */ + } } =20 /* Discard the cie_table, it is no longer needed. */