Prior to commit d1d096312176 ("tools: fix annoying "mkdir -p ..." logs
when building tools in parallel"), the top-level MAKEFLAGS=-rR
(disabling built-in rules/variables) was overridden by
subdirectory-specific MAKEFLAGS during tools compilation. This allowed
tools like pfrut and firewire to implicitly rely on Make's built-in rules.
After the aforementioned commit, the -rR flags from the top-level
Makefile began propagating to subdirectory builds. This broke tools
depending on implicit rules because:
1. -r (--no-builtin-rules) disabled implicit .c -> .o rules
2. -R (--no-builtin-variables) hid critical implicit variables like CC
Fix this by filtering out -rR from MAKEFLAGS.
Fixes: d1d096312176 ("tools: fix annoying "mkdir -p ..." logs when building tools in parallel")
Reported-by: k2ci <kernel-bot@xxxxxxxxxx>
Signed-off-by: Riwen Lu <luriwen@xxxxxxxxxx>
---
Makefile | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile
index d138b17b8840..abf9cfebaf4f 100644
--- a/Makefile
+++ b/Makefile
@@ -1431,11 +1431,11 @@ endif
tools/: FORCE
$(Q)mkdir -p $(objtree)/tools
- $(Q)$(MAKE) LDFLAGS= O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
+ $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(filter-out rR,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
tools/%: FORCE
$(Q)mkdir -p $(objtree)/tools
- $(Q)$(MAKE) LDFLAGS= O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
+ $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(filter-out rR,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
# ---------------------------------------------------------------------------
# Kernel selftest
--
2.25.1
