On Wed, Aug 19, 2020 at 08:31:51AM -0700, Yonghong Song wrote: > > > On 8/19/20 2:23 AM, Jiri Olsa wrote: > > The data of compressed section should be aligned to 4 > > (for 32bit) or 8 (for 64 bit) bytes. > > > > The binutils ld sets sh_addralign to 1, which makes libelf > > fail with misaligned section error during the update as > > reported by Jesper: > > > > FAILED elf_update(WRITE): invalid section alignment > > > > While waiting for ld fix, we can fix compressed sections > > sh_addralign value manually. > > > > Adding warning in -vv mode when the fix is triggered: > > > > $ ./tools/bpf/resolve_btfids/resolve_btfids -vv vmlinux > > ... > > section(36) .comment, size 44, link 0, flags 30, type=1 > > section(37) .debug_aranges, size 45684, link 0, flags 800, type=1 > > - fixing wrong alignment sh_addralign 16, expected 8 > > section(38) .debug_info, size 129104957, link 0, flags 800, type=1 > > - fixing wrong alignment sh_addralign 1, expected 8 > > section(39) .debug_abbrev, size 1152583, link 0, flags 800, type=1 > > - fixing wrong alignment sh_addralign 1, expected 8 > > section(40) .debug_line, size 7374522, link 0, flags 800, type=1 > > - fixing wrong alignment sh_addralign 1, expected 8 > > section(41) .debug_frame, size 702463, link 0, flags 800, type=1 > > section(42) .debug_str, size 1017571, link 0, flags 830, type=1 > > - fixing wrong alignment sh_addralign 1, expected 8 > > section(43) .debug_loc, size 3019453, link 0, flags 800, type=1 > > - fixing wrong alignment sh_addralign 1, expected 8 > > section(44) .debug_ranges, size 1744583, link 0, flags 800, type=1 > > - fixing wrong alignment sh_addralign 16, expected 8 > > section(45) .symtab, size 2955888, link 46, flags 0, type=2 > > section(46) .strtab, size 2613072, link 0, flags 0, type=3 > > ... > > update ok for vmlinux > > > > Another workaround is to disable compressed debug info data > > CONFIG_DEBUG_INFO_COMPRESSED kernel option. > > So CONFIG_DEBUG_INFO_COMPRESSED is required to reproduce the bug, right? correct > > I turned on CONFIG_DEBUG_INFO_COMPRESSED in my config and got a bunch of > build failures. > > ld: drivers/crypto/virtio/virtio_crypto_algs.o: unable to initialize > decompress status for section .debug_info > ld: drivers/crypto/virtio/virtio_crypto_algs.o: unable to initialize > decompress status for section .debug_info > ld: drivers/crypto/virtio/virtio_crypto_algs.o: unable to initialize > decompress status for section .debug_info > ld: drivers/crypto/virtio/virtio_crypto_algs.o: unable to initialize > decompress status for section .debug_info > drivers/crypto/virtio/virtio_crypto_algs.o: file not recognized: File format > not recognized > > ld: net/llc/llc_core.o: unable to initialize decompress status for section > .debug_info > ld: net/llc/llc_core.o: unable to initialize decompress status for section > .debug_info > ld: net/llc/llc_core.o: unable to initialize decompress status for section > .debug_info > ld: net/llc/llc_core.o: unable to initialize decompress status for section > .debug_info > net/llc/llc_core.o: file not recognized: File format not recognized > > ... > > The 'ld' in my system: > > $ ld -V > GNU ld version 2.30-74.el8 > Supported emulations: > elf_x86_64 > elf32_x86_64 > elf_i386 > elf_iamcu > i386linux > elf_l1om > elf_k1om > i386pep > i386pe > $ > > Do you know what is the issue here? mine's: GNU ld version 2.32-31.fc31 there's version info in commit: 10e68b02c861 Makefile: support compressed debug info Compress the debug information using zlib. Requires GCC 5.0+ or Clang 5.0+, binutils 2.26+, and zlib. cc-ing Nick Desaulniers, author of that patch.. any idea about the error above? thanks, jirka
