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ilo-amd64-openbsd.s: make use of pledge() and unveil()

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crc 2024-10-28 15:34:47 +01:00
parent a4832ca8c9
commit 9764ae2535
1 changed files with 57 additions and 44 deletions
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95
source/ilo-amd64-openbsd.s
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@ -1,7 +1,9 @@
/* AMD64 ilo, (c) 2023 Christopher Leonard, MIT License */
/* Adaptions to use libc on OpenBSD by Charles Childers */
.global main
.extern open, read, write, close, exit, lseek
.extern unveil, pledge
/* rax: top of stack */
/* rbx: data stack */
@ -32,6 +34,10 @@ default_blocks:
.asciz "ilo.blocks"
default_rom:
.asciz "ilo.rom"
pledges:
.asciz "stdio rpath wpath tty"
mode_rw:
.asciz "rw"
io_table:
.byte 0
@ -86,29 +92,29 @@ save_image:
ret
block_read:
mov (%rbx), %esi # Get the block number
shl $12, %esi # Multiply by 4096 (block size)
xor %edx, %edx # SEEK_SET
mov %rax, %rdi # File descriptor (from %rax)
call lseek # Call lseek
mov $4096, %edx # Number of bytes to read
lea (%r15, %r8, 4), %rsi # Buffer location
call read # Call read
mov -4(%rbx), %esi # Retrieve value from the stack
sub $8, %rbx # Update the stack pointer
mov (%rbx), %esi
shl $12, %esi
xor %edx, %edx
mov %rax, %rdi
call lseek
mov $4096, %edx
lea (%r15, %r8, 4), %rsi
call read
mov -4(%rbx), %esi
sub $8, %rbx
ret
block_write:
mov (%rbx), %esi # Get the block number
shl $12, %esi # Multiply by 4096 (block size)
xor %edx, %edx # SEEK_SET
mov %rax, %rdi # File descriptor (from %rax)
call lseek # Call lseek
mov $4096, %edx # Number of bytes to read
lea (%r15, %r8, 4), %rsi # Buffer location
mov (%rbx), %esi
shl $12, %esi
xor %edx, %edx
mov %rax, %rdi
call lseek
mov $4096, %edx
lea (%r15, %r8, 4), %rsi
call write
mov -4(%rbx), %esi # Retrieve value from the stack
sub $8, %rbx # Update the stack pointer
mov -4(%rbx), %esi
sub $8, %rbx
ret
.align 32
@ -292,33 +298,23 @@ io: mov %eax, %ecx
1: ret
ioa: push %rax
mov %rsp, %rsi /* buffer pointer */
mov $1, %edx /* write one byte */
mov $1, %edi /* file descriptor (stdout) */
mov %rsp, %rsi
mov $1, %edx
mov $1, %edi
call write
pop %rax
mov (%rbx), %eax
sub $4, %rbx
ret
xiob: add $4, %rbx
mov %eax, (%rbx)
push %rax
xor %edi, %edi /* file descriptor (stdin) */
mov %rsp, %rsi /* buffer pointer */
mov $1, %edx /* read one byte */
call read
pop %rax
ret
iob: add $4, %rbx
mov %eax, (%rbx)
xor %edi, %edi # %edi = 0 (stdin)
lea a(%rip), %rsi # Load address of 'a' into %rsi (buffer)
mov $1, %edx # %edx = 1 (read one byte)
call read # Call libc read: read(0, a, 1)
movzx a(%rip), %eax # Move the byte from 'a' into %eax (zero-extend)
ret
xor %edi, %edi
lea a(%rip), %rsi
mov $1, %edx
call read
movzx a(%rip), %eax
ret
ioc: mov %eax, %r8d
mov blocks(%rip), %rdi
@ -361,9 +357,25 @@ ioh: add $8, %rbx
shr $2, %eax
ret
main:
add_restrictions:
mov blocks(%rip), %rdi
lea mode_rw(%rip), %rsi
call unveil
xor %eax, %eax
mov rom(%rip), %rdi
lea mode_rw(%rip), %rsi
call unveil
xor %rdi, %rdi
xor %rsi, %rsi
call unveil
lea pledges(%rip), %rdi
xor %rsi, %rsi
call pledge
ret
main: xor %eax, %eax
lea memory(%rip), %r15
lea dstack-4(%rip), %rbx
lea astack-4(%rip), %r12
@ -385,7 +397,8 @@ main:
mov %rcx, blocks(%rip)
2: lea default_rom(%rip), %rcx
mov %rcx, rom(%rip)
3: call load_image
3: call add_restrictions
call load_image
_execute:
jmp 3f
.align 64