From 1d7a877a0f74a7b90d70ca8cc3c0db9461619b1a Mon Sep 17 00:00:00 2001 From: Nelson Chu Date: Mon, 29 Apr 2024 17:44:51 +0800 Subject: RISC-V: Segment fault for kernel purgatory when linking. This was originally reported by Ard Biesheuvel . The followings are reproduce steps, https://lore.kernel.org/all/202404260640.9GQVTmrw-lkp@intel.com/T/#u The segment fault happens in the riscv_elf_finish_dynamic_sections when the output got section is an ABS. Refer to MIPS code, they added an extra bfd_is_abs_section check to avoid ABS got, so this seems the right and easier way to go in the short-term. bfd/ * elfnn-riscv.c (riscv_elf_finish_dynamic_sections): Set sh_entsize and fill the got entries only when the got isn't an ABS section, and the size of got is larger than zero. The similar goes for gotplt, except we already reported error when the gotplt is an ABS. --- bfd/elfnn-riscv.c | 23 ++++++++++------------- 1 file changed, 10 insertions(+), 13 deletions(-) diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c index 604f6de..3fc8726 100644 --- a/bfd/elfnn-riscv.c +++ b/bfd/elfnn-riscv.c @@ -3569,7 +3569,7 @@ riscv_elf_finish_dynamic_sections (bfd *output_bfd, } } - if (htab->elf.sgotplt) + if (htab->elf.sgotplt && htab->elf.sgotplt->size > 0) { asection *output_section = htab->elf.sgotplt->output_section; @@ -3580,31 +3580,28 @@ riscv_elf_finish_dynamic_sections (bfd *output_bfd, return false; } - if (htab->elf.sgotplt->size > 0) - { - /* Write the first two entries in .got.plt, needed for the dynamic - linker. */ - bfd_put_NN (output_bfd, (bfd_vma) -1, htab->elf.sgotplt->contents); - bfd_put_NN (output_bfd, (bfd_vma) 0, - htab->elf.sgotplt->contents + GOT_ENTRY_SIZE); - } + /* Write the first two entries in .got.plt, needed for the dynamic + linker. */ + bfd_put_NN (output_bfd, (bfd_vma) -1, htab->elf.sgotplt->contents); + bfd_put_NN (output_bfd, (bfd_vma) 0, + htab->elf.sgotplt->contents + GOT_ENTRY_SIZE); elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE; } - if (htab->elf.sgot) + if (htab->elf.sgot && htab->elf.sgot->size > 0) { asection *output_section = htab->elf.sgot->output_section; - if (htab->elf.sgot->size > 0) + if (!bfd_is_abs_section (output_section)) { /* Set the first entry in the global offset table to the address of the dynamic section. */ bfd_vma val = sdyn ? sec_addr (sdyn) : 0; bfd_put_NN (output_bfd, val, htab->elf.sgot->contents); - } - elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE; + elf_section_data (output_section)->this_hdr.sh_entsize = GOT_ENTRY_SIZE; + } } /* Fill PLT and GOT entries for local STT_GNU_IFUNC symbols. */ -- cgit v1.1