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authorAndrey Konovalov <andreyknvl@google.com>2020-12-10 15:42:09 +1100
committerStephen Rothwell <sfr@canb.auug.org.au>2020-12-16 18:02:58 +1100
commite3abbc6ae2a12a594b89b886c80c94e0bc904816 (patch)
tree2d6120c51afe3d1ec8bed5f79f9cfb39c3ddede9
parentdd55ffd33744acba852a572e3437cce681d7dfc1 (diff)
downloadlinux-e3abbc6ae2a12a594b89b886c80c94e0bc904816.tar.gz
kasan, arm64: only use kasan_depth for software modes
This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. Hardware tag-based KASAN won't use kasan_depth. Only define and use it when one of the software KASAN modes are enabled. No functional changes for software modes. Link: https://lkml.kernel.org/r/e16f15aeda90bc7fb4dfc2e243a14b74cc5c8219.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
-rw-r--r--arch/arm64/mm/kasan_init.c11
-rw-r--r--include/linux/kasan.h18
-rw-r--r--include/linux/sched.h2
-rw-r--r--init/init_task.c2
-rw-r--r--mm/kasan/common.c2
-rw-r--r--mm/kasan/report.c2
6 files changed, 23 insertions, 14 deletions
diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
index ffeb80d5aa8d..5172799f831f 100644
--- a/arch/arm64/mm/kasan_init.c
+++ b/arch/arm64/mm/kasan_init.c
@@ -273,17 +273,22 @@ static void __init kasan_init_shadow(void)
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
}
+static void __init kasan_init_depth(void)
+{
+ init_task.kasan_depth = 0;
+}
+
#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS) */
static inline void __init kasan_init_shadow(void) { }
+static inline void __init kasan_init_depth(void) { }
+
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
void __init kasan_init(void)
{
kasan_init_shadow();
-
- /* At this point kasan is fully initialized. Enable error messages */
- init_task.kasan_depth = 0;
+ kasan_init_depth();
pr_info("KernelAddressSanitizer initialized\n");
}
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 9740c06a04a1..b272960e8396 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -52,6 +52,12 @@ static inline void *kasan_mem_to_shadow(const void *addr)
int kasan_add_zero_shadow(void *start, unsigned long size);
void kasan_remove_zero_shadow(void *start, unsigned long size);
+/* Enable reporting bugs after kasan_disable_current() */
+extern void kasan_enable_current(void);
+
+/* Disable reporting bugs for current task */
+extern void kasan_disable_current(void);
+
#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
static inline int kasan_add_zero_shadow(void *start, unsigned long size)
@@ -62,16 +68,13 @@ static inline void kasan_remove_zero_shadow(void *start,
unsigned long size)
{}
+static inline void kasan_enable_current(void) {}
+static inline void kasan_disable_current(void) {}
+
#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
#ifdef CONFIG_KASAN
-/* Enable reporting bugs after kasan_disable_current() */
-extern void kasan_enable_current(void);
-
-/* Disable reporting bugs for current task */
-extern void kasan_disable_current(void);
-
void kasan_unpoison_range(const void *address, size_t size);
void kasan_unpoison_task_stack(struct task_struct *task);
@@ -122,9 +125,6 @@ static inline void kasan_unpoison_range(const void *address, size_t size) {}
static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
-static inline void kasan_enable_current(void) {}
-static inline void kasan_disable_current(void) {}
-
static inline void kasan_alloc_pages(struct page *page, unsigned int order) {}
static inline void kasan_free_pages(struct page *page, unsigned int order) {}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index dfadcf0f9e30..e5ad6d354b7b 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1235,7 +1235,7 @@ struct task_struct {
u64 timer_slack_ns;
u64 default_timer_slack_ns;
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
unsigned int kasan_depth;
#endif
diff --git a/init/init_task.c b/init/init_task.c
index 15f6eb93a04f..8a992d73e6fb 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -176,7 +176,7 @@ struct task_struct init_task
.numa_group = NULL,
.numa_faults = NULL,
#endif
-#ifdef CONFIG_KASAN
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
.kasan_depth = 1,
#endif
#ifdef CONFIG_KCSAN
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index ae55570b4d32..52fa763d2169 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -47,6 +47,7 @@ void kasan_set_track(struct kasan_track *track, gfp_t flags)
track->stack = kasan_save_stack(flags);
}
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
void kasan_enable_current(void)
{
current->kasan_depth++;
@@ -56,6 +57,7 @@ void kasan_disable_current(void)
{
current->kasan_depth--;
}
+#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
void kasan_unpoison_range(const void *address, size_t size)
{
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index d140d26cfb31..914ab5cfc3ea 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -292,8 +292,10 @@ static void print_shadow_for_address(const void *addr)
static bool report_enabled(void)
{
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
if (current->kasan_depth)
return false;
+#endif
if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags))
return true;
return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags);