Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
objtool: Allow stack operations in UNWIND_HINT_UNDEFINED regions
If the code specified UNWIND_HINT_UNDEFINED, skip the "undefined stack
state" warning due to a stack operation. Just ignore the stack op and
continue to propagate the undefined state.
Link: https://lore.kernel.org/r/820c5b433f17c84e8761fb7465a8d319d706b1cf.1685981486.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
+13
+12
tools/objtool/check.c
+12
tools/objtool/check.c
···
33
33
static struct cfi_init_state initial_func_cfi;
34
34
static struct cfi_state init_cfi;
35
35
static struct cfi_state func_cfi;
36
+
static struct cfi_state force_undefined_cfi;
36
37
37
38
struct instruction *find_insn(struct objtool_file *file,
38
39
struct section *sec, unsigned long offset)
···
2241
2240
2242
2241
insn->hint = true;
2243
2242
2243
+
if (hint->type == UNWIND_HINT_TYPE_UNDEFINED) {
2244
+
insn->cfi = &force_undefined_cfi;
2245
+
continue;
2246
+
}
2247
+
2244
2248
if (hint->type == UNWIND_HINT_TYPE_SAVE) {
2245
2249
insn->hint = false;
2246
2250
insn->save = true;
···
2798
2792
{
2799
2793
struct cfi_reg *cfa = &cfi->cfa;
2800
2794
struct cfi_reg *regs = cfi->regs;
2795
+
2796
+
/* ignore UNWIND_HINT_UNDEFINED regions */
2797
+
if (cfi->force_undefined)
2798
+
return 0;
2801
2799
2802
2800
/* stack operations don't make sense with an undefined CFA */
2803
2801
if (cfa->base == CFI_UNDEFINED) {
···
4617
4607
init_cfi_state(&init_cfi);
4618
4608
init_cfi_state(&func_cfi);
4619
4609
set_func_state(&func_cfi);
4610
+
init_cfi_state(&force_undefined_cfi);
4611
+
force_undefined_cfi.force_undefined = true;
4620
4612
4621
4613
if (!cfi_hash_alloc(1UL << (file->elf->symbol_bits - 3)))
4622
4614
goto out;