int
pmc_save_user_callchain(uintptr_t *cc, int nframes, struct trapframe *tf)
{
int n;
uint32_t instr;
uintptr_t fp, oldfp, pc, r, sp;
KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
__LINE__, (void *) tf));
pc = PMC_TRAPFRAME_TO_PC(tf);
oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
sp = PMC_TRAPFRAME_TO_USER_SP(tf);
*cc++ = pc; n = 1;
r = fp + sizeof(uintptr_t); /* points to return address */
if (!PMC_IN_USERSPACE(pc))
return (n);
if (copyin((void *) pc, &instr, sizeof(instr)) != 0)
return (n);
if (PMC_AT_FUNCTION_PROLOGUE_PUSH_BP(instr) ||
PMC_AT_FUNCTION_EPILOGUE_RET(instr)) { /* ret */
if (copyin((void *) sp, &pc, sizeof(pc)) != 0)
return (n);
} else if (PMC_AT_FUNCTION_PROLOGUE_MOV_SP_BP(instr)) {
sp += sizeof(uintptr_t);
if (copyin((void *) sp, &pc, sizeof(pc)) != 0)
return (n);
} else if (copyin((void *) r, &pc, sizeof(pc)) != 0 ||
copyin((void *) fp, &fp, sizeof(fp)) != 0)
return (n);
for (; n < nframes;) {
if (pc == 0 || !PMC_IN_USERSPACE(pc))
break;
*cc++ = pc; n++;
if (fp < oldfp)
break;
r = fp + sizeof(uintptr_t); /* address of return address */
oldfp = fp;
if (copyin((void *) r, &pc, sizeof(pc)) != 0 ||
copyin((void *) fp, &fp, sizeof(fp)) != 0)
break;
}
return (n);
}
int
pmc_save_user_callchain(uintptr_t *cc, int maxsamples,
struct trapframe *tf)
{
uintptr_t pc, r, oldfp, fp;
struct thread *td;
int count;
KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
__LINE__, (void *) tf));
pc = PMC_TRAPFRAME_TO_PC(tf);
*cc++ = pc;
if ((td = curthread) == NULL)
return (1);
if (maxsamples <= 1)
return (1);
oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
if (!PMC_IN_USERSPACE(pc) ||
!PMC_IN_USERSPACE(fp))
return (1);
for (count = 1; count < maxsamples; count++) {
/* Use saved lr as pc. */
r = fp - sizeof(uintptr_t);
if (copyin((void *)r, &pc, sizeof(pc)) != 0)
break;
if (!PMC_IN_USERSPACE(pc))
break;
*cc++ = pc;
/* Switch to next frame up */
oldfp = fp;
r = fp - 3 * sizeof(uintptr_t);
if (copyin((void *)r, &fp, sizeof(fp)) != 0)
break;
if (fp < oldfp || !PMC_IN_USERSPACE(fp))
break;
}
return (count);
}
