Yinghai Lu <yinghai at kernel.org> writes: > On Sat, Nov 17, 2012 at 9:39 PM, Yinghai Lu <yinghai at kernel.org> wrote: >> On Sat, Nov 17, 2012 at 9:35 PM, Yinghai Lu <yinghai at kernel.org> wrote: >>> On Sat, Nov 17, 2012 at 9:20 PM, Eric W. Biederman >>> <ebiederm at xmission.com> wrote: >>>> Yinghai Lu <yinghai at kernel.org> writes: >>>>> >>>>> there is lots of R_X86_64_32 and R_X86_64_32S for 64bit purgatory. >>>>> >>>>> those come from global variables...could kill some by converting them static... >>>>> >>>>> but still have some global string or ro data.... >>>>> >>>>> build one big file include all .S ? >>>> >>>> For R_x86_64_32 and R_x86_64_32S the problem is that the instructions >>>> are using absolute 32bit addresses. >>>> >>>> It is probably overkill but we should be able to solve this with >>>> by adding "-mcmodel=large" to the build of purgatory. >>> >>> it kill some... >>> >>> still have left.... looks they from .S >>> >>> yhlu at linux-siqj:~/xx/xx/utils/kexec-tools> readelf --relocs >>> purgatory/purgatory.ro | grep R_X86_64_32 >>> 0000000005e9 00020000000b R_X86_64_32S 0000000000000000 .rodata + c0 >> >> looks like .S did not get that -mcmodel=large applied.. > > so -mcmodel=large only work with .c, but does not have effects on .S ? Yes it -mcmodel=large is about which instructions you generate. The instructions used determine the relocates. Just for playing with it the following patch modifies things so purgatory is 64bit clean. I don't know yet what to do with the 32bit and 16bit assembly. Eric diff --git a/purgatory/Makefile b/purgatory/Makefile index ee1679c..e39adec 100644 --- a/purgatory/Makefile +++ b/purgatory/Makefile @@ -64,6 +64,7 @@ $(PURGATORY): $(PURGATORY_OBJS) $(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^ # $(LD) $(LDFLAGS) $(EXTRA_LDFLAGS) --no-undefined -e purgatory_start -r -o $@ $(PURGATORY_OBJS) $(UTIL_LIB) + $(STRIP) --strip-debug $@ echo:: @echo "PURGATORY_SRCS $(PURGATORY_SRCS)" diff --git a/purgatory/arch/x86_64/Makefile b/purgatory/arch/x86_64/Makefile index 22b4228..2a768c6 100644 --- a/purgatory/arch/x86_64/Makefile +++ b/purgatory/arch/x86_64/Makefile @@ -2,7 +2,7 @@ # Purgatory x86_64 # -x86_64_PURGATORY_SRCS_native = purgatory/arch/x86_64/entry64-32.S +#x86_64_PURGATORY_SRCS_native = purgatory/arch/x86_64/entry64-32.S x86_64_PURGATORY_SRCS_native += purgatory/arch/x86_64/entry64.S x86_64_PURGATORY_SRCS_native += purgatory/arch/x86_64/setup-x86_64.S x86_64_PURGATORY_SRCS_native += purgatory/arch/x86_64/stack.S @@ -16,9 +16,11 @@ dist += purgatory/arch/x86_64/Makefile $(x86_64_PURGATORY_SRCS_native) \ purgatory/arch/x86_64/purgatory-x86_64.h # Don't add sources in i386/ to dist, as i386/Makefile adds them -x86_64_PURGATORY_SRCS += purgatory/arch/i386/entry32-16.S -x86_64_PURGATORY_SRCS += purgatory/arch/i386/entry32-16-debug.S +#x86_64_PURGATORY_SRCS += purgatory/arch/i386/entry32-16.S +#x86_64_PURGATORY_SRCS += purgatory/arch/i386/entry32-16-debug.S x86_64_PURGATORY_SRCS += purgatory/arch/i386/crashdump_backup.c x86_64_PURGATORY_SRCS += purgatory/arch/i386/console-x86.c x86_64_PURGATORY_SRCS += purgatory/arch/i386/vga.c x86_64_PURGATORY_SRCS += purgatory/arch/i386/pic.c + +x86_64_PURGATORY_EXTRA_CFLAGS = -mcmodel=large diff --git a/purgatory/arch/x86_64/entry64.S b/purgatory/arch/x86_64/entry64.S index 666023c..e3223b7 100644 --- a/purgatory/arch/x86_64/entry64.S +++ b/purgatory/arch/x86_64/entry64.S @@ -37,9 +37,10 @@ entry64: movl %eax, %fs movl %eax, %gs - movq $stack_init, %rsp + leaq stack_init(%rip), %rsp pushq $0x10 /* CS */ - pushq $new_cs_exit + leaq new_cs_exit(%rip), %rax + pushq %rax lretq new_cs_exit: diff --git a/purgatory/arch/x86_64/setup-x86_64.S b/purgatory/arch/x86_64/setup-x86_64.S index 74997fa..95572d8 100644 --- a/purgatory/arch/x86_64/setup-x86_64.S +++ b/purgatory/arch/x86_64/setup-x86_64.S @@ -42,10 +42,10 @@ purgatory_start: /* In 64bit mode the code segment is meaningless */ movq 0(%rsp), %rax - movq %rax, jump_back_entry + movq %rax, jump_back_entry(%rip) /* Setup a stack */ - movq $lstack_end, %rsp + leaq lstack_end(%rip), %rsp /* Call the C code */ call purgatory
