Created
August 24, 2024 06:59
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| diff --git a/lib.rs b/lib.rs | |
| index aa9c0fd..0742832 100644 | |
| --- a/lib.rs | |
| +++ b/lib.rs | |
| @@ -623,6 +623,29 @@ impl Macho { | |
| writer.write_all(self.linkedit_cmd.as_bytes())?; | |
| continue; | |
| } | |
| + | |
| + // Update the static in the __SUI_INTERNAL,__START segment to the address of the | |
| + // new section | |
| + const INTERNAL_START: [u8; 16] = *b"__SUI_INTERNAL\0\0"; | |
| + if segcmd.segname[..INTERNAL_START.len()] == INTERNAL_START { | |
| + // Find the offset of the __SUI_INTERNAL,__START data | |
| + let start_offset = segcmd.fileoff as usize; | |
| + let start_addr = self.seg.vmaddr; | |
| + | |
| + let orig = u64::from_le_bytes( | |
| + self.data[start_offset..start_offset + 8] | |
| + .try_into() | |
| + .unwrap(), | |
| + ); | |
| + println!("Original start address: 0x{:x}", orig); | |
| + println!("New start address: 0x{:x}", start_addr); | |
| + // Update the data at the offset | |
| + self.data[start_offset..start_offset + 8] | |
| + .copy_from_slice(&start_addr.to_le_bytes()); | |
| + // Length of the data | |
| + self.data[start_offset + 8..start_offset + 16] | |
| + .copy_from_slice(&(self.sec.size as u64).to_le_bytes()); | |
| + } | |
| } | |
| writer.write_all(&self.data[*offset..*offset + *cmdsize as usize])?; | |
| } | |
| @@ -665,6 +688,10 @@ mod macho { | |
| use std::ffi::CString; | |
| use std::os::raw::c_char; | |
| + #[link_section = "__SUI_INTERNAL,__START"] | |
| + #[used] | |
| + pub static mut START: [usize; 2] = [0, 0]; | |
| + | |
| extern "C" { | |
| pub fn getsectdata( | |
| segname: *const c_char, | |
| @@ -680,19 +707,29 @@ mod macho { | |
| let section_name = CString::new(section_name).ok()?; | |
| unsafe { | |
| + let vmaddr_slide = _dyld_get_image_vmaddr_slide(0); | |
| + if START[0] != 0 { | |
| + // Add the "virtual memory address slide" amount to ensure a valid pointer | |
| + // in cases where the virtual memory address have been adjusted by the OS. | |
| + return Some(std::slice::from_raw_parts( | |
| + (START[0] + vmaddr_slide) as *const u8, | |
| + START[1], | |
| + )); | |
| + } | |
| + | |
| let mut ptr = getsectdata( | |
| SEGNAME.as_ptr() as *const c_char, | |
| section_name.as_ptr() as *const c_char, | |
| &mut section_size as *mut usize, | |
| ); | |
| - if ptr.is_null() { | |
| + if ptr.is_null() || section_size == 0 { | |
| return None; | |
| } | |
| // Add the "virtual memory address slide" amount to ensure a valid pointer | |
| // in cases where the virtual memory address have been adjusted by the OS. | |
| - ptr = ptr.wrapping_add(_dyld_get_image_vmaddr_slide(0)); | |
| + ptr = ptr.wrapping_add(vmaddr_slide); | |
| Some(std::slice::from_raw_parts(ptr as *const u8, section_size)) | |
| } | |
| } |
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