objtool: Make instruction::stack_ops a single-linked list
authorPeter Zijlstra <peterz@infradead.org>
Wed, 8 Feb 2023 17:17:58 +0000 (18:17 +0100)
committerIngo Molnar <mingo@kernel.org>
Thu, 23 Feb 2023 08:20:59 +0000 (09:20 +0100)
 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) --- */
  unsigned int               len;                  /*    64     4 */
  enum insn_type             type;                 /*    68     4 */
  long unsigned int          immediate;            /*    72     8 */
  u16                        dead_end:1;           /*    80: 0  2 */
  u16                        ignore:1;             /*    80: 1  2 */
  u16                        ignore_alts:1;        /*    80: 2  2 */
  u16                        hint:1;               /*    80: 3  2 */
  u16                        save:1;               /*    80: 4  2 */
  u16                        restore:1;            /*    80: 5  2 */
  u16                        retpoline_safe:1;     /*    80: 6  2 */
  u16                        noendbr:1;            /*    80: 7  2 */
  u16                        entry:1;              /*    80: 8  2 */

  /* XXX 7 bits hole, try to pack */

  s8                         instr;                /*    82     1 */
  u8                         visited;              /*    83     1 */

  /* XXX 4 bytes hole, try to pack */

  struct alt_group *         alt_group;            /*    88     8 */
  struct symbol *            call_dest;            /*    96     8 */
  struct instruction *       jump_dest;            /*   104     8 */
  struct instruction *       first_jump_src;       /*   112     8 */
  struct reloc *             jump_table;           /*   120     8 */
  /* --- cacheline 2 boundary (128 bytes) --- */
  struct reloc *             reloc;                /*   128     8 */
  struct list_head           alts;                 /*   136    16 */
  struct symbol *            sym;                  /*   152     8 */
- struct list_head           stack_ops;            /*   160    16 */
- struct cfi_state *         cfi;                  /*   176     8 */
+ struct stack_op *          stack_ops;            /*   160     8 */
+ struct cfi_state *         cfi;                  /*   168     8 */

- /* size: 184, cachelines: 3, members: 29 */
- /* sum members: 178, holes: 1, sum holes: 4 */
+ /* size: 176, cachelines: 3, members: 29 */
+ /* sum members: 170, holes: 1, sum holes: 4 */
  /* sum bitfield members: 9 bits, bit holes: 1, sum bit holes: 7 bits */
- /* last cacheline: 56 bytes */
+ /* last cacheline: 48 bytes */
 };

pre: 5:58.22 real,   226.69 user,    131.22 sys,     26221520 mem
post: 5:58.50 real,   229.64 user,    128.65 sys,     26221520 mem

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org> # build only
Tested-by: Thomas Weißschuh <linux@weissschuh.net> # compile and run
Link: https://lore.kernel.org/r/20230208172245.362196959@infradead.org
tools/objtool/arch/x86/decode.c
tools/objtool/check.c
tools/objtool/include/objtool/arch.h
tools/objtool/include/objtool/check.h

index c5c49277cf1a95738cf8c9559377a80e0aee2254..9ef024fd648c1b39e039fc2ffb62a2aa8c344756 100644 (file)
@@ -105,7 +105,7 @@ bool arch_pc_relative_reloc(struct reloc *reloc)
 #define ADD_OP(op) \
        if (!(op = calloc(1, sizeof(*op)))) \
                return -1; \
-       else for (list_add_tail(&op->list, ops_list); op; op = NULL)
+       else for (*ops_list = op, ops_list = &op->next; op; op = NULL)
 
 /*
  * Helpers to decode ModRM/SIB:
@@ -148,7 +148,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec
                            unsigned long offset, unsigned int maxlen,
                            struct instruction *insn)
 {
-       struct list_head *ops_list = &insn->stack_ops;
+       struct stack_op **ops_list = &insn->stack_ops;
        const struct elf *elf = file->elf;
        struct insn ins;
        int x86_64, ret;
index b3b423d33cc242febe226e8649ed7e24085a5a22..8109d7405297cf9cbaf04aa28ed2ef679ac9c08f 100644 (file)
@@ -398,7 +398,6 @@ static int decode_instructions(struct objtool_file *file)
                        }
                        memset(insn, 0, sizeof(*insn));
                        INIT_LIST_HEAD(&insn->alts);
-                       INIT_LIST_HEAD(&insn->stack_ops);
                        INIT_LIST_HEAD(&insn->call_node);
 
                        insn->sec = sec;
@@ -1331,12 +1330,13 @@ static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *i
 
 static void remove_insn_ops(struct instruction *insn)
 {
-       struct stack_op *op, *tmp;
+       struct stack_op *op, *next;
 
-       list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) {
-               list_del(&op->list);
+       for (op = insn->stack_ops; op; op = next) {
+               next = op->next;
                free(op);
        }
+       insn->stack_ops = NULL;
 }
 
 static void annotate_call_site(struct objtool_file *file,
@@ -1781,7 +1781,6 @@ static int handle_group_alt(struct objtool_file *file,
                }
                memset(nop, 0, sizeof(*nop));
                INIT_LIST_HEAD(&nop->alts);
-               INIT_LIST_HEAD(&nop->stack_ops);
 
                nop->sec = special_alt->new_sec;
                nop->offset = special_alt->new_off + special_alt->new_len;
@@ -3226,7 +3225,7 @@ static int handle_insn_ops(struct instruction *insn,
 {
        struct stack_op *op;
 
-       list_for_each_entry(op, &insn->stack_ops, list) {
+       for (op = insn->stack_ops; op; op = op->next) {
 
                if (update_cfi_state(insn, next_insn, &state->cfi, op))
                        return 1;
index 73149f8090faf9ae1bd563bd2c8c98ac4b6ae01c..2b6d2ce4f9a5bfd7a9cdb2d343c662996ed10ead 100644 (file)
@@ -62,9 +62,9 @@ struct op_src {
 };
 
 struct stack_op {
+       struct stack_op *next;
        struct op_dest dest;
        struct op_src src;
-       struct list_head list;
 };
 
 struct instruction;
index acd7fae593484cdee64a2183669042e7b4cbccc1..23e98199936553f09b71adec162caabfc1b40439 100644 (file)
@@ -68,7 +68,7 @@ struct instruction {
        struct reloc *reloc;
        struct list_head alts;
        struct symbol *sym;
-       struct list_head stack_ops;
+       struct stack_op *stack_ops;
        struct cfi_state *cfi;
 };