perf annotate: Defer allocating sym_priv->hist array

Because symbol->end is not fixed up at symbol_filter time, only
after all symbols for a DSO are loaded, and that, for asm
symbols, may be bogus, causing segfaults when hits happen in
these symbols.

Reported-by: David Miller <davem@davemloft.net>
Reported-by: Anton Blanchard <anton@samba.org>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <stable@kernel.org> # for .33.x. Does not apply cleanly, needs backport.
LKML-Reference: <20100225155740.GB8553@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Arnaldo Carvalho de Melo 2010-02-25 12:57:40 -03:00 committed by Ingo Molnar
parent 3846df2e0a
commit 628ada0cb0
3 changed files with 32 additions and 29 deletions

View file

@ -53,32 +53,20 @@ struct sym_priv {
static const char *sym_hist_filter;
static int symbol_filter(struct map *map __used, struct symbol *sym)
static int sym__alloc_hist(struct symbol *self)
{
if (sym_hist_filter == NULL ||
strcmp(sym->name, sym_hist_filter) == 0) {
struct sym_priv *priv = symbol__priv(sym);
const int size = (sizeof(*priv->hist) +
(sym->end - sym->start) * sizeof(u64));
struct sym_priv *priv = symbol__priv(self);
const int size = (sizeof(*priv->hist) +
(self->end - self->start) * sizeof(u64));
priv->hist = malloc(size);
if (priv->hist)
memset(priv->hist, 0, size);
return 0;
}
/*
* FIXME: We should really filter it out, as we don't want to go thru symbols
* we're not interested, and if a DSO ends up with no symbols, delete it too,
* but right now the kernel loading routines in symbol.c bail out if no symbols
* are found, fix it later.
*/
return 0;
priv->hist = zalloc(size);
return priv->hist == NULL ? -1 : 0;
}
/*
* collect histogram counts
*/
static void hist_hit(struct hist_entry *he, u64 ip)
static int annotate__hist_hit(struct hist_entry *he, u64 ip)
{
unsigned int sym_size, offset;
struct symbol *sym = he->sym;
@ -88,11 +76,11 @@ static void hist_hit(struct hist_entry *he, u64 ip)
he->count++;
if (!sym || !he->map)
return;
return 0;
priv = symbol__priv(sym);
if (!priv->hist)
return;
if (priv->hist == NULL && sym__alloc_hist(sym) < 0)
return -ENOMEM;
sym_size = sym->end - sym->start;
offset = ip - sym->start;
@ -100,7 +88,7 @@ static void hist_hit(struct hist_entry *he, u64 ip)
pr_debug3("%s: ip=%#Lx\n", __func__, he->map->unmap_ip(he->map, ip));
if (offset >= sym_size)
return;
return 0;
h = priv->hist;
h->sum++;
@ -108,18 +96,31 @@ static void hist_hit(struct hist_entry *he, u64 ip)
pr_debug3("%#Lx %s: count++ [ip: %#Lx, %#Lx] => %Ld\n", he->sym->start,
he->sym->name, ip, ip - he->sym->start, h->ip[offset]);
return 0;
}
static int perf_session__add_hist_entry(struct perf_session *self,
struct addr_location *al, u64 count)
{
bool hit;
struct hist_entry *he = __perf_session__add_hist_entry(self, al, NULL,
count, &hit);
struct hist_entry *he;
if (sym_hist_filter != NULL &&
(al->sym == NULL || strcmp(sym_hist_filter, al->sym->name) != 0)) {
/* We're only interested in a symbol named sym_hist_filter */
if (al->sym != NULL) {
rb_erase(&al->sym->rb_node,
&al->map->dso->symbols[al->map->type]);
symbol__delete(al->sym);
}
return 0;
}
he = __perf_session__add_hist_entry(self, al, NULL, count, &hit);
if (he == NULL)
return -ENOMEM;
hist_hit(he, al->addr);
return 0;
return annotate__hist_hit(he, al->addr);
}
static int process_sample_event(event_t *event, struct perf_session *session)
@ -129,7 +130,7 @@ static int process_sample_event(event_t *event, struct perf_session *session)
dump_printf("(IP, %d): %d: %#Lx\n", event->header.misc,
event->ip.pid, event->ip.ip);
if (event__preprocess_sample(event, session, &al, symbol_filter) < 0) {
if (event__preprocess_sample(event, session, &al, NULL) < 0) {
pr_warning("problem processing %d event, skipping it.\n",
event->header.type);
return -1;

View file

@ -144,7 +144,7 @@ static struct symbol *symbol__new(u64 start, u64 len, const char *name)
return self;
}
static void symbol__delete(struct symbol *self)
void symbol__delete(struct symbol *self)
{
free(((void *)self) - symbol_conf.priv_size);
}

View file

@ -51,6 +51,8 @@ struct symbol {
char name[0];
};
void symbol__delete(struct symbol *self);
struct strlist;
struct symbol_conf {