| Message ID | 20230626075047.1872818-1-chenhuacai@loongson.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | MIPS: Loongson: Fix build error when make modules_install | expand |
On Mon, Jun 26, 2023 at 03:50:47PM +0800, Huacai Chen wrote: > After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of > cc-ifversion") we get a build error when make modules_install: > > cc1: error: '-mloongson-mmi' must be used with '-mhard-float' > > The reason is when make modules_install, 'call cc-option' doesn't work > in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi > applied and -march=loongson3a enable MMI instructions. The first sentence does not make much sense to me, specifically "in $(KBUILD_CFLAGS) of 'CHECKFLAGS'". What configuration and build command reproduces this? I do not see how '-mno-loongson-mmi' would fail to get added to cflags-y after 0e96ea5c3eb5, which should have had no functional change... I don't want to hang this change up since there is real breakage but I want to make sure we fully understand why 0e96ea5c3eb5 broke things and why this patch resolves it. > Fix this by partially reverting to the old logic, use 'call cc-option' > to conditionally apply -march=loongson3a and -march=mips64r2. > > Fixes: 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") > Cc: stable@vger.kernel.org > Cc: Nathan Chancellor <nathan@kernel.org> > Cc: Nick Desaulniers <ndesaulniers@google.com> > Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> > --- > arch/mips/Makefile | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > index a7a4ee66a9d3..7fb76d12829e 100644 > --- a/arch/mips/Makefile > +++ b/arch/mips/Makefile > @@ -186,11 +186,8 @@ cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap > # Some -march= flags enable MMI instructions, and GCC complains about that > # support being enabled alongside -msoft-float. Thus explicitly disable MMI. > cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) > -ifdef CONFIG_CPU_LOONGSON64 > cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap > -cflags-$(CONFIG_CC_IS_GCC) += -march=loongson3a > -cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2 > -endif > +cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-march=loongson3a,-march=mips64r2) > cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-mno-loongson-mmi) > > cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) > -- > 2.39.3 >
Hi, Nathan, On Tue, Jun 27, 2023 at 12:07 AM Nathan Chancellor <nathan@kernel.org> wrote: > > On Mon, Jun 26, 2023 at 03:50:47PM +0800, Huacai Chen wrote: > > After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of > > cc-ifversion") we get a build error when make modules_install: > > > > cc1: error: '-mloongson-mmi' must be used with '-mhard-float' > > > > The reason is when make modules_install, 'call cc-option' doesn't work > > in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi > > applied and -march=loongson3a enable MMI instructions. > > The first sentence does not make much sense to me, specifically "in > $(KBUILD_CFLAGS) of 'CHECKFLAGS'". What configuration and build command > reproduces this? I do not see how '-mno-loongson-mmi' would fail to get > added to cflags-y after 0e96ea5c3eb5, which should have had no > functional change... I don't want to hang this change up since there is > real breakage but I want to make sure we fully understand why > 0e96ea5c3eb5 broke things and why this patch resolves it. Please use loongson3_defconfig to build a loongson kernel with toolchains from here [1]: 'make' will succeed, but there is a build error when 'make modules_install'. And you should be careful because 'make modules_install' doesn't stop when the error occurs. [1] https://mirrors.edge.kernel.org/pub/tools/crosstool/ Huacai > > > Fix this by partially reverting to the old logic, use 'call cc-option' > > to conditionally apply -march=loongson3a and -march=mips64r2. > > > > Fixes: 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") > > Cc: stable@vger.kernel.org > > Cc: Nathan Chancellor <nathan@kernel.org> > > Cc: Nick Desaulniers <ndesaulniers@google.com> > > Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> > > --- > > arch/mips/Makefile | 5 +---- > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > > index a7a4ee66a9d3..7fb76d12829e 100644 > > --- a/arch/mips/Makefile > > +++ b/arch/mips/Makefile > > @@ -186,11 +186,8 @@ cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap > > # Some -march= flags enable MMI instructions, and GCC complains about that > > # support being enabled alongside -msoft-float. Thus explicitly disable MMI. > > cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) > > -ifdef CONFIG_CPU_LOONGSON64 > > cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap > > -cflags-$(CONFIG_CC_IS_GCC) += -march=loongson3a > > -cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2 > > -endif > > +cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-march=loongson3a,-march=mips64r2) > > cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-mno-loongson-mmi) > > > > cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) > > -- > > 2.39.3 > >
Hi Huacai, + Masahiro On Tue, Jun 27, 2023 at 11:11:27AM +0800, Huacai Chen wrote: > Hi, Nathan, > > On Tue, Jun 27, 2023 at 12:07 AM Nathan Chancellor <nathan@kernel.org> wrote: > > > > On Mon, Jun 26, 2023 at 03:50:47PM +0800, Huacai Chen wrote: > > > After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of > > > cc-ifversion") we get a build error when make modules_install: > > > > > > cc1: error: '-mloongson-mmi' must be used with '-mhard-float' > > > > > > The reason is when make modules_install, 'call cc-option' doesn't work > > > in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi > > > applied and -march=loongson3a enable MMI instructions. > > > > The first sentence does not make much sense to me, specifically "in > > $(KBUILD_CFLAGS) of 'CHECKFLAGS'". What configuration and build command > > reproduces this? I do not see how '-mno-loongson-mmi' would fail to get > > added to cflags-y after 0e96ea5c3eb5, which should have had no > > functional change... I don't want to hang this change up since there is > > real breakage but I want to make sure we fully understand why > > 0e96ea5c3eb5 broke things and why this patch resolves it. > Please use loongson3_defconfig to build a loongson kernel with > toolchains from here [1]: > 'make' will succeed, but there is a build error when 'make > modules_install'. And you should be careful because 'make > modules_install' doesn't stop when the error occurs. Excellent, thank you! I understand what is going on here and your patch should work to resolve it (although I think the commit message should be flushed out a little more with the following details) but I am curious if Masahiro has any thoughts around this. As you note, the error message comes from the CHECKFLAGS invocation of $(CC) but it has no impact on the final result of modules_install, it is purely a cosmetic issue from what I can tell. The error occurs because cc-option is defined in scripts/Makefile.compiler, which is not included in Makefile when running modules_install, as install targets are not supposed to require the compiler; see commit 805b2e1d427a ("kbuild: include Makefile.compiler only when compiler is needed"). As a result, the call to check for '-mno-loongson-mmi' just never happens. It would nice if '-mno-loongson-mmi' could be added unconditionally when using GCC but I can see that the flag has only existed since 9.x, so we do need to keep the cc-option call. I am fine with your change as long as it includes some of the above information (basically noting that while the original change should have been equivalent, the requirement of '-mno-loongson-mmi' when using certain Loongson '-march=' values with '-msoft-float' means that those Loongson '-march=' values need to be called with cc-option as well), even if clang will incur two more cc-option calls as a result (not the end of the world). Additionally, it seems like the same issue will occur when running modules_install when CONFIG_CPU_LOONGSON2E or CONFIG_CPU_LOONGSON2F are enabled, which I guess I also broke in commit 13ceb48bc19c ("MIPS: Loongson2ef: Remove unnecessary {as,cc}-option calls") :/ Sorry again for the breakage and thanks for the fix! Cheers, Nathan > > > Fix this by partially reverting to the old logic, use 'call cc-option' > > > to conditionally apply -march=loongson3a and -march=mips64r2. > > > > > > Fixes: 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") > > > Cc: stable@vger.kernel.org > > > Cc: Nathan Chancellor <nathan@kernel.org> > > > Cc: Nick Desaulniers <ndesaulniers@google.com> > > > Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> > > > --- > > > arch/mips/Makefile | 5 +---- > > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > > > index a7a4ee66a9d3..7fb76d12829e 100644 > > > --- a/arch/mips/Makefile > > > +++ b/arch/mips/Makefile > > > @@ -186,11 +186,8 @@ cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap > > > # Some -march= flags enable MMI instructions, and GCC complains about that > > > # support being enabled alongside -msoft-float. Thus explicitly disable MMI. > > > cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) > > > -ifdef CONFIG_CPU_LOONGSON64 > > > cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap > > > -cflags-$(CONFIG_CC_IS_GCC) += -march=loongson3a > > > -cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2 > > > -endif > > > +cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-march=loongson3a,-march=mips64r2) > > > cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-mno-loongson-mmi) > > > > > > cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) > > > -- > > > 2.39.3 > > >
Hi, Nathan, On Wed, Jun 28, 2023 at 5:28 AM Nathan Chancellor <nathan@kernel.org> wrote: > > Hi Huacai, > > + Masahiro > > On Tue, Jun 27, 2023 at 11:11:27AM +0800, Huacai Chen wrote: > > Hi, Nathan, > > > > On Tue, Jun 27, 2023 at 12:07 AM Nathan Chancellor <nathan@kernel.org> wrote: > > > > > > On Mon, Jun 26, 2023 at 03:50:47PM +0800, Huacai Chen wrote: > > > > After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of > > > > cc-ifversion") we get a build error when make modules_install: > > > > > > > > cc1: error: '-mloongson-mmi' must be used with '-mhard-float' > > > > > > > > The reason is when make modules_install, 'call cc-option' doesn't work > > > > in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi > > > > applied and -march=loongson3a enable MMI instructions. > > > > > > The first sentence does not make much sense to me, specifically "in > > > $(KBUILD_CFLAGS) of 'CHECKFLAGS'". What configuration and build command > > > reproduces this? I do not see how '-mno-loongson-mmi' would fail to get > > > added to cflags-y after 0e96ea5c3eb5, which should have had no > > > functional change... I don't want to hang this change up since there is > > > real breakage but I want to make sure we fully understand why > > > 0e96ea5c3eb5 broke things and why this patch resolves it. > > Please use loongson3_defconfig to build a loongson kernel with > > toolchains from here [1]: > > 'make' will succeed, but there is a build error when 'make > > modules_install'. And you should be careful because 'make > > modules_install' doesn't stop when the error occurs. > > Excellent, thank you! I understand what is going on here and your patch > should work to resolve it (although I think the commit message should be > flushed out a little more with the following details) but I am curious > if Masahiro has any thoughts around this. > > As you note, the error message comes from the CHECKFLAGS invocation of > $(CC) but it has no impact on the final result of modules_install, it is > purely a cosmetic issue from what I can tell. The error occurs because > cc-option is defined in scripts/Makefile.compiler, which is not included > in Makefile when running modules_install, as install targets are not > supposed to require the compiler; see commit 805b2e1d427a ("kbuild: > include Makefile.compiler only when compiler is needed"). As a result, > the call to check for '-mno-loongson-mmi' just never happens. > > It would nice if '-mno-loongson-mmi' could be added unconditionally when > using GCC but I can see that the flag has only existed since 9.x, so we > do need to keep the cc-option call. > > I am fine with your change as long as it includes some of the above > information (basically noting that while the original change should have > been equivalent, the requirement of '-mno-loongson-mmi' when using > certain Loongson '-march=' values with '-msoft-float' means that those > Loongson '-march=' values need to be called with cc-option as well), > even if clang will incur two more cc-option calls as a result (not the > end of the world). > > Additionally, it seems like the same issue will occur when running > modules_install when CONFIG_CPU_LOONGSON2E or CONFIG_CPU_LOONGSON2F are > enabled, which I guess I also broke in commit 13ceb48bc19c ("MIPS: > Loongson2ef: Remove unnecessary {as,cc}-option calls") :/ > > Sorry again for the breakage and thanks for the fix! OK, I will update the commit message and fix for LOONGSON2EF together. Huacai > > Cheers, > Nathan > > > > > Fix this by partially reverting to the old logic, use 'call cc-option' > > > > to conditionally apply -march=loongson3a and -march=mips64r2. > > > > > > > > Fixes: 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") > > > > Cc: stable@vger.kernel.org > > > > Cc: Nathan Chancellor <nathan@kernel.org> > > > > Cc: Nick Desaulniers <ndesaulniers@google.com> > > > > Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> > > > > --- > > > > arch/mips/Makefile | 5 +---- > > > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > > > > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > > > > index a7a4ee66a9d3..7fb76d12829e 100644 > > > > --- a/arch/mips/Makefile > > > > +++ b/arch/mips/Makefile > > > > @@ -186,11 +186,8 @@ cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap > > > > # Some -march= flags enable MMI instructions, and GCC complains about that > > > > # support being enabled alongside -msoft-float. Thus explicitly disable MMI. > > > > cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) > > > > -ifdef CONFIG_CPU_LOONGSON64 > > > > cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap > > > > -cflags-$(CONFIG_CC_IS_GCC) += -march=loongson3a > > > > -cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2 > > > > -endif > > > > +cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-march=loongson3a,-march=mips64r2) > > > > cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-mno-loongson-mmi) > > > > > > > > cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) > > > > -- > > > > 2.39.3 > > > >
diff --git a/arch/mips/Makefile b/arch/mips/Makefile index a7a4ee66a9d3..7fb76d12829e 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -186,11 +186,8 @@ cflags-$(CONFIG_CPU_LOONGSON2F) += -march=loongson2f -Wa,--trap # Some -march= flags enable MMI instructions, and GCC complains about that # support being enabled alongside -msoft-float. Thus explicitly disable MMI. cflags-$(CONFIG_CPU_LOONGSON2EF) += $(call cc-option,-mno-loongson-mmi) -ifdef CONFIG_CPU_LOONGSON64 cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap -cflags-$(CONFIG_CC_IS_GCC) += -march=loongson3a -cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2 -endif +cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-march=loongson3a,-march=mips64r2) cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-mno-loongson-mmi) cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,)
After commit 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") we get a build error when make modules_install: cc1: error: '-mloongson-mmi' must be used with '-mhard-float' The reason is when make modules_install, 'call cc-option' doesn't work in $(KBUILD_CFLAGS) of 'CHECKFLAGS'. Then there is no -mno-loongson-mmi applied and -march=loongson3a enable MMI instructions. Fix this by partially reverting to the old logic, use 'call cc-option' to conditionally apply -march=loongson3a and -march=mips64r2. Fixes: 0e96ea5c3eb5904e5dc2f ("MIPS: Loongson64: Clean up use of cc-ifversion") Cc: stable@vger.kernel.org Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> --- arch/mips/Makefile | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)