From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from yyc-mba.localdomain (cpe-174-109-102-187.nc.res.rr.com [174.109.102.187]) by sourceware.org (Postfix) with ESMTP id E107E3858406 for ; Wed, 18 May 2022 00:10:31 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E107E3858406 Received: by yyc-mba.localdomain (Postfix, from userid 1000) id 6EB2A171785; Tue, 17 May 2022 10:42:30 -0400 (EDT) From: Yichao Yu To: gdb-patches@sourceware.org, Luis Machado Subject: [PATCH v3] Return the regnum for PC (32) on aarch64 Date: Tue, 17 May 2022 10:41:43 -0400 Message-Id: <20220517144142.695287-1-yyc1992@gmail.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <058f6593-89ed-e13e-d082-def468995317@arm.com> References: <058f6593-89ed-e13e-d082-def468995317@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, FORGED_GMAIL_RCVD, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, GIT_PATCH_0, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_NONE, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, KAM_NUMSUBJECT, KAM_SHORT, KHOP_HELO_FCRDNS, NML_ADSP_CUSTOM_MED, NO_DNS_FOR_FROM, RCVD_IN_PBL, RCVD_IN_SORBS_DUL, RDNS_DYNAMIC, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 May 2022 00:10:33 -0000 This will allow the unwind info to explicitly specify a different value for the return address from the link register. Such usage, although uncommon, is valid and useful for signal frames. It is also endorsed by aadwarf64 from ARM (Note 9 in [1]). Ref https://sourceware.org/pipermail/gdb/2022-May/050091.html [1] https://github.com/ARM-software/abi-aa/blob/2022Q1/aadwarf64/aadwarf64.rst#dwarf-register-names --- gdb/aarch64-tdep.c | 3 + gdb/aarch64-tdep.h | 1 + gdb/testsuite/gdb.arch/aarch64-unwind-pc.S | 48 ++++++++++++++ gdb/testsuite/gdb.arch/aarch64-unwind-pc.exp | 70 ++++++++++++++++++++ 4 files changed, 122 insertions(+) create mode 100644 gdb/testsuite/gdb.arch/aarch64-unwind-pc.S create mode 100644 gdb/testsuite/gdb.arch/aarch64-unwind-pc.exp diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c index 9d06ebfe27c..f9eb455232f 100644 --- a/gdb/aarch64-tdep.c +++ b/gdb/aarch64-tdep.c @@ -2219,6 +2219,9 @@ aarch64_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg) if (reg == AARCH64_DWARF_SP) return AARCH64_SP_REGNUM; + if (reg == AARCH64_DWARF_PC) + return AARCH64_PC_REGNUM; + if (reg >= AARCH64_DWARF_V0 && reg <= AARCH64_DWARF_V0 + 31) return AARCH64_V0_REGNUM + reg - AARCH64_DWARF_V0; diff --git a/gdb/aarch64-tdep.h b/gdb/aarch64-tdep.h index e4cdebb6311..aa1bedbdac6 100644 --- a/gdb/aarch64-tdep.h +++ b/gdb/aarch64-tdep.h @@ -34,6 +34,7 @@ struct regset; /* AArch64 Dwarf register numbering. */ #define AARCH64_DWARF_X0 0 #define AARCH64_DWARF_SP 31 +#define AARCH64_DWARF_PC 32 #define AARCH64_DWARF_PAUTH_RA_STATE 34 #define AARCH64_DWARF_PAUTH_DMASK 35 #define AARCH64_DWARF_PAUTH_CMASK 36 diff --git a/gdb/testsuite/gdb.arch/aarch64-unwind-pc.S b/gdb/testsuite/gdb.arch/aarch64-unwind-pc.S new file mode 100644 index 00000000000..6cc4f80e349 --- /dev/null +++ b/gdb/testsuite/gdb.arch/aarch64-unwind-pc.S @@ -0,0 +1,48 @@ +/* Copyright 2022 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 + .globl main + .type main,#function +main: + .cfi_startproc + stp x29, x30, [sp, -16]! + .cfi_def_cfa sp, 16 + .cfi_offset x29, 0 + .cfi_offset x30, 8 + bl test_func + ldp x29, x30, [sp], 16 + .cfi_restore x29 + .cfi_restore x30 + .cfi_def_cfa sp, 0 + mov x0, 0 + ret + .cfi_endproc + + .globl test_func +test_func: + .cfi_startproc + // Unwind x30 to a different value + // CFA_val_expression x30 const2u 0x1234 + .cfi_escape 0x16, 30, 0x03, 0x0a, 0x34, 0x12 + // CFA_val_expression pc breg30 0 + .cfi_escape 0x16, 32, 0x02, 0x8e, 0x00 + mov x0, x30 + .cfi_register 32, x0 + mov x30, 0x1234 + ret x0 + .cfi_endproc diff --git a/gdb/testsuite/gdb.arch/aarch64-unwind-pc.exp b/gdb/testsuite/gdb.arch/aarch64-unwind-pc.exp new file mode 100644 index 00000000000..105b9a9cc3a --- /dev/null +++ b/gdb/testsuite/gdb.arch/aarch64-unwind-pc.exp @@ -0,0 +1,70 @@ +# Copyright 2022 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 . + +# This file is part of the gdb testsuite. + +# Test explicitly unwinding the PC DWARF register on aarch64 + +if {![is_aarch64_target]} then { + verbose "Skipping ${gdb_test_file_name}." + return +} + +standard_testfile .S + +if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } { + return -1 +} + +if ![runto_main] { + return -1 +} + +proc test_reg_vals {} { + gdb_test "p \$pc - &main" "= 8" "p \$pc" + gdb_test "p/x \$x30" "= 0x1234" "p \$x30" +} + +proc test_unwind_pc { inst } { + gdb_test "si" "$inst" "single step" + gdb_test "backtrace" \ + ".*#1.*in main ().*" \ + "backtrace" + gdb_test "up" "in main ().*" "parent frame" + test_reg_vals +} + +# Ready to enter the function +gdb_test "si" "bl test_func" "call site" +# Step through the 3 instructions in the function to make sure that +# we have the same unwind info throughout. +with_test_prefix "1st stepi" { + test_unwind_pc "mov x0, x30" +} +with_test_prefix "2nd stepi" { + test_unwind_pc "mov x30, 0x1234" +} +with_test_prefix "3rd stepi" { + test_unwind_pc "ret x0" +} +# Check again after we returned +with_test_prefix "final" { + # Check that we've stepped out (si prints out the new function name) + gdb_test "si" ".*main *().*" "single step out" + gdb_test "backtrace" \ + "#0\[\t \]+main ().*" \ + "backtrace" + test_reg_vals +} -- 2.36.1