From 4db71c0b79ff7e89a392f903f39251faa795d69c Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Wed, 2 Mar 2011 05:33:37 +0000 Subject: [PATCH] 2011-03-02 Yao Qi * arm-tdep.h (struct displaced_step_closure): Add two new fields is_thumb and insn_size. * arm-tdep.c (displaced_read_reg): Adjust correct pipeline offset on both ARM and Thumb mode. (arm_process_displaced_insn): Set is_thumb and insn_size. (arm_displaced_init_closure): Handle both 16-bit and 32-bit. (arm_displaced_step_fixup): Likewise. --- gdb/ChangeLog | 10 ++++++++ gdb/arm-tdep.c | 63 ++++++++++++++++++++++++++++++++++++++++++-------- gdb/arm-tdep.h | 11 +++++++++ 3 files changed, 74 insertions(+), 10 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 158d5fc86e..15fcd546be 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2011-03-02 Yao Qi + + * arm-tdep.h (struct displaced_step_closure): Add two new fields + is_thumb and insn_size. + * arm-tdep.c (displaced_read_reg): Adjust correct pipeline offset + on both ARM and Thumb mode. + (arm_process_displaced_insn): Set is_thumb and insn_size. + (arm_displaced_init_closure): Handle both 16-bit and 32-bit. + (arm_displaced_step_fixup): Likewise. + 2011-03-01 Michael Snyder * cli/cli-dump.c (dump_bfd_file): Check error return and warn. diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 8248418228..4c1810df30 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -5106,6 +5106,8 @@ arm_adjust_breakpoint_address (struct gdbarch *gdbarch, CORE_ADDR bpaddr) /* NOP instruction (mov r0, r0). */ #define ARM_NOP 0xe1a00000 +static int displaced_in_arm_mode (struct regcache *regs); + /* Helper for register reads for displaced stepping. In particular, this returns the PC as it would be seen by the instruction at its original location. */ @@ -5117,10 +5119,21 @@ displaced_read_reg (struct regcache *regs, CORE_ADDR from, int regno) if (regno == 15) { + /* Compute pipeline offset: + - When executing an ARM instruction, PC reads as the address of the + current instruction plus 8. + - When executing a Thumb instruction, PC reads as the address of the + current instruction plus 4. */ + + if (displaced_in_arm_mode (regs)) + from += 8; + else + from += 4; + if (debug_displaced) fprintf_unfiltered (gdb_stdlog, "displaced: read pc value %.8lx\n", - (unsigned long) from + 8); - return (ULONGEST) from + 8; /* Pipeline offset. */ + (unsigned long) from); + return (ULONGEST) from; } else { @@ -6861,6 +6874,8 @@ arm_process_displaced_insn (struct gdbarch *gdbarch, CORE_ADDR from, if (!displaced_in_arm_mode (regs)) return thumb_process_displaced_insn (gdbarch, from, to, regs, dsc); + dsc->is_thumb = 0; + dsc->insn_size = 4; insn = read_memory_unsigned_integer (from, 4, byte_order_for_code); if (debug_displaced) fprintf_unfiltered (gdb_stdlog, "displaced: stepping insn %.8lx " @@ -6904,23 +6919,49 @@ arm_displaced_init_closure (struct gdbarch *gdbarch, CORE_ADDR from, CORE_ADDR to, struct displaced_step_closure *dsc) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); - unsigned int i; + unsigned int i, len, offset; enum bfd_endian byte_order_for_code = gdbarch_byte_order_for_code (gdbarch); + int size = dsc->is_thumb? 2 : 4; + const unsigned char *bkp_insn; + offset = 0; /* Poke modified instruction(s). */ for (i = 0; i < dsc->numinsns; i++) { if (debug_displaced) - fprintf_unfiltered (gdb_stdlog, "displaced: writing insn %.8lx at " - "%.8lx\n", (unsigned long) dsc->modinsn[i], - (unsigned long) to + i * 4); - write_memory_unsigned_integer (to + i * 4, 4, byte_order_for_code, + { + fprintf_unfiltered (gdb_stdlog, "displaced: writing insn "); + if (size == 4) + fprintf_unfiltered (gdb_stdlog, "%.8lx", + dsc->modinsn[i]); + else if (size == 2) + fprintf_unfiltered (gdb_stdlog, "%.4x", + (unsigned short)dsc->modinsn[i]); + + fprintf_unfiltered (gdb_stdlog, " at %.8lx\n", + (unsigned long) to + offset); + + } + write_memory_unsigned_integer (to + offset, size, + byte_order_for_code, dsc->modinsn[i]); + offset += size; + } + + /* Choose the correct breakpoint instruction. */ + if (dsc->is_thumb) + { + bkp_insn = tdep->thumb_breakpoint; + len = tdep->thumb_breakpoint_size; + } + else + { + bkp_insn = tdep->arm_breakpoint; + len = tdep->arm_breakpoint_size; } /* Put breakpoint afterwards. */ - write_memory (to + dsc->numinsns * 4, tdep->arm_breakpoint, - tdep->arm_breakpoint_size); + write_memory (to + offset, bkp_insn, len); if (debug_displaced) fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ", @@ -6956,7 +6997,9 @@ arm_displaced_step_fixup (struct gdbarch *gdbarch, dsc->cleanup (gdbarch, regs, dsc); if (!dsc->wrote_to_pc) - regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, dsc->insn_addr + 4); + regcache_cooked_write_unsigned (regs, ARM_PC_REGNUM, + dsc->insn_addr + dsc->insn_size); + } #include "bfd-in2.h" diff --git a/gdb/arm-tdep.h b/gdb/arm-tdep.h index de3f6cca76..362be2e7e2 100644 --- a/gdb/arm-tdep.h +++ b/gdb/arm-tdep.h @@ -262,6 +262,17 @@ struct displaced_step_closure struct displaced_step_closure *dsc); } svc; } u; + + /* The size of original instruction, 2 or 4. */ + unsigned int insn_size; + /* True if the original insn (and thus all replacement insns) are Thumb + instead of ARM. */ + unsigned int is_thumb; + + /* The slots in the array is used in this way below, + - ARM instruction occupies one slot, + - Thumb 16 bit instruction occupies one slot, + - Thumb 32-bit instruction occupies *two* slots, one part for each. */ unsigned long modinsn[DISPLACED_MODIFIED_INSNS]; int numinsns; CORE_ADDR insn_addr; -- 2.34.1