Re: [PATCH v7 03/23] tools: lib: thermal: Initialize CFLAGS before including Makefile.include

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] This problem wasn't introduced by this patch, but the fix for the CFLAGS initialization order completely missed `tools/lib/bpf/Makefile`. This leaves it vulnerable to the `EXTRA_CFLAGS` expansion introduced later in the series.
--

commit d569bb22d825610f92ca0c5003854cd0736f3058
Author: Leo Yan <leo.yan@arm.com>

tools: lib: thermal: Initialize CFLAGS before including Makefile.include

This commit prepares the thermal lib Makefile for future changes to
tools/scripts/Makefile.include that may expand EXTRA_CFLAGS. It moves
the CFLAGS initialization before the include to ensure default compiler
options like -g and -Wall are not silently dropped.

> diff --git a/tools/lib/thermal/Makefile b/tools/lib/thermal/Makefile
> index 09d8f4ba6a0ab..b55fa42cefa47 100644
> --- a/tools/lib/thermal/Makefile
> +++ b/tools/lib/thermal/Makefile
> @@ -23,6 +23,14 @@ INSTALL = install
>  DESTDIR ?=
>  DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))'
>  
> +# Defer assigning EXTRA_CFLAGS to CFLAGS until after including
> +# tools/scripts/Makefile.include, as it may add flags to EXTRA_CFLAGS.
> +ifdef EXTRA_CFLAGS
> +  CFLAGS :=
> +else
> +  CFLAGS := -g -Wall
> +endif

[Severity: High]
This is a pre-existing issue, but it looks like this same vulnerable CFLAGS 
initialization order exists in tools/lib/bpf/Makefile.

Since a later patch in this series unconditionally populates EXTRA_CFLAGS 
via Makefile.include, does this mean libbpf will skip its default 
initialization and build without optimizations?

tools/lib/bpf/Makefile:
    ...
    include $(srctree)/tools/scripts/Makefile.include
    ...
    ifdef EXTRA_CFLAGS
      CFLAGS := $(EXTRA_CFLAGS)
    else
      CFLAGS := -g -O2
    endif

Should tools/lib/bpf/Makefile also be updated in this series to prevent 
a performance regression in libbpf?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260602-tools_build_fix_zero_init-v7-0-631baf679fe7@arm.com?part=3