Ben Hutchings
2018-Jul-17 02:55 UTC
[klibc] [PATCH] x86_64: Reduce ld max-page-size option again
Building klibc with binutils 2.30 results in the following layout for klibc.so: Idx Name Size VMA LMA File off Algn 0 .text 0000d1ff 0000000000200200 0000000000200200 00000200 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 1 .rodata 000031af 0000000000300000 0000000000300000 00100000 2**5 CONTENTS, ALLOC, LOAD, READONLY, DATA 2 .data.rel.ro 00000990 0000000000403660 0000000000403660 00103660 2**5 CONTENTS, ALLOC, LOAD, DATA 3 .data 00000140 0000000000404000 0000000000404000 00104000 2**5 CONTENTS, ALLOC, LOAD, DATA 4 .bss 000042f8 0000000000404140 0000000000404140 00104140 2**5 ALLOC The .text and .rodata sections have each been padded to the specified maximum page size of 1 MB, causing the following sections to overlap the executable. This causes all klibc executables to crash immediately. Since there's no architectural page size betwen 4 KB and 2MB, set max-page-size to 4 KB. Signed-off-by: Ben Hutchings <ben at decadent.org.uk> --- --- a/usr/klibc/arch/x86_64/MCONFIG +++ b/usr/klibc/arch/x86_64/MCONFIG @@ -30,10 +30,12 @@ KLIBCLDFLAGS = -m elf_x86_64 # calls, and work on the memory models for this architecture # 2 MB - normal binaries start at 4 MB # -# Recent binutils use max-page-size=0x200000 by default, which pushes +# binutils now uses max-page-size=0x200000 by default, which pushes # klibc.so data over the 4 MB mark, overlapping the executable. -# Revert to the old max-page-size=0x100000 value. -KLIBCSHAREDFLAGS = -Ttext 0x00200200 -z max-page-size=0x100000 +# The old default was max-page-size=0x100000, but that also results +# in a broken layout with binutils 2.30. Since there's no +# architectural page size betwen 4 KB and 2MB, set it to 4 KB. +KLIBCSHAREDFLAGS = -Ttext 0x00200200 -z max-page-size=0x1000 # Asm includes for x86_64 are in the merged x86 tree KLIBCARCHINCFLAGS = -I$(KLIBCKERNELOBJ)/arch/x86/include -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 811 bytes Desc: Digital signature URL: <http://www.zytor.com/pipermail/klibc/attachments/20180717/4181465b/attachment.sig>
Possibly Parallel Threads
- [klibc:master] x86_64: Reduce ld max-page-size option again
- [klibc:master] Kbuild: Remove KLIBCKERNELOBJ variable
- [klibc:master] Use -Ttext-segment to link shared library on all arches
- [klibc:master] x86_64: Use -Ttext-segment to avoid address collision
- x86_64: Use -Ttext-segment to avoid address collision