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    Subject[PATCH v5 09/33] objtool: check: Support data in text section
    Date
    Arm64 assembly code can mix code and data in text sections through the use
    of SYM_DATA_*() macros. Skip the content of these symbols when decoding
    instructions of text sections.

    Signed-off-by: Julien Thierry <jthierry@redhat.com>
    Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
    ---
    tools/objtool/check.c | 13 +++++++++++--
    tools/objtool/elf.c | 14 ++++++++++++++
    tools/objtool/include/objtool/elf.h | 1 +
    3 files changed, 26 insertions(+), 2 deletions(-)

    diff --git a/tools/objtool/check.c b/tools/objtool/check.c
    index c0feb6db7c6d..77911ca9cfff 100644
    --- a/tools/objtool/check.c
    +++ b/tools/objtool/check.c
    @@ -359,7 +359,7 @@ static int decode_instructions(struct objtool_file *file)
    {
    struct section *sec;
    struct symbol *func;
    - unsigned long offset;
    + unsigned long offset, next_offset;
    struct instruction *insn;
    int ret;

    @@ -377,7 +377,14 @@ static int decode_instructions(struct objtool_file *file)
    !strcmp(sec->name, ".entry.text"))
    sec->noinstr = true;

    - for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) {
    + for (offset = 0; offset < sec->sh.sh_size; offset = next_offset) {
    + struct symbol *obj_sym = find_object_containing(sec, offset);
    + if (obj_sym) {
    + /* This is data in the middle of text section, skip it */
    + next_offset = obj_sym->offset + obj_sym->len;
    + continue;
    + }
    +
    insn = malloc(sizeof(*insn));
    if (!insn) {
    WARN("malloc failed");
    @@ -410,6 +417,8 @@ static int decode_instructions(struct objtool_file *file)
    hash_add(file->insn_hash, &insn->hash, sec_offset_hash(sec, insn->offset));
    list_add_tail(&insn->list, &file->insn_list);
    nr_insns++;
    +
    + next_offset = offset + insn->len;
    }

    list_for_each_entry(func, &sec->symbol_list, list) {
    diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
    index c25e957c1e52..d7304e39f6b6 100644
    --- a/tools/objtool/elf.c
    +++ b/tools/objtool/elf.c
    @@ -236,6 +236,20 @@ struct symbol *find_func_containing(struct section *sec, unsigned long offset)
    return NULL;
    }

    +struct symbol *find_object_containing(const struct section *sec, unsigned long offset)
    +{
    + struct rb_node *node;
    +
    + rb_for_each(node, &offset, &sec->symbol_tree, symbol_by_offset) {
    + struct symbol *s = rb_entry(node, struct symbol, node);
    +
    + if (s->type == STT_OBJECT)
    + return s;
    + }
    +
    + return NULL;
    +}
    +
    struct symbol *find_symbol_by_name(const struct elf *elf, const char *name)
    {
    struct symbol *sym;
    diff --git a/tools/objtool/include/objtool/elf.h b/tools/objtool/include/objtool/elf.h
    index adebfbc2b518..8b0896935af1 100644
    --- a/tools/objtool/include/objtool/elf.h
    +++ b/tools/objtool/include/objtool/elf.h
    @@ -167,6 +167,7 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns
    struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
    unsigned long offset, unsigned int len);
    struct symbol *find_func_containing(struct section *sec, unsigned long offset);
    +struct symbol *find_object_containing(const struct section *sec, unsigned long offset);

    #define for_each_sec(file, sec) \
    list_for_each_entry(sec, &file->elf->sections, list)
    --
    2.17.1
    \
     
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