2021-03-08 08:57:01

by Yang Li

Subject: [PATCH] perf symbols: turn dso__fprintf_symbols_by_name into void function

This function always return '0' and no callers use the return value.
So make it a void function.

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
---
tools/perf/util/dso.h | 2 +-
tools/perf/util/symbol_fprintf.c | 5 +----
2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index cd2fe64..d7ebf21 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -364,7 +364,7 @@ struct dso *machine__findnew_kernel(struct machine *machine, const char *name,

void dso__reset_find_symbol_cache(struct dso *dso);

-size_t dso__fprintf_symbols_by_name(struct dso *dso, FILE *fp);
+void dso__fprintf_symbols_by_name(struct dso *dso, FILE *fp);
size_t dso__fprintf(struct dso *dso, FILE *fp);

static inline bool dso__is_vmlinux(struct dso *dso)
diff --git a/tools/perf/util/symbol_fprintf.c b/tools/perf/util/symbol_fprintf.c
index 35c936c..031584e 100644
--- a/tools/perf/util/symbol_fprintf.c
+++ b/tools/perf/util/symbol_fprintf.c
@@ -59,10 +59,9 @@ size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
return __symbol__fprintf_symname_offs(sym, NULL, false, false, fp);
}

-size_t dso__fprintf_symbols_by_name(struct dso *dso,
+void dso__fprintf_symbols_by_name(struct dso *dso,
FILE *fp)
{
- size_t ret = 0;
struct rb_node *nd;
struct symbol_name_rb_node *pos;

@@ -70,6 +69,4 @@ size_t dso__fprintf_symbols_by_name(struct dso *dso,
pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
fprintf(fp, "%s\n", pos->sym.name);
}
-
- return ret;
}
--
1.8.3.1

2021-03-08 14:22:44

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] perf symbols: turn dso__fprintf_symbols_by_name into void function

Em Mon, Mar 08, 2021 at 04:55:04PM +0800, Yang Li escreveu:
> This function always return '0' and no callers use the return value.
> So make it a void function.
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>
> ---
> tools/perf/util/dso.h | 2 +-
> tools/perf/util/symbol_fprintf.c | 5 +----
> 2 files changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
> index cd2fe64..d7ebf21 100644
> --- a/tools/perf/util/dso.h
> +++ b/tools/perf/util/dso.h
> @@ -364,7 +364,7 @@ struct dso *machine__findnew_kernel(struct machine *machine, const char *name,
>
> void dso__reset_find_symbol_cache(struct dso *dso);
>
> -size_t dso__fprintf_symbols_by_name(struct dso *dso, FILE *fp);
> +void dso__fprintf_symbols_by_name(struct dso *dso, FILE *fp);
> size_t dso__fprintf(struct dso *dso, FILE *fp);
>
> static inline bool dso__is_vmlinux(struct dso *dso)
> diff --git a/tools/perf/util/symbol_fprintf.c b/tools/perf/util/symbol_fprintf.c
> index 35c936c..031584e 100644
> --- a/tools/perf/util/symbol_fprintf.c
> +++ b/tools/perf/util/symbol_fprintf.c
> @@ -59,10 +59,9 @@ size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
> return __symbol__fprintf_symname_offs(sym, NULL, false, false, fp);
> }
>
> -size_t dso__fprintf_symbols_by_name(struct dso *dso,
> +void dso__fprintf_symbols_by_name(struct dso *dso,
> FILE *fp)
> {
> - size_t ret = 0;
> struct rb_node *nd;
> struct symbol_name_rb_node *pos;
>
> @@ -70,6 +69,4 @@ size_t dso__fprintf_symbols_by_name(struct dso *dso,
> pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
> fprintf(fp, "%s\n", pos->sym.name);
> }
> -
> - return ret;

The class__fprintf* functions follow the fprintf semantics, i.e. return
how many bytes were printed, so the fix should instead be the one below,
that I've commited to my tree, thanks for reporting!

- Arnaldo

commit 210e4c89ef61432040c6cd828fefa441f4887186
Author: Arnaldo Carvalho de Melo <[email protected]>
Date: Mon Mar 8 11:17:51 2021 -0300

perf symbols: Fix dso__fprintf_symbols_by_name() to return the number of printed chars

The 'ret' variable was initialized to zero but then it was not updated
from the fprintf() return, fix it.

Reported-by: Yang Li <[email protected]>
cc: Alexander Shishkin <[email protected]>
cc: Ingo Molnar <[email protected]>
cc: Jiri Olsa <[email protected]>
cc: Mark Rutland <[email protected]>
cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Srikar Dronamraju <[email protected]>
Fixes: 90f18e63fbd00513 ("perf symbols: List symbols in a dso in ascending name order")
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/perf/util/symbol_fprintf.c b/tools/perf/util/symbol_fprintf.c
index 35c936ce33efa6ea..2664fb65e47ada94 100644
--- a/tools/perf/util/symbol_fprintf.c
+++ b/tools/perf/util/symbol_fprintf.c
@@ -68,7 +68,7 @@ size_t dso__fprintf_symbols_by_name(struct dso *dso,

for (nd = rb_first_cached(&dso->symbol_names); nd; nd = rb_next(nd)) {
pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
- fprintf(fp, "%s\n", pos->sym.name);
+ ret += fprintf(fp, "%s\n", pos->sym.name);
}

return ret;