From: Peter Zijlstra peterz@infradead.org
stable inclusion from stable-v5.10.133 commit 33092b486686c31432c5354dbb18651e44200668 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5PTAS CVE: CVE-2022-29900,CVE-2022-23816,CVE-2022-29901
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 43d5430ad74ef5156353af7aec352426ec7a8e57 upstream.
Provide infrastructure for architectures to rewrite/augment compiler generated retpoline calls. Similar to what we do for static_call()s, keep track of the instructions that are retpoline calls.
Use the same list_head, since a retpoline call cannot also be a static_call.
Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Borislav Petkov bp@suse.de Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Miroslav Benes mbenes@suse.cz Link: https://lkml.kernel.org/r/20210326151300.130805730@infradead.org [bwh: Backported to 5.10: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Lin Yujun linyujun809@huawei.com Reviewed-by: Zhang Jianhua chris.zjh@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- tools/objtool/arch.h | 2 ++ tools/objtool/check.c | 34 +++++++++++++++++++++++++++++----- tools/objtool/check.h | 2 +- tools/objtool/objtool.c | 1 + tools/objtool/objtool.h | 1 + 5 files changed, 34 insertions(+), 6 deletions(-)
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h index 82896d7615f5..8918de4f8189 100644 --- a/tools/objtool/arch.h +++ b/tools/objtool/arch.h @@ -88,4 +88,6 @@ int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg);
bool arch_is_retpoline(struct symbol *sym);
+int arch_rewrite_retpolines(struct objtool_file *file); + #endif /* _ARCH_H */ diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 2cb409859081..f87a8782c817 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -451,7 +451,7 @@ static int create_static_call_sections(struct objtool_file *file) return 0;
idx = 0; - list_for_each_entry(insn, &file->static_call_list, static_call_node) + list_for_each_entry(insn, &file->static_call_list, call_node) idx++;
sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE, @@ -460,7 +460,7 @@ static int create_static_call_sections(struct objtool_file *file) return -1;
idx = 0; - list_for_each_entry(insn, &file->static_call_list, static_call_node) { + list_for_each_entry(insn, &file->static_call_list, call_node) {
site = (struct static_call_site *)sec->data->d_buf + idx; memset(site, 0, sizeof(struct static_call_site)); @@ -786,13 +786,16 @@ static int add_jump_destinations(struct objtool_file *file) else insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
+ list_add_tail(&insn->call_node, + &file->retpoline_call_list); + insn->retpoline_safe = true; continue; } else if (insn->func) { /* internal or external sibling call (with reloc) */ insn->call_dest = reloc->sym; if (insn->call_dest->static_call_tramp) { - list_add_tail(&insn->static_call_node, + list_add_tail(&insn->call_node, &file->static_call_list); } continue; @@ -854,7 +857,7 @@ static int add_jump_destinations(struct objtool_file *file) /* internal sibling call (without reloc) */ insn->call_dest = insn->jump_dest->func; if (insn->call_dest->static_call_tramp) { - list_add_tail(&insn->static_call_node, + list_add_tail(&insn->call_node, &file->static_call_list); } } @@ -938,6 +941,9 @@ static int add_call_destinations(struct objtool_file *file) insn->type = INSN_CALL_DYNAMIC; insn->retpoline_safe = true;
+ list_add_tail(&insn->call_node, + &file->retpoline_call_list); + remove_insn_ops(insn); continue;
@@ -945,7 +951,7 @@ static int add_call_destinations(struct objtool_file *file) insn->call_dest = reloc->sym;
if (insn->call_dest && insn->call_dest->static_call_tramp) { - list_add_tail(&insn->static_call_node, + list_add_tail(&insn->call_node, &file->static_call_list); }
@@ -1655,6 +1661,11 @@ static void mark_rodata(struct objtool_file *file) file->rodata = found; }
+__weak int arch_rewrite_retpolines(struct objtool_file *file) +{ + return 0; +} + static int decode_sections(struct objtool_file *file) { int ret; @@ -1683,6 +1694,10 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret;
+ /* + * Must be before add_special_section_alts() as that depends on + * jump_dest being set. + */ ret = add_jump_destinations(file); if (ret) return ret; @@ -1719,6 +1734,15 @@ static int decode_sections(struct objtool_file *file) if (ret) return ret;
+ /* + * Must be after add_special_section_alts(), since this will emit + * alternatives. Must be after add_{jump,call}_destination(), since + * those create the call insn lists. + */ + ret = arch_rewrite_retpolines(file); + if (ret) + return ret; + return 0; }
diff --git a/tools/objtool/check.h b/tools/objtool/check.h index d255c43b134a..e0ae2fc13e67 100644 --- a/tools/objtool/check.h +++ b/tools/objtool/check.h @@ -39,7 +39,7 @@ struct alt_group { struct instruction { struct list_head list; struct hlist_node hash; - struct list_head static_call_node; + struct list_head call_node; struct section *sec; unsigned long offset; unsigned int len; diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c index 9df0cd86d310..c0b1f5a99df9 100644 --- a/tools/objtool/objtool.c +++ b/tools/objtool/objtool.c @@ -61,6 +61,7 @@ struct objtool_file *objtool_open_read(const char *_objname)
INIT_LIST_HEAD(&file.insn_list); hash_init(file.insn_hash); + INIT_LIST_HEAD(&file.retpoline_call_list); INIT_LIST_HEAD(&file.static_call_list); file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment"); file.ignore_unreachables = no_unreachable; diff --git a/tools/objtool/objtool.h b/tools/objtool/objtool.h index 5e58d3537e2f..0b57150ea0fe 100644 --- a/tools/objtool/objtool.h +++ b/tools/objtool/objtool.h @@ -18,6 +18,7 @@ struct objtool_file { struct elf *elf; struct list_head insn_list; DECLARE_HASHTABLE(insn_hash, 20); + struct list_head retpoline_call_list; struct list_head static_call_list; bool ignore_unreachables, c_file, hints, rodata; };