Date: Fri, 7 Oct 2016 16:17:51 +0000 (UTC) From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r306812 - head/sys/boot/common Message-ID: <201610071617.u97GHpLf005854@repo.freebsd.org>
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Author: andrew Date: Fri Oct 7 16:17:51 2016 New Revision: 306812 URL: https://svnweb.freebsd.org/changeset/base/306812 Log: The bootloader self relocation code was slightly wrong for the R_AARCH64_RELATIVE relocation found on arm64. It would try to add the contents of the memory location being relocated to the base address and the relocation addend. This worked when the contents was zero, however this now seems to be set to the value of the addend so we add this twice. Fix this by just setting the memory to the computed value. Reviewed by: emaste MFC after: 1 week Sponsored by: DARPA, AFRL Differential Revision: https://reviews.freebsd.org/D8177 Modified: head/sys/boot/common/self_reloc.c Modified: head/sys/boot/common/self_reloc.c ============================================================================== --- head/sys/boot/common/self_reloc.c Fri Oct 7 15:42:20 2016 (r306811) +++ head/sys/boot/common/self_reloc.c Fri Oct 7 16:17:51 2016 (r306812) @@ -108,12 +108,18 @@ self_reloc(Elf_Addr baseaddr, ElfW_Dyn * break; case RELOC_TYPE_RELATIVE: - /* Address relative to the base address. */ newaddr = (Elf_Addr *)(rel->r_offset + baseaddr); - *newaddr += baseaddr; - /* Add the addend when the ABI uses them */ #ifdef ELF_RELA - *newaddr += rel->r_addend; + /* + * For R_AARCH64_RELATIVE we need to calculate the + * delta between the address we are run from and the + * address we are linked at. As the latter is 0 we + * just use the address we are run from for this. + */ + *newaddr = baseaddr + rel->r_addend; +#else + /* Address relative to the base address. */ + *newaddr += baseaddr; #endif break; default:
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