include/wrapper/vmalloc.h

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * wrapper/vmalloc.h
   4  *
   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
   7  * modules.
   8  *
   9  * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  10  */
  11
  12 #ifndef _LTTNG_WRAPPER_VMALLOC_H
  13 #define _LTTNG_WRAPPER_VMALLOC_H
  14
  15 #include <lttng/kernel-version.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/slab.h>
  18 #include <linux/mm.h>
  19
  20 #ifdef CONFIG_KALLSYMS
  21
  22 #include <linux/kallsyms.h>
  23 #include <wrapper/kallsyms.h>
  24 #include <lttng/kernel-version.h>
  25
  26 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,8,0))
  27
  28 /*
  29  * wrapper_vmalloc_sync_mappings was removed in v5.8, the vmalloc mappings
  30  * are now synchronized when they are created or torn down.
  31  */
  32 static inline
  33 void wrapper_vmalloc_sync_mappings(void)
  34 {}
  35
  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))
  48
  49 static inline
  50 void wrapper_vmalloc_sync_mappings(void)
  51 {
  52         void (*vmalloc_sync_mappings_sym)(void);
  53
  54         vmalloc_sync_mappings_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_mappings");
  55         if (vmalloc_sync_mappings_sym) {
  56                 vmalloc_sync_mappings_sym();
  57         } else {
  58 #ifdef CONFIG_X86
  59                 /*
  60                  * Only x86 needs vmalloc_sync_mappings to make sure LTTng does not
  61                  * trigger recursive page faults.
  62                  */
  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");
  65 #endif
  66         }
  67 }
  68
  69 /*
  70  * Canary function to check for 'vmalloc_sync_mappings()' at compile time.
  71  *
  72  * From 'include/linux/vmalloc.h':
  73  *
  74  *   void vmalloc_sync_mappings(void);
  75  */
  76 static inline
  77 void __canary__vmalloc_sync_mappings(void)
  78 {
  79         vmalloc_sync_mappings();
  80 }
  81
  82 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
  83
  84 /*
  85  * Map vmalloc_sync_mappings to vmalloc_sync_all() on kernels before 5.6.
  86  */
  87 static inline
  88 void wrapper_vmalloc_sync_mappings(void)
  89 {
  90         void (*vmalloc_sync_all_sym)(void);
  91
  92         vmalloc_sync_all_sym = (void *) kallsyms_lookup_funcptr("vmalloc_sync_all");
  93         if (vmalloc_sync_all_sym) {
  94                 vmalloc_sync_all_sym();
  95         } else {
  96 #ifdef CONFIG_X86
  97                 /*
  98                  * Only x86 needs vmalloc_sync_all to make sure LTTng does not
  99                  * trigger recursive page faults.
 100                  */
 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");
 103 #endif
 104         }
 105 }
 106
 107 /*
 108  * Canary function to check for 'vmalloc_sync_all()' at compile time.
 109  *
 110  * From 'include/linux/vmalloc.h':
 111  *
 112  *   void vmalloc_sync_all(void);
 113  */
 114 static inline
 115 void __canary__vmalloc_sync_all(void)
 116 {
 117         vmalloc_sync_all();
 118 }
 119
 120 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
 121
 122 #else /* CONFIG_KALLSYMS */
 123
 124 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,8,0))
 125
 126 /*
 127  * wrapper_vmalloc_sync_mappings was removed in v5.8, the vmalloc mappings
 128  * are now synchronized when they are created or torn down.
 129  */
 130 static inline
 131 void wrapper_vmalloc_sync_mappings(void)
 132 {}
 133
 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)
 145
 146 static inline
 147 void wrapper_vmalloc_sync_mappings(void)
 148 {
 149         return vmalloc_sync_mappings();
 150 }
 151
 152 #else /* #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
 153
 154 static inline
 155 void wrapper_vmalloc_sync_mappings(void)
 156 {
 157         return vmalloc_sync_all();
 158 }
 159
 160 #endif /* #else #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0)) */
 161
 162 #endif
 163
 164 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,12,0))
 165 static inline
 166 void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
 167 {
 168         void *ret;
 169
 170         ret = kvmalloc_node(size, flags, node);
 171         if (is_vmalloc_addr(ret)) {
 172                 /*
 173                  * Make sure we don't trigger recursive page faults in the
 174                  * tracing fast path.
 175                  */
 176                 wrapper_vmalloc_sync_mappings();
 177         }
 178         return ret;
 179 }
 180
 181 static inline
 182 void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
 183 {
 184         return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node);
 185 }
 186
 187 static inline
 188 void *lttng_kvmalloc(unsigned long size, gfp_t flags)
 189 {
 190         return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
 191 }
 192
 193 static inline
 194 void *lttng_kvzalloc(unsigned long size, gfp_t flags)
 195 {
 196         return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
 197 }
 198
 199 static inline
 200 void lttng_kvfree(const void *addr)
 201 {
 202         kvfree(addr);
 203 }
 204
 205 #else
 206
 207 #include <linux/slab.h>
 208
 209 static inline
 210 void print_vmalloc_node_range_warning(void)
 211 {
 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");
 215 }
 216
 217 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(4,0,0))
 218
 219 /*
 220  * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
 221  */
 222 static inline
 223 void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align,
 224                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 225                         pgprot_t prot, unsigned long vm_flags, int node,
 226                         const void *caller)
 227 {
 228 #ifdef CONFIG_KALLSYMS
 229         /*
 230          * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
 231          */
 232         void *(*lttng__vmalloc_node_range)(unsigned long size, unsigned long align,
 233                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 234                         pgprot_t prot, unsigned long vm_flags, int node,
 235                         const void *caller);
 236
 237         lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
 238         if (lttng__vmalloc_node_range)
 239                 return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot,
 240                                 vm_flags, node, caller);
 241 #endif
 242         if (node != NUMA_NO_NODE)
 243                 print_vmalloc_node_range_warning();
 244         return __vmalloc(size, gfp_mask, prot);
 245 }
 246
 247 /*
 248  * Canary function to check for '__vmalloc_node_range()' at compile time.
 249  *
 250  * From 'include/linux/vmalloc.h':
 251  *
 252  *   extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
 253  *                           unsigned long start, unsigned long end, gfp_t gfp_mask,
 254  *                           pgprot_t prot, unsigned long vm_flags, int node,
 255  *                           const void *caller);
 256  */
 257 static inline
 258 void *__canary____lttng_vmalloc_node_range(unsigned long size, unsigned long align,
 259                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 260                         pgprot_t prot, unsigned long vm_flags, int node,
 261                         const void *caller)
 262 {
 263         return __vmalloc_node_range(size, align, start, end, gfp_mask, prot,
 264                         vm_flags, node, caller);
 265 }
 266
 267 #elif (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,6,0))
 268
 269 /*
 270  * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
 271  */
 272 static inline
 273 void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align,
 274                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 275                         pgprot_t prot, unsigned long vm_flags, int node,
 276                         const void *caller)
 277 {
 278 #ifdef CONFIG_KALLSYMS
 279         /*
 280          * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
 281          */
 282         void *(*lttng__vmalloc_node_range)(unsigned long size, unsigned long align,
 283                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 284                         pgprot_t prot, int node, const void *caller);
 285
 286         lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
 287         if (lttng__vmalloc_node_range)
 288                 return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot,
 289                                 node, caller);
 290 #endif
 291         if (node != NUMA_NO_NODE)
 292                 print_vmalloc_node_range_warning();
 293         return __vmalloc(size, gfp_mask, prot);
 294 }
 295
 296 /*
 297  * Canary function to check for '__vmalloc_node_range()' at compile time.
 298  *
 299  * From 'include/linux/vmalloc.h':
 300  *
 301  *   extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
 302  *                           unsigned long start, unsigned long end, gfp_t gfp_mask,
 303  *                           pgprot_t prot, unsigned long vm_flags, int node,
 304  *                           const void *caller);
 305  */
 306 static inline
 307 void *__canary____lttng_vmalloc_node_range(unsigned long size, unsigned long align,
 308                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 309                         pgprot_t prot, int node, const void *caller)
 310 {
 311         return __vmalloc_node_range(size, align, start, end, gfp_mask, prot,
 312                         node, caller);
 313 }
 314
 315 #else /* (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(3,6,0)) */
 316
 317 /*
 318  * kallsyms wrapper of __vmalloc_node with a fallback to kmalloc_node.
 319  */
 320 static inline
 321 void *__lttng_vmalloc_node_range(unsigned long size, unsigned long align,
 322                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 323                         pgprot_t prot, unsigned long vm_flags, int node,
 324                         void *caller)
 325 {
 326 #ifdef CONFIG_KALLSYMS
 327         /*
 328          * If we have KALLSYMS, get * __vmalloc_node_range which is not exported.
 329          */
 330         void *(*lttng__vmalloc_node_range)(unsigned long size, unsigned long align,
 331                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 332                         pgprot_t prot, int node, void *caller);
 333
 334         lttng__vmalloc_node_range = (void *) kallsyms_lookup_funcptr("__vmalloc_node_range");
 335         if (lttng__vmalloc_node_range)
 336                 return lttng__vmalloc_node_range(size, align, start, end, gfp_mask, prot,
 337                                 node, caller);
 338 #endif
 339         if (node != NUMA_NO_NODE)
 340                 print_vmalloc_node_range_warning();
 341         return __vmalloc(size, gfp_mask, prot);
 342 }
 343
 344 /*
 345  * Canary function to check for '__vmalloc_node_range()' at compile time.
 346  *
 347  * From 'include/linux/vmalloc.h':
 348  *
 349  *   extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
 350  *                           unsigned long start, unsigned long end, gfp_t gfp_mask,
 351  *                           pgprot_t prot, unsigned long vm_flags, int node,
 352  *                           void *caller);
 353  */
 354 static inline
 355 void *__canary____lttng_vmalloc_node_range(unsigned long size, unsigned long align,
 356                         unsigned long start, unsigned long end, gfp_t gfp_mask,
 357                         pgprot_t prot, int node, void *caller)
 358 {
 359         return __vmalloc_node_range(size, align, start, end, gfp_mask, prot,
 360                         node, caller);
 361 }
 362
 363 #endif
 364
 365 /**
 366  * lttng_kvmalloc_node - attempt to allocate physically contiguous memory, but upon
 367  * failure, fall back to non-contiguous (vmalloc) allocation.
 368  * @size: size of the request.
 369  * @flags: gfp mask for the allocation - must be compatible with GFP_KERNEL.
 370  *
 371  * Uses kmalloc to get the memory but if the allocation fails then falls back
 372  * to the vmalloc allocator. Use lttng_kvfree to free the memory.
 373  *
 374  * Reclaim modifiers - __GFP_NORETRY, __GFP_REPEAT and __GFP_NOFAIL are not supported
 375  */
 376 static inline
 377 void *lttng_kvmalloc_node(unsigned long size, gfp_t flags, int node)
 378 {
 379         void *ret;
 380
 381         /*
 382          * vmalloc uses GFP_KERNEL for some internal allocations (e.g page tables)
 383          * so the given set of flags has to be compatible.
 384          */
 385         WARN_ON_ONCE((flags & GFP_KERNEL) != GFP_KERNEL);
 386
 387         /*
 388          * If the allocation fits in a single page, do not fallback.
 389          */
 390         if (size <= PAGE_SIZE) {
 391                 return kmalloc_node(size, flags, node);
 392         }
 393
 394         /*
 395          * Make sure that larger requests are not too disruptive - no OOM
 396          * killer and no allocation failure warnings as we have a fallback
 397          */
 398         ret = kmalloc_node(size, flags | __GFP_NOWARN | __GFP_NORETRY, node);
 399         if (!ret) {
 400                 ret = __lttng_vmalloc_node_range(size, 1,
 401                                 VMALLOC_START, VMALLOC_END,
 402                                 flags | __GFP_HIGHMEM, PAGE_KERNEL, 0,
 403                                 node, __builtin_return_address(0));
 404                 /*
 405                  * Make sure we don't trigger recursive page faults in the
 406                  * tracing fast path.
 407                  */
 408                 wrapper_vmalloc_sync_mappings();
 409         }
 410         return ret;
 411 }
 412
 413 static inline
 414 void *lttng_kvzalloc_node(unsigned long size, gfp_t flags, int node)
 415 {
 416         return lttng_kvmalloc_node(size, flags | __GFP_ZERO, node);
 417 }
 418
 419 static inline
 420 void *lttng_kvmalloc(unsigned long size, gfp_t flags)
 421 {
 422         return lttng_kvmalloc_node(size, flags, NUMA_NO_NODE);
 423 }
 424
 425 static inline
 426 void *lttng_kvzalloc(unsigned long size, gfp_t flags)
 427 {
 428         return lttng_kvzalloc_node(size, flags, NUMA_NO_NODE);
 429 }
 430
 431 static inline
 432 void lttng_kvfree(const void *addr)
 433 {
 434         if (is_vmalloc_addr(addr)) {
 435                 vfree(addr);
 436         } else {
 437                 kfree(addr);
 438         }
 439 }
 440 #endif
 441
 442 #endif /* _LTTNG_WRAPPER_VMALLOC_H */