1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_EXECMEM_ALLOC_H 3 #define _LINUX_EXECMEM_ALLOC_H 4 5 #include <linux/types.h> 6 #include <linux/moduleloader.h> 7 8 /** 9 * enum execmem_type - types of executable memory ranges 10 * 11 * There are several subsystems that allocate executable memory. 12 * Architectures define different restrictions on placement, 13 * permissions, alignment and other parameters for memory that can be used 14 * by these subsystems. 15 * Types in this enum identify subsystems that allocate executable memory 16 * and let architectures define parameters for ranges suitable for 17 * allocations by each subsystem. 18 * 19 * @EXECMEM_DEFAULT: default parameters that would be used for types that 20 * are not explicitly defined. 21 * @EXECMEM_MODULE_TEXT: parameters for module text sections 22 * @EXECMEM_KPROBES: parameters for kprobes 23 * @EXECMEM_FTRACE: parameters for ftrace 24 * @EXECMEM_BPF: parameters for BPF 25 * @EXECMEM_TYPE_MAX: 26 */ 27 enum execmem_type { 28 EXECMEM_DEFAULT, 29 EXECMEM_MODULE_TEXT = EXECMEM_DEFAULT, 30 EXECMEM_KPROBES, 31 EXECMEM_FTRACE, 32 EXECMEM_BPF, 33 EXECMEM_TYPE_MAX, 34 }; 35 36 /** 37 * struct execmem_range - definition of an address space suitable for code and 38 * related data allocations 39 * @start: address space start 40 * @end: address space end (inclusive) 41 * @pgprot: permissions for memory in this address space 42 * @alignment: alignment required for text allocations 43 */ 44 struct execmem_range { 45 unsigned long start; 46 unsigned long end; 47 pgprot_t pgprot; 48 unsigned int alignment; 49 }; 50 51 /** 52 * struct execmem_info - architecture parameters for code allocations 53 * @ranges: array of parameter sets defining architecture specific 54 * parameters for executable memory allocations. The ranges that are not 55 * explicitly initialized by an architecture use parameters defined for 56 * @EXECMEM_DEFAULT. 57 */ 58 struct execmem_info { 59 struct execmem_range ranges[EXECMEM_TYPE_MAX]; 60 }; 61 62 /** 63 * execmem_arch_setup - define parameters for allocations of executable memory 64 * 65 * A hook for architectures to define parameters for allocations of 66 * executable memory. These parameters should be filled into the 67 * @execmem_info structure. 68 * 69 * For architectures that do not implement this method a default set of 70 * parameters will be used 71 * 72 * Return: a structure defining architecture parameters and restrictions 73 * for allocations of executable memory 74 */ 75 struct execmem_info *execmem_arch_setup(void); 76 77 /** 78 * execmem_alloc - allocate executable memory 79 * @type: type of the allocation 80 * @size: how many bytes of memory are required 81 * 82 * Allocates memory that will contain executable code, either generated or 83 * loaded from kernel modules. 84 * 85 * The memory will have protections defined by architecture for executable 86 * region of the @type. 87 * 88 * Return: a pointer to the allocated memory or %NULL 89 */ 90 void *execmem_alloc(enum execmem_type type, size_t size); 91 92 /** 93 * execmem_free - free executable memory 94 * @ptr: pointer to the memory that should be freed 95 */ 96 void execmem_free(void *ptr); 97 98 #ifdef CONFIG_EXECMEM 99 void execmem_init(void); 100 #else 101 static inline void execmem_init(void) {} 102 #endif 103 104 #endif /* _LINUX_EXECMEM_ALLOC_H */ 105