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a90917c3 MD |
1 | #ifndef _LTTNG_WRAPPER_VMALLOC_H |
2 | #define _LTTNG_WRAPPER_VMALLOC_H | |
b13f3ebe | 3 | |
6d2a620c | 4 | /* |
886d51a3 | 5 | * wrapper/vmalloc.h |
6d2a620c MD |
6 | * |
7 | * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when | |
8 | * available, else we need to have a kernel that exports this function to GPL | |
9 | * modules. | |
10 | * | |
886d51a3 MD |
11 | * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
12 | * | |
13 | * This library is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU Lesser General Public | |
15 | * License as published by the Free Software Foundation; only | |
16 | * version 2.1 of the License. | |
17 | * | |
18 | * This library is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
21 | * Lesser General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU Lesser General Public | |
24 | * License along with this library; if not, write to the Free Software | |
25 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
6d2a620c MD |
26 | */ |
27 | ||
48f5e0b5 MJ |
28 | #include <linux/version.h> |
29 | #include <linux/vmalloc.h> | |
01ab5113 | 30 | #include <linux/mm.h> |
48f5e0b5 | 31 | |
6d2a620c MD |
32 | #ifdef CONFIG_KALLSYMS |
33 | ||
34 | #include <linux/kallsyms.h> | |
5a2f5e92 | 35 | #include <wrapper/kallsyms.h> |
6d2a620c MD |
36 | |
37 | static inline | |
38 | void wrapper_vmalloc_sync_all(void) | |
39 | { | |
40 | void (*vmalloc_sync_all_sym)(void); | |
41 | ||
c539a324 | 42 | vmalloc_sync_all_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_all"); |
6d2a620c MD |
43 | if (vmalloc_sync_all_sym) { |
44 | vmalloc_sync_all_sym(); | |
45 | } else { | |
46 | #ifdef CONFIG_X86 | |
47 | /* | |
48 | * Only x86 needs vmalloc_sync_all to make sure LTTng does not | |
49 | * trigger recursive page faults. | |
50 | */ | |
e36de50d MD |
51 | printk_once(KERN_WARNING "LTTng: vmalloc_sync_all symbol lookup failed.\n"); |
52 | printk_once(KERN_WARNING "Page fault handler and NMI tracing might trigger faults.\n"); | |
6d2a620c MD |
53 | #endif |
54 | } | |
55 | } | |
56 | #else | |
57 | ||
6d2a620c MD |
58 | static inline |
59 | void wrapper_vmalloc_sync_all(void) | |
60 | { | |
61 | return vmalloc_sync_all(); | |
62 | } | |
63 | #endif | |
b13f3ebe | 64 | |
48f5e0b5 MJ |
65 | #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0)) |
66 | static inline | |
67 | void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node) | |
68 | { | |
69 | void *ret; | |
70 | ||
71 | ret = kvmalloc_node(size, flags, node); | |
72 | if (is_vmalloc_addr(ret)) { | |
73 | /* | |
74 | * Make sure we don't trigger recursive page faults in the | |
75 | * tracing fast path. | |
76 | */ | |
77 | wrapper_vmalloc_sync_all(); | |
78 | } | |
79 | return ret; | |
80 | } | |
81 | ||
82 | static inline | |
83 | void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node) | |
84 | { | |
85 | return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node); | |
86 | } | |
87 | ||
88 | static inline | |
89 | void *lttng_kvmalloc(unsigned long size, gfp_t flags) | |
90 | { | |
91 | return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE); | |
92 | } | |
93 | ||
94 | static inline | |
95 | void *lttng_kvzalloc(unsigned long size, gfp_t flags) | |
96 | { | |
97 | return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE); | |
98 | } | |
99 | ||
100 | static inline | |
101 | void lttng_kvfree(const void *addr) | |
102 | { | |
103 | kvfree(addr); | |
104 | } | |
105 | ||
106 | #else | |
107 | ||
108 | #include <linux/slab.h> | |
48f5e0b5 | 109 | |
20eb87c9 MD |
110 | static inline |
111 | void print_vmalloc_node_range_warning(void) | |
112 | { | |
113 | printk_once(KERN_WARNING "LTTng: __vmalloc_node_range symbol lookup failed.\n"); | |
114 | printk_once(KERN_WARNING "Tracer performance will be degraded on NUMA systems.\n"); | |
115 | printk_once(KERN_WARNING "Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n"); | |
116 | } | |
117 | ||
48f5e0b5 MJ |
118 | /* |
119 | * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node. | |
120 | */ | |
121 | static inline | |
20eb87c9 MD |
122 | void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align, |
123 | unsigned long start, unsigned long end, gfp_t gfp_mask, | |
124 | pgprot_t prot, unsigned long vm_flags, int node, | |
125 | const void *caller) | |
48f5e0b5 | 126 | { |
48f5e0b5 MJ |
127 | #ifdef CONFIG_KALLSYMS |
128 | /* | |
20eb87c9 | 129 | * If we have KALLSYMS, get * __vmalloc_node_range which is not exported. |
48f5e0b5 | 130 | */ |
20eb87c9 MD |
131 | void *(*lttng__vmalloc_node_range)(unsigned long size, unsigned long align, |
132 | unsigned long start, unsigned long end, gfp_t gfp_mask, | |
133 | pgprot_t prot, unsigned long vm_flags, int node, | |
134 | const void *caller); | |
135 | ||
136 | lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range"); | |
137 | if (lttng__vmalloc_node_range) | |
138 | return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot, | |
139 | vm_flags, node, caller); | |
48f5e0b5 | 140 | #endif |
20eb87c9 MD |
141 | if (node != NUMA_NO_NODE) |
142 | print_vmalloc_node_range_warning(); | |
143 | return __vmalloc(size, gfp_mask, prot); | |
48f5e0b5 MJ |
144 | } |
145 | ||
146 | /** | |
147 | * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon | |
148 | * failure, fall back to non-contiguous (vmalloc) allocation. | |
149 | * @size: size of the request. | |
150 | * @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL. | |
151 | * | |
152 | * Uses kmalloc to get the memory but if the allocation fails then falls back | |
153 | * to the vmalloc allocator. Use lttng_kvfree to free the memory. | |
154 | * | |
155 | * Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported | |
156 | */ | |
157 | static inline | |
158 | void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node) | |
159 | { | |
160 | void *ret; | |
161 | ||
162 | /* | |
163 | * vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables) | |
164 | * so the given set of flags has to be compatible. | |
165 | */ | |
166 | WARN_ON_ONCE((flags & GFP_KERNEL) != GFP_KERNEL); | |
167 | ||
168 | /* | |
169 | * If the allocation fits in a single page, do not fallback. | |
170 | */ | |
171 | if (size <= PAGE_SIZE) { | |
172 | return kmalloc_node(size, flags, node); | |
173 | } | |
174 | ||
175 | /* | |
176 | * Make sure that larger requests are not too disruptive - no OOM | |
177 | * killer and no allocation failure warnings as we have a fallback | |
178 | */ | |
179 | ret = kmalloc_node(size, flags | __GFP_NOWARN | __GFP_NORETRY, node); | |
180 | if (!ret) { | |
20eb87c9 MD |
181 | ret = __lttng_vmalloc_node_range(size, 1, |
182 | VMALLOC_START, VMALLOC_END, | |
183 | flags | __GFP_HIGHMEM, PAGE_KERNEL, 0, | |
184 | node, __builtin_return_address(0)); | |
48f5e0b5 MJ |
185 | /* |
186 | * Make sure we don't trigger recursive page faults in the | |
187 | * tracing fast path. | |
188 | */ | |
189 | wrapper_vmalloc_sync_all(); | |
190 | } | |
191 | return ret; | |
192 | } | |
193 | ||
194 | static inline | |
195 | void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node) | |
196 | { | |
197 | return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node); | |
198 | } | |
199 | ||
200 | static inline | |
201 | void *lttng_kvmalloc(unsigned long size, gfp_t flags) | |
202 | { | |
203 | return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE); | |
204 | } | |
205 | ||
206 | static inline | |
207 | void *lttng_kvzalloc(unsigned long size, gfp_t flags) | |
208 | { | |
209 | return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE); | |
210 | } | |
211 | ||
212 | static inline | |
213 | void lttng_kvfree(const void *addr) | |
214 | { | |
215 | if (is_vmalloc_addr(addr)) { | |
216 | vfree(addr); | |
217 | } else { | |
218 | kfree(addr); | |
219 | } | |
220 | } | |
221 | #endif | |
222 | ||
a90917c3 | 223 | #endif /* _LTTNG_WRAPPER_VMALLOC_H */ |