From 1ce53adf13a54375d2a5c7cdbe341b2558389615 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 29 Jul 2010 01:47:53 +0200 Subject: modpost: support objects with more than 64k sections This patch makes modpost able to process object files with more than 64k sections. Needed for huge kernel builds (allyesconfig, for example) with -ffunction-sections. 64k sections handling is covered, for example, by this document: "IA-64 gABI Proposal 74: Section Indexes" http://www.codesourcery.com/public/cxx-abi/abi/prop-74-sindex.html Signed-off-by: Denys Vlasenko Signed-off-by: Anders Kaseorg Acked-by: Sam Ravnborg Cc: Rusty Russell Cc: Andi Kleen Signed-off-by: Michal Marek --- scripts/mod/modpost.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'scripts/mod/modpost.h') diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h index be987a44f250..0388cfccac8d 100644 --- a/scripts/mod/modpost.h +++ b/scripts/mod/modpost.h @@ -129,8 +129,51 @@ struct elf_info { const char *strtab; char *modinfo; unsigned int modinfo_len; + + /* support for 32bit section numbers */ + + unsigned int num_sections; /* max_secindex + 1 */ + unsigned int secindex_strings; + /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, + * take shndx from symtab_shndx_start[N] instead */ + Elf32_Word *symtab_shndx_start; + Elf32_Word *symtab_shndx_stop; }; +static inline int is_shndx_special(unsigned int i) +{ + return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE; +} + +/* shndx is in [0..SHN_LORESERVE) U (SHN_HIRESERVE, 0xfffffff], thus: + * shndx == 0 <=> sechdrs[0] + * ...... + * shndx == SHN_LORESERVE-1 <=> sechdrs[SHN_LORESERVE-1] + * shndx == SHN_HIRESERVE+1 <=> sechdrs[SHN_LORESERVE] + * shndx == SHN_HIRESERVE+2 <=> sechdrs[SHN_LORESERVE+1] + * ...... + * fyi: sym->st_shndx is uint16, SHN_LORESERVE = ff00, SHN_HIRESERVE = ffff, + * so basically we map 0000..feff -> 0000..feff + * ff00..ffff -> (you are a bad boy, dont do it) + * 10000..xxxx -> ff00..(xxxx-0x100) + */ +static inline unsigned int shndx2secindex(unsigned int i) +{ + if (i <= SHN_HIRESERVE) + return i; + return i - (SHN_HIRESERVE + 1 - SHN_LORESERVE); +} + +/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ +static inline unsigned int get_secindex(const struct elf_info *info, + const Elf_Sym *sym) +{ + if (sym->st_shndx != SHN_XINDEX) + return sym->st_shndx; + return shndx2secindex(info->symtab_shndx_start[sym - + info->symtab_start]); +} + /* file2alias.c */ extern unsigned int cross_build; void handle_moddevtable(struct module *mod, struct elf_info *info, -- cgit v1.2.3