From 80df194f0165cb540a2a984f95dd2b37948f54d7 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 13 Oct 2018 20:52:06 -0700 Subject: [PATCH] x86: detect unsupported relocation types Currently we support only relocations of type ELF64_R_TYPE or ELF32_R_TYPE. We should be warned if other relocation types appear in the relocation sections. This type of message has helped to identify code overwriting a relocation section before relocation and incorrect parsing of relocation tables. Signed-off-by: Heinrich Schuchardt Reviewed-by: Bin Meng Signed-off-by: Bin Meng --- arch/x86/lib/relocate.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/x86/lib/relocate.c b/arch/x86/lib/relocate.c index ed10755..4d09e4d 100644 --- a/arch/x86/lib/relocate.c +++ b/arch/x86/lib/relocate.c @@ -53,6 +53,15 @@ static void do_elf_reloc_fixups64(unsigned int text_base, uintptr_t size, Elf64_Addr *offset_ptr_ram; do { + unsigned long long type = ELF64_R_TYPE(re_src->r_info); + + if (type != R_X86_64_RELATIVE) { + printf("%s: unsupported relocation type 0x%llx " + "at %p, ", __func__, type, re_src); + printf("offset = 0x%llx\n", re_src->r_offset); + continue; + } + /* Get the location from the relocation entry */ offset_ptr_rom = (Elf64_Addr *)(uintptr_t)re_src->r_offset; @@ -91,6 +100,15 @@ static void do_elf_reloc_fixups32(unsigned int text_base, uintptr_t size, Elf32_Addr *offset_ptr_ram; do { + unsigned int type = ELF32_R_TYPE(re_src->r_info); + + if (type != R_386_RELATIVE) { + printf("%s: unsupported relocation type 0x%x " + "at %p, ", __func__, type, re_src); + printf("offset = 0x%x\n", re_src->r_offset); + continue; + } + /* Get the location from the relocation entry */ offset_ptr_rom = (Elf32_Addr *)(uintptr_t)re_src->r_offset;