From patchwork Sat Jun 20 15:44:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kratochvil X-Patchwork-Id: 7270 Received: (qmail 123312 invoked by alias); 20 Jun 2015 15:44:57 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 123302 invoked by uid 89); 20 Jun 2015 15:44:57 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.3 required=5.0 tests=AWL, BAYES_00, KAM_STOCKGEN, RP_MATCHES_RCVD, SPF_HELO_PASS, SPF_PASS autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Sat, 20 Jun 2015 15:44:55 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id A12A219CBEF for ; Sat, 20 Jun 2015 15:44:54 +0000 (UTC) Received: from host1.jankratochvil.net (ovpn-116-41.ams2.redhat.com [10.36.116.41]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t5KFio6b004824 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 20 Jun 2015 11:44:52 -0400 Date: Sat, 20 Jun 2015 17:44:49 +0200 From: Jan Kratochvil To: gdb-patches@sourceware.org Cc: Sergio Durigan Junior Subject: [patch] Do not skip prologue for asm (.S) files Message-ID: <20150620154449.GA24593@host1.jankratochvil.net> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-IsSubscribed: yes Hi, https://bugzilla.redhat.com/show_bug.cgi?id=1084404 GDB tries to skip prologue for .S files according to .debug_line but it then places the breakpoint to a location where it is never hit. This is because #defines in .S files cause prologue skipping which is completely inappropriate, for s390x: glibc/sysdeps/unix/syscall-template.S 78:/* This is a "normal" system call stub: if there is an error, 79: it returns -1 and sets errno. */ 80: 81:T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS) 82: ret 00000000000f4210 T __select Line Number Statements: Extended opcode 2: set Address to 0xf41c8 Advance Line by 80 to 81 Copy Advance PC by 102 to 0xf422e Special opcode 6: advance Address by 0 to 0xf422e and Line by 1 to 82 Special opcode 34: advance Address by 2 to 0xf4230 and Line by 1 to 83 Advance PC by 38 to 0xf4256 Extended opcode 1: End of Sequence Compilation Unit @ offset 0x28b3e0: <0><28b3eb>: Abbrev Number: 1 (DW_TAG_compile_unit) <28b3ec> DW_AT_stmt_list : 0x7b439 <28b3f0> DW_AT_low_pc : 0xf41c8 <28b3f8> DW_AT_high_pc : 0xf4256 <28b400> DW_AT_name : ../sysdeps/unix/syscall-template.S <28b423> DW_AT_comp_dir : /usr/src/debug////////glibc-2.17-c758a686/misc <28b452> DW_AT_producer : GNU AS 2.23.52.0.1 <28b465> DW_AT_language : 32769 (MIPS assembler) without debuginfo - correct address: (gdb) b select Breakpoint 1 at 0xf4210 with debuginfo, either with or without the fix: (gdb) b select Breakpoint 1 at 0xf41c8: file ../sysdeps/unix/syscall-template.S, line 81. One part is to make 'locations_valid' true even for asm files. /* Symtab has been compiled with both optimizations and debug info so that GDB may stop skipping prologues as variables locations are valid already at function entry points. */ unsigned int locations_valid : 1; The other part is to extend the 'locations_valid' functionality more - I have chosen mostly randomly this place. No regressions on {x86_64,x86_64-m32,i686}-fedora23pre-linux-gnu. Jan gdb/ChangeLog 2015-06-20 Jan Kratochvil * dwarf2read.c (process_full_comp_unit): Set LOCATIONS_VALID also for language_asm. * linespec.c (minsym_found): Reset sal.PC forCOMPUNIT_LOCATIONS_VALID. gdb/testsuite/ChangeLog 2015-06-20 Jan Kratochvil * gdb.arch/amd64-prologue-skip.S: New file. * gdb.arch/amd64-prologue-skip.exp: New file. diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c index d79b2e3..76ff66d 100644 --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -8096,7 +8096,7 @@ process_full_comp_unit (struct dwarf2_per_cu_data *per_cu, Still one can confuse GDB by using non-standard GCC compilation options - this waits on GCC PR other/32998 (-frecord-gcc-switches). */ - if (cu->has_loclist && gcc_4_minor >= 5) + if ((cu->has_loclist && gcc_4_minor >= 5) || cu->language == language_asm) cust->locations_valid = 1; if (gcc_4_minor >= 5) diff --git a/gdb/linespec.c b/gdb/linespec.c index d2089b5..a7ea41b 100644 --- a/gdb/linespec.c +++ b/gdb/linespec.c @@ -3454,7 +3454,17 @@ minsym_found (struct linespec_state *self, struct objfile *objfile, sal = find_pc_sect_line (pc, NULL, 0); if (self->funfirstline) - skip_prologue_sal (&sal); + { + if (sal.symtab != NULL + && COMPUNIT_LOCATIONS_VALID (SYMTAB_COMPUNIT (sal.symtab))) + { + sal.pc = MSYMBOL_VALUE_ADDRESS (objfile, msymbol); + sal.pc = gdbarch_convert_from_func_ptr_addr (gdbarch, sal.pc, + ¤t_target); + } + else + skip_prologue_sal (&sal); + } if (maybe_add_address (self->addr_set, objfile->pspace, sal.pc)) add_sal_to_sals (self, result, &sal, MSYMBOL_NATURAL_NAME (msymbol), 0); diff --git a/gdb/testsuite/gdb.arch/amd64-prologue-skip.S b/gdb/testsuite/gdb.arch/amd64-prologue-skip.S new file mode 100644 index 0000000..66b806a --- /dev/null +++ b/gdb/testsuite/gdb.arch/amd64-prologue-skip.S @@ -0,0 +1,28 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2015 Free Software Foundation, Inc. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + + .text +/*0*/ hlt +pushrbp: .globl pushrbp +#define PUSHRBP push %rbp; mov %rsp, %rbp; nop +/*1*/ PUSHRBP +/*6*/ hlt + +/*7*/ hlt +#define MINSYM nop; .globl minsym; minsym: nop +/*8*/ MINSYM +/*a*/ hlt diff --git a/gdb/testsuite/gdb.arch/amd64-prologue-skip.exp b/gdb/testsuite/gdb.arch/amd64-prologue-skip.exp new file mode 100644 index 0000000..015cd69 --- /dev/null +++ b/gdb/testsuite/gdb.arch/amd64-prologue-skip.exp @@ -0,0 +1,35 @@ +# Copyright 2010-2015 Free Software Foundation, Inc. + +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +standard_testfile .S +set binfile ${binfile}.o + +if { ![istarget x86_64-*-* ] || ![is_lp64_target] } { + verbose "Skipping ${testfile}." + return +} + +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" object {debug}] != "" } { + untested ${testfile} + return +} + +clean_restart ${binfile} + +gdb_test "break *pushrbp" " at 0x1: file .*" +gdb_test "break pushrbp" " at 0x1: file .*" + +gdb_test "break *minsym" " at 0x9: file .*" +gdb_test "break minsym" " at 0x9: file .*"