static void _stp_stack_user_print(struct context *c, int sym_flags)
{
struct pt_regs *regs = NULL;
int uregs_valid = 0;
struct uretprobe_instance *ri = NULL;
if (c->probe_type == _STP_PROBE_HANDLER_URETPROBE)
ri = c->ips.ri;
#ifdef STAPCONF_UPROBE_GET_PC
else if (c->probe_type == _STP_PROBE_HANDLER_UPROBE)
ri = GET_PC_URETPROBE_NONE;
#endif
regs = _stp_get_uregs(c);
uregs_valid = c->probe_flags & _STP_PROBE_STATE_FULL_UREGS;
if (! current->mm || ! regs) {
if (sym_flags & _STP_SYM_SYMBOL)
_stp_printf("<no user backtrace at %s>\n",
c->probe_point);
else
_stp_print("\n");
return;
}
/* print the current address */
#ifdef STAPCONF_UPROBE_GET_PC
if (c->probe_type == _STP_PROBE_HANDLER_URETPROBE && ri) {
if ((sym_flags & _STP_SYM_FULL) == _STP_SYM_FULL) {
_stp_print("Returning from: ");
/* ... otherwise this dereference fails */
_stp_print_addr(ri->rp->u.vaddr, sym_flags, current);
_stp_print("Returning to : ");
_stp_print_addr(ri->ret_addr, sym_flags, current);
} else
_stp_print_addr(ri->ret_addr, sym_flags, current);
} else {
_stp_print_addr(REG_IP(regs), sym_flags, current);
}
#else
_stp_print_addr(REG_IP(regs), sym_flags, current);
#endif
/* print rest of stack... */
#ifdef STP_USE_DWARF_UNWINDER
if (c->uregs == &c->uwcontext.info.regs) {
/* Unwinder needs the reg state, clear uregs ref. */
c->uregs = NULL;
c->probe_flags &= ~_STP_PROBE_STATE_FULL_UREGS;
}
__stp_dwarf_stack_user_print(regs, sym_flags, MAXBACKTRACE,
&c->uwcontext, ri, uregs_valid);
#else
/* User stack traces only supported for arches with dwarf unwinder. */
if (sym_flags & _STP_SYM_SYMBOL)
_stp_printf("<no user backtrace support on arch>\n");
else
_stp_print("\n");
#endif
}
static void _stp_stack_user_print(struct context *c, int sym_flags)
{
struct pt_regs *regs = NULL;
struct uretprobe_instance *ri = NULL;
unsigned n; unsigned long l;
if (c->probe_type == stp_probe_type_uretprobe)
ri = c->ips.ri;
#ifdef STAPCONF_UPROBE_GET_PC
else if (c->probe_type == stp_probe_type_uprobe)
ri = GET_PC_URETPROBE_NONE;
#endif
regs = _stp_get_uregs(c);
if (! current->mm || ! regs) {
if (sym_flags & _STP_SYM_SYMBOL)
_stp_printf("<no user backtrace at %s>\n",
c->probe_point);
else
_stp_print("\n");
return;
}
/* print the current address */
#ifdef STAPCONF_UPROBE_GET_PC
if (c->probe_type == stp_probe_type_uretprobe && ri) {
if ((sym_flags & _STP_SYM_FULL) == _STP_SYM_FULL) {
_stp_print("Returning from: ");
/* ... otherwise this dereference fails */
_stp_print_addr(ri->rp->u.vaddr, sym_flags, current);
_stp_print("Returning to : ");
}
}
#endif
_stp_print_addr(_stp_stack_user_get(c, 0), sym_flags, current);
/* print rest of stack... */
#ifdef STP_USE_DWARF_UNWINDER
for (n = 1; n < MAXBACKTRACE; n++) {
l = _stp_stack_user_get(c, n);
if (l == 0) break; // No user space fallback available
_stp_print_addr(l, sym_flags, current);
}
#else
/* User stack traces only supported for arches with dwarf unwinder. */
if (sym_flags & _STP_SYM_SYMBOL)
_stp_printf("<no user backtrace support on arch>\n");
else
_stp_print("\n");
#endif
}
static unsigned long _stp_stack_unwind_one_user(struct context *c, unsigned depth)
{
struct pt_regs *regs = NULL;
int uregs_valid = 0;
struct uretprobe_instance *ri = NULL;
struct unwind_frame_info *info = NULL;
int ret;
#ifdef STAPCONF_UPROBE_GET_PC
unsigned long maybe_pc;
#endif
if (c->probe_type == stp_probe_type_uretprobe)
ri = c->ips.ri;
#ifdef STAPCONF_UPROBE_GET_PC
else if (c->probe_type == stp_probe_type_uprobe)
ri = GET_PC_URETPROBE_NONE;
#endif
/* XXX: The computation that gives this is cached, so calling
* _stp_get_uregs multiple times is okay... probably. */
regs = _stp_get_uregs(c);
uregs_valid = c->full_uregs_p;
if (! current->mm || ! regs)
return 0; // no user backtrace at this probe point
if (depth == 0) { /* Start by fetching the current PC. */
dbug_unwind(1, "STARTING user unwind\n");
#ifdef STAPCONF_UPROBE_GET_PC
if (c->probe_type == stp_probe_type_uretprobe && ri) {
return ri->ret_addr;
} else {
return REG_IP(regs);
}
#else
return REG_IP(regs);
#endif
}
#ifdef STP_USE_DWARF_UNWINDER
info = &c->uwcontext_user.info;
dbug_unwind(1, "CONTINUING user unwind to depth %d\n", depth);
if (depth == 1) { /* need to clear uregs & set up uwcontext->info */
if (c->uregs == &c->uwcontext_user.info.regs) {
dbug_unwind(1, "clearing uregs\n");
/* Unwinder needs the reg state, clear uregs ref. */
c->uregs = NULL;
c->full_uregs_p = 0;
}
arch_unw_init_frame_info(info, regs, 0);
}
ret = unwind(&c->uwcontext_user, 1);
#ifdef STAPCONF_UPROBE_GET_PC
maybe_pc = 0;
if (ri) {
maybe_pc = uprobe_get_pc(ri, UNW_PC(info), UNW_SP(info));
if (!maybe_pc)
printk("SYSTEMTAP ERROR: uprobe_get_return returned 0\n");
else
UNW_PC(info) = maybe_pc;
}
#endif
dbug_unwind(1, "ret=%d PC=%llx SP=%llx\n", ret,
(unsigned long long) UNW_PC(info), (unsigned long long) UNW_SP(info));
/* check if unwind hit an error */
if (ret || ! _stp_valid_pc_addr(UNW_PC(info), current)) {
return 0;
}
return UNW_PC(info);
#else
/* User stack traces only supported for arches with dwarf unwinder. */
return 0;
#endif
}
