/* SPDX-License-Identifier: GPL-2.0-only */ /* * sorttable.h * * Added ORC unwind tables sort support and other updates: * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by: * Shile Zhang <shile.zhang@linux.alibaba.com> * * Copyright 2011 - 2012 Cavium, Inc. * * Some of code was taken out of arch/x86/kernel/unwind_orc.c, written by: * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> * * Some of this code was taken out of recordmcount.h written by: * * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved. * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc. */ #undef extable_ent_size #undef compare_extable #undef do_sort #undef Elf_Addr #undef Elf_Ehdr #undef Elf_Shdr #undef Elf_Rel #undef Elf_Rela #undef Elf_Sym #undef ELF_R_SYM #undef Elf_r_sym #undef ELF_R_INFO #undef Elf_r_info #undef ELF_ST_BIND #undef ELF_ST_TYPE #undef fn_ELF_R_SYM #undef fn_ELF_R_INFO #undef uint_t #undef _r #undef _w #ifdef SORTTABLE_64 # define extable_ent_size 16 # define compare_extable compare_extable_64 # define do_sort do_sort_64 # define Elf_Addr Elf64_Addr # define Elf_Ehdr Elf64_Ehdr # define Elf_Shdr Elf64_Shdr # define Elf_Rel Elf64_Rel # define Elf_Rela Elf64_Rela # define Elf_Sym Elf64_Sym # define ELF_R_SYM ELF64_R_SYM # define Elf_r_sym Elf64_r_sym # define ELF_R_INFO ELF64_R_INFO # define Elf_r_info Elf64_r_info # define ELF_ST_BIND ELF64_ST_BIND # define ELF_ST_TYPE ELF64_ST_TYPE # define fn_ELF_R_SYM fn_ELF64_R_SYM # define fn_ELF_R_INFO fn_ELF64_R_INFO # define uint_t uint64_t # define _r r8 # define _w w8 #else # define extable_ent_size 8 # define compare_extable compare_extable_32 # define do_sort do_sort_32 # define Elf_Addr Elf32_Addr # define Elf_Ehdr Elf32_Ehdr # define Elf_Shdr Elf32_Shdr # define Elf_Rel Elf32_Rel # define Elf_Rela Elf32_Rela # define Elf_Sym Elf32_Sym # define ELF_R_SYM ELF32_R_SYM # define Elf_r_sym Elf32_r_sym # define ELF_R_INFO ELF32_R_INFO # define Elf_r_info Elf32_r_info # define ELF_ST_BIND ELF32_ST_BIND # define ELF_ST_TYPE ELF32_ST_TYPE # define fn_ELF_R_SYM fn_ELF32_R_SYM # define fn_ELF_R_INFO fn_ELF32_R_INFO # define uint_t uint32_t # define _r r # define _w w #endif #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) /* ORC unwinder only support X86_64 */ #include <errno.h> #include <pthread.h> #include <asm/orc_types.h> #define ERRSTR_MAXSZ 256 char g_err[ERRSTR_MAXSZ]; int *g_orc_ip_table; struct orc_entry *g_orc_table; pthread_t orc_sort_thread; static inline unsigned long orc_ip(const int *ip) { return (unsigned long)ip + *ip; } static int orc_sort_cmp(const void *_a, const void *_b) { struct orc_entry *orc_a; const int *a = g_orc_ip_table + *(int *)_a; const int *b = g_orc_ip_table + *(int *)_b; unsigned long a_val = orc_ip(a); unsigned long b_val = orc_ip(b); if (a_val > b_val) return 1; if (a_val < b_val) return -1; /* * The "weak" section terminator entries need to always be on the left * to ensure the lookup code skips them in favor of real entries. * These terminator entries exist to handle any gaps created by * whitelisted .o files which didn't get objtool generation. */ orc_a = g_orc_table + (a - g_orc_ip_table); return orc_a->sp_reg == ORC_REG_UNDEFINED && !orc_a->end ? -1 : 1; } static void *sort_orctable(void *arg) { int i; int *idxs = NULL; int *tmp_orc_ip_table = NULL; struct orc_entry *tmp_orc_table = NULL; unsigned int *orc_ip_size = (unsigned int *)arg; unsigned int num_entries = *orc_ip_size / sizeof(int); unsigned int orc_size = num_entries * sizeof(struct orc_entry); idxs = (int *)malloc(*orc_ip_size); if (!idxs) { snprintf(g_err, ERRSTR_MAXSZ, "malloc idxs: %s", strerror(errno)); pthread_exit(g_err); } tmp_orc_ip_table = (int *)malloc(*orc_ip_size); if (!tmp_orc_ip_table) { snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_ip_table: %s", strerror(errno)); pthread_exit(g_err); } tmp_orc_table = (struct orc_entry *)malloc(orc_size); if (!tmp_orc_table) { snprintf(g_err, ERRSTR_MAXSZ, "malloc tmp_orc_table: %s", strerror(errno)); pthread_exit(g_err); } /* initialize indices array, convert ip_table to absolute address */ for (i = 0; i < num_entries; i++) { idxs[i] = i; tmp_orc_ip_table[i] = g_orc_ip_table[i] + i * sizeof(int); } memcpy(tmp_orc_table, g_orc_table, orc_size); qsort(idxs, num_entries, sizeof(int), orc_sort_cmp); for (i = 0; i < num_entries; i++) { if (idxs[i] == i) continue; /* convert back to relative address */ g_orc_ip_table[i] = tmp_orc_ip_table[idxs[i]] - i * sizeof(int); g_orc_table[i] = tmp_orc_table[idxs[i]]; } free(idxs); free(tmp_orc_ip_table); free(tmp_orc_table); pthread_exit(NULL); } #endif static int compare_extable(const void *a, const void *b) { Elf_Addr av = _r(a); Elf_Addr bv = _r(b); if (av < bv) return -1; if (av > bv) return 1; return 0; } static int do_sort(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) { int rc = -1; Elf_Shdr *s, *shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff)); Elf_Shdr *strtab_sec = NULL; Elf_Shdr *symtab_sec = NULL; Elf_Shdr *extab_sec = NULL; Elf_Sym *sym; const Elf_Sym *symtab; Elf32_Word *symtab_shndx = NULL; Elf_Sym *sort_needed_sym = NULL; Elf_Shdr *sort_needed_sec; Elf_Rel *relocs = NULL; int relocs_size = 0; uint32_t *sort_needed_loc; const char *secstrings; const char *strtab; char *extab_image; int extab_index = 0; int i; int idx; unsigned int shnum; unsigned int shstrndx; #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) unsigned int orc_ip_size = 0; unsigned int orc_size = 0; unsigned int orc_num_entries = 0; #endif shstrndx = r2(&ehdr->e_shstrndx); if (shstrndx == SHN_XINDEX) shstrndx = r(&shdr[0].sh_link); secstrings = (const char *)ehdr + _r(&shdr[shstrndx].sh_offset); shnum = r2(&ehdr->e_shnum); if (shnum == SHN_UNDEF) shnum = _r(&shdr[0].sh_size); for (i = 0, s = shdr; s < shdr + shnum; i++, s++) { idx = r(&s->sh_name); if (!strcmp(secstrings + idx, "__ex_table")) { extab_sec = s; extab_index = i; } if (!strcmp(secstrings + idx, ".symtab")) symtab_sec = s; if (!strcmp(secstrings + idx, ".strtab")) strtab_sec = s; if ((r(&s->sh_type) == SHT_REL || r(&s->sh_type) == SHT_RELA) && r(&s->sh_info) == extab_index) { relocs = (void *)ehdr + _r(&s->sh_offset); relocs_size = _r(&s->sh_size); } if (r(&s->sh_type) == SHT_SYMTAB_SHNDX) symtab_shndx = (Elf32_Word *)((const char *)ehdr + _r(&s->sh_offset)); #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) /* locate the ORC unwind tables */ if (!strcmp(secstrings + idx, ".orc_unwind_ip")) { orc_ip_size = s->sh_size; g_orc_ip_table = (int *)((void *)ehdr + s->sh_offset); } if (!strcmp(secstrings + idx, ".orc_unwind")) { orc_size = s->sh_size; g_orc_table = (struct orc_entry *)((void *)ehdr + s->sh_offset); } #endif } /* for loop */ #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) if (!g_orc_ip_table || !g_orc_table) { fprintf(stderr, "incomplete ORC unwind tables in file: %s\n", fname); goto out; } orc_num_entries = orc_ip_size / sizeof(int); if (orc_ip_size % sizeof(int) != 0 || orc_size % sizeof(struct orc_entry) != 0 || orc_num_entries != orc_size / sizeof(struct orc_entry)) { fprintf(stderr, "inconsistent ORC unwind table entries in file: %s\n", fname); goto out; } /* create thread to sort ORC unwind tables concurrently */ if (pthread_create(&orc_sort_thread, NULL, sort_orctable, &orc_ip_size)) { fprintf(stderr, "pthread_create orc_sort_thread failed '%s': %s\n", strerror(errno), fname); goto out; } #endif if (!extab_sec) { fprintf(stderr, "no __ex_table in file: %s\n", fname); goto out; } if (!symtab_sec) { fprintf(stderr, "no .symtab in file: %s\n", fname); goto out; } if (!strtab_sec) { fprintf(stderr, "no .strtab in file: %s\n", fname); goto out; } extab_image = (void *)ehdr + _r(&extab_sec->sh_offset); strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset); symtab = (const Elf_Sym *)((const char *)ehdr + _r(&symtab_sec->sh_offset)); if (custom_sort) { custom_sort(extab_image, _r(&extab_sec->sh_size)); } else { int num_entries = _r(&extab_sec->sh_size) / extable_ent_size; qsort(extab_image, num_entries, extable_ent_size, compare_extable); } /* If there were relocations, we no longer need them. */ if (relocs) memset(relocs, 0, relocs_size); /* find the flag main_extable_sort_needed */ for (sym = (void *)ehdr + _r(&symtab_sec->sh_offset); sym < sym + _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); sym++) { if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT) continue; if (!strcmp(strtab + r(&sym->st_name), "main_extable_sort_needed")) { sort_needed_sym = sym; break; } } if (!sort_needed_sym) { fprintf(stderr, "no main_extable_sort_needed symbol in file: %s\n", fname); goto out; } sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx), sort_needed_sym - symtab, symtab_shndx)]; sort_needed_loc = (void *)ehdr + _r(&sort_needed_sec->sh_offset) + _r(&sort_needed_sym->st_value) - _r(&sort_needed_sec->sh_addr); /* extable has been sorted, clear the flag */ w(0, sort_needed_loc); rc = 0; out: #if defined(SORTTABLE_64) && defined(UNWINDER_ORC_ENABLED) if (orc_sort_thread) { void *retval = NULL; /* wait for ORC tables sort done */ rc = pthread_join(orc_sort_thread, &retval); if (rc) fprintf(stderr, "pthread_join failed '%s': %s\n", strerror(errno), fname); else if (retval) { rc = -1; fprintf(stderr, "failed to sort ORC tables '%s': %s\n", (char *)retval, fname); } } #endif return rc; }