On Tue, May 5, 2020 at 10:52 PM Jiaxun Yang <[email protected]> wrote: > > Subject: [PATCH v6] MIPS: Truncate link address into 32bit for 32bit kernel > In-Reply-To: <[email protected]> > > LLD failed to link vmlinux with 64bit load address for 32bit ELF > while bfd will strip 64bit address into 32bit silently. > To fix LLD build, we should truncate load address provided by platform > into 32bit for 32bit kernel. > > Signed-off-by: Jiaxun Yang <[email protected]> > Link: https://github.com/ClangBuiltLinux/linux/issues/786 > Link: https://sourceware.org/bugzilla/show_bug.cgi?id=25784 > Reviewed-by: Fangrui Song <[email protected]> > Reviewed-by: Kees Cook <[email protected]> > Tested-by: Nathan Chancellor <[email protected]> > Cc: Maciej W. Rozycki <[email protected]>
Cool, this revision looks a bit simpler. Thanks for chasing this. Tested-by: Nick Desaulniers <[email protected]> > --- > V2: Take MaskRay's shell magic. > > V3: After spent an hour on dealing with special character issue in > Makefile, I gave up to do shell hacks and write a util in C instead. > Thanks Maciej for pointing out Makefile variable problem. > > v4: Finally we managed to find a Makefile method to do it properly > thanks to Kees. As it's too far from the initial version, I removed > Review & Test tag from Nick and Fangrui and Cc instead. > > v5: Care vmlinuz as well. > > v6: Rename to LIKER_LOAD_ADDRESS > --- > arch/mips/Makefile | 13 ++++++++++++- > arch/mips/boot/compressed/Makefile | 2 +- > arch/mips/kernel/vmlinux.lds.S | 2 +- > 3 files changed, 14 insertions(+), 3 deletions(-) > > diff --git a/arch/mips/Makefile b/arch/mips/Makefile > index e1c44aed8156..68c0f22fefc0 100644 > --- a/arch/mips/Makefile > +++ b/arch/mips/Makefile > @@ -288,12 +288,23 @@ ifdef CONFIG_64BIT > endif > endif > > +# When linking a 32-bit executable the LLVM linker cannot cope with a > +# 32-bit load address that has been sign-extended to 64 bits. Simply > +# remove the upper 32 bits then, as it is safe to do so with other > +# linkers. > +ifdef CONFIG_64BIT > + load-ld = $(load-y) > +else > + load-ld = $(subst 0xffffffff,0x,$(load-y)) > +endif > + > KBUILD_AFLAGS += $(cflags-y) > KBUILD_CFLAGS += $(cflags-y) > -KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y) > +KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y) > -DLINKER_LOAD_ADDRESS=$(load-ld) > KBUILD_CPPFLAGS += -DDATAOFFSET=$(if $(dataoffset-y),$(dataoffset-y),0) > > bootvars-y = VMLINUX_LOAD_ADDRESS=$(load-y) \ > + LINKER_LOAD_ADDRESS=$(load-ld) \ > VMLINUX_ENTRY_ADDRESS=$(entry-y) \ > PLATFORM="$(platform-y)" \ > ITS_INPUTS="$(its-y)" > diff --git a/arch/mips/boot/compressed/Makefile > b/arch/mips/boot/compressed/Makefile > index 0df0ee8a298d..3d391256ab7e 100644 > --- a/arch/mips/boot/compressed/Makefile > +++ b/arch/mips/boot/compressed/Makefile > @@ -90,7 +90,7 @@ ifneq ($(zload-y),) > VMLINUZ_LOAD_ADDRESS := $(zload-y) > else > VMLINUZ_LOAD_ADDRESS = $(shell $(obj)/calc_vmlinuz_load_addr \ > - $(obj)/vmlinux.bin $(VMLINUX_LOAD_ADDRESS)) > + $(obj)/vmlinux.bin $(LINKER_LOAD_ADDRESS)) > endif > UIMAGE_LOADADDR = $(VMLINUZ_LOAD_ADDRESS) > > diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S > index a5f00ec73ea6..5226cd8e4bee 100644 > --- a/arch/mips/kernel/vmlinux.lds.S > +++ b/arch/mips/kernel/vmlinux.lds.S > @@ -55,7 +55,7 @@ SECTIONS > /* . = 0xa800000000300000; */ > . = 0xffffffff80300000; > #endif > - . = VMLINUX_LOAD_ADDRESS; > + . = LINKER_LOAD_ADDRESS; > /* read-only */ > _text = .; /* Text and read-only data */ > .text : { > > -- -- Thanks, ~Nick Desaulniers
