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-rw-r--r--tools/objtool/check.c643
1 files changed, 372 insertions, 271 deletions
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9e3cc53a7f4c..8936a05f0e5a 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -8,7 +8,6 @@
#include <inttypes.h>
#include <sys/mman.h>
-#include <arch/elf.h>
#include <objtool/builtin.h>
#include <objtool/cfi.h>
#include <objtool/arch.h>
@@ -33,6 +32,7 @@ static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache;
static struct cfi_init_state initial_func_cfi;
static struct cfi_state init_cfi;
static struct cfi_state func_cfi;
+static struct cfi_state force_undefined_cfi;
struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset)
@@ -192,51 +192,11 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
struct instruction *insn;
bool empty = true;
- /*
- * Unfortunately these have to be hard coded because the noreturn
- * attribute isn't provided in ELF data. Keep 'em sorted.
- */
+#define NORETURN(func) __stringify(func),
static const char * const global_noreturns[] = {
- "__invalid_creds",
- "__kunit_abort",
- "__module_put_and_kthread_exit",
- "__reiserfs_panic",
- "__stack_chk_fail",
- "__ubsan_handle_builtin_unreachable",
- "arch_call_rest_init",
- "arch_cpu_idle_dead",
- "cpu_bringup_and_idle",
- "cpu_startup_entry",
- "do_exit",
- "do_group_exit",
- "do_task_dead",
- "ex_handler_msr_mce",
- "fortify_panic",
- "hlt_play_dead",
- "hv_ghcb_terminate",
- "kthread_complete_and_exit",
- "kthread_exit",
- "kunit_try_catch_throw",
- "lbug_with_loc",
- "machine_real_restart",
- "make_task_dead",
- "mpt_halt_firmware",
- "nmi_panic_self_stop",
- "panic",
- "panic_smp_self_stop",
- "rest_init",
- "resume_play_dead",
- "rewind_stack_and_make_dead",
- "sev_es_terminate",
- "snp_abort",
- "start_kernel",
- "stop_this_cpu",
- "usercopy_abort",
- "x86_64_start_kernel",
- "x86_64_start_reservations",
- "xen_cpu_bringup_again",
- "xen_start_kernel",
+#include "noreturns.h"
};
+#undef NORETURN
if (!func)
return false;
@@ -533,7 +493,7 @@ static int add_pv_ops(struct objtool_file *file, const char *symname)
{
struct symbol *sym, *func;
unsigned long off, end;
- struct reloc *rel;
+ struct reloc *reloc;
int idx;
sym = find_symbol_by_name(file->elf, symname);
@@ -543,19 +503,20 @@ static int add_pv_ops(struct objtool_file *file, const char *symname)
off = sym->offset;
end = off + sym->len;
for (;;) {
- rel = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off);
- if (!rel)
+ reloc = find_reloc_by_dest_range(file->elf, sym->sec, off, end - off);
+ if (!reloc)
break;
- func = rel->sym;
+ func = reloc->sym;
if (func->type == STT_SECTION)
- func = find_symbol_by_offset(rel->sym->sec, rel->addend);
+ func = find_symbol_by_offset(reloc->sym->sec,
+ reloc_addend(reloc));
- idx = (rel->offset - sym->offset) / sizeof(unsigned long);
+ idx = (reloc_offset(reloc) - sym->offset) / sizeof(unsigned long);
objtool_pv_add(file, idx, func);
- off = rel->offset + 1;
+ off = reloc_offset(reloc) + 1;
if (off > end)
break;
}
@@ -620,35 +581,40 @@ static struct instruction *find_last_insn(struct objtool_file *file,
*/
static int add_dead_ends(struct objtool_file *file)
{
- struct section *sec;
+ struct section *rsec;
struct reloc *reloc;
struct instruction *insn;
+ s64 addend;
/*
* Check for manually annotated dead ends.
*/
- sec = find_section_by_name(file->elf, ".rela.discard.unreachable");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.unreachable");
+ if (!rsec)
goto reachable;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
+
if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", sec->name);
+ WARN("unexpected relocation symbol type in %s", rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+
+ addend = reloc_addend(reloc);
+
+ insn = find_insn(file, reloc->sym->sec, addend);
if (insn)
insn = prev_insn_same_sec(file, insn);
- else if (reloc->addend == reloc->sym->sec->sh.sh_size) {
+ else if (addend == reloc->sym->sec->sh.sh_size) {
insn = find_last_insn(file, reloc->sym->sec);
if (!insn) {
WARN("can't find unreachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, reloc->addend);
+ reloc->sym->sec->name, addend);
return -1;
}
} else {
WARN("can't find unreachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, reloc->addend);
+ reloc->sym->sec->name, addend);
return -1;
}
@@ -662,28 +628,32 @@ reachable:
* GCC doesn't know the "ud2" is fatal, so it generates code as if it's
* not a dead end.
*/
- sec = find_section_by_name(file->elf, ".rela.discard.reachable");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.reachable");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
+
if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", sec->name);
+ WARN("unexpected relocation symbol type in %s", rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+
+ addend = reloc_addend(reloc);
+
+ insn = find_insn(file, reloc->sym->sec, addend);
if (insn)
insn = prev_insn_same_sec(file, insn);
- else if (reloc->addend == reloc->sym->sec->sh.sh_size) {
+ else if (addend == reloc->sym->sec->sh.sh_size) {
insn = find_last_insn(file, reloc->sym->sec);
if (!insn) {
WARN("can't find reachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, reloc->addend);
+ reloc->sym->sec->name, addend);
return -1;
}
} else {
WARN("can't find reachable insn at %s+0x%" PRIx64,
- reloc->sym->sec->name, reloc->addend);
+ reloc->sym->sec->name, addend);
return -1;
}
@@ -695,8 +665,8 @@ reachable:
static int create_static_call_sections(struct objtool_file *file)
{
- struct section *sec;
struct static_call_site *site;
+ struct section *sec;
struct instruction *insn;
struct symbol *key_sym;
char *key_name, *tmp;
@@ -716,22 +686,21 @@ static int create_static_call_sections(struct objtool_file *file)
list_for_each_entry(insn, &file->static_call_list, call_node)
idx++;
- sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE,
- sizeof(struct static_call_site), idx);
+ sec = elf_create_section_pair(file->elf, ".static_call_sites",
+ sizeof(*site), idx, idx * 2);
if (!sec)
return -1;
+ /* Allow modules to modify the low bits of static_call_site::key */
+ sec->sh.sh_flags |= SHF_WRITE;
+
idx = 0;
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' */
- if (elf_add_reloc_to_insn(file->elf, sec,
- idx * sizeof(struct static_call_site),
- R_X86_64_PC32,
- insn->sec, insn->offset))
+ if (!elf_init_reloc_text_sym(file->elf, sec,
+ idx * sizeof(*site), idx * 2,
+ insn->sec, insn->offset))
return -1;
/* find key symbol */
@@ -771,10 +740,10 @@ static int create_static_call_sections(struct objtool_file *file)
free(key_name);
/* populate reloc for 'key' */
- 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))
+ if (!elf_init_reloc_data_sym(file->elf, sec,
+ idx * sizeof(*site) + 4,
+ (idx * 2) + 1, key_sym,
+ is_sibling_call(insn) * STATIC_CALL_SITE_TAIL))
return -1;
idx++;
@@ -802,26 +771,18 @@ static int create_retpoline_sites_sections(struct objtool_file *file)
if (!idx)
return 0;
- sec = elf_create_section(file->elf, ".retpoline_sites", 0,
- sizeof(int), idx);
- if (!sec) {
- WARN("elf_create_section: .retpoline_sites");
+ sec = elf_create_section_pair(file->elf, ".retpoline_sites",
+ sizeof(int), idx, idx);
+ if (!sec)
return -1;
- }
idx = 0;
list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
- int *site = (int *)sec->data->d_buf + idx;
- *site = 0;
-
- if (elf_add_reloc_to_insn(file->elf, sec,
- idx * sizeof(int),
- R_X86_64_PC32,
- insn->sec, insn->offset)) {
- WARN("elf_add_reloc_to_insn: .retpoline_sites");
+ if (!elf_init_reloc_text_sym(file->elf, sec,
+ idx * sizeof(int), idx,
+ insn->sec, insn->offset))
return -1;
- }
idx++;
}
@@ -848,26 +809,18 @@ static int create_return_sites_sections(struct objtool_file *file)
if (!idx)
return 0;
- sec = elf_create_section(file->elf, ".return_sites", 0,
- sizeof(int), idx);
- if (!sec) {
- WARN("elf_create_section: .return_sites");
+ sec = elf_create_section_pair(file->elf, ".return_sites",
+ sizeof(int), idx, idx);
+ if (!sec)
return -1;
- }
idx = 0;
list_for_each_entry(insn, &file->return_thunk_list, call_node) {
- int *site = (int *)sec->data->d_buf + idx;
- *site = 0;
-
- if (elf_add_reloc_to_insn(file->elf, sec,
- idx * sizeof(int),
- R_X86_64_PC32,
- insn->sec, insn->offset)) {
- WARN("elf_add_reloc_to_insn: .return_sites");
+ if (!elf_init_reloc_text_sym(file->elf, sec,
+ idx * sizeof(int), idx,
+ insn->sec, insn->offset))
return -1;
- }
idx++;
}
@@ -900,12 +853,10 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file)
if (!idx)
return 0;
- sec = elf_create_section(file->elf, ".ibt_endbr_seal", 0,
- sizeof(int), idx);
- if (!sec) {
- WARN("elf_create_section: .ibt_endbr_seal");
+ sec = elf_create_section_pair(file->elf, ".ibt_endbr_seal",
+ sizeof(int), idx, idx);
+ if (!sec)
return -1;
- }
idx = 0;
list_for_each_entry(insn, &file->endbr_list, call_node) {
@@ -920,13 +871,10 @@ static int create_ibt_endbr_seal_sections(struct objtool_file *file)
!strcmp(sym->name, "cleanup_module")))
WARN("%s(): not an indirect call target", sym->name);
- if (elf_add_reloc_to_insn(file->elf, sec,
- idx * sizeof(int),
- R_X86_64_PC32,
- insn->sec, insn->offset)) {
- WARN("elf_add_reloc_to_insn: .ibt_endbr_seal");
+ if (!elf_init_reloc_text_sym(file->elf, sec,
+ idx * sizeof(int), idx,
+ insn->sec, insn->offset))
return -1;
- }
idx++;
}
@@ -938,7 +886,6 @@ static int create_cfi_sections(struct objtool_file *file)
{
struct section *sec;
struct symbol *sym;
- unsigned int *loc;
int idx;
sec = find_section_by_name(file->elf, ".cfi_sites");
@@ -959,7 +906,8 @@ static int create_cfi_sections(struct objtool_file *file)
idx++;
}
- sec = elf_create_section(file->elf, ".cfi_sites", 0, sizeof(unsigned int), idx);
+ sec = elf_create_section_pair(file->elf, ".cfi_sites",
+ sizeof(unsigned int), idx, idx);
if (!sec)
return -1;
@@ -971,13 +919,9 @@ static int create_cfi_sections(struct objtool_file *file)
if (strncmp(sym->name, "__cfi_", 6))
continue;
- 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,
- sym->sec, sym->offset))
+ if (!elf_init_reloc_text_sym(file->elf, sec,
+ idx * sizeof(unsigned int), idx,
+ sym->sec, sym->offset))
return -1;
idx++;
@@ -988,7 +932,7 @@ static int create_cfi_sections(struct objtool_file *file)
static int create_mcount_loc_sections(struct objtool_file *file)
{
- int addrsize = elf_class_addrsize(file->elf);
+ size_t addr_size = elf_addr_size(file->elf);
struct instruction *insn;
struct section *sec;
int idx;
@@ -1007,25 +951,26 @@ static int create_mcount_loc_sections(struct objtool_file *file)
list_for_each_entry(insn, &file->mcount_loc_list, call_node)
idx++;
- sec = elf_create_section(file->elf, "__mcount_loc", 0, addrsize, idx);
+ sec = elf_create_section_pair(file->elf, "__mcount_loc", addr_size,
+ idx, idx);
if (!sec)
return -1;
- sec->sh.sh_addralign = addrsize;
+ sec->sh.sh_addralign = addr_size;
idx = 0;
list_for_each_entry(insn, &file->mcount_loc_list, call_node) {
- void *loc;
- loc = sec->data->d_buf + idx;
- memset(loc, 0, addrsize);
+ struct reloc *reloc;
- if (elf_add_reloc_to_insn(file->elf, sec, idx,
- addrsize == sizeof(u64) ? R_ABS64 : R_ABS32,
- insn->sec, insn->offset))
+ reloc = elf_init_reloc_text_sym(file->elf, sec, idx * addr_size, idx,
+ insn->sec, insn->offset);
+ if (!reloc)
return -1;
- idx += addrsize;
+ set_reloc_type(file->elf, reloc, addr_size == 8 ? R_ABS64 : R_ABS32);
+
+ idx++;
}
return 0;
@@ -1035,7 +980,6 @@ 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");
@@ -1052,20 +996,17 @@ static int create_direct_call_sections(struct objtool_file *file)
list_for_each_entry(insn, &file->call_list, call_node)
idx++;
- sec = elf_create_section(file->elf, ".call_sites", 0, sizeof(unsigned int), idx);
+ sec = elf_create_section_pair(file->elf, ".call_sites",
+ sizeof(unsigned int), idx, 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))
+ if (!elf_init_reloc_text_sym(file->elf, sec,
+ idx * sizeof(unsigned int), idx,
+ insn->sec, insn->offset))
return -1;
idx++;
@@ -1080,28 +1021,29 @@ static int create_direct_call_sections(struct objtool_file *file)
static void add_ignores(struct objtool_file *file)
{
struct instruction *insn;
- struct section *sec;
+ struct section *rsec;
struct symbol *func;
struct reloc *reloc;
- sec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard");
+ if (!rsec)
return;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
switch (reloc->sym->type) {
case STT_FUNC:
func = reloc->sym;
break;
case STT_SECTION:
- func = find_func_by_offset(reloc->sym->sec, reloc->addend);
+ func = find_func_by_offset(reloc->sym->sec, reloc_addend(reloc));
if (!func)
continue;
break;
default:
- WARN("unexpected relocation symbol type in %s: %d", sec->name, reloc->sym->type);
+ WARN("unexpected relocation symbol type in %s: %d",
+ rsec->name, reloc->sym->type);
continue;
}
@@ -1320,21 +1262,21 @@ static void add_uaccess_safe(struct objtool_file *file)
*/
static int add_ignore_alternatives(struct objtool_file *file)
{
- struct section *sec;
+ struct section *rsec;
struct reloc *reloc;
struct instruction *insn;
- sec = find_section_by_name(file->elf, ".rela.discard.ignore_alts");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.ignore_alts");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", sec->name);
+ WARN("unexpected relocation symbol type in %s", rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
WARN("bad .discard.ignore_alts entry");
return -1;
@@ -1421,10 +1363,8 @@ static void annotate_call_site(struct objtool_file *file,
* noinstr text.
*/
if (opts.hack_noinstr && insn->sec->noinstr && sym->profiling_func) {
- if (reloc) {
- reloc->type = R_NONE;
- elf_write_reloc(file->elf, reloc);
- }
+ if (reloc)
+ set_reloc_type(file->elf, reloc, R_NONE);
elf_write_insn(file->elf, insn->sec,
insn->offset, insn->len,
@@ -1450,10 +1390,8 @@ static void annotate_call_site(struct objtool_file *file,
if (sibling)
WARN_INSN(insn, "tail call to __fentry__ !?!?");
if (opts.mnop) {
- if (reloc) {
- reloc->type = R_NONE;
- elf_write_reloc(file->elf, reloc);
- }
+ if (reloc)
+ set_reloc_type(file->elf, reloc, R_NONE);
elf_write_insn(file->elf, insn->sec,
insn->offset, insn->len,
@@ -1610,7 +1548,7 @@ static int add_jump_destinations(struct objtool_file *file)
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);
+ dest_off = arch_dest_reloc_offset(reloc_addend(reloc));
} else if (reloc->sym->retpoline_thunk) {
add_retpoline_call(file, insn);
continue;
@@ -1627,7 +1565,7 @@ static int add_jump_destinations(struct objtool_file *file)
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
dest_off = reloc->sym->sym.st_value +
- arch_dest_reloc_offset(reloc->addend);
+ arch_dest_reloc_offset(reloc_addend(reloc));
} else {
/* non-func asm code jumping to another file */
continue;
@@ -1744,7 +1682,7 @@ static int add_call_destinations(struct objtool_file *file)
}
} else if (reloc->sym->type == STT_SECTION) {
- dest_off = arch_dest_reloc_offset(reloc->addend);
+ dest_off = arch_dest_reloc_offset(reloc_addend(reloc));
dest = find_call_destination(reloc->sym->sec, dest_off);
if (!dest) {
WARN_INSN(insn, "can't find call dest symbol at %s+0x%lx",
@@ -1932,10 +1870,8 @@ static int handle_jump_alt(struct objtool_file *file,
if (opts.hack_jump_label && special_alt->key_addend & 2) {
struct reloc *reloc = insn_reloc(file, orig_insn);
- if (reloc) {
- reloc->type = R_NONE;
- elf_write_reloc(file->elf, reloc);
- }
+ if (reloc)
+ set_reloc_type(file->elf, reloc, R_NONE);
elf_write_insn(file->elf, orig_insn->sec,
orig_insn->offset, orig_insn->len,
arch_nop_insn(orig_insn->len));
@@ -2047,34 +1983,35 @@ out:
}
static int add_jump_table(struct objtool_file *file, struct instruction *insn,
- struct reloc *table)
+ struct reloc *next_table)
{
- struct reloc *reloc = table;
- struct instruction *dest_insn;
- struct alternative *alt;
struct symbol *pfunc = insn_func(insn)->pfunc;
+ struct reloc *table = insn_jump_table(insn);
+ struct instruction *dest_insn;
unsigned int prev_offset = 0;
+ struct reloc *reloc = table;
+ struct alternative *alt;
/*
* Each @reloc is a switch table relocation which points to the target
* instruction.
*/
- list_for_each_entry_from(reloc, &table->sec->reloc_list, list) {
+ for_each_reloc_from(table->sec, reloc) {
/* Check for the end of the table: */
- if (reloc != table && reloc->jump_table_start)
+ if (reloc != table && reloc == next_table)
break;
/* Make sure the table entries are consecutive: */
- if (prev_offset && reloc->offset != prev_offset + 8)
+ if (prev_offset && reloc_offset(reloc) != prev_offset + 8)
break;
/* Detect function pointers from contiguous objects: */
if (reloc->sym->sec == pfunc->sec &&
- reloc->addend == pfunc->offset)
+ reloc_addend(reloc) == pfunc->offset)
break;
- dest_insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ dest_insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!dest_insn)
break;
@@ -2091,7 +2028,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
alt->insn = dest_insn;
alt->next = insn->alts;
insn->alts = alt;
- prev_offset = reloc->offset;
+ prev_offset = reloc_offset(reloc);
}
if (!prev_offset) {
@@ -2135,7 +2072,7 @@ static struct reloc *find_jump_table(struct objtool_file *file,
table_reloc = arch_find_switch_table(file, insn);
if (!table_reloc)
continue;
- dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend);
+ dest_insn = find_insn(file, table_reloc->sym->sec, reloc_addend(table_reloc));
if (!dest_insn || !insn_func(dest_insn) || insn_func(dest_insn)->pfunc != func)
continue;
@@ -2177,29 +2114,39 @@ static void mark_func_jump_tables(struct objtool_file *file,
continue;
reloc = find_jump_table(file, func, insn);
- if (reloc) {
- reloc->jump_table_start = true;
+ if (reloc)
insn->_jump_table = reloc;
- }
}
}
static int add_func_jump_tables(struct objtool_file *file,
struct symbol *func)
{
- struct instruction *insn;
- int ret;
+ struct instruction *insn, *insn_t1 = NULL, *insn_t2;
+ int ret = 0;
func_for_each_insn(file, func, insn) {
if (!insn_jump_table(insn))
continue;
- ret = add_jump_table(file, insn, insn_jump_table(insn));
+ if (!insn_t1) {
+ insn_t1 = insn;
+ continue;
+ }
+
+ insn_t2 = insn;
+
+ ret = add_jump_table(file, insn_t1, insn_jump_table(insn_t2));
if (ret)
return ret;
+
+ insn_t1 = insn_t2;
}
- return 0;
+ if (insn_t1)
+ ret = add_jump_table(file, insn_t1, NULL);
+
+ return ret;
}
/*
@@ -2240,7 +2187,7 @@ static void set_func_state(struct cfi_state *state)
static int read_unwind_hints(struct objtool_file *file)
{
struct cfi_state cfi = init_cfi;
- struct section *sec, *relocsec;
+ struct section *sec;
struct unwind_hint *hint;
struct instruction *insn;
struct reloc *reloc;
@@ -2250,8 +2197,7 @@ static int read_unwind_hints(struct objtool_file *file)
if (!sec)
return 0;
- relocsec = sec->reloc;
- if (!relocsec) {
+ if (!sec->rsec) {
WARN("missing .rela.discard.unwind_hints section");
return -1;
}
@@ -2272,7 +2218,7 @@ static int read_unwind_hints(struct objtool_file *file)
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
WARN("can't find insn for unwind_hints[%d]", i);
return -1;
@@ -2280,6 +2226,11 @@ static int read_unwind_hints(struct objtool_file *file)
insn->hint = true;
+ if (hint->type == UNWIND_HINT_TYPE_UNDEFINED) {
+ insn->cfi = &force_undefined_cfi;
+ continue;
+ }
+
if (hint->type == UNWIND_HINT_TYPE_SAVE) {
insn->hint = false;
insn->save = true;
@@ -2326,16 +2277,17 @@ static int read_unwind_hints(struct objtool_file *file)
static int read_noendbr_hints(struct objtool_file *file)
{
- struct section *sec;
struct instruction *insn;
+ struct section *rsec;
struct reloc *reloc;
- sec = find_section_by_name(file->elf, ".rela.discard.noendbr");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.noendbr");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
- insn = find_insn(file, reloc->sym->sec, reloc->sym->offset + reloc->addend);
+ for_each_reloc(rsec, reloc) {
+ insn = find_insn(file, reloc->sym->sec,
+ reloc->sym->offset + reloc_addend(reloc));
if (!insn) {
WARN("bad .discard.noendbr entry");
return -1;
@@ -2349,21 +2301,21 @@ static int read_noendbr_hints(struct objtool_file *file)
static int read_retpoline_hints(struct objtool_file *file)
{
- struct section *sec;
+ struct section *rsec;
struct instruction *insn;
struct reloc *reloc;
- sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", sec->name);
+ WARN("unexpected relocation symbol type in %s", rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
WARN("bad .discard.retpoline_safe entry");
return -1;
@@ -2385,21 +2337,21 @@ static int read_retpoline_hints(struct objtool_file *file)
static int read_instr_hints(struct objtool_file *file)
{
- struct section *sec;
+ struct section *rsec;
struct instruction *insn;
struct reloc *reloc;
- sec = find_section_by_name(file->elf, ".rela.discard.instr_end");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.instr_end");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", sec->name);
+ WARN("unexpected relocation symbol type in %s", rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
WARN("bad .discard.instr_end entry");
return -1;
@@ -2408,17 +2360,17 @@ static int read_instr_hints(struct objtool_file *file)
insn->instr--;
}
- sec = find_section_by_name(file->elf, ".rela.discard.instr_begin");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.instr_begin");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", sec->name);
+ WARN("unexpected relocation symbol type in %s", rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
WARN("bad .discard.instr_begin entry");
return -1;
@@ -2432,21 +2384,21 @@ static int read_instr_hints(struct objtool_file *file)
static int read_validate_unret_hints(struct objtool_file *file)
{
- struct section *sec;
+ struct section *rsec;
struct instruction *insn;
struct reloc *reloc;
- sec = find_section_by_name(file->elf, ".rela.discard.validate_unret");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.validate_unret");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
if (reloc->sym->type != STT_SECTION) {
- WARN("unexpected relocation symbol type in %s", sec->name);
+ WARN("unexpected relocation symbol type in %s", rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
WARN("bad .discard.instr_end entry");
return -1;
@@ -2461,23 +2413,23 @@ static int read_validate_unret_hints(struct objtool_file *file)
static int read_intra_function_calls(struct objtool_file *file)
{
struct instruction *insn;
- struct section *sec;
+ struct section *rsec;
struct reloc *reloc;
- sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
- if (!sec)
+ rsec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls");
+ if (!rsec)
return 0;
- list_for_each_entry(reloc, &sec->reloc_list, list) {
+ for_each_reloc(rsec, reloc) {
unsigned long dest_off;
if (reloc->sym->type != STT_SECTION) {
WARN("unexpected relocation symbol type in %s",
- sec->name);
+ rsec->name);
return -1;
}
- insn = find_insn(file, reloc->sym->sec, reloc->addend);
+ insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));
if (!insn) {
WARN("bad .discard.intra_function_call entry");
return -1;
@@ -2833,6 +2785,10 @@ static int update_cfi_state(struct instruction *insn,
struct cfi_reg *cfa = &cfi->cfa;
struct cfi_reg *regs = cfi->regs;
+ /* ignore UNWIND_HINT_UNDEFINED regions */
+ if (cfi->force_undefined)
+ return 0;
+
/* stack operations don't make sense with an undefined CFA */
if (cfa->base == CFI_UNDEFINED) {
if (insn_func(insn)) {
@@ -3369,15 +3325,15 @@ static inline bool func_uaccess_safe(struct symbol *func)
static inline const char *call_dest_name(struct instruction *insn)
{
static char pvname[19];
- struct reloc *rel;
+ struct reloc *reloc;
int idx;
if (insn_call_dest(insn))
return insn_call_dest(insn)->name;
- rel = insn_reloc(NULL, insn);
- if (rel && !strcmp(rel->sym->name, "pv_ops")) {
- idx = (rel->addend / sizeof(void *));
+ reloc = insn_reloc(NULL, insn);
+ if (reloc && !strcmp(reloc->sym->name, "pv_ops")) {
+ idx = (reloc_addend(reloc) / sizeof(void *));
snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx);
return pvname;
}
@@ -3388,14 +3344,14 @@ static inline const char *call_dest_name(struct instruction *insn)
static bool pv_call_dest(struct objtool_file *file, struct instruction *insn)
{
struct symbol *target;
- struct reloc *rel;
+ struct reloc *reloc;
int idx;
- rel = insn_reloc(file, insn);
- if (!rel || strcmp(rel->sym->name, "pv_ops"))
+ reloc = insn_reloc(file, insn);
+ if (!reloc || strcmp(reloc->sym->name, "pv_ops"))
return false;
- idx = (arch_dest_reloc_offset(rel->addend) / sizeof(void *));
+ idx = (arch_dest_reloc_offset(reloc_addend(reloc)) / sizeof(void *));
if (file->pv_ops[idx].clean)
return true;
@@ -3657,8 +3613,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
ret = validate_branch(file, func, alt->insn, state);
if (ret) {
- if (opts.backtrace)
- BT_FUNC("(alt)", insn);
+ BT_INSN(insn, "(alt)");
return ret;
}
}
@@ -3703,8 +3658,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
ret = validate_branch(file, func,
insn->jump_dest, state);
if (ret) {
- if (opts.backtrace)
- BT_FUNC("(branch)", insn);
+ BT_INSN(insn, "(branch)");
return ret;
}
}
@@ -3802,8 +3756,8 @@ static int validate_unwind_hint(struct objtool_file *file,
{
if (insn->hint && !insn->visited && !insn->ignore) {
int ret = validate_branch(file, insn_func(insn), insn, *state);
- if (ret && opts.backtrace)
- BT_FUNC("<=== (hint)", insn);
+ if (ret)
+ BT_INSN(insn, "<=== (hint)");
return ret;
}
@@ -3841,7 +3795,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec)
static int validate_unret(struct objtool_file *file, struct instruction *insn)
{
struct instruction *next, *dest;
- int ret, warnings = 0;
+ int ret;
for (;;) {
next = next_insn_to_validate(file, insn);
@@ -3861,8 +3815,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
ret = validate_unret(file, alt->insn);
if (ret) {
- if (opts.backtrace)
- BT_FUNC("(alt)", insn);
+ BT_INSN(insn, "(alt)");
return ret;
}
}
@@ -3888,10 +3841,8 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
}
ret = validate_unret(file, insn->jump_dest);
if (ret) {
- if (opts.backtrace) {
- BT_FUNC("(branch%s)", insn,
- insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : "");
- }
+ BT_INSN(insn, "(branch%s)",
+ insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : "");
return ret;
}
@@ -3913,8 +3864,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
ret = validate_unret(file, dest);
if (ret) {
- if (opts.backtrace)
- BT_FUNC("(call)", insn);
+ BT_INSN(insn, "(call)");
return ret;
}
/*
@@ -3943,7 +3893,7 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
insn = next;
}
- return warnings;
+ return 0;
}
/*
@@ -4178,7 +4128,6 @@ static int add_prefix_symbols(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;
- int warnings = 0;
for_each_sec(file, sec) {
if (!(sec->sh.sh_flags & SHF_EXECINSTR))
@@ -4192,7 +4141,7 @@ static int add_prefix_symbols(struct objtool_file *file)
}
}
- return warnings;
+ return 0;
}
static int validate_symbol(struct objtool_file *file, struct section *sec,
@@ -4216,8 +4165,8 @@ static int validate_symbol(struct objtool_file *file, struct section *sec,
state->uaccess = sym->uaccess_safe;
ret = validate_branch(file, insn_func(insn), insn, *state);
- if (ret && opts.backtrace)
- BT_FUNC("<=== (sym)", insn);
+ if (ret)
+ BT_INSN(insn, "<=== (sym)");
return ret;
}
@@ -4333,8 +4282,8 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
for (reloc = insn_reloc(file, insn);
reloc;
reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- reloc->offset + 1,
- (insn->offset + insn->len) - (reloc->offset + 1))) {
+ reloc_offset(reloc) + 1,
+ (insn->offset + insn->len) - (reloc_offset(reloc) + 1))) {
/*
* static_call_update() references the trampoline, which
@@ -4344,10 +4293,11 @@ static int validate_ibt_insn(struct objtool_file *file, struct instruction *insn
continue;
off = reloc->sym->offset;
- if (reloc->type == R_X86_64_PC32 || reloc->type == R_X86_64_PLT32)
- off += arch_dest_reloc_offset(reloc->addend);
+ if (reloc_type(reloc) == R_X86_64_PC32 ||
+ reloc_type(reloc) == R_X86_64_PLT32)
+ off += arch_dest_reloc_offset(reloc_addend(reloc));
else
- off += reloc->addend;
+ off += reloc_addend(reloc);
dest = find_insn(file, reloc->sym->sec, off);
if (!dest)
@@ -4404,7 +4354,7 @@ static int validate_ibt_data_reloc(struct objtool_file *file,
struct instruction *dest;
dest = find_insn(file, reloc->sym->sec,
- reloc->sym->offset + reloc->addend);
+ reloc->sym->offset + reloc_addend(reloc));
if (!dest)
return 0;
@@ -4417,7 +4367,7 @@ static int validate_ibt_data_reloc(struct objtool_file *file,
return 0;
WARN_FUNC("data relocation to !ENDBR: %s",
- reloc->sec->base, reloc->offset,
+ reloc->sec->base, reloc_offset(reloc),
offstr(dest->sec, dest->offset));
return 1;
@@ -4444,7 +4394,7 @@ static int validate_ibt(struct objtool_file *file)
if (sec->sh.sh_flags & SHF_EXECINSTR)
continue;
- if (!sec->reloc)
+ if (!sec->rsec)
continue;
/*
@@ -4471,7 +4421,7 @@ static int validate_ibt(struct objtool_file *file)
strstr(sec->name, "__patchable_function_entries"))
continue;
- list_for_each_entry(reloc, &sec->reloc->reloc_list, list)
+ for_each_reloc(sec->rsec, reloc)
warnings += validate_ibt_data_reloc(file, reloc);
}
@@ -4511,9 +4461,40 @@ static int validate_sls(struct objtool_file *file)
return warnings;
}
+static bool ignore_noreturn_call(struct instruction *insn)
+{
+ struct symbol *call_dest = insn_call_dest(insn);
+
+ /*
+ * FIXME: hack, we need a real noreturn solution
+ *
+ * Problem is, exc_double_fault() may or may not return, depending on
+ * whether CONFIG_X86_ESPFIX64 is set. But objtool has no visibility
+ * to the kernel config.
+ *
+ * Other potential ways to fix it:
+ *
+ * - have compiler communicate __noreturn functions somehow
+ * - remove CONFIG_X86_ESPFIX64
+ * - read the .config file
+ * - add a cmdline option
+ * - create a generic objtool annotation format (vs a bunch of custom
+ * formats) and annotate it
+ */
+ if (!strcmp(call_dest->name, "exc_double_fault")) {
+ /* prevent further unreachable warnings for the caller */
+ insn->sym->warned = 1;
+ return true;
+ }
+
+ return false;
+}
+
static int validate_reachable_instructions(struct objtool_file *file)
{
- struct instruction *insn;
+ struct instruction *insn, *prev_insn;
+ struct symbol *call_dest;
+ int warnings = 0;
if (file->ignore_unreachables)
return 0;
@@ -4522,13 +4503,127 @@ static int validate_reachable_instructions(struct objtool_file *file)
if (insn->visited || ignore_unreachable_insn(file, insn))
continue;
+ prev_insn = prev_insn_same_sec(file, insn);
+ if (prev_insn && prev_insn->dead_end) {
+ call_dest = insn_call_dest(prev_insn);
+ if (call_dest && !ignore_noreturn_call(prev_insn)) {
+ WARN_INSN(insn, "%s() is missing a __noreturn annotation",
+ call_dest->name);
+ warnings++;
+ continue;
+ }
+ }
+
WARN_INSN(insn, "unreachable instruction");
- return 1;
+ warnings++;
+ }
+
+ return warnings;
+}
+
+/* 'funcs' is a space-separated list of function names */
+static int disas_funcs(const char *funcs)
+{
+ const char *objdump_str, *cross_compile;
+ int size, ret;
+ char *cmd;
+
+ cross_compile = getenv("CROSS_COMPILE");
+
+ objdump_str = "%sobjdump -wdr %s | gawk -M -v _funcs='%s' '"
+ "BEGIN { split(_funcs, funcs); }"
+ "/^$/ { func_match = 0; }"
+ "/<.*>:/ { "
+ "f = gensub(/.*<(.*)>:/, \"\\\\1\", 1);"
+ "for (i in funcs) {"
+ "if (funcs[i] == f) {"
+ "func_match = 1;"
+ "base = strtonum(\"0x\" $1);"
+ "break;"
+ "}"
+ "}"
+ "}"
+ "{"
+ "if (func_match) {"
+ "addr = strtonum(\"0x\" $1);"
+ "printf(\"%%04x \", addr - base);"
+ "print;"
+ "}"
+ "}' 1>&2";
+
+ /* fake snprintf() to calculate the size */
+ size = snprintf(NULL, 0, objdump_str, cross_compile, objname, funcs) + 1;
+ if (size <= 0) {
+ WARN("objdump string size calculation failed");
+ return -1;
+ }
+
+ cmd = malloc(size);
+
+ /* real snprintf() */
+ snprintf(cmd, size, objdump_str, cross_compile, objname, funcs);
+ ret = system(cmd);
+ if (ret) {
+ WARN("disassembly failed: %d", ret);
+ return -1;
}
return 0;
}
+static int disas_warned_funcs(struct objtool_file *file)
+{
+ struct symbol *sym;
+ char *funcs = NULL, *tmp;
+
+ for_each_sym(file, sym) {
+ if (sym->warned) {
+ if (!funcs) {
+ funcs = malloc(strlen(sym->name) + 1);
+ strcpy(funcs, sym->name);
+ } else {
+ tmp = malloc(strlen(funcs) + strlen(sym->name) + 2);
+ sprintf(tmp, "%s %s", funcs, sym->name);
+ free(funcs);
+ funcs = tmp;
+ }
+ }
+ }
+
+ if (funcs)
+ disas_funcs(funcs);
+
+ return 0;
+}
+
+struct insn_chunk {
+ void *addr;
+ struct insn_chunk *next;
+};
+
+/*
+ * Reduce peak RSS usage by freeing insns memory before writing the ELF file,
+ * which can trigger more allocations for .debug_* sections whose data hasn't
+ * been read yet.
+ */
+static void free_insns(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct insn_chunk *chunks = NULL, *chunk;
+
+ for_each_insn(file, insn) {
+ if (!insn->idx) {
+ chunk = malloc(sizeof(*chunk));
+ chunk->addr = insn;
+ chunk->next = chunks;
+ chunks = chunk;
+ }
+ }
+
+ for (chunk = chunks; chunk; chunk = chunk->next)
+ free(chunk->addr);
+}
+
int check(struct objtool_file *file)
{
int ret, warnings = 0;
@@ -4537,6 +4632,8 @@ int check(struct objtool_file *file)
init_cfi_state(&init_cfi);
init_cfi_state(&func_cfi);
set_func_state(&func_cfi);
+ init_cfi_state(&force_undefined_cfi);
+ force_undefined_cfi.force_undefined = true;
if (!cfi_hash_alloc(1UL << (file->elf->symbol_bits - 3)))
goto out;
@@ -4673,6 +4770,10 @@ int check(struct objtool_file *file)
warnings += ret;
}
+ free_insns(file);
+
+ if (opts.verbose)
+ disas_warned_funcs(file);
if (opts.stats) {
printf("nr_insns_visited: %ld\n", nr_insns_visited);
generated by cgit v1.2.3 (git 2.39.0) at 2025-01-19 05:07:34 +0300