stacktrace: move filter_irq_stacks() to kernel/stacktrace.c

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().

Link: https://lkml.kernel.org/r/20210923104803.2620285-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h
index b2f7e7c6ba54d57c4953da0f03a2dc7d8c2c852f..d29860966bc91423cc73fd8a4eb019b1b9a1c7d4 100644 (file)
--- a/include/linux/stackdepot.h
+++ b/include/linux/stackdepot.h
@@ -25,8 +25,6 @@ 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 9edecb494e9e2d5414367598238f7a5396dfc679..bef158815e83d6071cd186b6f5e8c4de5dfd88b1 100644 (file)
--- 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 9f8117c7cfddee066477b27b6bafc397155da03a..9c625257023d295cc0d5946ca1186a2792e10a06 100644 (file)
--- 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 bda58597e3756d30122f9d1ea6a5f7e16a27bba5..09485dc5bd1281b945b2ac60e577fe1ca28f88d2 100644 (file)
--- 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>
@@ -371,26 +370,3 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
        return __stack_depot_save(entries, nr_entries, alloc_flags, true);
 }
 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);