diff options
| -rw-r--r-- | gdb/ChangeLog | 8 | ||||
| -rw-r--r-- | gdb/s390-linux-tdep.c | 115 |
2 files changed, 123 insertions, 0 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index e44d0f8..b53946d 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,6 +1,14 @@ 2015-11-04 Marcin Kościelnicki <koriakin@0x04.net> PR/18376 + * gdb/s390-linux-tdep.c (s390_is_partial_instruction): New function. + (s390_software_single_step): New function. + (s390_displaced_step_hw_singlestep): New function. + (s390_gdbarch_init): Fill gdbarch slots with the above. + +2015-11-04 Marcin Kościelnicki <koriakin@0x04.net> + + PR/18376 * gdb/configure.tgt: Add linux-record.o to s390*-linux. * gdb/s390-linux-tdep.c: #include "linux-record.h", "record-full.h" (s390_linux_record_tdep): New static global variable. diff --git a/gdb/s390-linux-tdep.c b/gdb/s390-linux-tdep.c index b11ea7a..3ce6336 100644 --- a/gdb/s390-linux-tdep.c +++ b/gdb/s390-linux-tdep.c @@ -526,6 +526,119 @@ s390_pseudo_register_reggroup_p (struct gdbarch *gdbarch, int regnum, } +/* A helper for s390_software_single_step, decides if an instruction + is a partial-execution instruction that needs to be executed until + completion when in record mode. If it is, returns 1 and writes + instruction length to a pointer. */ + +static int +s390_is_partial_instruction (struct gdbarch *gdbarch, CORE_ADDR loc, int *len) +{ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + uint16_t insn; + + insn = read_memory_integer (loc, 2, byte_order); + + switch (insn >> 8) + { + case 0xa8: /* MVCLE */ + *len = 4; + return 1; + + case 0xeb: + { + insn = read_memory_integer (loc + 4, 2, byte_order); + if ((insn & 0xff) == 0x8e) + { + /* MVCLU */ + *len = 6; + return 1; + } + } + break; + } + + switch (insn) + { + case 0xb255: /* MVST */ + case 0xb263: /* CMPSC */ + case 0xb2a5: /* TRE */ + case 0xb2a6: /* CU21 */ + case 0xb2a7: /* CU12 */ + case 0xb9b0: /* CU14 */ + case 0xb9b1: /* CU24 */ + case 0xb9b2: /* CU41 */ + case 0xb9b3: /* CU42 */ + case 0xb92a: /* KMF */ + case 0xb92b: /* KMO */ + case 0xb92f: /* KMC */ + case 0xb92d: /* KMCTR */ + case 0xb92e: /* KM */ + case 0xb93c: /* PPNO */ + case 0xb990: /* TRTT */ + case 0xb991: /* TRTO */ + case 0xb992: /* TROT */ + case 0xb993: /* TROO */ + *len = 4; + return 1; + } + + return 0; +} + +/* Implement the "software_single_step" gdbarch method, needed to single step + through instructions like MVCLE in record mode, to make sure they are + executed to completion. Without that, record will save the full length + of destination buffer on every iteration, even though the CPU will only + process about 4kiB of it each time, leading to O(n**2) memory and time + complexity. */ + +static int +s390_software_single_step (struct frame_info *frame) +{ + struct gdbarch *gdbarch = get_frame_arch (frame); + struct address_space *aspace = get_frame_address_space (frame); + CORE_ADDR loc = get_frame_pc (frame); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + int len; + uint16_t insn; + + /* Special handling only if recording. */ + if (!record_full_is_used ()) + return 0; + + /* First, match a partial instruction. */ + if (!s390_is_partial_instruction (gdbarch, loc, &len)) + return 0; + + loc += len; + + /* Second, look for a branch back to it. */ + insn = read_memory_integer (loc, 2, byte_order); + if (insn != 0xa714) /* BRC with mask 1 */ + return 0; + + insn = read_memory_integer (loc + 2, 2, byte_order); + if (insn != (uint16_t) -(len / 2)) + return 0; + + loc += 4; + + /* Found it, step past the whole thing. */ + + insert_single_step_breakpoint (gdbarch, aspace, loc); + + return 1; +} + +static int +s390_displaced_step_hw_singlestep (struct gdbarch *gdbarch, + struct displaced_step_closure *closure) +{ + return 1; +} + + /* Maps for register sets. */ static const struct regcache_map_entry s390_gregmap[] = @@ -7721,6 +7834,8 @@ s390_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) /* Stack grows downward. */ set_gdbarch_inner_than (gdbarch, core_addr_lessthan); set_gdbarch_breakpoint_from_pc (gdbarch, s390_breakpoint_from_pc); + set_gdbarch_software_single_step (gdbarch, s390_software_single_step); + set_gdbarch_displaced_step_hw_singlestep (gdbarch, s390_displaced_step_hw_singlestep); set_gdbarch_skip_prologue (gdbarch, s390_skip_prologue); set_gdbarch_stack_frame_destroyed_p (gdbarch, s390_stack_frame_destroyed_p); |