From 00abd38408127a57861698a8bffba65849de6bbd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 15 Sep 2022 13:11:09 +0200 Subject: objtool: Add .call_sites section In preparation for call depth tracking provide a section which collects all direct calls. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220915111146.016511961@infradead.org --- tools/objtool/check.c | 51 +++++++++++++++++++++++++++++++++ tools/objtool/include/objtool/objtool.h | 1 + tools/objtool/objtool.c | 1 + 3 files changed, 53 insertions(+) (limited to 'tools/objtool') diff --git a/tools/objtool/check.c b/tools/objtool/check.c index bb7c8196bf57..f578e030e8bb 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -902,6 +902,49 @@ static int create_mcount_loc_sections(struct objtool_file *file) return 0; } +static int create_direct_call_sections(struct objtool_file *file) +{ + struct instruction *insn; + struct section *sec; + unsigned int *loc; + int idx; + + sec = find_section_by_name(file->elf, ".call_sites"); + if (sec) { + INIT_LIST_HEAD(&file->call_list); + WARN("file already has .call_sites section, skipping"); + return 0; + } + + if (list_empty(&file->call_list)) + return 0; + + idx = 0; + list_for_each_entry(insn, &file->call_list, call_node) + idx++; + + sec = elf_create_section(file->elf, ".call_sites", 0, sizeof(unsigned int), idx); + if (!sec) + return -1; + + idx = 0; + list_for_each_entry(insn, &file->call_list, call_node) { + + loc = (unsigned int *)sec->data->d_buf + idx; + memset(loc, 0, sizeof(unsigned int)); + + if (elf_add_reloc_to_insn(file->elf, sec, + idx * sizeof(unsigned int), + R_X86_64_PC32, + insn->sec, insn->offset)) + return -1; + + idx++; + } + + return 0; +} + /* * Warnings shouldn't be reported for ignored functions. */ @@ -1279,6 +1322,9 @@ static void annotate_call_site(struct objtool_file *file, return; } + if (insn->type == INSN_CALL && !insn->sec->init) + list_add_tail(&insn->call_node, &file->call_list); + if (!sibling && dead_end_function(file, sym)) insn->dead_end = true; } @@ -4305,6 +4351,11 @@ int check(struct objtool_file *file) if (ret < 0) goto out; warnings += ret; + + ret = create_direct_call_sections(file); + if (ret < 0) + goto out; + warnings += ret; } if (opts.mcount) { diff --git a/tools/objtool/include/objtool/objtool.h b/tools/objtool/include/objtool/objtool.h index 7f2d1b095333..6b40977bcdb1 100644 --- a/tools/objtool/include/objtool/objtool.h +++ b/tools/objtool/include/objtool/objtool.h @@ -28,6 +28,7 @@ struct objtool_file { struct list_head static_call_list; struct list_head mcount_loc_list; struct list_head endbr_list; + struct list_head call_list; bool ignore_unreachables, hints, rodata; unsigned int nr_endbr; diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c index a7ecc32e3512..6affd8067f83 100644 --- a/tools/objtool/objtool.c +++ b/tools/objtool/objtool.c @@ -106,6 +106,7 @@ struct objtool_file *objtool_open_read(const char *_objname) INIT_LIST_HEAD(&file.static_call_list); INIT_LIST_HEAD(&file.mcount_loc_list); INIT_LIST_HEAD(&file.endbr_list); + INIT_LIST_HEAD(&file.call_list); file.ignore_unreachables = opts.no_unreachable; file.hints = false; -- cgit v1.2.3