perf tools: elf_sym__is_function() should accept "zero" sized functions

Asm routines that end up having size equal to zero are not really
zero sized, and as now we do kernel_maps__fixup_sym_end, at least
for kernel routines this gets fixed.

A similar fixup needs to be done for the userspace bits as well,
but as this fixup started only because in /proc/kallsyms we don't
have the end address nor the function size, it appeared here first.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1254796503-27203-1-git-send-email-acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/util/symbol.c

@@ -324,8 +324,7 @@ static inline int elf_sym__is_function(const GElf_Sym *sym)
 {
 	return elf_sym__type(sym) == STT_FUNC &&
 	       sym->st_name != 0 &&
-	       sym->st_shndx != SHN_UNDEF &&
-	       sym->st_size != 0;
+	       sym->st_shndx != SHN_UNDEF;
 }
 
 static inline int elf_sym__is_label(const GElf_Sym *sym)