From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx> check.c implements static stack validation. But the instruction-related code that it contains can be shared with other types of validation. E.g., dynamic FP validation. Move the instruction-related code to its own files - insn.h and insn.c. Signed-off-by: Madhavan T. Venkataraman <madvenka@xxxxxxxxxxxxxxxxxxx> --- tools/objtool/Build | 1 + tools/objtool/check.c | 231 -------------------------- tools/objtool/include/objtool/check.h | 92 +--------- tools/objtool/include/objtool/insn.h | 163 ++++++++++++++++++ tools/objtool/insn.c | 195 ++++++++++++++++++++++ 5 files changed, 360 insertions(+), 322 deletions(-) create mode 100644 tools/objtool/include/objtool/insn.h create mode 100644 tools/objtool/insn.c diff --git a/tools/objtool/Build b/tools/objtool/Build index 9f23d1f4c716..c04e36267379 100644 --- a/tools/objtool/Build +++ b/tools/objtool/Build @@ -6,6 +6,7 @@ objtool-y += check.o objtool-y += special.o objtool-y += builtin-check.o objtool-y += cfi.o +objtool-y += insn.o objtool-y += elf.o objtool-y += objtool.o diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 803764f4d4d8..619f7467e39c 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -28,121 +28,6 @@ struct alternative { bool skip_orig; }; -struct instruction *find_insn(struct objtool_file *file, - struct section *sec, unsigned long offset) -{ - struct instruction *insn; - - hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) { - if (insn->sec == sec && insn->offset == offset) - return insn; - } - - return NULL; -} - -struct instruction *next_insn_same_sec(struct objtool_file *file, - struct instruction *insn) -{ - if (insn->idx == INSN_CHUNK_MAX) - return find_insn(file, insn->sec, insn->offset + insn->len); - - insn++; - if (!insn->len) - return NULL; - - return insn; -} - -static struct instruction *next_insn_same_func(struct objtool_file *file, - struct instruction *insn) -{ - struct instruction *next = next_insn_same_sec(file, insn); - struct symbol *func = insn_func(insn); - - if (!func) - return NULL; - - if (next && insn_func(next) == func) - return next; - - /* Check if we're already in the subfunction: */ - if (func == func->cfunc) - return NULL; - - /* Move to the subfunction: */ - return find_insn(file, func->cfunc->sec, func->cfunc->offset); -} - -static struct instruction *prev_insn_same_sec(struct objtool_file *file, - struct instruction *insn) -{ - if (insn->idx == 0) { - if (insn->prev_len) - return find_insn(file, insn->sec, insn->offset - insn->prev_len); - return NULL; - } - - return insn - 1; -} - -static struct instruction *prev_insn_same_sym(struct objtool_file *file, - struct instruction *insn) -{ - struct instruction *prev = prev_insn_same_sec(file, insn); - - if (prev && insn_func(prev) == insn_func(insn)) - return prev; - - return NULL; -} - -#define for_each_insn(file, insn) \ - for (struct section *__sec, *__fake = (struct section *)1; \ - __fake; __fake = NULL) \ - for_each_sec(file, __sec) \ - sec_for_each_insn(file, __sec, insn) - -#define func_for_each_insn(file, func, insn) \ - for (insn = find_insn(file, func->sec, func->offset); \ - insn; \ - insn = next_insn_same_func(file, insn)) - -#define sym_for_each_insn(file, sym, insn) \ - for (insn = find_insn(file, sym->sec, sym->offset); \ - insn && insn->offset < sym->offset + sym->len; \ - insn = next_insn_same_sec(file, insn)) - -#define sym_for_each_insn_continue_reverse(file, sym, insn) \ - for (insn = prev_insn_same_sec(file, insn); \ - insn && insn->offset >= sym->offset; \ - insn = prev_insn_same_sec(file, insn)) - -#define sec_for_each_insn_from(file, insn) \ - for (; insn; insn = next_insn_same_sec(file, insn)) - -#define sec_for_each_insn_continue(file, insn) \ - for (insn = next_insn_same_sec(file, insn); insn; \ - insn = next_insn_same_sec(file, insn)) - -static inline struct symbol *insn_call_dest(struct instruction *insn) -{ - if (insn->type == INSN_JUMP_DYNAMIC || - insn->type == INSN_CALL_DYNAMIC) - return NULL; - - return insn->_call_dest; -} - -static inline struct reloc *insn_jump_table(struct instruction *insn) -{ - if (insn->type == INSN_JUMP_DYNAMIC || - insn->type == INSN_CALL_DYNAMIC) - return insn->_jump_table; - - return NULL; -} - static bool is_jump_table_jump(struct instruction *insn) { struct alt_group *alt_group = insn->alt_group; @@ -282,21 +167,6 @@ static bool dead_end_function(struct objtool_file *file, struct symbol *func) return __dead_end_function(file, func, 0); } -static void init_insn_state(struct objtool_file *file, struct insn_state *state, - struct section *sec) -{ - memset(state, 0, sizeof(*state)); - init_cfi_state(&state->cfi); - - /* - * We need the full vmlinux for noinstr validation, otherwise we can - * not correctly determine insn_call_dest(insn)->sec (external symbols - * do not have a section). - */ - if (opts.link && opts.noinstr && sec) - state->noinstr = sec->noinstr; -} - static unsigned long nr_insns; static unsigned long nr_insns_visited; @@ -501,19 +371,6 @@ static int init_pv_ops(struct objtool_file *file) return 0; } -static struct instruction *find_last_insn(struct objtool_file *file, - struct section *sec) -{ - struct instruction *insn = NULL; - unsigned int offset; - unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0; - - for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--) - insn = find_insn(file, sec, offset); - - return insn; -} - /* * Mark "ud2" instructions and manually annotated dead ends. */ @@ -1263,26 +1120,6 @@ __weak bool arch_is_rethunk(struct symbol *sym) return false; } -static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) -{ - struct reloc *reloc; - - if (insn->no_reloc) - return NULL; - - if (!file) - return NULL; - - reloc = find_reloc_by_dest_range(file->elf, insn->sec, - insn->offset, insn->len); - if (!reloc) { - insn->no_reloc = 1; - return NULL; - } - - return reloc; -} - static void remove_insn_ops(struct instruction *insn) { struct stack_op *op, *next; @@ -1446,24 +1283,6 @@ static void add_return_call(struct objtool_file *file, struct instruction *insn, list_add_tail(&insn->call_node, &file->return_thunk_list); } -static bool is_first_func_insn(struct objtool_file *file, - struct instruction *insn, struct symbol *sym) -{ - if (insn->offset == sym->offset) - return true; - - /* Allow direct CALL/JMP past ENDBR */ - if (opts.ibt) { - struct instruction *prev = prev_insn_same_sym(file, insn); - - if (prev && prev->type == INSN_ENDBR && - insn->offset == sym->offset + prev->len) - return true; - } - - return false; -} - /* * A sibling call is a tail-call to another symbol -- to differentiate from a * recursive tail-call which is to the same symbol. @@ -3224,56 +3043,6 @@ static int handle_insn_ops(struct instruction *insn, return 0; } -static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2) -{ - struct cfi_state *cfi1 = insn->cfi; - int i; - - if (!cfi1) { - WARN("CFI missing"); - return false; - } - - if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) { - - WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d", - insn->sec, insn->offset, - cfi1->cfa.base, cfi1->cfa.offset, - cfi2->cfa.base, cfi2->cfa.offset); - - } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) { - for (i = 0; i < CFI_NUM_REGS; i++) { - if (!memcmp(&cfi1->regs[i], &cfi2->regs[i], - sizeof(struct cfi_reg))) - continue; - - WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", - insn->sec, insn->offset, - i, cfi1->regs[i].base, cfi1->regs[i].offset, - i, cfi2->regs[i].base, cfi2->regs[i].offset); - break; - } - - } else if (cfi1->type != cfi2->type) { - - WARN_FUNC("stack state mismatch: type1=%d type2=%d", - insn->sec, insn->offset, cfi1->type, cfi2->type); - - } else if (cfi1->drap != cfi2->drap || - (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) || - (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) { - - WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", - insn->sec, insn->offset, - cfi1->drap, cfi1->drap_reg, cfi1->drap_offset, - cfi2->drap, cfi2->drap_reg, cfi2->drap_offset); - - } else - return true; - - return false; -} - static inline bool func_uaccess_safe(struct symbol *func) { if (func) diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h index 3e7c7004f7df..450ebc092b1f 100644 --- a/tools/objtool/include/objtool/check.h +++ b/tools/objtool/include/objtool/check.h @@ -7,17 +7,7 @@ #define _CHECK_H #include <stdbool.h> -#include <objtool/cfi.h> -#include <objtool/arch.h> - -struct insn_state { - struct cfi_state cfi; - unsigned int uaccess_stack; - bool uaccess; - bool df; - bool noinstr; - s8 instr; -}; +#include <objtool/insn.h> struct alt_group { /* @@ -36,89 +26,9 @@ struct alt_group { struct cfi_state **cfi; }; -#define INSN_CHUNK_BITS 8 -#define INSN_CHUNK_SIZE (1 << INSN_CHUNK_BITS) -#define INSN_CHUNK_MAX (INSN_CHUNK_SIZE - 1) - -struct instruction { - struct hlist_node hash; - struct list_head call_node; - struct section *sec; - unsigned long offset; - unsigned long immediate; - - u8 len; - u8 prev_len; - u8 type; - s8 instr; - - u32 idx : INSN_CHUNK_BITS, - dead_end : 1, - ignore : 1, - ignore_alts : 1, - hint : 1, - save : 1, - restore : 1, - retpoline_safe : 1, - noendbr : 1, - entry : 1, - visited : 4, - no_reloc : 1; - /* 10 bit hole */ - - struct alt_group *alt_group; - struct instruction *jump_dest; - struct instruction *first_jump_src; - union { - struct symbol *_call_dest; - struct reloc *_jump_table; - }; - struct alternative *alts; - struct symbol *sym; - struct stack_op *stack_ops; - struct cfi_state *cfi; -}; - -static inline struct symbol *insn_func(struct instruction *insn) -{ - struct symbol *sym = insn->sym; - - if (sym && sym->type != STT_FUNC) - sym = NULL; - - return sym; -} - #define VISITED_BRANCH 0x01 #define VISITED_BRANCH_UACCESS 0x02 #define VISITED_BRANCH_MASK 0x03 #define VISITED_ENTRY 0x04 -static inline bool is_static_jump(struct instruction *insn) -{ - return insn->type == INSN_JUMP_CONDITIONAL || - insn->type == INSN_JUMP_UNCONDITIONAL; -} - -static inline bool is_dynamic_jump(struct instruction *insn) -{ - return insn->type == INSN_JUMP_DYNAMIC || - insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL; -} - -static inline bool is_jump(struct instruction *insn) -{ - return is_static_jump(insn) || is_dynamic_jump(insn); -} - -struct instruction *find_insn(struct objtool_file *file, - struct section *sec, unsigned long offset); - -struct instruction *next_insn_same_sec(struct objtool_file *file, struct instruction *insn); - -#define sec_for_each_insn(file, _sec, insn) \ - for (insn = find_insn(file, _sec, 0); \ - insn && insn->sec == _sec; \ - insn = next_insn_same_sec(file, insn)) - #endif /* _CHECK_H */ diff --git a/tools/objtool/include/objtool/insn.h b/tools/objtool/include/objtool/insn.h new file mode 100644 index 000000000000..edd46b5ea1e4 --- /dev/null +++ b/tools/objtool/include/objtool/insn.h @@ -0,0 +1,163 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@xxxxxxxxxx> + */ + +#ifndef _INSN_H +#define _INSN_H + +#include <objtool/objtool.h> +#include <objtool/arch.h> + +#define INSN_CHUNK_BITS 8 +#define INSN_CHUNK_SIZE (1 << INSN_CHUNK_BITS) +#define INSN_CHUNK_MAX (INSN_CHUNK_SIZE - 1) + +struct insn_state { + struct cfi_state cfi; + unsigned int uaccess_stack; + bool uaccess; + bool df; + bool noinstr; + s8 instr; +}; + +struct instruction { + struct hlist_node hash; + struct list_head call_node; + struct section *sec; + unsigned long offset; + unsigned long immediate; + + u8 len; + u8 prev_len; + u8 type; + s8 instr; + + u32 idx : INSN_CHUNK_BITS, + dead_end : 1, + ignore : 1, + ignore_alts : 1, + hint : 1, + save : 1, + restore : 1, + retpoline_safe : 1, + noendbr : 1, + entry : 1, + visited : 4, + no_reloc : 1; + /* 10 bit hole */ + + struct alt_group *alt_group; + struct instruction *jump_dest; + struct instruction *first_jump_src; + union { + struct symbol *_call_dest; + struct reloc *_jump_table; + }; + struct alternative *alts; + struct symbol *sym; + struct stack_op *stack_ops; + struct cfi_state *cfi; +}; + +static inline struct symbol *insn_func(struct instruction *insn) +{ + struct symbol *sym = insn->sym; + + if (sym && sym->type != STT_FUNC) + sym = NULL; + + return sym; +} + +static inline bool is_static_jump(struct instruction *insn) +{ + return insn->type == INSN_JUMP_CONDITIONAL || + insn->type == INSN_JUMP_UNCONDITIONAL; +} + +static inline bool is_dynamic_jump(struct instruction *insn) +{ + return insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_JUMP_DYNAMIC_CONDITIONAL; +} + +static inline bool is_jump(struct instruction *insn) +{ + return is_static_jump(insn) || is_dynamic_jump(insn); +} + +static inline struct symbol *insn_call_dest(struct instruction *insn) +{ + if (insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_CALL_DYNAMIC) + return NULL; + + return insn->_call_dest; +} + +static inline struct reloc *insn_jump_table(struct instruction *insn) +{ + if (insn->type == INSN_JUMP_DYNAMIC || + insn->type == INSN_CALL_DYNAMIC) + return insn->_jump_table; + + return NULL; +} + +void init_insn_state(struct objtool_file *file, struct insn_state *state, + struct section *sec); +struct instruction *find_insn(struct objtool_file *file, + struct section *sec, unsigned long offset); +struct instruction *find_last_insn(struct objtool_file *file, + struct section *sec); +struct instruction *prev_insn_same_sec(struct objtool_file *file, + struct instruction *insn); +struct instruction *prev_insn_same_sym(struct objtool_file *file, + struct instruction *insn); +struct instruction *next_insn_same_sec(struct objtool_file *file, + struct instruction *insn); +struct instruction *next_insn_same_func(struct objtool_file *file, + struct instruction *insn); +struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn); +bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2); +bool same_function(struct instruction *insn1, struct instruction *insn2); +bool is_first_func_insn(struct objtool_file *file, + struct instruction *insn, struct symbol *sym); + + +#define for_each_insn(file, insn) \ + for (struct section *__sec, *__fake = (struct section *)1; \ + __fake; __fake = NULL) \ + for_each_sec(file, __sec) \ + sec_for_each_insn(file, __sec, insn) + +#define sec_for_each_insn(file, _sec, insn) \ + for (insn = find_insn(file, _sec, 0); \ + insn && insn->sec == _sec; \ + insn = next_insn_same_sec(file, insn)) + +#define func_for_each_insn(file, func, insn) \ + for (insn = find_insn(file, func->sec, func->offset); \ + insn; \ + insn = next_insn_same_func(file, insn)) + +#define sym_for_each_insn(file, sym, insn) \ + for (insn = find_insn(file, sym->sec, sym->offset); \ + insn && insn->offset < sym->offset + sym->len; \ + insn = next_insn_same_sec(file, insn)) + +#define sym_for_each_insn_continue_reverse(file, sym, insn) \ + for (insn = prev_insn_same_sec(file, insn); \ + insn && insn->offset >= sym->offset; \ + insn = prev_insn_same_sec(file, insn)) + +#define sec_for_each_insn_from(file, insn) \ + for (; insn; insn = next_insn_same_sec(file, insn)) + +#define sec_for_each_insn_continue(file, insn) \ + for (insn = next_insn_same_sec(file, insn); insn; \ + insn = next_insn_same_sec(file, insn)) + +#endif /* _INSN_H */ diff --git a/tools/objtool/insn.c b/tools/objtool/insn.c new file mode 100644 index 000000000000..c020cb84489d --- /dev/null +++ b/tools/objtool/insn.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@xxxxxxxxxx> + */ + +#include <string.h> + +#include <objtool/builtin.h> +#include <objtool/insn.h> +#include <objtool/warn.h> + +struct instruction *find_insn(struct objtool_file *file, + struct section *sec, unsigned long offset) +{ + struct instruction *insn; + + hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) { + if (insn->sec == sec && insn->offset == offset) + return insn; + } + + return NULL; +} + +struct instruction *next_insn_same_sec(struct objtool_file *file, + struct instruction *insn) +{ + if (insn->idx == INSN_CHUNK_MAX) + return find_insn(file, insn->sec, insn->offset + insn->len); + + insn++; + if (!insn->len) + return NULL; + + return insn; +} + +struct instruction *next_insn_same_func(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *next = next_insn_same_sec(file, insn); + struct symbol *func = insn_func(insn); + + if (!func) + return NULL; + + if (next && insn_func(next) == func) + return next; + + /* Check if we're already in the subfunction: */ + if (func == func->cfunc) + return NULL; + + /* Move to the subfunction: */ + return find_insn(file, func->cfunc->sec, func->cfunc->offset); +} + +struct instruction *prev_insn_same_sec(struct objtool_file *file, + struct instruction *insn) +{ + if (insn->idx == 0) { + if (insn->prev_len) + return find_insn(file, insn->sec, insn->offset - insn->prev_len); + return NULL; + } + + return insn - 1; +} + +struct instruction *prev_insn_same_sym(struct objtool_file *file, + struct instruction *insn) +{ + struct instruction *prev = prev_insn_same_sec(file, insn); + + if (prev && insn_func(prev) == insn_func(insn)) + return prev; + + return NULL; +} + +void init_insn_state(struct objtool_file *file, struct insn_state *state, + struct section *sec) +{ + memset(state, 0, sizeof(*state)); + init_cfi_state(&state->cfi); + + /* + * We need the full vmlinux for noinstr validation, otherwise we can + * not correctly determine insn_call_dest(insn)->sec (external symbols + * do not have a section). + */ + if (opts.link && opts.noinstr && sec) + state->noinstr = sec->noinstr; +} + +struct instruction *find_last_insn(struct objtool_file *file, + struct section *sec) +{ + struct instruction *insn = NULL; + unsigned int offset; + unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0; + + for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--) + insn = find_insn(file, sec, offset); + + return insn; +} + +struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) +{ + struct reloc *reloc; + + if (insn->no_reloc) + return NULL; + + if (!file) + return NULL; + + reloc = find_reloc_by_dest_range(file->elf, insn->sec, + insn->offset, insn->len); + if (!reloc) { + insn->no_reloc = 1; + return NULL; + } + + return reloc; +} + +bool is_first_func_insn(struct objtool_file *file, + struct instruction *insn, struct symbol *sym) +{ + if (insn->offset == sym->offset) + return true; + + /* Allow direct CALL/JMP past ENDBR */ + if (opts.ibt) { + struct instruction *prev = prev_insn_same_sym(file, insn); + + if (prev && prev->type == INSN_ENDBR && + insn->offset == sym->offset + prev->len) + return true; + } + + return false; +} + +bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2) +{ + struct cfi_state *cfi1 = insn->cfi; + int i; + + if (!cfi1) { + WARN("CFI missing"); + return false; + } + + if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) { + + WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d", + insn->sec, insn->offset, + cfi1->cfa.base, cfi1->cfa.offset, + cfi2->cfa.base, cfi2->cfa.offset); + + } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) { + for (i = 0; i < CFI_NUM_REGS; i++) { + if (!memcmp(&cfi1->regs[i], &cfi2->regs[i], + sizeof(struct cfi_reg))) + continue; + + WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", + insn->sec, insn->offset, + i, cfi1->regs[i].base, cfi1->regs[i].offset, + i, cfi2->regs[i].base, cfi2->regs[i].offset); + break; + } + + } else if (cfi1->type != cfi2->type) { + + WARN_FUNC("stack state mismatch: type1=%d type2=%d", + insn->sec, insn->offset, cfi1->type, cfi2->type); + + } else if (cfi1->drap != cfi2->drap || + (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) || + (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) { + + WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", + insn->sec, insn->offset, + cfi1->drap, cfi1->drap_reg, cfi1->drap_offset, + cfi2->drap, cfi2->drap_reg, cfi2->drap_offset); + + } else + return true; + + return false; +} -- 2.39.2