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 <linux/version.h>
16 #include <linux/vmalloc.h>
19 #ifdef CONFIG_KALLSYMS
21 #include <linux/kallsyms.h>
22 #include <wrapper/kallsyms.h>
23 #include <lttng/kernel-version.h>
25 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0) \
26 || LTTNG_KERNEL_RANGE(5,5,12, 5,6,0) \
27 || LTTNG_KERNEL_RANGE(5,4,28, 5,5,0) \
28 || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
29 || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
30 || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
31 || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
32 || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0)) \
33 || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,16,0,0) \
34 || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
35 || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)
38 void wrapper_vmalloc_sync_mappings(void)
40 void (*vmalloc_sync_mappings_sym
)(void);
42 vmalloc_sync_mappings_sym
= (void *) kallsyms_lookup_funcptr("vmalloc_sync_mappings");
43 if (vmalloc_sync_mappings_sym
) {
44 vmalloc_sync_mappings_sym();
48 * Only x86 needs vmalloc_sync_mappings to make sure LTTng does not
49 * trigger recursive page faults.
51 printk_once(KERN_WARNING
"LTTng: vmalloc_sync_mappings symbol lookup failed.\n");
52 printk_once(KERN_WARNING
"Page fault handler and NMI tracing might trigger faults.\n");
57 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
60 * Map vmalloc_sync_mappings to vmalloc_sync_all() on kernels before 5.7.
63 void wrapper_vmalloc_sync_mappings(void)
65 void (*vmalloc_sync_all_sym
)(void);
67 vmalloc_sync_all_sym
= (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
68 if (vmalloc_sync_all_sym
) {
69 vmalloc_sync_all_sym();
73 * Only x86 needs vmalloc_sync_all to make sure LTTng does not
74 * trigger recursive page faults.
76 printk_once(KERN_WARNING
"LTTng: vmalloc_sync_all symbol lookup failed.\n");
77 printk_once(KERN_WARNING
"Page fault handler and NMI tracing might trigger faults.\n");
82 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
86 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0) \
87 || LTTNG_KERNEL_RANGE(5,5,12, 5,6,0) \
88 || LTTNG_KERNEL_RANGE(5,4,28, 5,5,0) \
89 || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
90 || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
91 || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
92 || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
93 || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0)) \
94 || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,18,0,0) \
95 || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
96 || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)
99 void wrapper_vmalloc_sync_mappings(void)
101 return vmalloc_sync_mappings();
104 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
107 void wrapper_vmalloc_sync_mappings(void)
109 return vmalloc_sync_all();
112 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
116 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
118 void *lttng_kvmalloc_node(unsigned long size
, gfp_t flags
, int node
)
122 ret
= kvmalloc_node(size
, flags
, node
);
123 if (is_vmalloc_addr(ret
)) {
125 * Make sure we don't trigger recursive page faults in the
128 wrapper_vmalloc_sync_mappings();
134 void *lttng_kvzalloc_node(unsigned long size
, gfp_t flags
, int node
)
136 return lttng_kvmalloc_node(size
, flags
| __GFP_ZERO
, node
);
140 void *lttng_kvmalloc(unsigned long size
, gfp_t flags
)
142 return lttng_kvmalloc_node(size
, flags
, NUMA_NO_NODE
);
146 void *lttng_kvzalloc(unsigned long size
, gfp_t flags
)
148 return lttng_kvzalloc_node(size
, flags
, NUMA_NO_NODE
);
152 void lttng_kvfree(const void *addr
)
159 #include <linux/slab.h>
162 void print_vmalloc_node_range_warning(void)
164 printk_once(KERN_WARNING
"LTTng: __vmalloc_node_range symbol lookup failed.\n");
165 printk_once(KERN_WARNING
"Tracer performance will be degraded on NUMA systems.\n");
166 printk_once(KERN_WARNING
"Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n");
170 * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
173 void *__lttng_vmalloc_node_range(unsigned long size
, unsigned long align
,
174 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
175 pgprot_t prot
, unsigned long vm_flags
, int node
,
178 #ifdef CONFIG_KALLSYMS
180 * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
182 void *(*lttng__vmalloc_node_range
)(unsigned long size
, unsigned long align
,
183 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
184 pgprot_t prot
, unsigned long vm_flags
, int node
,
187 lttng__vmalloc_node_range
= (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
188 if (lttng__vmalloc_node_range
)
189 return lttng__vmalloc_node_range(size
, align
, start
, end
, gfp_mask
, prot
,
190 vm_flags
, node
, caller
);
192 if (node
!= NUMA_NO_NODE
)
193 print_vmalloc_node_range_warning();
194 return __vmalloc(size
, gfp_mask
, prot
);
198 * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
199 * failure, fall back to non-contiguous (vmalloc) allocation.
200 * @size: size of the request.
201 * @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
203 * Uses kmalloc to get the memory but if the allocation fails then falls back
204 * to the vmalloc allocator. Use lttng_kvfree to free the memory.
206 * Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
209 void *lttng_kvmalloc_node(unsigned long size
, gfp_t flags
, int node
)
214 * vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables)
215 * so the given set of flags has to be compatible.
217 WARN_ON_ONCE((flags
& GFP_KERNEL
) != GFP_KERNEL
);
220 * If the allocation fits in a single page, do not fallback.
222 if (size
<= PAGE_SIZE
) {
223 return kmalloc_node(size
, flags
, node
);
227 * Make sure that larger requests are not too disruptive - no OOM
228 * killer and no allocation failure warnings as we have a fallback
230 ret
= kmalloc_node(size
, flags
| __GFP_NOWARN
| __GFP_NORETRY
, node
);
232 ret
= __lttng_vmalloc_node_range(size
, 1,
233 VMALLOC_START
, VMALLOC_END
,
234 flags
| __GFP_HIGHMEM
, PAGE_KERNEL
, 0,
235 node
, __builtin_return_address(0));
237 * Make sure we don't trigger recursive page faults in the
240 wrapper_vmalloc_sync_mappings();
246 void *lttng_kvzalloc_node(unsigned long size
, gfp_t flags
, int node
)
248 return lttng_kvmalloc_node(size
, flags
| __GFP_ZERO
, node
);
252 void *lttng_kvmalloc(unsigned long size
, gfp_t flags
)
254 return lttng_kvmalloc_node(size
, flags
, NUMA_NO_NODE
);
258 void *lttng_kvzalloc(unsigned long size
, gfp_t flags
)
260 return lttng_kvzalloc_node(size
, flags
, NUMA_NO_NODE
);
264 void lttng_kvfree(const void *addr
)
266 if (is_vmalloc_addr(addr
)) {
274 #endif /* _LTTNG_WRAPPER_VMALLOC_H */