From 6e9718089b05403947d8255423a849d425305925 Mon Sep 17 00:00:00 2001 From: Youling Tang Date: Sat, 1 Apr 2023 11:18:53 +0800 Subject: backends: add checks for _GLOBAL_OFFSET_TABLE_ on loongarch Add handling of _GLOBAL_OFFSET_TABLE_. Before applying the patch: $ ./src/elflint --gnu-ld ./src/elflint section [35] '.symtab': _GLOBAL_OFFSET_TABLE_ symbol value 0x68548 does not match .got.plt section address 0x68238 After applying the patch: $ ./src/elflint --gnu-ld ./src/elflint No errors Signed-off-by: Liwei Ge Signed-off-by: Youling Tang --- backends/ChangeLog | 5 +++++ backends/loongarch_init.c | 1 + backends/loongarch_symbol.c | 35 +++++++++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+) diff --git a/backends/ChangeLog b/backends/ChangeLog index 9eee3036..7bde2919 100644 --- a/backends/ChangeLog +++ b/backends/ChangeLog @@ -1,3 +1,8 @@ +2023-04-01 Youling Tang + + * loongarch_init.c (loongarch_init): Hook check_special_symbol. + * loongarch_symbol.c (loongarch_check_special_symbol): New function. + 2023-04-01 Youling Tang * loongarch_reloc.def: Add RELOC_TYPE B16 to RELAX. diff --git a/backends/loongarch_init.c b/backends/loongarch_init.c index 59d8cc3d..b641b07f 100644 --- a/backends/loongarch_init.c +++ b/backends/loongarch_init.c @@ -46,6 +46,7 @@ loongarch_init (Elf *elf __attribute__ ((unused)), loongarch_init_reloc (eh); HOOK (eh, reloc_simple_type); HOOK (eh, machine_flag_check); + HOOK (eh, check_special_symbol); return eh; } diff --git a/backends/loongarch_symbol.c b/backends/loongarch_symbol.c index 43306ab8..5ce55bad 100644 --- a/backends/loongarch_symbol.c +++ b/backends/loongarch_symbol.c @@ -79,3 +79,38 @@ loongarch_machine_flag_check (GElf_Word flags) return ((flags &~ (EF_LARCH_ABI_MODIFIER_MASK | EF_LARCH_OBJABI_V1)) == 0); } + +/* Check whether given symbol's st_value and st_size are OK despite failing + normal checks. */ +bool +loongarch_check_special_symbol (Elf *elf, const GElf_Sym *sym, + const char *name, const GElf_Shdr *destshdr) +{ + if (name != NULL + && strcmp (name, "_GLOBAL_OFFSET_TABLE_") == 0) + { + size_t shstrndx; + if (elf_getshdrstrndx (elf, &shstrndx) != 0) + return false; + const char *sname = elf_strptr (elf, shstrndx, destshdr->sh_name); + if (sname != NULL + && (strcmp (sname, ".got") == 0 || strcmp (sname, ".got.plt") == 0)) + { + Elf_Scn *scn = NULL; + while ((scn = elf_nextscn (elf, scn)) != NULL) + { + GElf_Shdr shdr_mem; + GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem); + if (shdr != NULL) + { + sname = elf_strptr (elf, shstrndx, shdr->sh_name); + if (sname != NULL && strcmp (sname, ".got") == 0) + return (sym->st_value >= shdr->sh_addr + && sym->st_value < shdr->sh_addr + shdr->sh_size); + } + } + } + } + + return false; +} -- cgit v1.2.1