diff options
Diffstat (limited to 'gdb/rs6000-tdep.c')
| -rw-r--r-- | gdb/rs6000-tdep.c | 68 |
1 files changed, 57 insertions, 11 deletions
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c index 5176fa0..785f451 100644 --- a/gdb/rs6000-tdep.c +++ b/gdb/rs6000-tdep.c @@ -974,6 +974,61 @@ rs6000_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *bp_addr, #define BXL_INSN 0x4c000000 #define BP_INSN 0x7C000008 +/* Instruction masks used during single-stepping of atomic + sequences. */ +#define LWARX_MASK 0xfc0007fe +#define LWARX_INSTRUCTION 0x7c000028 +#define LDARX_INSTRUCTION 0x7c0000A8 +#define STWCX_MASK 0xfc0007ff +#define STWCX_INSTRUCTION 0x7c00012d +#define STDCX_INSTRUCTION 0x7c0001ad + +/* We can't displaced step atomic sequences. Otherwise this is just + like simple_displaced_step_copy_insn. */ + +static struct displaced_step_closure * +ppc_displaced_step_copy_insn (struct gdbarch *gdbarch, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs) +{ + size_t len = gdbarch_max_insn_length (gdbarch); + gdb_byte *buf = xmalloc (len); + struct cleanup *old_chain = make_cleanup (xfree, buf); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int insn; + + read_memory (from, buf, len); + + insn = extract_signed_integer (buf, PPC_INSN_SIZE, byte_order); + + /* Assume all atomic sequences start with a lwarx/ldarx instruction. */ + if ((insn & LWARX_MASK) == LWARX_INSTRUCTION + || (insn & LWARX_MASK) == LDARX_INSTRUCTION) + { + if (debug_displaced) + { + fprintf_unfiltered (gdb_stdlog, + "displaced: can't displaced step " + "atomic sequence at %s\n", + paddress (gdbarch, from)); + } + do_cleanups (old_chain); + return NULL; + } + + write_memory (to, buf, len); + + if (debug_displaced) + { + fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ", + paddress (gdbarch, from), paddress (gdbarch, to)); + displaced_step_dump_bytes (gdb_stdlog, buf, len); + } + + discard_cleanups (old_chain); + return (struct displaced_step_closure *) buf; +} + /* Fix up the state of registers and memory after having single-stepped a displaced instruction. */ static void @@ -983,8 +1038,7 @@ ppc_displaced_step_fixup (struct gdbarch *gdbarch, struct regcache *regs) { enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); - /* Since we use simple_displaced_step_copy_insn, our closure is a - copy of the instruction. */ + /* Our closure is a copy of the instruction. */ ULONGEST insn = extract_unsigned_integer ((gdb_byte *) closure, PPC_INSN_SIZE, byte_order); ULONGEST opcode = 0; @@ -1077,14 +1131,6 @@ ppc_displaced_step_hw_singlestep (struct gdbarch *gdbarch, return 1; } -/* Instruction masks used during single-stepping of atomic sequences. */ -#define LWARX_MASK 0xfc0007fe -#define LWARX_INSTRUCTION 0x7c000028 -#define LDARX_INSTRUCTION 0x7c0000A8 -#define STWCX_MASK 0xfc0007ff -#define STWCX_INSTRUCTION 0x7c00012d -#define STDCX_INSTRUCTION 0x7c0001ad - /* Checks for an atomic sequence of instructions beginning with a LWARX/LDARX instruction and ending with a STWCX/STDCX instruction. If such a sequence is found, attempt to step through it. A breakpoint is placed at the end of @@ -5923,7 +5969,7 @@ rs6000_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) /* Setup displaced stepping. */ set_gdbarch_displaced_step_copy_insn (gdbarch, - simple_displaced_step_copy_insn); + ppc_displaced_step_copy_insn); set_gdbarch_displaced_step_hw_singlestep (gdbarch, ppc_displaced_step_hw_singlestep); set_gdbarch_displaced_step_fixup (gdbarch, ppc_displaced_step_fixup); |