1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
5 * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
6 * available, else we need to have a kernel that exports this function to GPL
9 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
12 #ifndef _LTTNG_WRAPPER_VMALLOC_H
13 #define _LTTNG_WRAPPER_VMALLOC_H
15 #include <lttng/kernel-version.h>
16 #include <linux/vmalloc.h>
17 #include <linux/slab.h>
20 #ifdef CONFIG_KALLSYMS
22 #include <linux/kallsyms.h>
23 #include <wrapper/kallsyms.h>
24 #include <lttng/kernel-version.h>
26 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,8,0))
29 * wrapper_vmalloc_sync_mappings was removed in v5.8, the vmalloc mappings
30 * are now synchronized when they are created or torn down.
33 void wrapper_vmalloc_sync_mappings(void)
36 #elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0) \
37 || LTTNG_KERNEL_RANGE(5,5,12, 5,6,0) \
38 || LTTNG_KERNEL_RANGE(5,4,28, 5,5,0) \
39 || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
40 || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
41 || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
42 || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
43 || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0) \
44 || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,16,0,0) \
45 || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
46 || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0) \
47 || LTTNG_RHEL_KERNEL_RANGE(4,18,0,240,0,0, 4,19,0,0,0,0))
50 void wrapper_vmalloc_sync_mappings(void)
52 void (*vmalloc_sync_mappings_sym
)(void);
54 vmalloc_sync_mappings_sym
= (void *) kallsyms_lookup_funcptr("vmalloc_sync_mappings");
55 if (vmalloc_sync_mappings_sym
) {
56 vmalloc_sync_mappings_sym();
60 * Only x86 needs vmalloc_sync_mappings to make sure LTTng does not
61 * trigger recursive page faults.
63 printk_once(KERN_WARNING
"LTTng: vmalloc_sync_mappings symbol lookup failed.\n");
64 printk_once(KERN_WARNING
"LTTng: Page fault handler and NMI tracing might trigger faults.\n");
70 * Canary function to check for 'vmalloc_sync_mappings()' at compile time.
72 * From 'include/linux/vmalloc.h':
74 * void vmalloc_sync_mappings(void);
77 void __canary__vmalloc_sync_mappings(void)
79 vmalloc_sync_mappings();
82 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
85 * Map vmalloc_sync_mappings to vmalloc_sync_all() on kernels before 5.6.
88 void wrapper_vmalloc_sync_mappings(void)
90 void (*vmalloc_sync_all_sym
)(void);
92 vmalloc_sync_all_sym
= (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
93 if (vmalloc_sync_all_sym
) {
94 vmalloc_sync_all_sym();
98 * Only x86 needs vmalloc_sync_all to make sure LTTng does not
99 * trigger recursive page faults.
101 printk_once(KERN_WARNING
"LTTng: vmalloc_sync_all symbol lookup failed.\n");
102 printk_once(KERN_WARNING
"LTTng: Page fault handler and NMI tracing might trigger faults.\n");
108 * Canary function to check for 'vmalloc_sync_all()' at compile time.
110 * From 'include/linux/vmalloc.h':
112 * void vmalloc_sync_all(void);
115 void __canary__vmalloc_sync_all(void)
120 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
122 #else /* CONFIG_KALLSYMS */
124 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,8,0))
127 * wrapper_vmalloc_sync_mappings was removed in v5.8, the vmalloc mappings
128 * are now synchronized when they are created or torn down.
131 void wrapper_vmalloc_sync_mappings(void)
134 #elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0) \
135 || LTTNG_KERNEL_RANGE(5,5,12, 5,6,0) \
136 || LTTNG_KERNEL_RANGE(5,4,28, 5,5,0) \
137 || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
138 || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
139 || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
140 || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
141 || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0)) \
142 || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,18,0,0) \
143 || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
144 || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)
147 void wrapper_vmalloc_sync_mappings(void)
149 return vmalloc_sync_mappings();
152 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
155 void wrapper_vmalloc_sync_mappings(void)
157 return vmalloc_sync_all();
160 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
162 #endif /* CONFIG_KALLSYMS */
164 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,12,0))
166 void *lttng_kvmalloc_node(unsigned long size
, gfp_t flags
, int node
)
170 ret
= kvmalloc_node(size
, flags
, node
);
171 if (is_vmalloc_addr(ret
)) {
173 * Make sure we don't trigger recursive page faults in the
176 wrapper_vmalloc_sync_mappings();
182 void *lttng_kvzalloc_node(unsigned long size
, gfp_t flags
, int node
)
184 return lttng_kvmalloc_node(size
, flags
| __GFP_ZERO
, node
);
188 void *lttng_kvmalloc(unsigned long size
, gfp_t flags
)
190 return lttng_kvmalloc_node(size
, flags
, NUMA_NO_NODE
);
194 void *lttng_kvzalloc(unsigned long size
, gfp_t flags
)
196 return lttng_kvzalloc_node(size
, flags
, NUMA_NO_NODE
);
200 void lttng_kvfree(const void *addr
)
205 #else /* >= LTTNG_KERNEL_VERSION(4,12,0) */
207 #include <linux/slab.h>
210 void print_vmalloc_node_range_warning(void)
212 printk_once(KERN_WARNING
"LTTng: __vmalloc_node_range symbol lookup failed.\n");
213 printk_once(KERN_WARNING
"LTTng: Tracer performance will be degraded on NUMA systems.\n");
214 printk_once(KERN_WARNING
"LTTng: Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n");
218 * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
221 void *__lttng_vmalloc_node_range(unsigned long size
, unsigned long align
,
222 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
223 pgprot_t prot
, unsigned long vm_flags
, int node
,
226 #ifdef CONFIG_KALLSYMS
228 * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
230 void *(*lttng__vmalloc_node_range
)(unsigned long size
, unsigned long align
,
231 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
232 pgprot_t prot
, unsigned long vm_flags
, int node
,
235 lttng__vmalloc_node_range
= (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
236 if (lttng__vmalloc_node_range
)
237 return lttng__vmalloc_node_range(size
, align
, start
, end
, gfp_mask
, prot
,
238 vm_flags
, node
, caller
);
240 if (node
!= NUMA_NO_NODE
)
241 print_vmalloc_node_range_warning();
242 return __vmalloc(size
, gfp_mask
, prot
);
246 * Canary function to check for '__vmalloc_node_range()' at compile time.
248 * From 'include/linux/vmalloc.h':
250 * extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
251 * unsigned long start, unsigned long end, gfp_t gfp_mask,
252 * pgprot_t prot, unsigned long vm_flags, int node,
253 * const void *caller);
256 void *__canary____lttng_vmalloc_node_range(unsigned long size
, unsigned long align
,
257 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
258 pgprot_t prot
, unsigned long vm_flags
, int node
,
261 return __vmalloc_node_range(size
, align
, start
, end
, gfp_mask
, prot
,
262 vm_flags
, node
, caller
);
266 * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
267 * failure, fall back to non-contiguous (vmalloc) allocation.
268 * @size: size of the request.
269 * @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
271 * Uses kmalloc to get the memory but if the allocation fails then falls back
272 * to the vmalloc allocator. Use lttng_kvfree to free the memory.
274 * Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
277 void *lttng_kvmalloc_node(unsigned long size
, gfp_t flags
, int node
)
282 * vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables)
283 * so the given set of flags has to be compatible.
285 WARN_ON_ONCE((flags
& GFP_KERNEL
) != GFP_KERNEL
);
288 * If the allocation fits in a single page, do not fallback.
290 if (size
<= PAGE_SIZE
) {
291 return kmalloc_node(size
, flags
, node
);
295 * Make sure that larger requests are not too disruptive - no OOM
296 * killer and no allocation failure warnings as we have a fallback
298 ret
= kmalloc_node(size
, flags
| __GFP_NOWARN
| __GFP_NORETRY
, node
);
300 ret
= __lttng_vmalloc_node_range(size
, 1,
301 VMALLOC_START
, VMALLOC_END
,
302 flags
| __GFP_HIGHMEM
, PAGE_KERNEL
, 0,
303 node
, __builtin_return_address(0));
305 * Make sure we don't trigger recursive page faults in the
308 wrapper_vmalloc_sync_mappings();
314 void *lttng_kvzalloc_node(unsigned long size
, gfp_t flags
, int node
)
316 return lttng_kvmalloc_node(size
, flags
| __GFP_ZERO
, node
);
320 void *lttng_kvmalloc(unsigned long size
, gfp_t flags
)
322 return lttng_kvmalloc_node(size
, flags
, NUMA_NO_NODE
);
326 void *lttng_kvzalloc(unsigned long size
, gfp_t flags
)
328 return lttng_kvzalloc_node(size
, flags
, NUMA_NO_NODE
);
332 void lttng_kvfree(const void *addr
)
334 if (is_vmalloc_addr(addr
)) {
340 #endif /* >= LTTNG_KERNEL_VERSION(4,12,0) */
342 #endif /* _LTTNG_WRAPPER_VMALLOC_H */