Commit f39f21b3 authored by Marco Elver's avatar Marco Elver Committed by Linus Torvalds
Browse files

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: default avatarMarco Elver <elver@google.com>
Acked-by: default avatarDmitry 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a1554c00

include/linux/stackdepot.h

+0 −2
Original line number Diff line number Diff line
@@ -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

include/linux/stacktrace.h

+1 −0
Original line number Diff line number Diff line
@@ -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

kernel/stacktrace.c

+30 −0
Original line number Diff line number Diff line
@@ -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);

lib/stackdepot.c

+0 −24
Original line number Diff line number Diff line
@@ -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);