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
  ...

56 files changed, 152 insertions, 127 deletions

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index e9cf7193eb81..582d96548385 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -9,6 +9,7 @@
  * This file handles the architecture-dependent parts of process handling.
  */
 
+#include <linux/cpu.h>
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/sched.h>
@@ -59,9 +60,10 @@ void arch_cpu_idle(void)
 	wtint(0);
 }
 
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	wtint(INT_MAX);
+	BUG();
 }
 #endif /* ALPHA_WTINT */
 
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 0b8c25763adc..f4a4ac028b6b 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -320,7 +320,7 @@ void __cpu_die(unsigned int cpu)
  * of the other hotplug-cpu capable cores, so presumably coming
  * out of idle fixes this.
  */
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	unsigned int cpu = smp_processor_id();
 
@@ -382,6 +382,8 @@ void arch_cpu_idle_dead(void)
 		: "r" (task_stack_page(current) + THREAD_SIZE - 8),
 		  "r" (current)
 		: "r0");
+
+	unreachable();
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
@@ -777,7 +779,7 @@ void smp_send_stop(void)
  * kdump fails. So split out the panic_smp_self_stop() and add
  * set_cpu_online(smp_processor_id(), false).
  */
-void panic_smp_self_stop(void)
+void __noreturn panic_smp_self_stop(void)
 {
 	pr_debug("CPU %u will stop doing anything useful since another CPU has paniced\n",
 	         smp_processor_id());
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h
index 92963f98afec..e73af709cb7a 100644
--- a/arch/arm64/include/asm/exception.h
+++ b/arch/arm64/include/asm/exception.h
@@ -31,7 +31,7 @@ static inline unsigned long disr_to_esr(u64 disr)
 	return esr;
 }
 
-asmlinkage void handle_bad_stack(struct pt_regs *regs);
+asmlinkage void __noreturn handle_bad_stack(struct pt_regs *regs);
 
 asmlinkage void el1t_64_sync_handler(struct pt_regs *regs);
 asmlinkage void el1t_64_irq_handler(struct pt_regs *regs);
@@ -80,5 +80,5 @@ void do_el1_fpac(struct pt_regs *regs, unsigned long esr);
 void do_serror(struct pt_regs *regs, unsigned long esr);
 void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags);
 
-void panic_bad_stack(struct pt_regs *regs, unsigned long esr, unsigned long far);
+void __noreturn panic_bad_stack(struct pt_regs *regs, unsigned long esr, unsigned long far);
 #endif	/* __ASM_EXCEPTION_H */
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index fc55f5a57a06..f2d26235bfb4 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -100,10 +100,10 @@ static inline void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
 extern int __cpu_disable(void);
 
 extern void __cpu_die(unsigned int cpu);
-extern void cpu_die(void);
-extern void cpu_die_early(void);
+extern void __noreturn cpu_die(void);
+extern void __noreturn cpu_die_early(void);
 
-static inline void cpu_park_loop(void)
+static inline void __noreturn cpu_park_loop(void)
 {
 	for (;;) {
 		wfe();
@@ -123,7 +123,7 @@ static inline void update_cpu_boot_status(int val)
  * which calls for a kernel panic. Update the boot status and park the calling
  * CPU.
  */
-static inline void cpu_panic_kernel(void)
+static inline void __noreturn cpu_panic_kernel(void)
 {
 	update_cpu_boot_status(CPU_PANIC_KERNEL);
 	cpu_park_loop();
@@ -143,7 +143,6 @@ bool cpus_are_stuck_in_kernel(void);
 
 extern void crash_smp_send_stop(void);
 extern bool smp_crash_stop_failed(void);
-extern void panic_smp_self_stop(void);
 
 #endif /* ifndef __ASSEMBLY__ */
 
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index cce1167199e3..3af3c01c93a6 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -840,7 +840,7 @@ UNHANDLED(el0t, 32, error)
 #endif /* CONFIG_COMPAT */
 
 #ifdef CONFIG_VMAP_STACK
-asmlinkage void noinstr handle_bad_stack(struct pt_regs *regs)
+asmlinkage void noinstr __noreturn handle_bad_stack(struct pt_regs *regs)
 {
 	unsigned long esr = read_sysreg(esr_el1);
 	unsigned long far = read_sysreg(far_el1);
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index b5bed62483cb..0fcc4eb1a7ab 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -69,7 +69,7 @@ void (*pm_power_off)(void);
 EXPORT_SYMBOL_GPL(pm_power_off);
 
 #ifdef CONFIG_HOTPLUG_CPU
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
        cpu_die();
 }
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 4e8327264255..05fe797e4203 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -361,7 +361,7 @@ void __cpu_die(unsigned int cpu)
  * Called from the idle thread for the CPU which has been shutdown.
  *
  */
-void cpu_die(void)
+void __noreturn cpu_die(void)
 {
 	unsigned int cpu = smp_processor_id();
 	const struct cpu_operations *ops = get_cpu_ops(cpu);
@@ -398,7 +398,7 @@ static void __cpu_try_die(int cpu)
  * Kill the calling secondary CPU, early in bringup before it is turned
  * online.
  */
-void cpu_die_early(void)
+void __noreturn cpu_die_early(void)
 {
 	int cpu = smp_processor_id();
 
@@ -816,7 +816,7 @@ void arch_irq_work_raise(void)
 }
 #endif
 
-static void local_cpu_stop(void)
+static void __noreturn local_cpu_stop(void)
 {
 	set_cpu_online(smp_processor_id(), false);
 
@@ -830,7 +830,7 @@ static void local_cpu_stop(void)
  * that cpu_online_mask gets correctly updated and smp_send_stop() can skip
  * CPUs that have already stopped themselves.
  */
-void panic_smp_self_stop(void)
+void __noreturn panic_smp_self_stop(void)
 {
 	local_cpu_stop();
 }
@@ -839,7 +839,7 @@ void panic_smp_self_stop(void)
 static atomic_t waiting_for_crash_ipi = ATOMIC_INIT(0);
 #endif
 
-static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
+static void __noreturn ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
 {
 #ifdef CONFIG_KEXEC_CORE
 	crash_save_cpu(regs, cpu);
@@ -854,6 +854,8 @@ static void ipi_cpu_crash_stop(unsigned int cpu, struct pt_regs *regs)
 
 	/* just in case */
 	cpu_park_loop();
+#else
+	BUG();
 #endif
 }
 
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 4a79ba100799..4bb1b8f47298 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -863,7 +863,7 @@ void bad_el0_sync(struct pt_regs *regs, int reason, unsigned long esr)
 DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack)
 	__aligned(16);
 
-void panic_bad_stack(struct pt_regs *regs, unsigned long esr, unsigned long far)
+void __noreturn panic_bad_stack(struct pt_regs *regs, unsigned long esr, unsigned long far)
 {
 	unsigned long tsk_stk = (unsigned long)current->stack;
 	unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr);
@@ -905,7 +905,6 @@ void __noreturn arm64_serror_panic(struct pt_regs *regs, unsigned long esr)
 	nmi_panic(regs, "Asynchronous SError Interrupt");
 
 	cpu_park_loop();
-	unreachable();
 }
 
 bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned long esr)
diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
index b45d1073307f..9c7a20b73ac6 100644
--- a/arch/csky/kernel/smp.c
+++ b/arch/csky/kernel/smp.c
@@ -300,7 +300,7 @@ void __cpu_die(unsigned int cpu)
 	pr_notice("CPU%u: shutdown\n", cpu);
 }
 
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	idle_task_exit();
 
@@ -317,5 +317,7 @@ void arch_cpu_idle_dead(void)
 		"jmpi	csky_start_secondary"
 		:
 		: "r" (secondary_stack));
+
+	BUG();
 }
 #endif
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index f6195a0a00ae..9a5cd9fad3a9 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -201,7 +201,7 @@ __setup("nohalt", nohalt_setup);
 
 #ifdef CONFIG_HOTPLUG_CPU
 /* We don't actually take CPU down, just spin without interrupts. */
-static inline void play_dead(void)
+static inline void __noreturn play_dead(void)
 {
 	unsigned int this_cpu = smp_processor_id();
 
@@ -219,13 +219,13 @@ static inline void play_dead(void)
 	BUG();
 }
 #else
-static inline void play_dead(void)
+static inline void __noreturn play_dead(void)
 {
 	BUG();
 }
 #endif /* CONFIG_HOTPLUG_CPU */
 
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	play_dead();
 }
diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/smp.h
index d82687390b4a..416b653bccb4 100644
--- a/arch/loongarch/include/asm/smp.h
+++ b/arch/loongarch/include/asm/smp.h
@@ -99,7 +99,7 @@ static inline void __cpu_die(unsigned int cpu)
 	loongson_cpu_die(cpu);
 }
 
-extern void play_dead(void);
+extern void __noreturn play_dead(void);
 #endif
 
 #endif /* __ASM_SMP_H */
diff --git a/arch/loongarch/kernel/process.c b/arch/loongarch/kernel/process.c
index fa2443c7afb2..b71e17c1cc0c 100644
--- a/arch/loongarch/kernel/process.c
+++ b/arch/loongarch/kernel/process.c
@@ -62,7 +62,7 @@ unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
 EXPORT_SYMBOL(boot_option_idle_override);
 
 #ifdef CONFIG_HOTPLUG_CPU
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	play_dead();
 }
diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index 8c6e227cb29d..51f328169a7b 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -336,7 +336,7 @@ void play_dead(void)
 	iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_CLEAR);
 
 	init_fn();
-	unreachable();
+	BUG();
 }
 
 #endif
diff --git a/arch/mips/cavium-octeon/smp.c b/arch/mips/cavium-octeon/smp.c
index 89954f5f87fb..4212584e6efa 100644
--- a/arch/mips/cavium-octeon/smp.c
+++ b/arch/mips/cavium-octeon/smp.c
@@ -20,6 +20,7 @@
 #include <asm/mmu_context.h>
 #include <asm/time.h>
 #include <asm/setup.h>
+#include <asm/smp.h>
 
 #include <asm/octeon/octeon.h>
 
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
index 5d9ff61004ca..4eee29b7845c 100644
--- a/arch/mips/include/asm/smp.h
+++ b/arch/mips/include/asm/smp.h
@@ -88,7 +88,7 @@ static inline void __cpu_die(unsigned int cpu)
 	mp_ops->cpu_die(cpu);
 }
 
-extern void play_dead(void);
+extern void __noreturn play_dead(void);
 #endif
 
 #ifdef CONFIG_KEXEC
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 093dbbd6b843..a3225912c862 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -40,7 +40,7 @@
 #include <asm/stacktrace.h>
 
 #ifdef CONFIG_HOTPLUG_CPU
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	play_dead();
 }
diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index f5d7bfa3472a..15466d4cf4a0 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -54,6 +54,8 @@ static void bmips_set_reset_vec(int cpu, u32 val);
 
 #ifdef CONFIG_SMP
 
+#include <asm/smp.h>
+
 /* initial $sp, $gp - used by arch/mips/kernel/bmips_vec.S */
 unsigned long bmips_smp_boot_sp;
 unsigned long bmips_smp_boot_gp;
@@ -413,6 +415,8 @@ void __ref play_dead(void)
 	"	wait\n"
 	"	j	bmips_secondary_reentry\n"
 	: : : "memory");
+
+	BUG();
 }
 
 #endif /* CONFIG_HOTPLUG_CPU */
diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
index f968a319d87f..62f677b2306f 100644
--- a/arch/mips/kernel/smp-cps.c
+++ b/arch/mips/kernel/smp-cps.c
@@ -20,6 +20,7 @@
 #include <asm/mipsregs.h>
 #include <asm/pm-cps.h>
 #include <asm/r4kcache.h>
+#include <asm/smp.h>
 #include <asm/smp-cps.h>
 #include <asm/time.h>
 #include <asm/uasm.h>
diff --git a/arch/mips/loongson64/smp.c b/arch/mips/loongson64/smp.c
index 90c783981197..b0e8bb9fa036 100644
--- a/arch/mips/loongson64/smp.c
+++ b/arch/mips/loongson64/smp.c
@@ -14,6 +14,7 @@
 #include <linux/cpufreq.h>
 #include <linux/kexec.h>
 #include <asm/processor.h>
+#include <asm/smp.h>
 #include <asm/time.h>
 #include <asm/tlbflush.h>
 #include <asm/cacheflush.h>
@@ -808,6 +809,7 @@ out:
 	state_addr = &per_cpu(cpu_state, cpu);
 	mb();
 	play_dead_at_ckseg1(state_addr);
+	BUG();
 }
 
 static int loongson3_disable_clock(unsigned int cpu)
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index c064719b49b0..97c6f875bd0e 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -159,7 +159,7 @@ EXPORT_SYMBOL(running_on_qemu);
 /*
  * Called from the idle thread for the CPU which has been shutdown.
  */
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 #ifdef CONFIG_HOTPLUG_CPU
 	idle_task_exit();
diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 6c6cb53d7045..aaaa576d0e15 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -67,7 +67,7 @@ void start_secondary(void *unused);
 extern int smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us);
 extern int smp_send_safe_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us);
 extern void smp_send_debugger_break(void);
-extern void start_secondary_resume(void);
+extern void __noreturn start_secondary_resume(void);
 extern void smp_generic_give_timebase(void);
 extern void smp_generic_take_timebase(void);
 
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index b2e0d3ce4261..246201d0d879 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -480,7 +480,7 @@ void early_setup_secondary(void)
 
 #endif /* CONFIG_SMP */
 
-void panic_smp_self_stop(void)
+void __noreturn panic_smp_self_stop(void)
 {
 	hard_irq_disable();
 	spin_begin();
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 7db6b3faea65..bf9744034c3a 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -1752,7 +1752,7 @@ void __cpu_die(unsigned int cpu)
 		smp_ops->cpu_die(cpu);
 }
 
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	/*
 	 * Disable on the down path. This will be re-enabled by
diff --git a/arch/riscv/kernel/cpu-hotplug.c b/arch/riscv/kernel/cpu-hotplug.c
index 39235cf50652..a941adc7cbf2 100644
--- a/arch/riscv/kernel/cpu-hotplug.c
+++ b/arch/riscv/kernel/cpu-hotplug.c
@@ -72,7 +72,7 @@ void __cpu_die(unsigned int cpu)
 /*
  * Called from the idle thread for the CPU which has been shutdown.
  */
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	idle_task_exit();
 
diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index 38e267c7bff7..e7239aaf428b 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -88,7 +88,7 @@ void arch_cpu_idle_exit(void)
 {
 }
 
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	cpu_die();
 }
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 8ec5cdf9dadc..4259b6c50516 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -396,7 +396,7 @@ int __init arch_early_irq_init(void)
 	return 0;
 }
 
-void __init arch_call_rest_init(void)
+void __init __noreturn arch_call_rest_init(void)
 {
 	unsigned long stack;
 
diff --git a/arch/sh/include/asm/smp-ops.h b/arch/sh/include/asm/smp-ops.h
index e27702130eb6..97331fcb7b85 100644
--- a/arch/sh/include/asm/smp-ops.h
+++ b/arch/sh/include/asm/smp-ops.h
@@ -24,9 +24,10 @@ static inline void plat_smp_setup(void)
 	mp_ops->smp_setup();
 }
 
-static inline void play_dead(void)
+static inline void __noreturn play_dead(void)
 {
 	mp_ops->play_dead();
+	BUG();
 }
 
 extern void register_smp_ops(struct plat_smp_ops *ops);
@@ -42,7 +43,7 @@ static inline void register_smp_ops(struct plat_smp_ops *ops)
 {
 }
 
-static inline void play_dead(void)
+static inline void __noreturn play_dead(void)
 {
 	BUG();
 }
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
index 3418c40f0099..d662503b0665 100644
--- a/arch/sh/kernel/idle.c
+++ b/arch/sh/kernel/idle.c
@@ -4,6 +4,7 @@
  *
  *  Copyright (C) 2002 - 2009  Paul Mundt
  */
+#include <linux/cpu.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/mm.h>
@@ -29,7 +30,7 @@ void default_idle(void)
 	clear_bl_bit();
 }
 
-void arch_cpu_idle_dead(void)
+void __noreturn arch_cpu_idle_dead(void)
 {
 	play_dead();
 }
diff --git a/arch/sparc/include/asm/smp_64.h b/arch/sparc/include/asm/smp_64.h
index e75783b6abc4..505b6700805d 100644
--- a/