From c6f5dc28fb3d736fa8d7f7d31e0664a9c772c299 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 8 Feb 2023 18:18:02 +0100 Subject: objtool: Union instruction::{call_dest,jump_table} MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The instruction call_dest and jump_table members can never be used at the same time, their usage depends on type. struct instruction { struct list_head list; /* 0 16 */ struct hlist_node hash; /* 16 16 */ struct list_head call_node; /* 32 16 */ struct section * sec; /* 48 8 */ long unsigned int offset; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ long unsigned int immediate; /* 64 8 */ unsigned int len; /* 72 4 */ u8 type; /* 76 1 */ /* Bitfield combined with previous fields */ u16 dead_end:1; /* 76: 8 2 */ u16 ignore:1; /* 76: 9 2 */ u16 ignore_alts:1; /* 76:10 2 */ u16 hint:1; /* 76:11 2 */ u16 save:1; /* 76:12 2 */ u16 restore:1; /* 76:13 2 */ u16 retpoline_safe:1; /* 76:14 2 */ u16 noendbr:1; /* 76:15 2 */ u16 entry:1; /* 78: 0 2 */ u16 visited:4; /* 78: 1 2 */ u16 no_reloc:1; /* 78: 5 2 */ /* XXX 2 bits hole, try to pack */ /* Bitfield combined with next fields */ s8 instr; /* 79 1 */ struct alt_group * alt_group; /* 80 8 */ - struct symbol * call_dest; /* 88 8 */ - struct instruction * jump_dest; /* 96 8 */ - struct instruction * first_jump_src; /* 104 8 */ - struct reloc * jump_table; /* 112 8 */ - struct alternative * alts; /* 120 8 */ + struct instruction * jump_dest; /* 88 8 */ + struct instruction * first_jump_src; /* 96 8 */ + union { + struct symbol * _call_dest; /* 104 8 */ + struct reloc * _jump_table; /* 104 8 */ + }; /* 104 8 */ + struct alternative * alts; /* 112 8 */ + struct symbol * sym; /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ - struct symbol * sym; /* 128 8 */ - struct stack_op * stack_ops; /* 136 8 */ - struct cfi_state * cfi; /* 144 8 */ + struct stack_op * stack_ops; /* 128 8 */ + struct cfi_state * cfi; /* 136 8 */ - /* size: 152, cachelines: 3, members: 29 */ - /* sum members: 150 */ + /* size: 144, cachelines: 3, members: 28 */ + /* sum members: 142 */ /* sum bitfield members: 14 bits, bit holes: 1, sum bit holes: 2 bits */ - /* last cacheline: 24 bytes */ + /* last cacheline: 16 bytes */ }; pre: 5:39.35 real, 215.58 user, 123.69 sys, 23448736 mem post: 5:38.18 real, 213.25 user, 124.90 sys, 23449040 mem Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Acked-by: Josh Poimboeuf Tested-by: Nathan Chancellor # build only Tested-by: Thomas Weißschuh # compile and run Link: https://lore.kernel.org/r/20230208172245.640914454@infradead.org --- tools/objtool/check.c | 73 ++++++++++++++++++++++------------- tools/objtool/include/objtool/check.h | 6 ++- 2 files changed, 50 insertions(+), 29 deletions(-) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 6d0ce2395554..6f0adb2f76c6 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -114,16 +114,34 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file, 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; - if (insn->jump_table) + if (insn_jump_table(insn)) return true; /* Retpoline alternative for a jump table? */ return alt_group && alt_group->orig_group && - alt_group->orig_group->first_insn->jump_table; + insn_jump_table(alt_group->orig_group->first_insn); } static bool is_sibling_call(struct instruction *insn) @@ -137,8 +155,8 @@ static bool is_sibling_call(struct instruction *insn) return !is_jump_table_jump(insn); } - /* add_jump_destinations() sets insn->call_dest for sibling calls. */ - return (is_static_jump(insn) && insn->call_dest); + /* add_jump_destinations() sets insn_call_dest(insn) for sibling calls. */ + return (is_static_jump(insn) && insn_call_dest(insn)); } /* @@ -274,8 +292,8 @@ static void init_insn_state(struct objtool_file *file, struct insn_state *state, /* * We need the full vmlinux for noinstr validation, otherwise we can - * not correctly determine insn->call_dest->sec (external symbols do - * not have a section). + * 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; @@ -678,7 +696,7 @@ static int create_static_call_sections(struct objtool_file *file) return -1; /* find key symbol */ - key_name = strdup(insn->call_dest->name); + key_name = strdup(insn_call_dest(insn)->name); if (!key_name) { perror("strdup"); return -1; @@ -709,7 +727,7 @@ static int create_static_call_sections(struct objtool_file *file) * trampoline address. This is fixed up in * static_call_add_module(). */ - key_sym = insn->call_dest; + key_sym = insn_call_dest(insn); } free(key_name); @@ -1340,7 +1358,7 @@ static void annotate_call_site(struct objtool_file *file, struct instruction *insn, bool sibling) { struct reloc *reloc = insn_reloc(file, insn); - struct symbol *sym = insn->call_dest; + struct symbol *sym = insn_call_dest(insn); if (!sym) sym = reloc->sym; @@ -1425,7 +1443,7 @@ static void annotate_call_site(struct objtool_file *file, static void add_call_dest(struct objtool_file *file, struct instruction *insn, struct symbol *dest, bool sibling) { - insn->call_dest = dest; + insn->_call_dest = dest; if (!dest) return; @@ -1683,12 +1701,12 @@ static int add_call_destinations(struct objtool_file *file) if (insn->ignore) continue; - if (!insn->call_dest) { + if (!insn_call_dest(insn)) { WARN_FUNC("unannotated intra-function call", insn->sec, insn->offset); return -1; } - if (insn_func(insn) && insn->call_dest->type != STT_FUNC) { + if (insn_func(insn) && insn_call_dest(insn)->type != STT_FUNC) { WARN_FUNC("unsupported call to non-function", insn->sec, insn->offset); return -1; @@ -2125,7 +2143,7 @@ static void mark_func_jump_tables(struct objtool_file *file, reloc = find_jump_table(file, func, insn); if (reloc) { reloc->jump_table_start = true; - insn->jump_table = reloc; + insn->_jump_table = reloc; } } } @@ -2137,10 +2155,10 @@ static int add_func_jump_tables(struct objtool_file *file, int ret; func_for_each_insn(file, func, insn) { - if (!insn->jump_table) + if (!insn_jump_table(insn)) continue; - ret = add_jump_table(file, insn, insn->jump_table); + ret = add_jump_table(file, insn, insn_jump_table(insn)); if (ret) return ret; } @@ -2612,8 +2630,8 @@ static int decode_sections(struct objtool_file *file) static bool is_fentry_call(struct instruction *insn) { if (insn->type == INSN_CALL && - insn->call_dest && - insn->call_dest->fentry) + insn_call_dest(insn) && + insn_call_dest(insn)->fentry) return true; return false; @@ -3320,8 +3338,8 @@ static inline const char *call_dest_name(struct instruction *insn) struct reloc *rel; int idx; - if (insn->call_dest) - return insn->call_dest->name; + if (insn_call_dest(insn)) + return insn_call_dest(insn)->name; rel = insn_reloc(NULL, insn); if (rel && !strcmp(rel->sym->name, "pv_ops")) { @@ -3403,13 +3421,13 @@ static int validate_call(struct objtool_file *file, struct insn_state *state) { if (state->noinstr && state->instr <= 0 && - !noinstr_call_dest(file, insn, insn->call_dest)) { + !noinstr_call_dest(file, insn, insn_call_dest(insn))) { WARN_FUNC("call to %s() leaves .noinstr.text section", insn->sec, insn->offset, call_dest_name(insn)); return 1; } - if (state->uaccess && !func_uaccess_safe(insn->call_dest)) { + if (state->uaccess && !func_uaccess_safe(insn_call_dest(insn))) { WARN_FUNC("call to %s() with UACCESS enabled", insn->sec, insn->offset, call_dest_name(insn)); return 1; @@ -3847,11 +3865,11 @@ static int validate_entry(struct objtool_file *file, struct instruction *insn) /* fallthrough */ case INSN_CALL: - dest = find_insn(file, insn->call_dest->sec, - insn->call_dest->offset); + dest = find_insn(file, insn_call_dest(insn)->sec, + insn_call_dest(insn)->offset); if (!dest) { WARN("Unresolved function after linking!?: %s", - insn->call_dest->name); + insn_call_dest(insn)->name); return -1; } @@ -3952,13 +3970,13 @@ static int validate_retpoline(struct objtool_file *file) static bool is_kasan_insn(struct instruction *insn) { return (insn->type == INSN_CALL && - !strcmp(insn->call_dest->name, "__asan_handle_no_return")); + !strcmp(insn_call_dest(insn)->name, "__asan_handle_no_return")); } static bool is_ubsan_insn(struct instruction *insn) { return (insn->type == INSN_CALL && - !strcmp(insn->call_dest->name, + !strcmp(insn_call_dest(insn)->name, "__ubsan_handle_builtin_unreachable")); } @@ -4036,7 +4054,8 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio * It may also insert a UD2 after calling a __noreturn function. */ prev_insn = list_prev_entry(insn, list); - if ((prev_insn->dead_end || dead_end_function(file, prev_insn->call_dest)) && + if ((prev_insn->dead_end || + dead_end_function(file, insn_call_dest(prev_insn))) && (insn->type == INSN_BUG || (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest && insn->jump_dest->type == INSN_BUG))) diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h index fffc8b86f9f3..ab6deaed9777 100644 --- a/tools/objtool/include/objtool/check.h +++ b/tools/objtool/include/objtool/check.h @@ -62,10 +62,12 @@ struct instruction { s8 instr; struct alt_group *alt_group; - struct symbol *call_dest; struct instruction *jump_dest; struct instruction *first_jump_src; - struct reloc *jump_table; + union { + struct symbol *_call_dest; + struct reloc *_jump_table; + }; struct alternative *alts; struct symbol *sym; struct stack_op *stack_ops; -- cgit