[PATCH v3 04/12] arch/arm: don't initialize kasan if it's disabled

[PATCH v3 04/12] arch/arm: don't initialize kasan if it's disabled

[Baoquan He]

And also add code to enable kasan_flag_enabled, this is for later
usage.

Here call jump_label_init() early in setup_arch() so that later
kasan_init() can enable static key kasan_flag_enabled. Put
jump_label_init() beofre parse_early_param() as other architectures
do.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm/kernel/setup.c  | 6 ++++++
 arch/arm/mm/kasan_init.c | 6 ++++++
 2 files changed, 12 insertions(+)

diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 0bfd66c7ada0..453a47a4c715 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -1135,6 +1135,12 @@ void __init setup_arch(char **cmdline_p)
 	early_fixmap_init();
 	early_ioremap_init();
 
+	/*
+	 * Initialise the static keys early as they may be enabled by the
+	 * kasan_init() or early parameters.
+	 */
+	jump_label_init();
+
 	parse_early_param();
 
 #ifdef CONFIG_MMU
diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c
index 111d4f703136..c764e1b9c9c5 100644
--- a/arch/arm/mm/kasan_init.c
+++ b/arch/arm/mm/kasan_init.c
@@ -212,6 +212,8 @@ void __init kasan_init(void)
 	phys_addr_t pa_start, pa_end;
 	u64 i;
 
+	if (kasan_arg_disabled)
+		return;
 	/*
 	 * We are going to perform proper setup of shadow memory.
 	 *
@@ -300,6 +302,10 @@ void __init kasan_init(void)
 	local_flush_tlb_all();
 
 	memset(kasan_early_shadow_page, 0, PAGE_SIZE);
+
+	/* KASAN is now initialized, enable it. */
+	static_branch_enable(&kasan_flag_enabled);
+
 	pr_info("Kernel address sanitizer initialized\n");
 	init_task.kasan_depth = 0;
 }
-- 
2.41.0

[PATCH v3 05/12] arch/arm64: don't initialize kasan if it's disabled

[Baoquan He]

And also add code to enable kasan_flag_enabled, this is for later
usage.

And also need skip kasan_populate_early_vm_area_shadow() if kasan
is disabled.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm64/mm/kasan_init.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index d541ce45daeb..0e4ffe3f5d0e 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -384,6 +384,9 @@ void __init kasan_populate_early_vm_area_shadow(void *start, unsigned long size)
 {
 	unsigned long shadow_start, shadow_end;
 
+	if (!kasan_enabled())
+		return;
+
 	if (!is_vmalloc_or_module_addr(start))
 		return;
 
@@ -397,6 +400,9 @@ void __init kasan_populate_early_vm_area_shadow(void *start, unsigned long size)
 
 void __init kasan_init(void)
 {
+	if (kasan_arg_disabled)
+		return;
+
 	kasan_init_shadow();
 	kasan_init_depth();
 #if defined(CONFIG_KASAN_GENERIC)
@@ -405,6 +411,7 @@ void __init kasan_init(void)
 	 * Software and Hardware Tag-Based modes still require
 	 * kasan_init_sw_tags() and kasan_init_hw_tags() correspondingly.
 	 */
+	static_branch_enable(&kasan_flag_enabled);
 	pr_info("KernelAddressSanitizer initialized (generic)\n");
 #endif
 }
-- 
2.41.0