Re: [PATCH v4] Makefile.compiler: replace cc-ifversion with compiler-specific macros
From: Shreeya Patel
Date: Tue May 02 2023 - 05:48:58 EST
Hi Thorsten,
On 28/04/23 13:11, Thorsten Leemhuis wrote:
Hi Shreeya!
On 27.04.23 13:53, Shreeya Patel wrote:
On 19/09/22 22:38, Nick Desaulniers wrote:
cc-ifversion is GCC specific. Replace it with compiler specific
variants. Update the users of cc-ifversion to use these new macros.
Link: https://github.com/ClangBuiltLinux/linux/issues/350
Link:
https://lore.kernel.org/llvm/CAGG=3QWSAUakO42kubrCap8fp-gm1ERJJAYXTnP1iHk_wrH=BQ@xxxxxxxxxxxxxx/
Suggested-by: Bill Wendling <morbo@xxxxxxxxxx>
Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
KernelCI found this patch causes a regression in the
baseline.logintest on qemu_arm-virt-gicv3-uefi [1],
see the bisection report for more details [2].
Let me know if you have any questions.
[1] https://linux.kernelci.org/test/case/id/644596a0beca2ead032e8669/
[2] https://groups.io/g/kernelci-results/message/40804> [...]
#regzbot introduced: 88b61e3bff93
How much of this text is auto generated? I ask for two reasons:
None of this text is auto generated yet but we plan to do it soon once
we think the format of the reporting email is good enough for people to
understand
and look into it. Which is why your comments are really helpful here.
* You made regzbot track this, which is great, but didn't specify a
title. That is fine in general, if the subject round about says what the
regression is about. But in this case it doesn't; hence it would be
great if you in the future could specify one through "#regzbot title:"
or adjust the mail's subject (I guess the former is what developers will
prefer).
Noted. If I think the title is not very explanatory then I'll change it
to reflect the problem in future.
* I'm not a developer that has to look into bugs like this, but from my
experience I expect a lot more developers are likely willing to look
into reports like this if you specified what the actual problem is --
ideally with the relevant error messages.
Side note: I for one still am unsure what this is actually about after
looking at the page you provided as [1] and clicking on a few links
there (which took me a few minutes, which I guess not everyone is
willing to invest). I noticed two kernel warning in the log (one from
"arch/arm/kernel/insn.c:48 __arm_gen_branch+0x88/0xa4", the other
"kernel/trace/ftrace.c:2176 ftrace_bug+0x340/0x3b4") and a complaint
UBSAN (btw: those newlines in the logs make things harder to read, at
least for me).
For this particular regression, it is possible that the following kernel
warnings/errors could be the reason of failure.
572 20:30:46.811318 <3>[ 0.417001][ T1] UBSAN:
array-index-out-of-bounds in ../arch/arm/mach-sunxi/mc_smp.c:811:29
574 20:30:46.812203 <3>[ 0.417963][ T1] index 2 is out of
range for type 'sunxi_mc_smp_data [2]'
and
426 20:30:44.726421 <4>[ 0.000000][ T0] WARNING: CPU: 0 PID: 0
at kernel/trace/ftrace.c:2176 ftrace_bug+0x340/0x3b4
428 20:30:44.727284 <4>[ 0.000000][ T0] Modules linked in:
430 20:30:44.728487 <4>[ 0.000000][ T0] CPU: 0 PID: 0 Comm:
swapper Tainted: G W 6.3.0 #1
.........
I understand that it might be more helpful to atleast put little more
information about what is causing the regression here.
I'll provide some more details in future for it to be easy for
developers to look into it.
To check if those were old or new problems, I tired to go back in the
history and on page 9 found an entry for the last succeeding test. But
clicking on the logs got me a 404 :-/
Then I looked at the logs on [1] again and in the html view "Boot
result: FAIL". Is that the actual problem?
Unfortunately, we do have some broken links in the current KernelCI
dashboard but the KernelCI team
is working on a new API and database interface which will fix these issues.
It might not be worth to spend time to fix issues on the current
dashboard since the process for getting the archived
logs is not very straightforward.
What I can do from my side is to attach logs of the working kernel if I
can get them through LAVA.
But one thing to note is that even LAVA stores limited logs and we won't
be able to provide them always like in this case
since the regression has been happening from a long time.
Thanks for your input though, we will work on it and get a better format
ready for reporting the regressions.
Thanks,
Shreeya Patel
Ciao, Thorsten
P.S.: let me update the regzbot title while at it:
#regzbot title: kernelci: qemu_arm-virt-gicv3-uefi stopped booting
---
Changes v3 -> v4:
* Split into its own patch again from series, as per Masahiro.
* Rebase on top of b0839b281c427e844143dba3893e25c83cdd6c17 and update
clang -Wformat logic in scripts/Makefile.extrawarn, as per Masahiro.
Documentation/kbuild/makefiles.rst | 29 ++++++++++++---------
Makefile | 6 ++---
drivers/gpu/drm/amd/display/dc/dml/Makefile | 2 +-
scripts/Makefile.compiler | 10 ++++---
scripts/Makefile.extrawarn | 4 +--
5 files changed, 29 insertions(+), 22 deletions(-)
diff --git a/Documentation/kbuild/makefiles.rst
b/Documentation/kbuild/makefiles.rst
index 11a296e52d68..ee7e3ea1fbe1 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -682,22 +682,27 @@ more details, with real examples.
In the above example, -Wno-unused-but-set-variable will be added to
KBUILD_CFLAGS only if gcc really accepts it.
- cc-ifversion
- cc-ifversion tests the version of $(CC) and equals the fourth
parameter
- if version expression is true, or the fifth (if given) if the
version
- expression is false.
+ gcc-min-version
+ gcc-min-version tests if the value of $(CONFIG_GCC_VERSION) is
greater than
+ or equal to the provided value and evaluates to y if so.
Example::
- #fs/reiserfs/Makefile
- ccflags-y := $(call cc-ifversion, -lt, 0402, -O1)
+ cflags-$(call gcc-min-version, 70100) := -foo
- In this example, ccflags-y will be assigned the value -O1 if the
- $(CC) version is less than 4.2.
- cc-ifversion takes all the shell operators:
- -eq, -ne, -lt, -le, -gt, and -ge
- The third parameter may be a text as in this example, but it may
also
- be an expanded variable or a macro.
+ In this example, cflags-y will be assigned the value -foo if
$(CC) is gcc and
+ $(CONFIG_GCC_VERSION) is >= 7.1.
+
+ clang-min-version
+ clang-min-version tests if the value of $(CONFIG_CLANG_VERSION)
is greater
+ than or equal to the provided value and evaluates to y if so.
+
+ Example::
+
+ cflags-$(call clang-min-version, 110000) := -foo
+
+ In this example, cflags-y will be assigned the value -foo if
$(CC) is clang
+ and $(CONFIG_CLANG_VERSION) is >= 11.0.0.
cc-cross-prefix
cc-cross-prefix is used to check if there exists a $(CC) in path
with
diff --git a/Makefile b/Makefile
index 298f69060f10..411c8480b37e 100644
--- a/Makefile
+++ b/Makefile
@@ -790,7 +790,6 @@ KBUILD_CFLAGS += $(stackp-flags-y)
KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
-KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
ifdef CONFIG_CC_IS_CLANG
KBUILD_CPPFLAGS += -Qunused-arguments
@@ -972,7 +971,6 @@ ifdef CONFIG_CC_IS_GCC
KBUILD_CFLAGS += -Wno-maybe-uninitialized
endif
-ifdef CONFIG_CC_IS_GCC
# The allocators already balk at large sizes, so silence the compiler
# warnings for bounds checks involving those possible values. While
# -Wno-alloc-size-larger-than would normally be used here, earlier
versions
@@ -984,8 +982,8 @@ ifdef CONFIG_CC_IS_GCC
# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
# choice, we must perform a versioned check to disable this warning.
# https://lore.kernel.org/lkml/20210824115859.187f272f@xxxxxxxxxxxxxxxx
-KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901,
-Wno-alloc-size-larger-than)
-endif
+KBUILD_CFLAGS-$(call gcc-min-version, 90100) +=
-Wno-alloc-size-larger-than
+KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
# disable invalid "can't wrap" optimizations for signed / pointers
KBUILD_CFLAGS += -fno-strict-overflow
diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile
b/drivers/gpu/drm/amd/display/dc/dml/Makefile
index cb81ed2fbd53..d70838edba80 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
@@ -34,7 +34,7 @@ dml_ccflags := -mhard-float -maltivec
endif
ifdef CONFIG_CC_IS_GCC
-ifeq ($(call cc-ifversion, -lt, 0701, y), y)
+ifneq ($(call gcc-min-version, 70100),y)
IS_OLD_GCC = 1
endif
endif
diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler
index 94d0d40cddb3..9d18fb91890e 100644
--- a/scripts/Makefile.compiler
+++ b/scripts/Makefile.compiler
@@ -61,9 +61,13 @@ cc-option-yn = $(call try-run,\
cc-disable-warning = $(call try-run,\
$(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -W$(strip
$(1)) -c -x c /dev/null -o "$$TMP",-Wno-$(strip $(1)))
-# cc-ifversion
-# Usage: EXTRA_CFLAGS += $(call cc-ifversion, -lt, 0402, -O1)
-cc-ifversion = $(shell [ $(CONFIG_GCC_VERSION)0 $(1) $(2)000 ] &&
echo $(3) || echo $(4))
+# gcc-min-version
+# Usage: cflags-$(call gcc-min-version, 70100) += -foo
+gcc-min-version = $(shell [ $(CONFIG_GCC_VERSION) -ge $(1) ] && echo y)
+
+# clang-min-version
+# Usage: cflags-$(call clang-min-version, 110000) += -foo
+clang-min-version = $(shell [ $(CONFIG_CLANG_VERSION) -ge $(1) ] &&
echo y)
# ld-option
# Usage: KBUILD_LDFLAGS += $(call ld-option, -X, -Y)
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 6ae482158bc4..5769c1939d40 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -48,7 +48,7 @@ else
ifdef CONFIG_CC_IS_CLANG
KBUILD_CFLAGS += -Wno-initializer-overrides
# Clang before clang-16 would warn on default argument promotions.
-ifeq ($(shell [ $(CONFIG_CLANG_VERSION) -lt 160000 ] && echo y),y)
+ifneq ($(call clang-min-version, 160000),y)
# Disable -Wformat
KBUILD_CFLAGS += -Wno-format
# Then re-enable flags that were part of the -Wformat group that aren't
@@ -56,7 +56,7 @@ KBUILD_CFLAGS += -Wno-format
KBUILD_CFLAGS += -Wformat-extra-args -Wformat-invalid-specifier
KBUILD_CFLAGS += -Wformat-zero-length -Wnonnull
# Requires clang-12+.
-ifeq ($(shell [ $(CONFIG_CLANG_VERSION) -ge 120000 ] && echo y),y)
+ifeq ($(call clang-min-version, 120000),y)
KBUILD_CFLAGS += -Wformat-insufficient-args
endif
endif