@@ -529,6 +529,11 @@ int arch_decode_instruction(const struct
}
break;
+ case 0xcc:
+ /* int3 */
+ *type = INSN_TRAP;
+ break;
+
case 0xe3:
/* jecxz/jrcxz */
*type = INSN_JUMP_CONDITIONAL;
@@ -665,10 +670,10 @@ const char *arch_ret_insn(int len)
{
static const char ret[5][5] = {
{ BYTE_RET },
- { BYTE_RET, BYTES_NOP1 },
- { BYTE_RET, BYTES_NOP2 },
- { BYTE_RET, BYTES_NOP3 },
- { BYTE_RET, BYTES_NOP4 },
+ { BYTE_RET, 0xcc },
+ { BYTE_RET, 0xcc, BYTES_NOP1 },
+ { BYTE_RET, 0xcc, BYTES_NOP2 },
+ { BYTE_RET, 0xcc, BYTES_NOP3 },
};
if (len < 1 || len > 5) {
@@ -20,7 +20,7 @@
#include <objtool/objtool.h>
bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
- validate_dup, vmlinux, mcount, noinstr, backup;
+ validate_dup, vmlinux, mcount, noinstr, backup, sls;
static const char * const check_usage[] = {
"objtool check [<options>] file.o",
@@ -45,6 +45,7 @@ const struct option check_options[] = {
OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
OPT_BOOLEAN('M', "mcount", &mcount, "generate __mcount_loc"),
OPT_BOOLEAN('B', "backup", &backup, "create .orig files before modification"),
+ OPT_BOOLEAN('S', "sls", &sls, "validate straight-line-speculation"),
OPT_END(),
};
@@ -2776,6 +2776,12 @@ static int validate_branch(struct objtoo
switch (insn->type) {
case INSN_RETURN:
+ if (next_insn && next_insn->type == INSN_TRAP) {
+ next_insn->ignore = true;
+ } else if (sls && !insn->retpoline_safe) {
+ WARN_FUNC("missing int3 after ret",
+ insn->sec, insn->offset);
+ }
return validate_return(func, insn, &state);
case INSN_CALL:
@@ -2819,6 +2825,14 @@ static int validate_branch(struct objtoo
break;
case INSN_JUMP_DYNAMIC:
+ if (next_insn && next_insn->type == INSN_TRAP) {
+ next_insn->ignore = true;
+ } else if (sls && !insn->retpoline_safe) {
+ WARN_FUNC("missing int3 after indirect jump",
+ insn->sec, insn->offset);
+ }
+
+ /* fallthrough */
case INSN_JUMP_DYNAMIC_CONDITIONAL:
if (is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
@@ -26,6 +26,7 @@ enum insn_type {
INSN_CLAC,
INSN_STD,
INSN_CLD,
+ INSN_TRAP,
INSN_OTHER,
};
@@ -9,7 +9,7 @@
extern const struct option check_options[];
extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
- validate_dup, vmlinux, mcount, noinstr, backup;
+ validate_dup, vmlinux, mcount, noinstr, backup, sls;
extern int cmd_parse_options(int argc, const char **argv, const char * const usage[]);