diff options
Diffstat (limited to 'usr/src/uts/intel/dtrace/fasttrap_isa.c')
| -rw-r--r-- | usr/src/uts/intel/dtrace/fasttrap_isa.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/usr/src/uts/intel/dtrace/fasttrap_isa.c b/usr/src/uts/intel/dtrace/fasttrap_isa.c index 5b0c0a9383..c8f222e429 100644 --- a/usr/src/uts/intel/dtrace/fasttrap_isa.c +++ b/usr/src/uts/intel/dtrace/fasttrap_isa.c @@ -104,6 +104,8 @@ #define FASTTRAP_JLE 0x7e #define FASTTRAP_JG 0x7f +#define FASTTRAP_NOP 0x90 + #define FASTTRAP_MOV_EAX 0xb8 #define FASTTRAP_MOV_ECX 0xb9 @@ -230,7 +232,7 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, uintptr_t pc, size_t len = FASTTRAP_MAX_INSTR_SIZE; size_t first = MIN(len, PAGESIZE - (pc & PAGEOFFSET)); uint_t start = 0; - int rmindex; + int rmindex, size; uint8_t seg, rex = 0; /* @@ -252,14 +254,13 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, uintptr_t pc, /* * If the disassembly fails, then we have a malformed instruction. */ - if ((tp->ftt_size = dtrace_instr_size_isa(instr, p->p_model, - &rmindex)) <= 0) + if ((size = dtrace_instr_size_isa(instr, p->p_model, &rmindex)) <= 0) return (-1); /* * Make sure the disassembler isn't completely broken. */ - ASSERT(-1 <= rmindex && rmindex < tp->ftt_size); + ASSERT(-1 <= rmindex && rmindex < size); /* * If the computed size is greater than the number of bytes read, @@ -267,9 +268,10 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, uintptr_t pc, * page boundary and the subsequent page was missing or because of * some malicious user. */ - if (tp->ftt_size > len) + if (size > len) return (-1); + tp->ftt_size = (uint8_t)size; tp->ftt_segment = FASTTRAP_SEG_NONE; /* @@ -503,6 +505,21 @@ fasttrap_tracepoint_init(proc_t *p, fasttrap_tracepoint_t *tp, uintptr_t pc, tp->ftt_type = FASTTRAP_T_PUSHL_EBP; break; + case FASTTRAP_NOP: +#ifdef __amd64 + ASSERT(p->p_model == DATAMODEL_LP64 || rex == 0); + + /* + * On amd64 we have to be careful not to confuse a nop + * (actually xchgl %eax, %eax) with an instruction using + * the same opcode, but that does something different + * (e.g. xchgl %r8d, %eax or xcghq %r8, %rax). + */ + if (FASTTRAP_REX_B(rex) == 0) +#endif + tp->ftt_type = FASTTRAP_T_NOP; + break; + case FASTTRAP_INT3: /* * The pid provider shares the int3 trap with debugger @@ -1253,6 +1270,10 @@ fasttrap_pid_probe(struct regs *rp) break; } + case FASTTRAP_T_NOP: + new_pc = pc + tp->ftt_size; + break; + case FASTTRAP_T_JMP: case FASTTRAP_T_CALL: if (tp->ftt_code == 0) { @@ -1603,7 +1624,6 @@ done: } } - ASSERT(new_pc != 0); rp->r_pc = new_pc; return (0); |