diff options
Diffstat (limited to 'gdb/rs6000-tdep.c')
| -rw-r--r-- | gdb/rs6000-tdep.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/gdb/rs6000-tdep.c b/gdb/rs6000-tdep.c index 96b28ec..e9f8a86 100644 --- a/gdb/rs6000-tdep.c +++ b/gdb/rs6000-tdep.c @@ -729,12 +729,13 @@ deal_with_atomic_sequence (struct regcache *regcache) CORE_ADDR breaks[2] = {-1, -1}; CORE_ADDR loc = pc; CORE_ADDR branch_bp; /* Breakpoint at branch instruction's destination. */ + CORE_ADDR closing_insn; /* Instruction that closes the atomic sequence. */ int insn = read_memory_integer (loc, PPC_INSN_SIZE); int insn_count; int index; int last_breakpoint = 0; /* Defaults to 0 (no breakpoints placed). */ const int atomic_sequence_length = 16; /* Instruction sequence length. */ - const int opcode = BC_INSTRUCTION; /* Branch instruction's OPcode. */ + int opcode; /* Branch instruction's OPcode. */ int bc_insn_count = 0; /* Conditional branch instruction count. */ /* Assume all atomic sequences start with a lwarx/ldarx instruction. */ @@ -758,6 +759,7 @@ deal_with_atomic_sequence (struct regcache *regcache) return 0; /* More than one conditional branch found, fallback to the standard single-step code. */ + opcode = insn >> 26; branch_bp = branch_dest (opcode, insn, pc, breaks[0]); if (branch_bp != -1) @@ -778,14 +780,19 @@ deal_with_atomic_sequence (struct regcache *regcache) && (insn & STWCX_MASK) != STDCX_INSTRUCTION) return 0; + closing_insn = loc; loc += PPC_INSN_SIZE; insn = read_memory_integer (loc, PPC_INSN_SIZE); /* Insert a breakpoint right after the end of the atomic sequence. */ breaks[0] = loc; - /* Check for duplicated breakpoints. */ - if (last_breakpoint && (breaks[1] == breaks[0])) + /* Check for duplicated breakpoints. Check also for a breakpoint + placed (branch instruction's destination) at the stwcx/stdcx + instruction, this resets the reservation and take us back to the + lwarx/ldarx instruction at the beginning of the atomic sequence. */ + if (last_breakpoint && ((breaks[1] == breaks[0]) + || (breaks[1] == closing_insn))) last_breakpoint = 0; /* Effectively inserts the breakpoints. */ |