From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29092 invoked by alias); 28 Feb 2004 18:35:09 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 29085 invoked from network); 28 Feb 2004 18:35:09 -0000 Received: from unknown (HELO nevyn.them.org) (66.93.172.17) by sources.redhat.com with SMTP; 28 Feb 2004 18:35:09 -0000 Received: from drow by nevyn.them.org with local (Exim 4.30 #1 (Debian)) id 1Ax9Iq-0004Yf-Ab; Sat, 28 Feb 2004 13:35:08 -0500 Date: Sat, 28 Feb 2004 18:35:00 -0000 From: Daniel Jacobowitz To: gdb-patches@sources.redhat.com Cc: rearnsha@arm.com Subject: [rfa/arm] Handle bx and blx Message-ID: <20040228183508.GA17481@nevyn.them.org> Mail-Followup-To: gdb-patches@sources.redhat.com, rearnsha@arm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.1i X-SW-Source: 2004-02/txt/msg00852.txt.bz2 The software single-step implementation in GDB doesn't know either BX or BLX. This results in losing control of the inferior when we single-step over them. I based this on the ARM ARM, so I'm pretty sure I've got the numbers correct. OK to check in? -- Daniel Jacobowitz MontaVista Software Debian GNU/Linux Developer 2004-02-28 Daniel Jacobowitz * arm-tdep.c (thumb_get_next_pc): Handle BX. (arm_get_next_pc): Handle BX and BLX. Index: gdb/arm-tdep.c =================================================================== RCS file: /big/fsf/rsync/src-cvs/src/gdb/arm-tdep.c,v retrieving revision 1.164 diff -u -p -r1.164 arm-tdep.c --- gdb/arm-tdep.c 16 Feb 2004 21:49:21 -0000 1.164 +++ gdb/arm-tdep.c 28 Feb 2004 03:37:18 -0000 @@ -1657,6 +1658,17 @@ thumb_get_next_pc (CORE_ADDR pc) offset = (sbits (inst1, 0, 10) << 12) + (bits (inst2, 0, 10) << 1); nextpc = pc_val + offset; } + else if ((inst1 & 0xff80) == 0x4700) /* branch and exchange (bx) */ + { + if (bits (inst1, 3, 6) == 0x0f) + nextpc = pc_val; + else + nextpc = read_register (bits (inst1, 3, 6)); + + nextpc = ADDR_BITS_REMOVE (nextpc); + if (nextpc == pc) + error ("Infinite loop detected"); + } return nextpc; } @@ -1697,6 +1709,20 @@ arm_get_next_pc (CORE_ADDR pc) && bits (this_instr, 4, 7) == 9) /* multiply */ error ("Illegal update to pc in instruction"); + /* BX , BLX */ + if (bits (this_instr, 4, 28) == 0x12fff1 + || bits (this_instr, 4, 28) == 0x12fff3) + { + rn = bits (this_instr, 0, 3); + result = (rn == 15) ? pc_val + 8 : read_register (rn); + nextpc = (CORE_ADDR) ADDR_BITS_REMOVE (result); + + if (nextpc == pc) + error ("Infinite loop detected"); + + return nextpc; + } + /* Multiply into PC */ c = (status & FLAG_C) ? 1 : 0; rn = bits (this_instr, 16, 19); @@ -1862,6 +1888,10 @@ arm_get_next_pc (CORE_ADDR pc) { nextpc = BranchDest (pc, this_instr); + /* BLX */ + if (bits (this_instr, 28, 31) == INST_NV) + nextpc |= bit (this_instr, 24) << 1; + nextpc = ADDR_BITS_REMOVE (nextpc); if (nextpc == pc) error ("Infinite loop detected");