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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_EXECMEM_ALLOC_H
#define _LINUX_EXECMEM_ALLOC_H
#include <linux/types.h>
#include <linux/moduleloader.h>
#if (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)) && \
!defined(CONFIG_KASAN_VMALLOC)
#include <linux/kasan.h>
#define MODULE_ALIGN (PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
#else
#define MODULE_ALIGN PAGE_SIZE
#endif
/**
* enum execmem_type - types of executable memory ranges
*
* There are several subsystems that allocate executable memory.
* Architectures define different restrictions on placement,
* permissions, alignment and other parameters for memory that can be used
* by these subsystems.
* Types in this enum identify subsystems that allocate executable memory
* and let architectures define parameters for ranges suitable for
* allocations by each subsystem.
*
* @EXECMEM_DEFAULT: default parameters that would be used for types that
* are not explicitly defined.
* @EXECMEM_MODULE_TEXT: parameters for module text sections
* @EXECMEM_KPROBES: parameters for kprobes
* @EXECMEM_FTRACE: parameters for ftrace
* @EXECMEM_BPF: parameters for BPF
* @EXECMEM_MODULE_DATA: parameters for module data sections
* @EXECMEM_TYPE_MAX:
*/
enum execmem_type {
EXECMEM_DEFAULT,
EXECMEM_MODULE_TEXT = EXECMEM_DEFAULT,
EXECMEM_KPROBES,
EXECMEM_FTRACE,
EXECMEM_BPF,
EXECMEM_MODULE_DATA,
EXECMEM_TYPE_MAX,
};
/**
* enum execmem_range_flags - options for executable memory allocations
* @EXECMEM_KASAN_SHADOW: allocate kasan shadow
*/
enum execmem_range_flags {
EXECMEM_KASAN_SHADOW = (1 << 0),
};
/**
* struct execmem_range - definition of an address space suitable for code and
* related data allocations
* @start: address space start
* @end: address space end (inclusive)
* @fallback_start: start of the secondary address space range for fallback
* allocations on architectures that require it
* @fallback_end: start of the secondary address space (inclusive)
* @pgprot: permissions for memory in this address space
* @alignment: alignment required for text allocations
* @flags: options for memory allocations for this range
*/
struct execmem_range {
unsigned long start;
unsigned long end;
unsigned long fallback_start;
unsigned long fallback_end;
pgprot_t pgprot;
unsigned int alignment;
enum execmem_range_flags flags;
};
/**
* struct execmem_info - architecture parameters for code allocations
* @ranges: array of parameter sets defining architecture specific
* parameters for executable memory allocations. The ranges that are not
* explicitly initialized by an architecture use parameters defined for
* @EXECMEM_DEFAULT.
*/
struct execmem_info {
struct execmem_range ranges[EXECMEM_TYPE_MAX];
};
/**
* execmem_arch_setup - define parameters for allocations of executable memory
*
* A hook for architectures to define parameters for allocations of
* executable memory. These parameters should be filled into the
* @execmem_info structure.
*
* For architectures that do not implement this method a default set of
* parameters will be used
*
* Return: a structure defining architecture parameters and restrictions
* for allocations of executable memory
*/
struct execmem_info *execmem_arch_setup(void);
/**
* execmem_alloc - allocate executable memory
* @type: type of the allocation
* @size: how many bytes of memory are required
*
* Allocates memory that will contain executable code, either generated or
* loaded from kernel modules.
*
* Allocates memory that will contain data coupled with executable code,
* like data sections in kernel modules.
*
* The memory will have protections defined by architecture for executable
* region of the @type.
*
* Return: a pointer to the allocated memory or %NULL
*/
void *execmem_alloc(enum execmem_type type, size_t size);
/**
* execmem_free - free executable memory
* @ptr: pointer to the memory that should be freed
*/
void execmem_free(void *ptr);
#if defined(CONFIG_EXECMEM) && !defined(CONFIG_ARCH_WANTS_EXECMEM_LATE)
void execmem_init(void);
#else
static inline void execmem_init(void) {}
#endif
#endif /* _LINUX_EXECMEM_ALLOC_H */
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