aboutsummaryrefslogtreecommitdiff
path: root/tools/objtool/check.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/objtool/check.c')
-rw-r--r--tools/objtool/check.c236
1 files changed, 118 insertions, 118 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 5e5388a38e2a..9ed1a4cd00dc 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -108,6 +108,18 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file,
for (insn = next_insn_same_sec(file, insn); insn; \
insn = next_insn_same_sec(file, insn))
+static bool is_jump_table_jump(struct instruction *insn)
+{
+ struct alt_group *alt_group = insn->alt_group;
+
+ if (insn->jump_table)
+ return true;
+
+ /* Retpoline alternative for a jump table? */
+ return alt_group && alt_group->orig_group &&
+ alt_group->orig_group->first_insn->jump_table;
+}
+
static bool is_sibling_call(struct instruction *insn)
{
/*
@@ -120,7 +132,7 @@ static bool is_sibling_call(struct instruction *insn)
/* An indirect jump is either a sibling call or a jump to a table. */
if (insn->type == INSN_JUMP_DYNAMIC)
- return list_empty(&insn->alts);
+ return !is_jump_table_jump(insn);
/* add_jump_destinations() sets insn->call_dest for sibling calls. */
return (is_static_jump(insn) && insn->call_dest);
@@ -433,8 +445,7 @@ reachable:
static int create_static_call_sections(struct objtool_file *file)
{
- struct section *sec, *reloc_sec;
- struct reloc *reloc;
+ struct section *sec;
struct static_call_site *site;
struct instruction *insn;
struct symbol *key_sym;
@@ -452,7 +463,7 @@ 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,
@@ -460,36 +471,18 @@ static int create_static_call_sections(struct objtool_file *file)
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->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));
/* populate reloc for 'addr' */
- reloc = malloc(sizeof(*reloc));
-
- if (!reloc) {
- perror("malloc");
- return -1;
- }
- memset(reloc, 0, sizeof(*reloc));
-
- insn_to_reloc_sym_addend(insn->sec, insn->offset, reloc);
- if (!reloc->sym) {
- WARN_FUNC("static call tramp: missing containing symbol",
- insn->sec, insn->offset);
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(struct static_call_site),
+ R_X86_64_PC32,
+ insn->sec, insn->offset))
return -1;
- }
-
- reloc->type = R_X86_64_PC32;
- reloc->offset = idx * sizeof(struct static_call_site);
- reloc->sec = reloc_sec;
- elf_add_reloc(file->elf, reloc);
/* find key symbol */
key_name = strdup(insn->call_dest->name);
@@ -526,32 +519,21 @@ static int create_static_call_sections(struct objtool_file *file)
free(key_name);
/* populate reloc for 'key' */
- reloc = malloc(sizeof(*reloc));
- if (!reloc) {
- perror("malloc");
+ if (elf_add_reloc(file->elf, sec,
+ idx * sizeof(struct static_call_site) + 4,
+ R_X86_64_PC32, key_sym,
+ is_sibling_call(insn) * STATIC_CALL_SITE_TAIL))
return -1;
- }
- memset(reloc, 0, sizeof(*reloc));
- reloc->sym = key_sym;
- reloc->addend = is_sibling_call(insn) ? STATIC_CALL_SITE_TAIL : 0;
- reloc->type = R_X86_64_PC32;
- reloc->offset = idx * sizeof(struct static_call_site) + 4;
- reloc->sec = reloc_sec;
- elf_add_reloc(file->elf, reloc);
idx++;
}
- if (elf_rebuild_reloc_section(file->elf, reloc_sec))
- return -1;
-
return 0;
}
static int create_mcount_loc_sections(struct objtool_file *file)
{
- struct section *sec, *reloc_sec;
- struct reloc *reloc;
+ struct section *sec;
unsigned long *loc;
struct instruction *insn;
int idx;
@@ -574,49 +556,21 @@ static int create_mcount_loc_sections(struct objtool_file *file)
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");
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(unsigned long),
+ R_X86_64_64,
+ insn->sec, insn->offset))
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;
}
@@ -850,6 +804,30 @@ static int add_ignore_alternatives(struct objtool_file *file)
return 0;
}
+__weak bool arch_is_retpoline(struct symbol *sym)
+{
+ return false;
+}
+
+#define NEGATIVE_RELOC ((void *)-1L)
+
+static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn)
+{
+ if (insn->reloc == NEGATIVE_RELOC)
+ return NULL;
+
+ if (!insn->reloc) {
+ insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!insn->reloc) {
+ insn->reloc = NEGATIVE_RELOC;
+ return NULL;
+ }
+ }
+
+ return insn->reloc;
+}
+
/*
* Find the destination instructions for all jumps.
*/
@@ -864,16 +842,14 @@ static int add_jump_destinations(struct objtool_file *file)
if (!is_static_jump(insn))
continue;
- reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ reloc = insn_reloc(file, insn);
if (!reloc) {
dest_sec = insn->sec;
dest_off = arch_jump_destination(insn);
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc->addend);
- } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) ||
- !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) {
+ } else if (arch_is_retpoline(reloc->sym)) {
/*
* Retpoline jumps are really dynamic jumps in
* disguise, so convert them accordingly.
@@ -883,13 +859,16 @@ 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;
@@ -951,7 +930,7 @@ 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);
}
}
@@ -995,8 +974,7 @@ static int add_call_destinations(struct objtool_file *file)
if (insn->type != INSN_CALL)
continue;
- reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ reloc = insn_reloc(file, insn);
if (!reloc) {
dest_off = arch_jump_destination(insn);
insn->call_dest = find_call_destination(insn->sec, dest_off);
@@ -1026,9 +1004,29 @@ static int add_call_destinations(struct objtool_file *file)
dest_off);
return -1;
}
+
+ } else if (arch_is_retpoline(reloc->sym)) {
+ /*
+ * Retpoline calls are really dynamic calls in
+ * disguise, so convert them accordingly.
+ */
+ insn->type = INSN_CALL_DYNAMIC;
+ insn->retpoline_safe = true;
+
+ list_add_tail(&insn->call_node,
+ &file->retpoline_call_list);
+
+ remove_insn_ops(insn);
+ continue;
+
} else
insn->call_dest = reloc->sym;
+ if (insn->call_dest && insn->call_dest->static_call_tramp) {
+ list_add_tail(&insn->call_node,
+ &file->static_call_list);
+ }
+
/*
* Many compilers cannot disable KCOV with a function attribute
* so they need a little help, NOP out any KCOV calls from noinstr
@@ -1175,8 +1173,7 @@ static int handle_group_alt(struct objtool_file *file,
* alternatives code can adjust the relative offsets
* accordingly.
*/
- alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ alt_reloc = insn_reloc(file, insn);
if (alt_reloc &&
!arch_support_alt_relocation(special_alt, insn, alt_reloc)) {
@@ -1751,6 +1748,11 @@ 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;
@@ -1772,10 +1774,17 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
+ /*
+ * Must be before add_{jump_call}_destination.
+ */
ret = read_static_call_tramps(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;
@@ -1784,6 +1793,10 @@ static int decode_sections(struct objtool_file *file)
if (ret)
return ret;
+ /*
+ * Must be before add_call_destination(); it changes INSN_CALL to
+ * INSN_JUMP.
+ */
ret = read_intra_function_calls(file);
if (ret)
return ret;
@@ -1808,6 +1821,15 @@ 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;
}
@@ -1959,8 +1981,9 @@ static void restore_reg(struct cfi_state *cfi, unsigned char reg)
* 41 5d pop %r13
* c3 retq
*/
-static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
- struct stack_op *op)
+static int update_cfi_state(struct instruction *insn,
+ struct instruction *next_insn,
+ struct cfi_state *cfi, struct stack_op *op)
{
struct cfi_reg *cfa = &cfi->cfa;
struct cfi_reg *regs = cfi->regs;
@@ -2019,7 +2042,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
}
else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP &&
- cfa->base == CFI_BP) {
+ (cfa->base == CFI_BP || cfa->base == cfi->drap_reg)) {
/*
* mov %rbp, %rsp
@@ -2161,7 +2184,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
break;
}
- if (op->dest.reg == cfi->cfa.base) {
+ if (op->dest.reg == cfi->cfa.base && !(next_insn && next_insn->hint)) {
WARN_FUNC("unsupported stack register modification",
insn->sec, insn->offset);
return -1;
@@ -2216,7 +2239,7 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
cfa->offset = 0;
cfi->drap_offset = -1;
- } else if (regs[op->dest.reg].offset == -cfi->stack_size) {
+ } else if (cfi->stack_size == -regs[op->dest.reg].offset) {
/* pop %reg */
restore_reg(cfi, op->dest.reg);
@@ -2357,26 +2380,6 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
break;
- case OP_DEST_LEAVE:
- if ((!cfi->drap && cfa->base != CFI_BP) ||
- (cfi->drap && cfa->base != cfi->drap_reg)) {
- WARN_FUNC("leave instruction with modified stack frame",
- insn->sec, insn->offset);
- return -1;
- }
-
- /* leave (mov %rbp, %rsp; pop %rbp) */
-
- cfi->stack_size = -cfi->regs[CFI_BP].offset - 8;
- restore_reg(cfi, CFI_BP);
-
- if (!cfi->drap) {
- cfa->base = CFI_SP;
- cfa->offset -= 8;
- }
-
- break;
-
case OP_DEST_MEM:
if (op->src.type != OP_SRC_POP && op->src.type != OP_SRC_POPF) {
WARN_FUNC("unknown stack-related memory operation",
@@ -2433,13 +2436,15 @@ static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn
return 0;
}
-static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
+static int handle_insn_ops(struct instruction *insn,
+ struct instruction *next_insn,
+ struct insn_state *state)
{
struct stack_op *op;
list_for_each_entry(op, &insn->stack_ops, list) {
- if (update_cfi_state(insn, &state->cfi, op))
+ if (update_cfi_state(insn, next_insn, &state->cfi, op))
return 1;
if (!insn->alt_group)
@@ -2722,7 +2727,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
return 0;
}
- if (handle_insn_ops(insn, &state))
+ if (handle_insn_ops(insn, next_insn, &state))
return 1;
switch (insn->type) {
@@ -2746,11 +2751,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
if (dead_end_function(file, insn->call_dest))
return 0;
- if (insn->type == INSN_CALL && insn->call_dest->static_call_tramp) {
- list_add_tail(&insn->static_call_node,
- &file->static_call_list);
- }
-
break;
case INSN_JUMP_CONDITIONAL: