[PATCH -tip v5 1/2] irq: Introduce CONFIG_IRQENTRY kconfig

[Masami Hiramatsu <mhiramat@kernel.org>]

Introduce CONFIG_IRQENTRY to simplify generating
irqentry and softirqentry text sections.
Currently generating those sections depends on
CONFIG_FUNCTION_GRAPH_TRACER and/or CONFIG_KASAN, in
each source code. This moves those #ifdef dependencies
into Kconfig, instead of the actual code. This makes
it scalable for other user of irqentry section.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 arch/arm/include/asm/traps.h      |    2 +-
 arch/arm64/include/asm/traps.h    |    2 +-
 arch/x86/entry/entry_64.S         |    2 +-
 include/asm-generic/vmlinux.lds.h |    4 ++--
 include/linux/interrupt.h         |    2 +-
 kernel/irq/Kconfig                |    4 ++++
 kernel/trace/Kconfig              |    1 +
 lib/Kconfig.kasan                 |    1 +
 8 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/traps.h b/arch/arm/include/asm/traps.h
index f555bb3664dc..6a768d61d15e 100644
--- a/arch/arm/include/asm/traps.h
+++ b/arch/arm/include/asm/traps.h
@@ -18,7 +18,7 @@ struct undef_hook {
 void register_undef_hook(struct undef_hook *hook);
 void unregister_undef_hook(struct undef_hook *hook);
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#ifdef CONFIG_IRQENTRY
 static inline int __in_irqentry_text(unsigned long ptr)
 {
 	extern char __irqentry_text_start[];
diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index 02e9035b0685..24eafb139902 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -37,7 +37,7 @@ void unregister_undef_hook(struct undef_hook *hook);
 
 void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr);
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#ifdef CONFIG_IRQENTRY
 static inline int __in_irqentry_text(unsigned long ptr)
 {
 	return ptr >= (unsigned long)&__irqentry_text_start &&
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index aa58155187c5..5300372fadc9 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -766,7 +766,7 @@ apicinterrupt3 \num trace(\sym) smp_trace(\sym)
 #endif
 
 /* Make sure APIC interrupt handlers end up in the irqentry section: */
-#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+#ifdef CONFIG_IRQENTRY
 # define PUSH_SECTION_IRQENTRY	.pushsection .irqentry.text, "ax"
 # define POP_SECTION_IRQENTRY	.popsection
 #else
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index fffc9bdae025..a45712768f97 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -483,7 +483,7 @@
 		*(.entry.text)						\
 		VMLINUX_SYMBOL(__entry_text_end) = .;
 
-#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+#ifdef CONFIG_IRQENTRY
 #define IRQENTRY_TEXT							\
 		ALIGN_FUNCTION();					\
 		VMLINUX_SYMBOL(__irqentry_text_start) = .;		\
@@ -493,7 +493,7 @@
 #define IRQENTRY_TEXT
 #endif
 
-#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+#ifdef CONFIG_IRQENTRY
 #define SOFTIRQENTRY_TEXT						\
 		ALIGN_FUNCTION();					\
 		VMLINUX_SYMBOL(__softirqentry_text_start) = .;		\
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index a2fddddb0d60..6adad995d8fd 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -726,7 +726,7 @@ extern int early_irq_init(void);
 extern int arch_probe_nr_irqs(void);
 extern int arch_early_irq_init(void);
 
-#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
+#ifdef CONFIG_IRQENTRY
 /*
  * We want to know which function is an entrypoint of a hardirq or a softirq.
  */
diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
index 27c4e774071c..fd4a69c28700 100644
--- a/kernel/irq/Kconfig
+++ b/kernel/irq/Kconfig
@@ -126,4 +126,8 @@ config GENERIC_IRQ_DEBUGFS
 
 	  If you don't know what to do here, say N.
 
+# Generate irqentry and softirqentry text sections
+config IRQENTRY
+	bool
+
 endmenu
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 434c840e2d82..2556a7ca8cdc 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -150,6 +150,7 @@ config FUNCTION_GRAPH_TRACER
 	depends on HAVE_FUNCTION_GRAPH_TRACER
 	depends on FUNCTION_TRACER
 	depends on !X86_32 || !CC_OPTIMIZE_FOR_SIZE
+	select IRQENTRY
 	default y
 	help
 	  Enable the kernel to trace a function at both its return
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
index bd38aab05929..09daa0d505e6 100644
--- a/lib/Kconfig.kasan
+++ b/lib/Kconfig.kasan
@@ -8,6 +8,7 @@ config KASAN
 	depends on SLUB || (SLAB && !DEBUG_SLAB)
 	select CONSTRUCTORS
 	select STACKDEPOT
+	select IRQENTRY
 	help
 	  Enables kernel address sanitizer - runtime memory debugger,
 	  designed to find out-of-bounds accesses and use-after-free bugs.