Tree/Branch: v3.18.86 Git describe: v3.18.86 Commit: 1d2acf22c2 Linux 3.18.86
Build Time: 67 min 20 sec
Passed: 9 / 9 (100.00 %) Failed: 0 / 9 ( 0.00 %)
Errors: 0 Warnings: 1 Section Mismatches: 0
------------------------------------------------------------------------------- defconfigs with issues (other than build errors): 2 warnings 0 mismatches : x86_64-defconfig
-------------------------------------------------------------------------------
Warnings Summary: 1 2 ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address]
=============================================================================== Detailed per-defconfig build reports below:
------------------------------------------------------------------------------- x86_64-defconfig : PASS, 0 errors, 2 warnings, 0 section mismatches
Warnings: ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] -------------------------------------------------------------------------------
Passed with no errors, warnings or mismatches:
arm64-allnoconfig arm64-allmodconfig arm-multi_v5_defconfig arm-multi_v7_defconfig arm-allmodconfig arm-allnoconfig x86_64-allnoconfig arm64-defconfig close failed in file object destructor: sys.excepthook is missing lost sys.stderr
On Wed, Dec 6, 2017 at 1:18 AM, Build bot for Mark Brown broonie@kernel.org wrote:
x86_64-defconfig : PASS, 0 errors, 2 warnings, 0 section mismatches
Warnings: ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address]
This warning keeps coming up in 3.18 and 4.1 builds, which lack a backport of
ef6000b4c670 ("Disable the __builtin_return_address() warning globally after all")
The other build bots use different gcc versions that don't report the warning here, so only Mark's bot triggers it. The warning in this file is harmless, and the patch only turns off the warning flag.
Arnd
On Wed, Jan 03, 2018 at 12:24:12AM +0100, Arnd Bergmann wrote:
On Wed, Dec 6, 2017 at 1:18 AM, Build bot for Mark Brown broonie@kernel.org wrote:
x86_64-defconfig : PASS, 0 errors, 2 warnings, 0 section mismatches
Warnings: ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address]
This warning keeps coming up in 3.18 and 4.1 builds, which lack a backport of
ef6000b4c670 ("Disable the __builtin_return_address() warning globally after all")
The other build bots use different gcc versions that don't report the warning here, so only Mark's bot triggers it. The warning in this file is harmless, and the patch only turns off the warning flag.
Ah, I tried to figure this one out in the past, thanks for this, I'll queue it up soon. Hm, this isn't in 4.4.y, why is it not showing up there? Due to a different backport of this type of thing?
odd,
greg k-h
On Wed, Jan 03, 2018 at 10:54:16AM +0100, Greg KH wrote:
On Wed, Jan 03, 2018 at 12:24:12AM +0100, Arnd Bergmann wrote:
On Wed, Dec 6, 2017 at 1:18 AM, Build bot for Mark Brown broonie@kernel.org wrote:
x86_64-defconfig : PASS, 0 errors, 2 warnings, 0 section mismatches
Warnings: ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address]
This warning keeps coming up in 3.18 and 4.1 builds, which lack a backport of
ef6000b4c670 ("Disable the __builtin_return_address() warning globally after all")
The other build bots use different gcc versions that don't report the warning here, so only Mark's bot triggers it. The warning in this file is harmless, and the patch only turns off the warning flag.
Ah, I tried to figure this one out in the past, thanks for this, I'll queue it up soon. Hm, this isn't in 4.4.y, why is it not showing up there? Due to a different backport of this type of thing?
Nope, doesn't apply to 3.18 at all, as the main part of this patch is already in there. I don't really understand it, it seems that the cc-disable-warning option isn't working for me for 3.18 at all in my local builds. I spent a few hours on it last week, but gave up in the end :(
thanks,
greg k-h
On Wed, Jan 3, 2018 at 10:57 AM, Greg KH gregkh@linuxfoundation.org wrote:
On Wed, Jan 03, 2018 at 10:54:16AM +0100, Greg KH wrote:
On Wed, Jan 03, 2018 at 12:24:12AM +0100, Arnd Bergmann wrote:
On Wed, Dec 6, 2017 at 1:18 AM, Build bot for Mark Brown broonie@kernel.org wrote:
x86_64-defconfig : PASS, 0 errors, 2 warnings, 0 section mismatches
Warnings: ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address] ../include/linux/ftrace.h:632:36: warning: calling '__builtin_return_address' with a nonzero argument is unsafe [-Wframe-address]
This warning keeps coming up in 3.18 and 4.1 builds, which lack a backport of
ef6000b4c670 ("Disable the __builtin_return_address() warning globally after all")
The other build bots use different gcc versions that don't report the warning here, so only Mark's bot triggers it. The warning in this file is harmless, and the patch only turns off the warning flag.
Ah, I tried to figure this one out in the past, thanks for this, I'll queue it up soon. Hm, this isn't in 4.4.y, why is it not showing up there? Due to a different backport of this type of thing?
Nope, doesn't apply to 3.18 at all, as the main part of this patch is already in there. I don't really understand it, it seems that the cc-disable-warning option isn't working for me for 3.18 at all in my local builds. I spent a few hours on it last week, but gave up in the end :(
Right, this is more mysterious than I thought. I see now that the original patch 124a3d88fa20 ("Disable "frame-address" warning") was backported into 3.18, just not the revert 377ccbb48373 ("Makefile: Mute warning for __builtin_return_address(>0) for tracing only") and the subsequent revert^2 ef6000b4c670 ("Disable the __builtin_return_address() warning globally after all").
I have checked that on my build box, the warning is successfully disabled with gcc-6 and higher (tried 6.1.1, 6.3.1, 7.0.0, 7.1.1) and older compilers have neither the warning nor the option to disable it. I also tried reproducing the warning on arm and aarch64 with some other modifications but I get a different warning there:
kernel/sched/core.c: In function 'preempt_count_sub': include/linux/ftrace.h:632:36: warning: unsupported argument to '__builtin_return_address'
Greg and Mark, which x86-64 compiler versions do you use?
Arnd
On Wed, Jan 3, 2018 at 3:59 PM, Mark Brown broonie@kernel.org wrote:
On Wed, Jan 03, 2018 at 03:52:12PM +0100, Arnd Bergmann wrote:
Greg and Mark, which x86-64 compiler versions do you use?
gcc (Debian 6.3.0-18) 6.3.0 20170516
I installed that version here, same as my other gcc-6 versions, the "-Wno-frame-address" option gets set and interpreted correctly:
$ git checkout v3.18.91 ; touch kernel/sched/core.c ; make V=1 defconfig kernel/sched/core.o CC=gcc-6 2>&1 | tail ... gcc-6 -Wp,-MD,kernel/sched/.core.o.d -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/6/include -I./arch/x86/include -Iarch/x86/include/generated -Iinclude -I./arch/x86/include/uapi -Iarch/x86/include/generated/uapi -I./include/uapi -Iinclude/generated/uapi -include ./include/linux/kconfig.h -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -std=gnu89 -m64 -mno-80387 -mno-fp-ret-in-387 -mtune=generic -mno-red-zone -mcmodel=kernel -funit-at-a-time -maccumulate-outgoing-args -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -DCONFIG_AS_FXSAVEQ=1 -DCONFIG_AS_CRC32=1 -DCONFIG_AS_AVX=1 -DCONFIG_AS_AVX2=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -fno-delete-null-pointer-checks -Wno-frame-address -fno-PIE -O2 --param=allow-store-data-races=0 -Wframe-larger-than=2048 -fno-stack-protector -Wno-unused-but-set-variable -Wno-unused-const-variable -fno-omit-frame-pointer -fno-optimize-sibling-calls -fno-var-tracking-assignments -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fno-stack-check -fconserve-stack -Werror=implicit-int -Werror=strict-prototypes -Werror=date-time -DCC_HAVE_ASM_GOTO -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(core)" -D"KBUILD_MODNAME=KBUILD_STR(core)" -c -o kernel/sched/core.o kernel/sched/core.c
It might be a problem with different 'make' versions, or something else in the environment that leads to "-Wno-frame-address" not being set on the command line instead.
Arnd
On Wed, Jan 03, 2018 at 04:32:35PM +0100, Arnd Bergmann wrote:
It might be a problem with different 'make' versions, or something else in the environment that leads to "-Wno-frame-address" not being set on the command line instead.
I'm using "GNU Make 4.1" - this is all just the default Debian stuff, I've not customized my x86 host environment.
On Wed, Jan 03, 2018 at 03:41:21PM +0000, Mark Brown wrote:
On Wed, Jan 03, 2018 at 04:32:35PM +0100, Arnd Bergmann wrote:
It might be a problem with different 'make' versions, or something else in the environment that leads to "-Wno-frame-address" not being set on the command line instead.
I'm using "GNU Make 4.1" - this is all just the default Debian stuff, I've not customized my x86 host environment.
Make 4.2.1 here with gcc 7.2.1 and I get tons of build warnings on my 3.18.y tree on my laptop, but my build machine running Fedora (make 4.2.1 and gcc 7.2.1) I get no build warnings at all.
I've given up trying to track it down for my laptop, something is preventing the compiler flag from being added to the gcc command line, and I don't care anymore...
thanks,
greg k-h
kernel-build-reports@lists.linaro.org
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Mark Brown