Re: [PATCH] Revert "selftests: error out if kernel header files are not yet built"

From: Marcos Paulo de Souza
Date: Mon Dec 11 2023 - 07:06:06 EST


On Mon, 2023-12-11 at 16:00 +0500, Muhammad Usama Anjum wrote:
> On 12/9/23 7:01 AM, John Hubbard wrote:
> > This reverts commit 9fc96c7c19df ("selftests: error out if kernel
> > header
> > files are not yet built").
> I don't think whole of this commit needs to be reverted. Lets leave
> the
> warning message as it is and just remove the condition to abort the
> compilation.

Reverting or just printing the warning would work for our testcases, as
long as it doesn't error out.

>
> >
> > It turns out that requiring the kernel headers to be built as a
> > prerequisite to building selftests, does not work in many cases.
> > For
> > example, Peter Zijlstra writes:
> >
> > "My biggest beef with the whole thing is that I simply do not want
> > to use
> > 'make headers', it doesn't work for me.
> >
> > I have a ton of output directories and I don't care to build tools
> > into
> > the output dirs, in fact some of them flat out refuse to work that
> > way
> > (bpf comes to mind)." [1]
> >
> > Therefore, stop erroring out on the selftests build. Additional
> > patches
> > will be required in order to change over to not requiring the
> > kernel
> > headers.
> >
> > [1]
> > https://lore.kernel.org/20231208221007.GO28727@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > Cc: Anders Roxell <anders.roxell@xxxxxxxxxx>
> > Cc: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
> > Cc: David Hildenbrand <david@xxxxxxxxxx>
> > Cc: Peter Xu <peterx@xxxxxxxxxx>
> > Cc: Jonathan Corbet <corbet@xxxxxxx>
> > Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> > Cc: Shuah Khan <shuah@xxxxxxxxxx>
> > Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
> > ---
> >  tools/testing/selftests/Makefile | 21 +----------------
> >  tools/testing/selftests/lib.mk   | 40 +++-------------------------
> > ----
> >  2 files changed, 4 insertions(+), 57 deletions(-)
> >
> > diff --git a/tools/testing/selftests/Makefile
> > b/tools/testing/selftests/Makefile
> > index 3b2061d1c1a5..8247a7c69c36 100644
> > --- a/tools/testing/selftests/Makefile
> > +++ b/tools/testing/selftests/Makefile
> > @@ -155,12 +155,10 @@ ifneq ($(KBUILD_OUTPUT),)
> >    abs_objtree := $(realpath $(abs_objtree))
> >    BUILD := $(abs_objtree)/kselftest
> >    KHDR_INCLUDES := -isystem ${abs_objtree}/usr/include
> > -  KHDR_DIR := ${abs_objtree}/usr/include
> >  else
> >    BUILD := $(CURDIR)
> >    abs_srctree := $(shell cd $(top_srcdir) && pwd)
> >    KHDR_INCLUDES := -isystem ${abs_srctree}/usr/include
> > -  KHDR_DIR := ${abs_srctree}/usr/include
> >    DEFAULT_INSTALL_HDR_PATH := 1
> >  endif
> >  
> > @@ -174,7 +172,7 @@ export KHDR_INCLUDES
> >  # all isn't the first target in the file.
> >  .DEFAULT_GOAL := all
> >  
> > -all: kernel_header_files
> > +all:
> >   @ret=1;
> > \
> >   for TARGET in $(TARGETS); do \
> >   BUILD_TARGET=$$BUILD/$$TARGET; \
> > @@ -185,23 +183,6 @@ all: kernel_header_files
> >   ret=$$((ret * $$?)); \
> >   done; exit $$ret;
> >  
> > -kernel_header_files:
> > - @ls $(KHDR_DIR)/linux/*.h >/dev/null
> > 2>/dev/null;                          \
> > - if [ $$? -ne 0 ];
> > then                                                     \
> > -           
> > RED='\033[1;31m';                                                 
> > \
> > -           
> > NOCOLOR='\033[0m';                                                
> > \
> > -           
> > echo;                                                             
> > \
> > -            echo -e "$${RED}error$${NOCOLOR}: missing kernel
> > header files.";   \
> > -            echo "Please run this and try
> > again:";                             \
> > -           
> > echo;                                                             
> > \
> > -            echo "    cd
> > $(top_srcdir)";                                       \
> > -            echo "    make
> > headers";                                           \
> > -           
> > echo;                                                             
> > \
> > -     exit
> > 1;                                                                \
> > - fi
> > -
> > -.PHONY: kernel_header_files
> > -
> >  run_tests: all
> >   @for TARGET in $(TARGETS); do \
> >   BUILD_TARGET=$$BUILD/$$TARGET; \
> > diff --git a/tools/testing/selftests/lib.mk
> > b/tools/testing/selftests/lib.mk
> > index 118e0964bda9..aa646e0661f3 100644
> > --- a/tools/testing/selftests/lib.mk
> > +++ b/tools/testing/selftests/lib.mk
> > @@ -44,26 +44,10 @@ endif
> >  selfdir = $(realpath $(dir $(filter %/lib.mk,$(MAKEFILE_LIST))))
> >  top_srcdir = $(selfdir)/../../..
> >  
> > -ifeq ("$(origin O)", "command line")
> > -  KBUILD_OUTPUT := $(O)
> > +ifeq ($(KHDR_INCLUDES),)
> > +KHDR_INCLUDES := -isystem $(top_srcdir)/usr/include
> >  endif
> >  
> > -ifneq ($(KBUILD_OUTPUT),)
> > -  # Make's built-in functions such as $(abspath ...), $(realpath
> > ...) cannot
> > -  # expand a shell special character '~'. We use a somewhat
> > tedious way here.
> > -  abs_objtree := $(shell cd $(top_srcdir) && mkdir -p
> > $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
> > -  $(if $(abs_objtree),, \
> > -    $(error failed to create output directory "$(KBUILD_OUTPUT)"))
> > -  # $(realpath ...) resolves symlinks
> > -  abs_objtree := $(realpath $(abs_objtree))
> > -  KHDR_DIR := ${abs_objtree}/usr/include
> > -else
> > -  abs_srctree := $(shell cd $(top_srcdir) && pwd)
> > -  KHDR_DIR := ${abs_srctree}/usr/include
> > -endif
> > -
> > -KHDR_INCLUDES := -isystem $(KHDR_DIR)
> > -
> >  # The following are built by lib.mk common compile rules.
> >  # TEST_CUSTOM_PROGS should be used by tests that require
> >  # custom build rule and prevent common build rule use.
> > @@ -74,25 +58,7 @@ TEST_GEN_PROGS := $(patsubst
> > %,$(OUTPUT)/%,$(TEST_GEN_PROGS))
> >  TEST_GEN_PROGS_EXTENDED := $(patsubst
> > %,$(OUTPUT)/%,$(TEST_GEN_PROGS_EXTENDED))
> >  TEST_GEN_FILES := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_FILES))
> >  
> > -all: kernel_header_files $(TEST_GEN_PROGS)
> > $(TEST_GEN_PROGS_EXTENDED) \
> > -     $(TEST_GEN_FILES)
> > -
> > -kernel_header_files:
> > - @ls $(KHDR_DIR)/linux/*.h >/dev/null
> > 2>/dev/null;                      \
> > - if [ $$? -ne 0 ];
> > then                                                 \
> > -           
> > RED='\033[1;31m';                                                 
> > \
> > -           
> > NOCOLOR='\033[0m';                                                
> > \
> > -           
> > echo;                                                             
> > \
> > -            echo -e "$${RED}error$${NOCOLOR}: missing kernel
> > header files.";   \
> > -            echo "Please run this and try
> > again:";                             \
> > -           
> > echo;                                                             
> > \
> > -            echo "    cd
> > $(top_srcdir)";                                       \
> > -            echo "    make
> > headers";                                           \
> > -           
> > echo;                                                             
> > \
> > -     exit 1; \
> > - fi
> > -
> > -.PHONY: kernel_header_files
> > +all: $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED)
> > $(TEST_GEN_FILES)
> >  
> >  define RUN_TESTS
> >   BASE_DIR="$(selfdir)"; \
>