[PATCH v2 1/5] stacktrace: move filter_irq_stacks() to kernel/stacktrace.c

From: Marco Elver
Date: Tue Sep 21 2021 - 06:10:45 EST


filter_irq_stacks() has little to do with the stackdepot implementation,
except that it is usually used by users (such as KASAN) of stackdepot to
reduce the stack trace.

However, filter_irq_stacks() itself is not useful without a stack trace
as obtained by stack_trace_save() and friends.

Therefore, move filter_irq_stacks() to kernel/stacktrace.c, so that new
users of filter_irq_stacks() do not have to start depending on
STACKDEPOT only for filter_irq_stacks().

Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
---
v2:
* New patch.
---
include/linux/stackdepot.h | 2 --
include/linux/stacktrace.h | 1 +
kernel/stacktrace.c | 30 ++++++++++++++++++++++++++++++
lib/stackdepot.c | 24 ------------------------
4 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index 6bb4bc1a5f54..22919a94ca19 100644
--- a/include/linux/stackdepot.h
+++ b/include/linux/stackdepot.h
@@ -19,8 +19,6 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
unsigned int stack_depot_fetch(depot_stack_handle_t handle,
unsigned long **entries);

-unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries);
-
#ifdef CONFIG_STACKDEPOT
int stack_depot_init(void);
#else
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
index 9edecb494e9e..bef158815e83 100644
--- a/include/linux/stacktrace.h
+++ b/include/linux/stacktrace.h
@@ -21,6 +21,7 @@ unsigned int stack_trace_save_tsk(struct task_struct *task,
unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store,
unsigned int size, unsigned int skipnr);
unsigned int stack_trace_save_user(unsigned long *store, unsigned int size);
+unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries);

/* Internal interfaces. Do not use in generic code */
#ifdef CONFIG_ARCH_STACKWALK
diff --git a/kernel/stacktrace.c b/kernel/stacktrace.c
index 9f8117c7cfdd..9c625257023d 100644
--- a/kernel/stacktrace.c
+++ b/kernel/stacktrace.c
@@ -13,6 +13,7 @@
#include <linux/export.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>
+#include <linux/interrupt.h>

/**
* stack_trace_print - Print the entries in the stack trace
@@ -373,3 +374,32 @@ unsigned int stack_trace_save_user(unsigned long *store, unsigned int size)
#endif /* CONFIG_USER_STACKTRACE_SUPPORT */

#endif /* !CONFIG_ARCH_STACKWALK */
+
+static inline bool in_irqentry_text(unsigned long ptr)
+{
+ return (ptr >= (unsigned long)&__irqentry_text_start &&
+ ptr < (unsigned long)&__irqentry_text_end) ||
+ (ptr >= (unsigned long)&__softirqentry_text_start &&
+ ptr < (unsigned long)&__softirqentry_text_end);
+}
+
+/**
+ * filter_irq_stacks - Find first IRQ stack entry in trace
+ * @entries: Pointer to stack trace array
+ * @nr_entries: Number of entries in the storage array
+ *
+ * Return: Number of trace entries until IRQ stack starts.
+ */
+unsigned int filter_irq_stacks(unsigned long *entries, unsigned int nr_entries)
+{
+ unsigned int i;
+
+ for (i = 0; i < nr_entries; i++) {
+ if (in_irqentry_text(entries[i])) {
+ /* Include the irqentry function into the stack. */
+ return i + 1;
+ }
+ }
+ return nr_entries;
+}
+EXPORT_SYMBOL_GPL(filter_irq_stacks);
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 0a2e417f83cb..e90f0f19e77f 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -20,7 +20,6 @@
*/

#include <linux/gfp.h>
-#include <linux/interrupt.h>
#include <linux/jhash.h>
#include <linux/kernel.h>
#include <linux/mm.h>
@@ -341,26 +340,3 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
return retval;
}
EXPORT_SYMBOL_GPL(stack_depot_save);
-
-static inline int in_irqentry_text(unsigned long ptr)
-{
- return (ptr >= (unsigned long)&__irqentry_text_start &&
- ptr < (unsigned long)&__irqentry_text_end) ||
- (ptr >= (unsigned long)&__softirqentry_text_start &&
- ptr < (unsigned long)&__softirqentry_text_end);
-}
-
-unsigned int filter_irq_stacks(unsigned long *entries,
- unsigned int nr_entries)
-{
- unsigned int i;
-
- for (i = 0; i < nr_entries; i++) {
- if (in_irqentry_text(entries[i])) {
- /* Include the irqentry function into the stack. */
- return i + 1;
- }
- }
- return nr_entries;
-}
-EXPORT_SYMBOL_GPL(filter_irq_stacks);
--
2.33.0.464.g1972c5931b-goog