diff options
| -rw-r--r-- | tools/objtool/builtin-check.c | 1 | ||||
| -rw-r--r-- | tools/objtool/check.c | 33 | ||||
| -rw-r--r-- | tools/objtool/elf.c | 31 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/builtin.h | 1 | ||||
| -rw-r--r-- | tools/objtool/include/objtool/elf.h | 2 |
5 files changed, 67 insertions, 1 deletions
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c index 0a04f8ea4432..95fcecee60ce 100644 --- a/tools/objtool/builtin-check.c +++ b/tools/objtool/builtin-check.c @@ -75,6 +75,7 @@ const struct option check_options[] = { OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"), OPT_BOOLEAN(0, "rethunk", &opts.rethunk, "validate and annotate rethunk usage"), OPT_BOOLEAN(0, "unret", &opts.unret, "validate entry unret placement"), + OPT_INTEGER(0, "prefix", &opts.prefix, "generate prefix symbols"), OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"), OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"), OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"), diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 7936312e10c7..27f35f5f831a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3417,7 +3417,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, if (func && insn_func(insn) && func != insn_func(insn)->pfunc) { /* Ignore KCFI type preambles, which always fall through */ - if (!strncmp(func->name, "__cfi_", 6)) + if (!strncmp(func->name, "__cfi_", 6) || + !strncmp(func->name, "__pfx_", 6)) return 0; WARN("%s() falls through to next function %s()", @@ -3972,6 +3973,34 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio return false; } +static int add_prefix_symbol(struct objtool_file *file, struct symbol *func, + struct instruction *insn) +{ + if (!opts.prefix) + return 0; + + for (;;) { + struct instruction *prev = list_prev_entry(insn, list); + u64 offset; + + if (&prev->list == &file->insn_list) + break; + + if (prev->type != INSN_NOP) + break; + + offset = func->offset - prev->offset; + if (offset >= opts.prefix) { + if (offset == opts.prefix) + elf_create_prefix_symbol(file->elf, func, opts.prefix); + break; + } + insn = prev; + } + + return 0; +} + static int validate_symbol(struct objtool_file *file, struct section *sec, struct symbol *sym, struct insn_state *state) { @@ -3990,6 +4019,8 @@ static int validate_symbol(struct objtool_file *file, struct section *sec, if (!insn || insn->ignore || insn->visited) return 0; + add_prefix_symbol(file, sym, insn); + state->uaccess = sym->uaccess_safe; ret = validate_branch(file, insn_func(insn), insn, *state); diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 36dc78796f58..3d636d12d679 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -819,6 +819,37 @@ elf_create_section_symbol(struct elf *elf, struct section *sec) return sym; } +static int elf_add_string(struct elf *elf, struct section *strtab, char *str); + +struct symbol * +elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size) +{ + struct symbol *sym = calloc(1, sizeof(*sym)); + size_t namelen = strlen(orig->name) + sizeof("__pfx_"); + char *name = malloc(namelen); + + if (!sym || !name) { + perror("malloc"); + return NULL; + } + + snprintf(name, namelen, "__pfx_%s", orig->name); + + sym->name = name; + sym->sec = orig->sec; + + sym->sym.st_name = elf_add_string(elf, NULL, name); + sym->sym.st_info = orig->sym.st_info; + sym->sym.st_value = orig->sym.st_value - size; + sym->sym.st_size = size; + + sym = __elf_create_symbol(elf, sym); + if (sym) + elf_add_symbol(elf, sym); + + return sym; +} + int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, unsigned long offset, unsigned int type, struct section *insn_sec, unsigned long insn_off) diff --git a/tools/objtool/include/objtool/builtin.h b/tools/objtool/include/objtool/builtin.h index 22092a9f3cf6..f341b620dead 100644 --- a/tools/objtool/include/objtool/builtin.h +++ b/tools/objtool/include/objtool/builtin.h @@ -26,6 +26,7 @@ struct opts { bool stackval; bool static_call; bool uaccess; + int prefix; /* options: */ bool backtrace; diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h index 9e96a613c50f..b6974e3173aa 100644 --- a/tools/objtool/include/objtool/elf.h +++ b/tools/objtool/include/objtool/elf.h @@ -146,6 +146,8 @@ static inline bool has_multiple_files(struct elf *elf) struct elf *elf_open_read(const char *name, int flags); struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr); +struct symbol *elf_create_prefix_symbol(struct elf *elf, struct symbol *orig, long size); + int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset, unsigned int type, struct symbol *sym, s64 addend); int elf_add_reloc_to_insn(struct elf *elf, struct section *sec, |