Commit | Line | Data |
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c942fddf | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
cd11016e AP |
2 | /* |
3 | * A generic stack depot implementation | |
4 | * | |
5 | * Author: Alexander Potapenko <glider@google.com> | |
6 | * Copyright (C) 2016 Google, Inc. | |
7 | * | |
8 | * Based on code by Dmitry Chernenkov. | |
cd11016e AP |
9 | */ |
10 | ||
11 | #ifndef _LINUX_STACKDEPOT_H | |
12 | #define _LINUX_STACKDEPOT_H | |
13 | ||
7857ccdf ME |
14 | #include <linux/gfp.h> |
15 | ||
cd11016e | 16 | typedef u32 depot_stack_handle_t; |
83a4f1ef AP |
17 | /* |
18 | * Number of bits in the handle that stack depot doesn't use. Users may store | |
19 | * information in them. | |
20 | */ | |
21 | #define STACK_DEPOT_EXTRA_BITS 5 | |
cd11016e | 22 | |
11ac25c6 ME |
23 | depot_stack_handle_t __stack_depot_save(unsigned long *entries, |
24 | unsigned int nr_entries, | |
83a4f1ef | 25 | unsigned int extra_bits, |
11ac25c6 ME |
26 | gfp_t gfp_flags, bool can_alloc); |
27 | ||
2dba5eb1 | 28 | /* |
a5f1783b VB |
29 | * Every user of stack depot has to call stack_depot_init() during its own init |
30 | * when it's decided that it will be calling stack_depot_save() later. This is | |
31 | * recommended for e.g. modules initialized later in the boot process, when | |
32 | * slab_is_available() is true. | |
2dba5eb1 VB |
33 | * |
34 | * The alternative is to select STACKDEPOT_ALWAYS_INIT to have stack depot | |
35 | * enabled as part of mm_init(), for subsystems where it's known at compile time | |
36 | * that stack depot will be used. | |
a5f1783b VB |
37 | * |
38 | * Another alternative is to call stack_depot_want_early_init(), when the | |
39 | * decision to use stack depot is taken e.g. when evaluating kernel boot | |
40 | * parameters, which precedes the enablement point in mm_init(). | |
41 | * | |
42 | * stack_depot_init() and stack_depot_want_early_init() can be called regardless | |
43 | * of CONFIG_STACKDEPOT and are no-op when disabled. The actual save/fetch/print | |
44 | * functions should only be called from code that makes sure CONFIG_STACKDEPOT | |
45 | * is enabled. | |
2dba5eb1 | 46 | */ |
a5f1783b | 47 | #ifdef CONFIG_STACKDEPOT |
2dba5eb1 VB |
48 | int stack_depot_init(void); |
49 | ||
a5f1783b VB |
50 | void __init stack_depot_want_early_init(void); |
51 | ||
52 | /* This is supposed to be called only from mm_init() */ | |
53 | int __init stack_depot_early_init(void); | |
2dba5eb1 | 54 | #else |
a5f1783b VB |
55 | static inline int stack_depot_init(void) { return 0; } |
56 | ||
57 | static inline void stack_depot_want_early_init(void) { } | |
58 | ||
2dba5eb1 VB |
59 | static inline int stack_depot_early_init(void) { return 0; } |
60 | #endif | |
61 | ||
c0cfc337 TG |
62 | depot_stack_handle_t stack_depot_save(unsigned long *entries, |
63 | unsigned int nr_entries, gfp_t gfp_flags); | |
cd11016e | 64 | |
c0cfc337 TG |
65 | unsigned int stack_depot_fetch(depot_stack_handle_t handle, |
66 | unsigned long **entries); | |
cd11016e | 67 | |
83a4f1ef AP |
68 | unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle); |
69 | ||
0f68d45e IK |
70 | int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size, |
71 | int spaces); | |
72 | ||
505be481 IK |
73 | void stack_depot_print(depot_stack_handle_t stack); |
74 | ||
cd11016e | 75 | #endif |