Merge tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar:

 - Mark arch_cpu_idle_dead() __noreturn, make all architectures &
   drivers that did this inconsistently follow this new, common
   convention, and fix all the fallout that objtool can now detect
   statically

 - Fix/improve the ORC unwinder becoming unreliable due to
   UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK
   and UNWIND_HINT_UNDEFINED to resolve it

 - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code

 - Generate ORC data for __pfx code

 - Add more __noreturn annotations to various kernel startup/shutdown
   and panic functions

 - Misc improvements & fixes

* tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  x86/hyperv: Mark hv_ghcb_terminate() as noreturn
  scsi: message: fusion: Mark mpt_halt_firmware() __noreturn
  x86/cpu: Mark {hlt,resume}_play_dead() __noreturn
  btrfs: Mark btrfs_assertfail() __noreturn
  objtool: Include weak functions in global_noreturns check
  cpu: Mark nmi_panic_self_stop() __noreturn
  cpu: Mark panic_smp_self_stop() __noreturn
  arm64/cpu: Mark cpu_park_loop() and friends __noreturn
  x86/head: Mark *_start_kernel() __noreturn
  init: Mark start_kernel() __noreturn
  init: Mark [arch_call_]rest_init() __noreturn
  objtool: Generate ORC data for __pfx code
  x86/linkage: Fix padding for typed functions
  objtool: Separate prefix code from stack validation code
  objtool: Remove superfluous dead_end_function() check
  objtool: Add symbol iteration helpers
  objtool: Add WARN_INSN()
  scripts/objdump-func: Support multiple functions
  context_tracking: Fix KCSAN noinstr violation
  objtool: Add stackleak instrumentation to uaccess safe list
  ...

2 files changed, 57 insertions, 200 deletions

diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h
deleted file mode 100644
index 9ac3df3fccf0..000000000000
--- a/tools/include/linux/objtool.h
+++ /dev/null
@@ -1,200 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_OBJTOOL_H
-#define _LINUX_OBJTOOL_H
-
-#ifndef __ASSEMBLY__
-
-#include <linux/types.h>
-
-/*
- * This struct is used by asm and inline asm code to manually annotate the
- * location of registers on the stack.
- */
-struct unwind_hint {
-	u32		ip;
-	s16		sp_offset;
-	u8		sp_reg;
-	u8		type;
-	u8		signal;
-	u8		end;
-};
-#endif
-
-/*
- * UNWIND_HINT_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP
- * (the caller's SP right before it made the call).  Used for all callable
- * functions, i.e. all C code and all callable asm functions.
- *
- * UNWIND_HINT_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset
- * points to a fully populated pt_regs from a syscall, interrupt, or exception.
- *
- * UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
- * sp_reg+sp_offset points to the iret return frame.
- *
- * UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
- * Useful for code which doesn't have an ELF function annotation.
- *
- * UNWIND_HINT_ENTRY: machine entry without stack, SYSCALL/SYSENTER etc.
- */
-#define UNWIND_HINT_TYPE_CALL		0
-#define UNWIND_HINT_TYPE_REGS		1
-#define UNWIND_HINT_TYPE_REGS_PARTIAL	2
-#define UNWIND_HINT_TYPE_FUNC		3
-#define UNWIND_HINT_TYPE_ENTRY		4
-#define UNWIND_HINT_TYPE_SAVE		5
-#define UNWIND_HINT_TYPE_RESTORE	6
-
-#ifdef CONFIG_OBJTOOL
-
-#include <asm/asm.h>
-
-#ifndef __ASSEMBLY__
-
-#define UNWIND_HINT(sp_reg, sp_offset, type, signal, end)	\
-	"987: \n\t"						\
-	".pushsection .discard.unwind_hints\n\t"		\
-	/* struct unwind_hint */				\
-	".long 987b - .\n\t"					\
-	".short " __stringify(sp_offset) "\n\t"			\
-	".byte " __stringify(sp_reg) "\n\t"			\
-	".byte " __stringify(type) "\n\t"			\
-	".byte " __stringify(signal) "\n\t"			\
-	".byte " __stringify(end) "\n\t"			\
-	".balign 4 \n\t"					\
-	".popsection\n\t"
-
-/*
- * This macro marks the given function's stack frame as "non-standard", which
- * tells objtool to ignore the function when doing stack metadata validation.
- * It should only be used in special cases where you're 100% sure it won't
- * affect the reliability of frame pointers and kernel stack traces.
- *
- * For more information, see tools/objtool/Documentation/objtool.txt.
- */
-#define STACK_FRAME_NON_STANDARD(func) \
-	static void __used __section(".discard.func_stack_frame_non_standard") \
-		*__func_stack_frame_non_standard_##func = func
-
-/*
- * STACK_FRAME_NON_STANDARD_FP() is a frame-pointer-specific function ignore
- * for the case where a function is intentionally missing frame pointer setup,
- * but otherwise needs objtool/ORC coverage when frame pointers are disabled.
- */
-#ifdef CONFIG_FRAME_POINTER
-#define STACK_FRAME_NON_STANDARD_FP(func) STACK_FRAME_NON_STANDARD(func)
-#else
-#define STACK_FRAME_NON_STANDARD_FP(func)
-#endif
-
-#define ANNOTATE_NOENDBR					\
-	"986: \n\t"						\
-	".pushsection .discard.noendbr\n\t"			\
-	_ASM_PTR " 986b\n\t"					\
-	".popsection\n\t"
-
-#define ASM_REACHABLE							\
-	"998:\n\t"							\
-	".pushsection .discard.reachable\n\t"				\
-	".long 998b - .\n\t"						\
-	".popsection\n\t"
-
-#else /* __ASSEMBLY__ */
-
-/*
- * This macro indicates that the following intra-function call is valid.
- * Any non-annotated intra-function call will cause objtool to issue a warning.
- */
-#define ANNOTATE_INTRA_FUNCTION_CALL				\
-	999:							\
-	.pushsection .discard.intra_function_calls;		\
-	.long 999b;						\
-	.popsection;
-
-/*
- * In asm, there are two kinds of code: normal C-type callable functions and
- * the rest.  The normal callable functions can be called by other code, and
- * don't do anything unusual with the stack.  Such normal callable functions
- * are annotated with the ENTRY/ENDPROC macros.  Most asm code falls in this
- * category.  In this case, no special debugging annotations are needed because
- * objtool can automatically generate the ORC data for the ORC unwinder to read
- * at runtime.
- *
- * Anything which doesn't fall into the above category, such as syscall and
- * interrupt handlers, tends to not be called directly by other functions, and
- * often does unusual non-C-function-type things with the stack pointer.  Such
- * code needs to be annotated such that objtool can understand it.  The
- * following CFI hint macros are for this type of code.
- *
- * These macros provide hints to objtool about the state of the stack at each
- * instruction.  Objtool starts from the hints and follows the code flow,
- * making automatic CFI adjustments when it sees pushes and pops, filling out
- * the debuginfo as necessary.  It will also warn if it sees any
- * inconsistencies.
- */
-.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0 end=0
-.Lunwind_hint_ip_\@:
-	.pushsection .discard.unwind_hints
-		/* struct unwind_hint */
-		.long .Lunwind_hint_ip_\@ - .
-		.short \sp_offset
-		.byte \sp_reg
-		.byte \type
-		.byte \signal
-		.byte \end
-		.balign 4
-	.popsection
-.endm
-
-.macro STACK_FRAME_NON_STANDARD func:req
-	.pushsection .discard.func_stack_frame_non_standard, "aw"
-	_ASM_PTR \func
-	.popsection
-.endm
-
-.macro STACK_FRAME_NON_STANDARD_FP func:req
-#ifdef CONFIG_FRAME_POINTER
-	STACK_FRAME_NON_STANDARD \func
-#endif
-.endm
-
-.macro ANNOTATE_NOENDBR
-.Lhere_\@:
-	.pushsection .discard.noendbr
-	.quad	.Lhere_\@
-	.popsection
-.endm
-
-.macro REACHABLE
-.Lhere_\@:
-	.pushsection .discard.reachable
-	.long	.Lhere_\@ - .
-	.popsection
-.endm
-
-#endif /* __ASSEMBLY__ */
-
-#else /* !CONFIG_OBJTOOL */
-
-#ifndef __ASSEMBLY__
-
-#define UNWIND_HINT(sp_reg, sp_offset, type, signal, end) \
-	"\n\t"
-#define STACK_FRAME_NON_STANDARD(func)
-#define STACK_FRAME_NON_STANDARD_FP(func)
-#define ANNOTATE_NOENDBR
-#define ASM_REACHABLE
-#else
-#define ANNOTATE_INTRA_FUNCTION_CALL
-.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 signal=0 end=0
-.endm
-.macro STACK_FRAME_NON_STANDARD func:req
-.endm
-.macro ANNOTATE_NOENDBR
-.endm
-.macro REACHABLE
-.endm
-#endif
-
-#endif /* CONFIG_OBJTOOL */
-
-#endif /* _LINUX_OBJTOOL_H */
diff --git a/tools/include/linux/objtool_types.h b/tools/include/linux/objtool_types.h
new file mode 100644
index 000000000000..453a4f4ef39d
--- /dev/null
+++ b/tools/include/linux/objtool_types.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_OBJTOOL_TYPES_H
+#define _LINUX_OBJTOOL_TYPES_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+/*
+ * This struct is used by asm and inline asm code to manually annotate the
+ * location of registers on the stack.
+ */
+struct unwind_hint {
+	u32		ip;
+	s16		sp_offset;
+	u8		sp_reg;
+	u8		type;
+	u8		signal;
+};
+
+#endif /* __ASSEMBLY__ */
+
+/*
+ * UNWIND_HINT_TYPE_UNDEFINED: A blind spot in ORC coverage which can result in
+ * a truncated and unreliable stack unwind.
+ *
+ * UNWIND_HINT_TYPE_END_OF_STACK: The end of the kernel stack unwind before
+ * hitting user entry, boot code, or fork entry (when there are no pt_regs
+ * available).
+ *
+ * UNWIND_HINT_TYPE_CALL: Indicates that sp_reg+sp_offset resolves to PREV_SP
+ * (the caller's SP right before it made the call).  Used for all callable
+ * functions, i.e. all C code and all callable asm functions.
+ *
+ * UNWIND_HINT_TYPE_REGS: Used in entry code to indicate that sp_reg+sp_offset
+ * points to a fully populated pt_regs from a syscall, interrupt, or exception.
+ *
+ * UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
+ * sp_reg+sp_offset points to the iret return frame.
+ *
+ * UNWIND_HINT_TYPE_FUNC: Generate the unwind metadata of a callable function.
+ * Useful for code which doesn't have an ELF function annotation.
+ *
+ * UNWIND_HINT_TYPE_{SAVE,RESTORE}: Save the unwind metadata at a certain
+ * location so that it can be restored later.
+ */
+#define UNWIND_HINT_TYPE_UNDEFINED	0
+#define UNWIND_HINT_TYPE_END_OF_STACK	1
+#define UNWIND_HINT_TYPE_CALL		2
+#define UNWIND_HINT_TYPE_REGS		3
+#define UNWIND_HINT_TYPE_REGS_PARTIAL	4
+/* The below hint types don't have corresponding ORC types */
+#define UNWIND_HINT_TYPE_FUNC		5
+#define UNWIND_HINT_TYPE_SAVE		6
+#define UNWIND_HINT_TYPE_RESTORE	7
+
+#endif /* _LINUX_OBJTOOL_TYPES_H */