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-rw-r--r--tools/objtool/check.c97
1 files changed, 96 insertions, 1 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 331a763d8775..080a3d6cbd75 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -249,7 +249,7 @@ static void init_insn_state(struct insn_state *state, struct section *sec)
* not correctly determine insn->call_dest->sec (external symbols do
* not have a section).
*/
- if (vmlinux && sec)
+ if (vmlinux && noinstr && sec)
state->noinstr = sec->noinstr;
}
@@ -548,6 +548,78 @@ static int create_static_call_sections(struct objtool_file *file)
return 0;
}
+static int create_mcount_loc_sections(struct objtool_file *file)
+{
+ struct section *sec, *reloc_sec;
+ struct reloc *reloc;
+ unsigned long *loc;
+ struct instruction *insn;
+ int idx;
+
+ sec = find_section_by_name(file->elf, "__mcount_loc");
+ if (sec) {
+ INIT_LIST_HEAD(&file->mcount_loc_list);
+ WARN("file already has __mcount_loc section, skipping");
+ return 0;
+ }
+
+ if (list_empty(&file->mcount_loc_list))
+ return 0;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node)
+ idx++;
+
+ sec = elf_create_section(file->elf, "__mcount_loc", 0, sizeof(unsigned long), idx);
+ if (!sec)
+ return -1;
+
+ reloc_sec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
+ if (!reloc_sec)
+ return -1;
+
+ idx = 0;
+ list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) {
+
+ loc = (unsigned long *)sec->data->d_buf + idx;
+ memset(loc, 0, sizeof(unsigned long));
+
+ reloc = malloc(sizeof(*reloc));
+ if (!reloc) {
+ perror("malloc");
+ return -1;
+ }
+ memset(reloc, 0, sizeof(*reloc));
+
+ if (insn->sec->sym) {
+ reloc->sym = insn->sec->sym;
+ reloc->addend = insn->offset;
+ } else {
+ reloc->sym = find_symbol_containing(insn->sec, insn->offset);
+
+ if (!reloc->sym) {
+ WARN("missing symbol for insn at offset 0x%lx\n",
+ insn->offset);
+ return -1;
+ }
+
+ reloc->addend = insn->offset - reloc->sym->offset;
+ }
+
+ reloc->type = R_X86_64_64;
+ reloc->offset = idx * sizeof(unsigned long);
+ reloc->sec = reloc_sec;
+ elf_add_reloc(file->elf, reloc);
+
+ idx++;
+ }
+
+ if (elf_rebuild_reloc_section(file->elf, reloc_sec))
+ return -1;
+
+ return 0;
+}
+
/*
* Warnings shouldn't be reported for ignored functions.
*/
@@ -975,6 +1047,22 @@ static int add_call_destinations(struct objtool_file *file)
insn->type = INSN_NOP;
}
+ if (mcount && !strcmp(insn->call_dest->name, "__fentry__")) {
+ if (reloc) {
+ reloc->type = R_NONE;
+ elf_write_reloc(file->elf, reloc);
+ }
+
+ elf_write_insn(file->elf, insn->sec,
+ insn->offset, insn->len,
+ arch_nop_insn(insn->len));
+
+ insn->type = INSN_NOP;
+
+ list_add_tail(&insn->mcount_loc_node,
+ &file->mcount_loc_list);
+ }
+
/*
* Whatever stack impact regular CALLs have, should be undone
* by the RETURN of the called function.
@@ -3048,6 +3136,13 @@ int check(struct objtool_file *file)
goto out;
warnings += ret;
+ if (mcount) {
+ ret = create_mcount_loc_sections(file);
+ if (ret < 0)
+ goto out;
+ warnings += ret;
+ }
+
out:
/*
* For now, don't fail the kernel build on fatal warnings. These