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(5,4,28, 5,5,0) \
27 || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
28 || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
29 || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
30 || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
31 || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0)) \
32 || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,16,0,0) \
33 || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
34 || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)
37 void wrapper_vmalloc_sync_mappings(void)
39 void (*vmalloc_sync_mappings_sym
)(void);
41 vmalloc_sync_mappings_sym
= (void *) kallsyms_lookup_funcptr("vmalloc_sync_mappings");
42 if (vmalloc_sync_mappings_sym
) {
43 vmalloc_sync_mappings_sym();
47 * Only x86 needs vmalloc_sync_mappings to make sure LTTng does not
48 * trigger recursive page faults.
50 printk_once(KERN_WARNING
"LTTng: vmalloc_sync_mappings symbol lookup failed.\n");
51 printk_once(KERN_WARNING
"Page fault handler and NMI tracing might trigger faults.\n");
56 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
59 * Map vmalloc_sync_mappings to vmalloc_sync_all() on kernels before 5.7.
62 void wrapper_vmalloc_sync_mappings(void)
64 void (*vmalloc_sync_all_sym
)(void);
66 vmalloc_sync_all_sym
= (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
67 if (vmalloc_sync_all_sym
) {
68 vmalloc_sync_all_sym();
72 * Only x86 needs vmalloc_sync_all to make sure LTTng does not
73 * trigger recursive page faults.
75 printk_once(KERN_WARNING
"LTTng: vmalloc_sync_all symbol lookup failed.\n");
76 printk_once(KERN_WARNING
"Page fault handler and NMI tracing might trigger faults.\n");
81 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
85 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0) \
86 || LTTNG_KERNEL_RANGE(5,4,28, 5,5,0) \
87 || LTTNG_KERNEL_RANGE(5,2,37, 5,3,0) \
88 || LTTNG_KERNEL_RANGE(4,19,113, 4,20,0) \
89 || LTTNG_KERNEL_RANGE(4,14,175, 4,15,0) \
90 || LTTNG_KERNEL_RANGE(4,9,218, 4,10,0) \
91 || LTTNG_KERNEL_RANGE(4,4,218, 4,5,0)) \
92 || LTTNG_UBUNTU_KERNEL_RANGE(4,15,18,97, 4,18,0,0) \
93 || LTTNG_UBUNTU_KERNEL_RANGE(5,0,21,48, 5,1,0,0) \
94 || LTTNG_UBUNTU_KERNEL_RANGE(5,3,18,52, 5,4,0,0)
97 void wrapper_vmalloc_sync_mappings(void)
99 return vmalloc_sync_mappings();
102 #else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
105 void wrapper_vmalloc_sync_mappings(void)
107 return vmalloc_sync_all();
110 #endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0)) */
114 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,12,0))
116 void *lttng_kvmalloc_node(unsigned long size
, gfp_t flags
, int node
)
120 ret
= kvmalloc_node(size
, flags
, node
);
121 if (is_vmalloc_addr(ret
)) {
123 * Make sure we don't trigger recursive page faults in the
126 wrapper_vmalloc_sync_mappings();
132 void *lttng_kvzalloc_node(unsigned long size
, gfp_t flags
, int node
)
134 return lttng_kvmalloc_node(size
, flags
| __GFP_ZERO
, node
);
138 void *lttng_kvmalloc(unsigned long size
, gfp_t flags
)
140 return lttng_kvmalloc_node(size
, flags
, NUMA_NO_NODE
);
144 void *lttng_kvzalloc(unsigned long size
, gfp_t flags
)
146 return lttng_kvzalloc_node(size
, flags
, NUMA_NO_NODE
);
150 void lttng_kvfree(const void *addr
)
157 #include <linux/slab.h>
160 void print_vmalloc_node_range_warning(void)
162 printk_once(KERN_WARNING
"LTTng: __vmalloc_node_range symbol lookup failed.\n");
163 printk_once(KERN_WARNING
"Tracer performance will be degraded on NUMA systems.\n");
164 printk_once(KERN_WARNING
"Please rebuild your kernel with CONFIG_KALLSYMS enabled.\n");
168 * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
171 void *__lttng_vmalloc_node_range(unsigned long size
, unsigned long align
,
172 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
173 pgprot_t prot
, unsigned long vm_flags
, int node
,
176 #ifdef CONFIG_KALLSYMS
178 * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
180 void *(*lttng__vmalloc_node_range
)(unsigned long size
, unsigned long align
,
181 unsigned long start
, unsigned long end
, gfp_t gfp_mask
,
182 pgprot_t prot
, unsigned long vm_flags
, int node
,
185 lttng__vmalloc_node_range
= (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
186 if (lttng__vmalloc_node_range
)
187 return lttng__vmalloc_node_range(size
, align
, start
, end
, gfp_mask
, prot
,
188 vm_flags
, node
, caller
);
190 if (node
!= NUMA_NO_NODE
)
191 print_vmalloc_node_range_warning();
192 return __vmalloc(size
, gfp_mask
, prot
);
196 * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
197 * failure, fall back to non-contiguous (vmalloc) allocation.
198 * @size: size of the request.
199 * @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
201 * Uses kmalloc to get the memory but if the allocation fails then falls back
202 * to the vmalloc allocator. Use lttng_kvfree to free the memory.
204 * Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
207 void *lttng_kvmalloc_node(unsigned long size
, gfp_t flags
, int node
)
212 * vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables)
213 * so the given set of flags has to be compatible.
215 WARN_ON_ONCE((flags
& GFP_KERNEL
) != GFP_KERNEL
);
218 * If the allocation fits in a single page, do not fallback.
220 if (size
<= PAGE_SIZE
) {
221 return kmalloc_node(size
, flags
, node
);
225 * Make sure that larger requests are not too disruptive - no OOM
226 * killer and no allocation failure warnings as we have a fallback
228 ret
= kmalloc_node(size
, flags
| __GFP_NOWARN
| __GFP_NORETRY
, node
);
230 ret
= __lttng_vmalloc_node_range(size
, 1,
231 VMALLOC_START
, VMALLOC_END
,
232 flags
| __GFP_HIGHMEM
, PAGE_KERNEL
, 0,
233 node
, __builtin_return_address(0));
235 * Make sure we don't trigger recursive page faults in the
238 wrapper_vmalloc_sync_mappings();
244 void *lttng_kvzalloc_node(unsigned long size
, gfp_t flags
, int node
)
246 return lttng_kvmalloc_node(size
, flags
| __GFP_ZERO
, node
);
250 void *lttng_kvmalloc(unsigned long size
, gfp_t flags
)
252 return lttng_kvmalloc_node(size
, flags
, NUMA_NO_NODE
);
256 void *lttng_kvzalloc(unsigned long size
, gfp_t flags
)
258 return lttng_kvzalloc_node(size
, flags
, NUMA_NO_NODE
);
262 void lttng_kvfree(const void *addr
)
264 if (is_vmalloc_addr(addr
)) {
272 #endif /* _LTTNG_WRAPPER_VMALLOC_H */