diff options
Diffstat (limited to 'lib/objc-asm.S')
| -rw-r--r-- | lib/objc-asm.S | 139 |
1 files changed, 44 insertions, 95 deletions
diff --git a/lib/objc-asm.S b/lib/objc-asm.S index 94d9de9..7bfe159 100644 --- a/lib/objc-asm.S +++ b/lib/objc-asm.S @@ -1,122 +1,71 @@ -/* These all forward to the IMP obtained from block->get_imp(block); this - * signature is just so that I don't have to have two different assembly - * implementations for the temporary and fake-old blocks. To make things - * confusing, we don't know whether it will be called as stret or not, so we - * have to guess. - * (Could avoid the guessing by generating custom assembly instead, like - * Substrate does, but meh.) - */ -.globl _temp_block_invoke -.section __TEXT,__text,regular,pure_instructions -#if defined(__x86_64__) -_temp_block_invoke: - push %rcx - mov 0x10(%rsi), %rax /* block if stret, else self */ - lea _temp_block_invoke(%rip), %rcx - cmp %rax, %rcx - pop %rcx - je 2f +#include "objc.h" +.text +.align _PAGE_SHIFT +#ifdef __arm__ +.thumb_func _remap_start +.thumb +#endif +.globl _remap_start +_remap_start: - mov 0x20(%rdi), %rax /* get_imp */ - push %rdi; push %rsi; push %rdx; push %rcx; push %r8; push %r9 - call *%rax - pop %r9; pop %r8; pop %rcx; pop %rdx; pop %rdi; pop %rsi - mov 0x28(%rsi), %rsi /* selector */ - jmp *%rax -2: /* stret */ - mov 0x20(%rsi), %rax /* get_imp */ +.set i, 0 +#define my_rpe (0b + (_PAGE_SIZE - i * TRAMPOLINE_SIZE + i * REMAP_PAGE_ENTRY_SIZE)) +.rept TRAMPOLINES_PER_PAGE +0: +#if defined(__x86_64__) push %rdi; push %rsi; push %rdx; push %rcx; push %r8; push %r9 - mov %rsi, %rdi - call *%rax - pop %r9; pop %r8; pop %rcx; pop %rsi; pop %rdx; pop %rdi - mov 0x28(%rdx), %rdx /* selector */ + lea my_rpe(%rip), %rdx + mov 8(%rdx), %rdi + mov 16(%rdx), %rsi + call *(%rdx) + pop %r9; pop %r8; pop %rcx; pop %rdx; pop %rsi; pop %rdi jmp *%rax #elif defined(__i386__) -_temp_block_invoke: call 1f 1: pop %edx - lea _temp_block_invoke-1b(%edx), %edx - mov 8(%esp), %ecx /* block if stret, else self */ - mov 0xc(%ecx), %eax - cmp %eax, %edx - je 2f - - mov 4(%esp), %eax /* block */ - push %eax - mov 0x14(%eax), %eax /* get_imp */ - call *%eax - add $4, %esp - mov 8(%esp), %edx /* self */ - mov 4(%esp), %ecx /* block */ - mov %edx, 4(%esp) - mov 0x18(%ecx), %ecx - mov %ecx, 8(%esp) - jmp *%eax -2: /* stret */ - int3 - mov 8(%esp), %eax /* block */ - push %eax - mov 0x14(%eax), %eax /* get_imp */ - call *%eax - add $4, %esp - int3 - mov 12(%esp), %ecx /* self */ - mov %ecx, 8(%esp) - mov 8(%esp), %ecx /* block */ - mov 0x18(%ecx), %ecx - mov %ecx, 12(%esp) + lea my_rpe-1b(%edx), %edx + push 8(%edx) + push 4(%edx) + call *(%edx) + add 8, %esp jmp *%eax #elif defined(__arm__) -.thumb_func _temp_block_invoke -.thumb -_temp_block_invoke: -1: - ldr r9, [r1, #0xc] - adr r12, 1b - cmp r9, r12 - beq 2f - push {r0-r4, lr} /* r4 for align */ - ldr r9, [r0, #0x14] - blx r9 - mov r12, r0 - pop {r0-r4, lr} + mov r3, #(my_rpe - 1f) + add r3, pc +1: + ldr r0, [r3, #4] + ldr r1, [r3, #8] + ldr r2, [r3] + blx r2 mov r9, r0 - mov r0, r1 - ldr r1, [r9, #0x18] - bx r12 -2: /* stret */ - push {r0-r3, lr} - ldr r9, [r1, #0x14] - blx r9 - mov r12, r0 - pop {r0-r3, lr} - mov r9, r1 - mov r1, r2 - ldr r2, [r9, #0x18] - bx r12 + pop {r0-r4, lr} + bx r9 #elif defined(__arm64__) -.align 2 -_temp_block_invoke: stp x7, x6, [sp, #-0x10]! stp x5, x4, [sp, #-0x10]! stp x3, x2, [sp, #-0x10]! stp x1, x0, [sp, #-0x10]! str x30, [sp, #-0x10]! - ldr x9, [x0, #0x20] - blr x9 - mov x10, x0 + ldr x0, my_rpe+4 + ldr x1, my_rpe+8 + ldr x2, my_rpe + blr x2 + mov x9, x0 ldr x30, [sp], #0x10 - ldp x0, x9, [sp], #0x10 + ldp x1, x0, [sp], #0x10 ldp x3, x2, [sp], #0x10 ldp x5, x4, [sp], #0x10 ldp x7, x6, [sp], #0x10 - ldr x1, [x9, #0x28] - br x10 + br x9 #else #error No forwarding assembly definition for this arch #endif + +.set i, i + 1 +.endr + |