Commit 97450311 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'objtool-urgent-2026-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull objtool fixes from Ingo Molnar:

 - Fix cross-build bug by using HOSTCFLAGS for HAVE_XXHASH test

 - Fix klp bug by fixing detection of corrupt static branch/call entries

 - Handle unsupported pr_debug() usage more gracefully

 - Fix hypothetical klp bug by avoiding NULL pointer dereference when
   printing code symbol name

 - Fix data alignment bug in elf_add_data() causing mangled strings

 - Fix confusing ERROR_INSN() error message

 - Handle unexpected Clang RSP musical chairs causing false positive
   warnings

 - Fix another objtool stack overflow in validate_branch()

* tag 'objtool-urgent-2026-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix another stack overflow in validate_branch()
  objtool: Handle Clang RSP musical chairs
  objtool: Fix ERROR_INSN() error message
  objtool: Fix data alignment in elf_add_data()
  objtool: Use HOSTCFLAGS for HAVE_XXHASH test
  objtool/klp: Avoid NULL pointer dereference when printing code symbol name
  objtool/klp: Disable unsupported pr_debug() usage
  objtool/klp: Fix detection of corrupt static branch/call entries
parents be2e3750 9a73f085

tools/objtool/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ endif 


ifeq ($(ARCH_HAS_KLP),y)

	HAVE_XXHASH = $(shell printf "$(pound)include <xxhash.h>\nXXH3_state_t *state;int main() {}" | \

		      $(HOSTCC) -xc - -o /dev/null -lxxhash 2> /dev/null && echo y || echo n)

		      $(HOSTCC) $(HOSTCFLAGS) -xc - -o /dev/null -lxxhash 2> /dev/null && echo y || echo n)

	ifeq ($(HAVE_XXHASH),y)

		BUILD_KLP	 := y

		LIBXXHASH_CFLAGS := $(shell $(HOSTPKG_CONFIG) libxxhash --cflags 2>/dev/null) \

tools/objtool/arch/x86/decode.c

+23 −39
Original line number Diff line number Diff line
@@ -395,19 +395,17 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec 
		if (!rex_w)

			break;



		if (modrm_reg == CFI_SP) {



		if (mod_is_reg()) {

				/* mov %rsp, reg */

			/* mov reg, reg */

			ADD_OP(op) {

				op->src.type = OP_SRC_REG;

					op->src.reg = CFI_SP;

				op->src.reg = modrm_reg;

				op->dest.type = OP_DEST_REG;

				op->dest.reg = modrm_rm;

			}

			break;

		}



			} else {

		/* skip RIP relative displacement */

		if (is_RIP())

			break;
@@ -420,6 +418,7 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec 
		}



		/* mov %rsp, disp(%reg) */

		if (modrm_reg == CFI_SP) {

			ADD_OP(op) {

				op->src.type = OP_SRC_REG;

				op->src.reg = CFI_SP;
@@ -430,21 +429,6 @@ int arch_decode_instruction(struct objtool_file *file, const struct section *sec 
			break;

		}



			break;

		}



		if (rm_is_reg(CFI_SP)) {



			/* mov reg, %rsp */

			ADD_OP(op) {

				op->src.type = OP_SRC_REG;

				op->src.reg = modrm_reg;

				op->dest.type = OP_DEST_REG;

				op->dest.reg = CFI_SP;

			}

			break;

		}



		fallthrough;

	case 0x88:

		if (!rex_w)

tools/objtool/check.c

+19 −5
Original line number Diff line number Diff line
@@ -3000,6 +3000,20 @@ static int update_cfi_state(struct instruction *insn, 
				cfi->stack_size += 8;

			}



			else if (cfi->vals[op->src.reg].base == CFI_CFA) {

				/*

				 * Clang RSP musical chairs:

				 *

				 *   mov %rsp, %rdx [handled above]

				 *   ...

				 *   mov %rdx, %rbx [handled here]

				 *   ...

				 *   mov %rbx, %rsp [handled above]

				 */

				cfi->vals[op->dest.reg].base = CFI_CFA;

				cfi->vals[op->dest.reg].offset = cfi->vals[op->src.reg].offset;

			}





			break;
@@ -3734,7 +3748,7 @@ static void checksum_update_insn(struct objtool_file *file, struct symbol *func, 
static int validate_branch(struct objtool_file *file, struct symbol *func,

			   struct instruction *insn, struct insn_state state);

static int do_validate_branch(struct objtool_file *file, struct symbol *func,

			      struct instruction *insn, struct insn_state state);

			      struct instruction *insn, struct insn_state *state);



static int validate_insn(struct objtool_file *file, struct symbol *func,

			 struct instruction *insn, struct insn_state *statep,
@@ -3999,7 +4013,7 @@ static int validate_insn(struct objtool_file *file, struct symbol *func, 
 * tools/objtool/Documentation/objtool.txt.

 */

static int do_validate_branch(struct objtool_file *file, struct symbol *func,

			      struct instruction *insn, struct insn_state state)

			      struct instruction *insn, struct insn_state *state)

{

	struct instruction *next_insn, *prev_insn = NULL;

	bool dead_end;
@@ -4030,7 +4044,7 @@ static int do_validate_branch(struct objtool_file *file, struct symbol *func, 
			return 1;

		}



		ret = validate_insn(file, func, insn, &state, prev_insn, next_insn,

		ret = validate_insn(file, func, insn, state, prev_insn, next_insn,

				    &dead_end);



		if (!insn->trace) {
@@ -4041,7 +4055,7 @@ static int do_validate_branch(struct objtool_file *file, struct symbol *func, 
		}



		if (!dead_end && !next_insn) {

			if (state.cfi.cfa.base == CFI_UNDEFINED)

			if (state->cfi.cfa.base == CFI_UNDEFINED)

				return 0;

			if (file->ignore_unreachables)

				return 0;
@@ -4066,7 +4080,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, 
	int ret;



	trace_depth_inc();

	ret = do_validate_branch(file, func, insn, state);

	ret = do_validate_branch(file, func, insn, &state);

	trace_depth_dec();



	return ret;

tools/objtool/elf.c

+1 −1
Original line number Diff line number Diff line
@@ -1375,7 +1375,7 @@ void *elf_add_data(struct elf *elf, struct section *sec, const void *data, size_ 
		memcpy(sec->data->d_buf, data, size);



	sec->data->d_size = size;

	sec->data->d_align = 1;

	sec->data->d_align = sec->sh.sh_addralign;



	offset = ALIGN(sec->sh.sh_size, sec->sh.sh_addralign);

	sec->sh.sh_size = offset + size;

tools/objtool/include/objtool/warn.h

+1 −1
Original line number Diff line number Diff line
@@ -107,7 +107,7 @@ static inline char *offstr(struct section *sec, unsigned long offset) 
#define ERROR_ELF(format, ...) __WARN_ELF(ERROR_STR, format, ##__VA_ARGS__)

#define ERROR_GLIBC(format, ...) __WARN_GLIBC(ERROR_STR, format, ##__VA_ARGS__)

#define ERROR_FUNC(sec, offset, format, ...) __WARN_FUNC(ERROR_STR, sec, offset, format, ##__VA_ARGS__)

#define ERROR_INSN(insn, format, ...) WARN_FUNC(insn->sec, insn->offset, format, ##__VA_ARGS__)

#define ERROR_INSN(insn, format, ...) ERROR_FUNC(insn->sec, insn->offset, format, ##__VA_ARGS__)



extern bool debug;

extern int indent;