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perf probe: Search concrete out-of-line instances

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gcc 4.6 generates a concrete out-of-line instance when there is a
function which is implicitly inlined somewhere but also has its own
instance. The concrete out-of-line instance means that it has an
abstract origin of the function which is referred by not only
inlined-subroutines but also a concrete subprogram.

Since current dwarf_func_inline_instances() can find only instances of
inlined-subroutines, this introduces new die_walk_instances() to find
both of subprogram and inlined-subroutines.

e.g. without this,
Available variables at sched_group_rt_period
        @<cpu_rt_period_read_uint+9>
                struct task_group*      tg

perf probe failed to find actual subprogram instance of
sched_group_rt_period().

With this,

Available variables at sched_group_rt_period
        @<cpu_rt_period_read_uint+9>
                struct task_group*      tg
        @<sched_group_rt_period+0>
                struct task_group*      tg

Now it found the sched_group_rt_period() itself.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2011-08-11 20:03:11 +09:00 committed by Arnaldo Carvalho de Melo
parent f182e3e13c
commit db0d2c6420
3 changed files with 83 additions and 35 deletions
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58
tools/perf/util/dwarf-aux.c
View file

@ -453,6 +453,64 @@ Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
return die_mem;
}
struct __instance_walk_param {
void *addr;
int (*callback)(Dwarf_Die *, void *);
void *data;
int retval;
};
static int __die_walk_instances_cb(Dwarf_Die *inst, void *data)
{
struct __instance_walk_param *iwp = data;
Dwarf_Attribute attr_mem;
Dwarf_Die origin_mem;
Dwarf_Attribute *attr;
Dwarf_Die *origin;
attr = dwarf_attr(inst, DW_AT_abstract_origin, &attr_mem);
if (attr == NULL)
return DIE_FIND_CB_CONTINUE;
origin = dwarf_formref_die(attr, &origin_mem);
if (origin == NULL || origin->addr != iwp->addr)
return DIE_FIND_CB_CONTINUE;
iwp->retval = iwp->callback(inst, iwp->data);
return (iwp->retval) ? DIE_FIND_CB_END : DIE_FIND_CB_CONTINUE;
}
/**
* die_walk_instances - Walk on instances of given DIE
* @or_die: an abstract original DIE
* @callback: a callback function which is called with instance DIE
* @data: user data
*
* Walk on the instances of give @in_die. @in_die must be an inlined function
* declartion. This returns the return value of @callback if it returns
* non-zero value, or -ENOENT if there is no instance.
*/
int die_walk_instances(Dwarf_Die *or_die, int (*callback)(Dwarf_Die *, void *),
void *data)
{
Dwarf_Die cu_die;
Dwarf_Die die_mem;
struct __instance_walk_param iwp = {
.addr = or_die->addr,
.callback = callback,
.data = data,
.retval = -ENOENT,
};
if (dwarf_diecu(or_die, &cu_die, NULL, NULL) == NULL)
return -ENOENT;
die_find_child(&cu_die, __die_walk_instances_cb, &iwp, &die_mem);
return iwp.retval;
}
/* Line walker internal parameters */
struct __line_walk_param {
bool recursive;

4
tools/perf/util/dwarf-aux.h
View file

@ -80,6 +80,10 @@ extern Dwarf_Die *die_find_realfunc(Dwarf_Die *cu_die, Dwarf_Addr addr,
extern Dwarf_Die *die_find_inlinefunc(Dwarf_Die *sp_die, Dwarf_Addr addr,
Dwarf_Die *die_mem);
/* Walk on the instances of given DIE */
extern int die_walk_instances(Dwarf_Die *in_die,
int (*callback)(Dwarf_Die *, void *), void *data);
/* Walker on lines (Note: line number will not be sorted) */
typedef int (* line_walk_callback_t) (const char *fname, int lineno,
Dwarf_Addr addr, void *data);

56
tools/perf/util/probe-finder.c
View file

@ -924,42 +924,39 @@ static int find_probe_point_lazy(Dwarf_Die *sp_die, struct probe_finder *pf)
return die_walk_lines(sp_die, probe_point_lazy_walker, pf);
}
/* Callback parameter with return value */
struct dwarf_callback_param {
void *data;
int retval;
};
static int probe_point_inline_cb(Dwarf_Die *in_die, void *data)
{
struct dwarf_callback_param *param = data;
struct probe_finder *pf = param->data;
struct probe_finder *pf = data;
struct perf_probe_point *pp = &pf->pev->point;
Dwarf_Addr addr;
int ret;
if (pp->lazy_line)
param->retval = find_probe_point_lazy(in_die, pf);
ret = find_probe_point_lazy(in_die, pf);
else {
/* Get probe address */
if (dwarf_entrypc(in_die, &addr) != 0) {
pr_warning("Failed to get entry address of %s.\n",
dwarf_diename(in_die));
param->retval = -ENOENT;
return DWARF_CB_ABORT;
return -ENOENT;
}
pf->addr = addr;
pf->addr += pp->offset;
pr_debug("found inline addr: 0x%jx\n",
(uintmax_t)pf->addr);
param->retval = call_probe_finder(in_die, pf);
if (param->retval < 0)
return DWARF_CB_ABORT;
ret = call_probe_finder(in_die, pf);
}
return DWARF_CB_OK;
return ret;
}
/* Callback parameter with return value for libdw */
struct dwarf_callback_param {
void *data;
int retval;
};
/* Search function from function name */
static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
{
@ -996,14 +993,10 @@ static int probe_point_search_cb(Dwarf_Die *sp_die, void *data)
/* TODO: Check the address in this function */
param->retval = call_probe_finder(sp_die, pf);
}
} else {
struct dwarf_callback_param _param = {.data = (void *)pf,
.retval = 0};
} else
/* Inlined function: search instances */
dwarf_func_inline_instances(sp_die, probe_point_inline_cb,
&_param);
param->retval = _param.retval;
}
param->retval = die_walk_instances(sp_die,
probe_point_inline_cb, (void *)pf);
return DWARF_CB_ABORT; /* Exit; no same symbol in this CU. */
}
@ -1452,16 +1445,14 @@ static int find_line_range_by_line(Dwarf_Die *sp_die, struct line_finder *lf)
static int line_range_inline_cb(Dwarf_Die *in_die, void *data)
{
struct dwarf_callback_param *param = data;
param->retval = find_line_range_by_line(in_die, param->data);
find_line_range_by_line(in_die, data);
/*
* We have to check all instances of inlined function, because
* some execution paths can be optimized out depends on the
* function argument of instances
*/
return DWARF_CB_OK;
return 0;
}
/* Search function from function name */
@ -1489,15 +1480,10 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data)
pr_debug("New line range: %d to %d\n", lf->lno_s, lf->lno_e);
lr->start = lf->lno_s;
lr->end = lf->lno_e;
if (dwarf_func_inline(sp_die)) {
struct dwarf_callback_param _param;
_param.data = (void *)lf;
_param.retval = 0;
dwarf_func_inline_instances(sp_die,
line_range_inline_cb,
&_param);
param->retval = _param.retval;
} else
if (dwarf_func_inline(sp_die))
param->retval = die_walk_instances(sp_die,
line_range_inline_cb, lf);
else
param->retval = find_line_range_by_line(sp_die, lf);
return DWARF_CB_ABORT;
}