perf annotate: Fix off by one symbol hist size allocation and hit accounting
Arnaldo Carvalho de Melo [Wed, 28 Mar 2012 15:49:35 +0000 (12:49 -0300)]
We were not noticing it because symbol__inc_addr_samples was erroneously
dropping samples that hit the last byte in a function.

Working on a fix for a problem reported by David Miller, Stephane
Eranian and Sorin Dumitru, where addresses < sym->start were causing
problems, I noticed this other problem.

Cc: David Ahern <dsahern@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sorin Dumitru <dumitru.sorin87@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-pqjaq4cr1xs2xen73pjhbav4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/annotate.c

index 31ba2a2..199f69e 100644 (file)
@@ -28,8 +28,8 @@ int symbol__annotate_init(struct map *map __used, struct symbol *sym)
 int symbol__alloc_hist(struct symbol *sym)
 {
        struct annotation *notes = symbol__annotation(sym);
-       size_t sizeof_sym_hist = (sizeof(struct sym_hist) +
-                                 (sym->end - sym->start) * sizeof(u64));
+       const size_t size = sym->end - sym->start + 1;
+       size_t sizeof_sym_hist = (sizeof(struct sym_hist) + size * sizeof(u64));
 
        notes->src = zalloc(sizeof(*notes->src) + symbol_conf.nr_events * sizeof_sym_hist);
        if (notes->src == NULL)
@@ -64,7 +64,7 @@ int symbol__inc_addr_samples(struct symbol *sym, struct map *map,
 
        pr_debug3("%s: addr=%#" PRIx64 "\n", __func__, map->unmap_ip(map, addr));
 
-       if (addr >= sym->end)
+       if (addr > sym->end)
                return 0;
 
        offset = addr - sym->start;