Re: [PATCH] scripts: bloat-o-meter: avoid shell for nm invocation

[David Laight <david.laight.linux@gmail.com>]

On Sun, 27 Sep 2026 10:34:41 +0500
iamzayn19 <iamzayn19@gmail.com> wrote:

> bloat-o-meter builds the nm command with string formatting and then
> executes it through the shell. Object file paths containing spaces are
> split before nm sees them, so the comparison silently reports empty
> results for those files.

Where are pathnames with spaces coming from?
Make doesn't support them.
Even some windows build environments don't support them.

David

> 
> Invoke nm with subprocess argv instead. This preserves paths as single
> arguments and avoids shell interpretation of filenames and tool prefixes.
> 
> Assisted-by: LLM
> Signed-off-by: iamzayn19 <iamzayn19@gmail.com>
> ---
>  scripts/bloat-o-meter | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/scripts/bloat-o-meter b/scripts/bloat-o-meter
> index 5868a8b..72edbb7 100755
> --- a/scripts/bloat-o-meter
> +++ b/scripts/bloat-o-meter
> @@ -7,7 +7,7 @@
>  # This software may be used and distributed according to the terms
>  # of the GNU General Public License, incorporated herein by reference.
>  
> -import sys, os, re, argparse
> +import argparse, re, subprocess
>  from signal import signal, SIGPIPE, SIG_DFL
>  
>  signal(SIGPIPE, SIG_DFL)
> @@ -31,8 +31,11 @@ def getsizes(file, format):
>      if args.prefix:
>          nm = "{}nm".format(args.prefix)
>  
> -    with os.popen("{} --size-sort {}".format(nm, file)) as f:
> -        for line in f:
> +    with subprocess.Popen([nm, "--size-sort", file], stdout=subprocess.PIPE,
> +                          text=True) as f:
> +        if f.stdout is None:
> +            return sym
> +        for line in f.stdout:
>              if line.startswith("\n") or ":" in line:
>                  continue
>              size, type, name = line.split()
> @@ -49,6 +52,7 @@ def getsizes(file, format):
>                  # statics and some other optimizations adds random .NUMBER
>                  name = re_NUMBER.sub('', name)
>                  sym[name] = sym.get(name, 0) + int(size, 16)
> +        f.wait()
>      return sym
>  
>  def calc(oldfile, newfile, format):