search for: st_name

...is work? I propose to encode metadata information about a symbol in special absolute symbols, "__sym_attr_metadata.<int>", that the linker can recognize when scanning the symbol table for an incoming object file. In an ELF symbol table entry: typedef struct { Elf32_Word st_name; Elf32_Addr st_value; Elf32_Word st_size; unsigned char st_info; unsigned char st_other; Elf32_Half st_shndx; } Elf32_Sym; typedef struct { Elf64_Word st_name; unsigned char st_info; unsigned char st_other; Elf64_Ha...

...to encode metadata information about a symbol in special absolute symbols, “__sym_attr_metadata.<int>”, that the linker can recognize when scanning the symbol table for an incoming object file. In an ELF symbol table entry: > > > > typedef struct { > > Elf32_Word st_name; > > Elf32_Addr st_value; > > Elf32_Word st_size; > > unsigned char st_info; > > unsigned char st_other; > > Elf32_Half st_shndx; > > } Elf32_Sym; > > > > typedef struct { > > Elf64_Word...

...rmation about a symbol in special absolute symbols, “__sym_attr_metadata.<int>”, that the linker can recognize when scanning the symbol table for an incoming object file. In an ELF symbol table entry: > > > > typedef struct { > > Elf32_Word st_name; > > Elf32_Addr st_value; > > Elf32_Word st_size; > > unsigned char st_info; > > unsigned char st_other; > > Elf32_Half st_shndx; > > } Elf32_Sym; > >...

This adds [f]getc() and fgets() for parsing config files. Probably hard to avoid. Still trying to decide if I actually want to add system() or not. -hpa

...ttr_metadata.<int>”, that the linker can recognize when scanning the symbol table for an incoming object file. In an ELF symbol table entry: > > > > > > > > > > > > typedef struct { > > > > > > Elf32_Word st_name; > > > > > > Elf32_Addr st_value; > > > > > > Elf32_Word st_size; > > > > > > unsigned char st_info; > > > > > > unsigned char st_other; > > > &...

...ttr_metadata.<int>”, that the linker can recognize when scanning the symbol table for an incoming object file. In an ELF symbol table entry: > > > > > > > > > > > > typedef struct { > > > > > > Elf32_Word st_name; > > > > > > Elf32_Addr st_value; > > > > > > Elf32_Word st_size; > > > > > > unsigned char st_info; > > > > > > unsigned char st_other; > > > &...

...canning the symbol table for an incoming object file. In an >> ELF symbol table entry: >> > > > >> > > > >> > > > >> > > > typedef struct { >> > > > >> > > > Elf32_Word st_name; >> > > > >> > > > Elf32_Addr st_value; >> > > > >> > > > Elf32_Word st_size; >> > > > >> > > > unsigned char st_info; >> > > > >>...

...ec[i].sh_link].sh_size); + if (ret != sec[sec[i].sh_link].sh_size) + err(1, "Reading string table"); + break; + } + } + + /* We now have a pointer to the symtab, start searching for the symbol */ + for (i = 0; i < nsyms; i++) { + if ((syms[i].st_shndx == SHN_UNDEF) || !syms[i].st_name) + continue; + if (!strcmp("boot_level4_pgt", + (char *)((u64)syms[i].st_name + strtab))) { + *pgdir_addr = syms[i].st_value - *page_offset; + break; + } + } + + if (!*pgdir_addr) + err(1,"Unable to find boot pgdir"); + + *ird_size = load_initrd(initrd, mem); + /*...

...ec[i].sh_link].sh_size); + if (ret != sec[sec[i].sh_link].sh_size) + err(1, "Reading string table"); + break; + } + } + + /* We now have a pointer to the symtab, start searching for the symbol */ + for (i = 0; i < nsyms; i++) { + if ((syms[i].st_shndx == SHN_UNDEF) || !syms[i].st_name) + continue; + if (!strcmp("boot_level4_pgt", + (char *)((u64)syms[i].st_name + strtab))) { + *pgdir_addr = syms[i].st_value - *page_offset; + break; + } + } + + if (!*pgdir_addr) + err(1,"Unable to find boot pgdir"); + + *ird_size = load_initrd(initrd, mem); + /*...

...common.c @@ -322,7 +322,7 @@ int check_symbols(struct elf_module *module) for(i = 1; i < module->symtable_size; i++) { - crt_sym = (Elf32_Sym*)(module->sym_table + i * module->syment_size); + crt_sym = symbol_get_entry(module, i); crt_name = module->str_table + crt_sym->st_name; strong_count = 0; @@ -434,7 +434,7 @@ static Elf32_Sym *module_find_symbol_sysv(const char *name, struct elf_module *m while (crt_index != STN_UNDEF) { - crt_sym = (Elf32_Sym*)(module->sym_table + crt_index*module->syment_size); + crt_sym = symbol_get_entry(module, crt_index);...

...er can > recognize when scanning the symbol table for an incoming object file. In an > ELF symbol table entry: > > > > > > > > > > > > > > > > typedef struct { > > > > > > > > Elf32_Word st_name; > > > > > > > > Elf32_Addr st_value; > > > > > > > > Elf32_Word st_size; > > > > > > > > unsigned char st_info; > > > > > > > > unsig...

...solute for + * modules to correctly reference it. Similar to s390 implementation. + */ + strings = (void *) ehdr + sechdrs[symtab->sh_link].sh_offset; + for (i = 0; i < symtab->sh_size/sizeof(Elf_Sym); i++) { + if (syms[i].st_shndx != SHN_UNDEF) + continue; + name = strings + syms[i].st_name; + if (!strcmp(name, "_GLOBAL_OFFSET_TABLE_")) { + syms[i].st_shndx = SHN_ABS; + break; + } + } + return 0; +} +#endif + void *module_alloc(unsigned long size) { void *p; @@ -190,16 +358,20 @@ int apply_relocate_add(Elf64_Shdr *sechdrs, if ((s64)val != *(s32 *)loc) goto...

...7 @@ void print_elf_symbols(struct elf_module *module) { } #endif //ELF_DEBUG -static FILE *findpath(char *name) +FILE *findpath(char *name) { char path[FILENAME_MAX]; FILE *f; @@ -321,7 +321,7 @@ int check_symbols(struct elf_module *module) crt_name = module->str_table + crt_sym->st_name; strong_count = 0; - weak_count = 0; + weak_count = (ELF32_ST_BIND(crt_sym->st_info) == STB_WEAK); for_each_module(crt_module) { @@ -345,6 +345,14 @@ int check_symbols(struct elf_module *module) if (crt_sym->st_shndx == SHN_UNDEF) { // We have an undefined symbol +...

From: Matt Fleming <matt.fleming at intel.com> Since we can't use __intcall() for EFI, and since we can now have the ELF module code resolve all our symbols at runtime, we should delete as many references to __intcall() as possible and just access the symbols directly. The most interesting patch is the support for weak symbols. We need to be able to reference derivative-specific

...ec[i].sh_link].sh_size); + if (ret != sec[sec[i].sh_link].sh_size) + err(1, "Reading string table"); + break; + } + } + + /* We now have a pointer to the symtab, start searching for the symbol */ + for (i = 0; i < nsyms; i++) { + if ((syms[i].st_shndx == SHN_UNDEF) || !syms[i].st_name) + continue; + if (!strcmp("boot_level4_pgt", + (char *)((u64)syms[i].st_name + strtab))) { + *pgdir_addr = syms[i].st_value - *page_offset; + break; + } + } + + if (!*pgdir_addr) + err(1,"Unable to find boot pgdir"); + + *ird_size = load_initrd(initrd, mem); + + /*...

...ec[i].sh_link].sh_size); + if (ret != sec[sec[i].sh_link].sh_size) + err(1, "Reading string table"); + break; + } + } + + /* We now have a pointer to the symtab, start searching for the symbol */ + for (i = 0; i < nsyms; i++) { + if ((syms[i].st_shndx == SHN_UNDEF) || !syms[i].st_name) + continue; + if (!strcmp("boot_level4_pgt", + (char *)((u64)syms[i].st_name + strtab))) { + *pgdir_addr = syms[i].st_value - *page_offset; + break; + } + } + + if (!*pgdir_addr) + err(1,"Unable to find boot pgdir"); + + *ird_size = load_initrd(initrd, mem); + + /*...

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

Changes: - patch v2: - Adapt patch to work post KPTI and compiler changes - Redo all performance testing with latest configs and compilers - Simplify mov macro on PIE (MOVABS now) - Reduce GOT footprint - patch v1: - Simplify ftrace implementation. - Use gcc mstack-protector-guard-reg=%gs with PIE when possible. - rfc v3: - Use --emit-relocs instead of -pie to reduce

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to

These patches make the changes necessary to build the kernel as Position Independent Executable (PIE) on x86_64. A PIE kernel can be relocated below the top 2G of the virtual address space. It allows to optionally extend the KASLR randomization range from 1G to 3G. Thanks a lot to Ard Biesheuvel & Kees Cook on their feedback on compiler changes, PIE support and KASLR in general. Thanks to