stripInstructionPtrAuthCode

Some platforms use pointer authentication - the upper bits of instruction pointers contain a signature. This function clears these signature bits to make the pointer usable.

Function parameters

Parameters

ptr:usize

How is this different than `Module` when the host is Windows?

Types

WindowsModule: How is this different than `Module` when the host is Windows?
UnwindContext
VirtualMachine: This is a virtual machine that runs DWARF call frame instructions.

Functions in this namespace

Functions

open
init
deinit
getModuleForAddress
getModuleNameForAddress
readElfDebugInfo: Reads debug info from an ELF file, or the current binary if none in specified.
unwindFrameMachO: Unwind a frame using MachO compact unwind info (from __unwind_info).
stripInstructionPtrAuthCode: Some platforms use pointer authentication - the upper bits of instruction pointers contain a signature.
unwindFrameDwarf: Unwind a stack frame using DWARF unwinding info, updating the register context.
supportsUnwinding: Tells whether unwinding for this target is *implemented* here in the Zig

Error sets in this namespace

Error Sets

OpenError

Tells whether unwinding for the host is implemented.

Values

supports_unwinding: Tells whether unwinding for the host is implemented.

Source

Implementation

pub inline fn stripInstructionPtrAuthCode(ptr: usize) usize {
    if (native_arch.isAARCH64()) {
        // `hint 0x07` maps to `xpaclri` (or `nop` if the hardware doesn't support it)
        // The save / restore is because `xpaclri` operates on x30 (LR)
        return asm (
            \\mov x16, x30
            \\mov x30, x15
            \\hint 0x07
            \\mov x15, x30
            \\mov x30, x16
            : [ret] "={x15}" (-> usize),
            : [ptr] "{x15}" (ptr),
            : .{ .x16 = true });
    }

    return ptr;
}