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-rw-r--r--gdb/ChangeLog10
-rw-r--r--gdb/arm-tdep.c63
-rw-r--r--gdb/arm-tdep.h11
3 files changed, 74 insertions, 10 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 158d5fc..15fcd54 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,13 @@
+2011-03-02 Yao Qi <yao@codesourcery.com>
+
+ * 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 <msnyder@vmware.com>
* 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 8248418..4c1810d 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 de3f6cc..362be2e 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;