infix_executable_t Struct Reference

Internal representation of an executable memory block for JIT code. More...

#include <infix_internals.h>

Public Attributes
int	shm_fd
void *	rx_ptr
void *	rw_ptr
size_t	size

Detailed Description

Internal representation of an executable memory block for JIT code.

This struct encapsulates the platform-specific details of allocating and managing executable memory in a way that is compliant with modern OS security features like W^X (Write XOR Execute). It supports two primary strategies:

1. Single-Mapping W^X (Windows/macOS/Android): A single memory region is allocated as Read-Write (rw_ptr). After the JIT compiler writes the machine code to this region, its permissions are changed to Read-Execute. In this model, rx_ptr and rw_ptr point to the same address.
2. Dual-Mapping W^X (Linux/BSD): A single underlying shared memory object is mapped into the process's address space twice: once as Read-Write (rw_ptr) and once as Read-Execute (rx_ptr). The pointers have different virtual addresses but point to the same physical memory. This is required on systems with stricter W^X enforcement.

Member Data Documentation

rw_ptr

void* infix_executable_t::rw_ptr

The read-write memory address. The JIT compiler writes machine code here.

rx_ptr

void* infix_executable_t::rx_ptr

The read-execute memory address. This is the callable function pointer.

shm_fd

int infix_executable_t::shm_fd

The file descriptor for shared memory on dual-mapping POSIX systems. -1 otherwise.

size

size_t infix_executable_t::size

The size of the allocated memory region in bytes.

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The documentation for this struct was generated from the following file:

• src/common/infix_internals.h