| Message ID | 20190408212648.2407234-2-arnd@arndb.de |
|---|---|
| State | Accepted |
| Commit | 96ca7674ea66e9f0e2cb9f75588d4d16e5abb724 |
| Headers | show |
| Series | [01/12] s390: remove -fno-strength-reduce flag | expand |
On Mon, 8 Apr 2019 23:26:15 +0200 Arnd Bergmann <arnd@arndb.de> wrote: > clang does not support 31 bit object files on s390, so skip > the 32-bit vdso here, and only build it when using gcc to compile > the kernel. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Added to s390/linux:features for the next merge window. Thanks. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.
On Mon, Apr 8, 2019 at 2:27 PM Arnd Bergmann <arnd@arndb.de> wrote: > > clang does not support 31 bit object files on s390, so skip > the 32-bit vdso here, and only build it when using gcc to compile > the kernel. What's the build failure? Would you mind filing a bug against LLVM's issue tracker for it, please? > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/s390/Kconfig | 3 +++ > arch/s390/kernel/Makefile | 2 +- > arch/s390/kernel/vdso.c | 10 +++++----- > 3 files changed, 9 insertions(+), 6 deletions(-) > > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > index b6e3d0653002..8cd860cba4d1 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -388,6 +388,9 @@ config COMPAT > (and some other stuff like libraries and such) is needed for > executing 31 bit applications. It is safe to say "Y". > > +config COMPAT_VDSO > + def_bool COMPAT && !CC_IS_CLANG > + > config SYSVIPC_COMPAT > def_bool y if COMPAT && SYSVIPC > > diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile > index 8a62c7f72e1b..1222db6d4ee9 100644 > --- a/arch/s390/kernel/Makefile > +++ b/arch/s390/kernel/Makefile > @@ -86,7 +86,7 @@ obj-$(CONFIG_TRACEPOINTS) += trace.o > > # vdso > obj-y += vdso64/ > -obj-$(CONFIG_COMPAT) += vdso32/ > +obj-$(CONFIG_COMPAT_VDSO) += vdso32/ > > chkbss := head64.o early_nobss.o > include $(srctree)/arch/s390/scripts/Makefile.chkbss > diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c > index e7920a68a12e..243d8b1185bf 100644 > --- a/arch/s390/kernel/vdso.c > +++ b/arch/s390/kernel/vdso.c > @@ -29,7 +29,7 @@ > #include <asm/vdso.h> > #include <asm/facility.h> > > -#ifdef CONFIG_COMPAT > +#ifdef CONFIG_COMPAT_VDSO > extern char vdso32_start, vdso32_end; > static void *vdso32_kbase = &vdso32_start; > static unsigned int vdso32_pages; > @@ -55,7 +55,7 @@ static vm_fault_t vdso_fault(const struct vm_special_mapping *sm, > > vdso_pagelist = vdso64_pagelist; > vdso_pages = vdso64_pages; > -#ifdef CONFIG_COMPAT > +#ifdef CONFIG_COMPAT_VDSO > if (vma->vm_mm->context.compat_mm) { > vdso_pagelist = vdso32_pagelist; > vdso_pages = vdso32_pages; > @@ -76,7 +76,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, > unsigned long vdso_pages; > > vdso_pages = vdso64_pages; > -#ifdef CONFIG_COMPAT > +#ifdef CONFIG_COMPAT_VDSO > if (vma->vm_mm->context.compat_mm) > vdso_pages = vdso32_pages; > #endif > @@ -223,7 +223,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) > return 0; > > vdso_pages = vdso64_pages; > -#ifdef CONFIG_COMPAT > +#ifdef CONFIG_COMPAT_VDSO > mm->context.compat_mm = is_compat_task(); > if (mm->context.compat_mm) > vdso_pages = vdso32_pages; > @@ -280,7 +280,7 @@ static int __init vdso_init(void) > int i; > > vdso_init_data(vdso_data); > -#ifdef CONFIG_COMPAT > +#ifdef CONFIG_COMPAT_VDSO > /* Calculate the size of the 32 bit vDSO */ > vdso32_pages = ((&vdso32_end - &vdso32_start > + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1; > -- > 2.20.0 > -- Thanks, ~Nick Desaulniers
On Wed, Apr 10, 2019 at 6:26 PM 'Nick Desaulniers' via Clang Built Linux <clang-built-linux@googlegroups.com> wrote: > > On Mon, Apr 8, 2019 at 2:27 PM Arnd Bergmann <arnd@arndb.de> wrote: > > > > clang does not support 31 bit object files on s390, so skip > > the 32-bit vdso here, and only build it when using gcc to compile > > the kernel. > > What's the build failure? Would you mind filing a bug against LLVM's > issue tracker for it, please? As far as I can tell, llvm does only supports 64-bit output for s390, so this is not a bug but rather a missing feature that seems highly unlikely to ever get added. 32-bit (31-bit) mode on s390 is only used for very old existing binaries, and the vdso support is optional there. Arnd
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index b6e3d0653002..8cd860cba4d1 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -388,6 +388,9 @@ config COMPAT (and some other stuff like libraries and such) is needed for executing 31 bit applications. It is safe to say "Y". +config COMPAT_VDSO + def_bool COMPAT && !CC_IS_CLANG + config SYSVIPC_COMPAT def_bool y if COMPAT && SYSVIPC diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 8a62c7f72e1b..1222db6d4ee9 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -86,7 +86,7 @@ obj-$(CONFIG_TRACEPOINTS) += trace.o # vdso obj-y += vdso64/ -obj-$(CONFIG_COMPAT) += vdso32/ +obj-$(CONFIG_COMPAT_VDSO) += vdso32/ chkbss := head64.o early_nobss.o include $(srctree)/arch/s390/scripts/Makefile.chkbss diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c index e7920a68a12e..243d8b1185bf 100644 --- a/arch/s390/kernel/vdso.c +++ b/arch/s390/kernel/vdso.c @@ -29,7 +29,7 @@ #include <asm/vdso.h> #include <asm/facility.h> -#ifdef CONFIG_COMPAT +#ifdef CONFIG_COMPAT_VDSO extern char vdso32_start, vdso32_end; static void *vdso32_kbase = &vdso32_start; static unsigned int vdso32_pages; @@ -55,7 +55,7 @@ static vm_fault_t vdso_fault(const struct vm_special_mapping *sm, vdso_pagelist = vdso64_pagelist; vdso_pages = vdso64_pages; -#ifdef CONFIG_COMPAT +#ifdef CONFIG_COMPAT_VDSO if (vma->vm_mm->context.compat_mm) { vdso_pagelist = vdso32_pagelist; vdso_pages = vdso32_pages; @@ -76,7 +76,7 @@ static int vdso_mremap(const struct vm_special_mapping *sm, unsigned long vdso_pages; vdso_pages = vdso64_pages; -#ifdef CONFIG_COMPAT +#ifdef CONFIG_COMPAT_VDSO if (vma->vm_mm->context.compat_mm) vdso_pages = vdso32_pages; #endif @@ -223,7 +223,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) return 0; vdso_pages = vdso64_pages; -#ifdef CONFIG_COMPAT +#ifdef CONFIG_COMPAT_VDSO mm->context.compat_mm = is_compat_task(); if (mm->context.compat_mm) vdso_pages = vdso32_pages; @@ -280,7 +280,7 @@ static int __init vdso_init(void) int i; vdso_init_data(vdso_data); -#ifdef CONFIG_COMPAT +#ifdef CONFIG_COMPAT_VDSO /* Calculate the size of the 32 bit vDSO */ vdso32_pages = ((&vdso32_end - &vdso32_start + PAGE_SIZE - 1) >> PAGE_SHIFT) + 1;
clang does not support 31 bit object files on s390, so skip the 32-bit vdso here, and only build it when using gcc to compile the kernel. Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- arch/s390/Kconfig | 3 +++ arch/s390/kernel/Makefile | 2 +- arch/s390/kernel/vdso.c | 10 +++++----- 3 files changed, 9 insertions(+), 6 deletions(-) -- 2.20.0