vendor/backtrace/src/symbolize/gimli/libs_dl_iterate_phdr.rs

   1 // Other Unix (e.g. Linux) platforms use ELF as an object file format
   2 // and typically implement an API called `dl_iterate_phdr` to load
   3 // native libraries.
   4
   5 use super::mystd::borrow::ToOwned;
   6 use super::mystd::env;
   7 use super::mystd::ffi::{CStr, OsStr};
   8 use super::mystd::os::unix::prelude::*;
   9 use super::{Library, LibrarySegment, OsString, Vec};
  10 use core::slice;
  11
  12 pub(super) fn native_libraries() -> Vec<Library> {
  13     let mut ret = Vec::new();
  14     unsafe {
  15         libc::dl_iterate_phdr(Some(callback), &mut ret as *mut Vec<_> as *mut _);
  16     }
  17     return ret;
  18 }
  19
  20 // `info` should be a valid pointers.
  21 // `vec` should be a valid pointer to a `std::Vec`.
  22 unsafe extern "C" fn callback(
  23     info: *mut libc::dl_phdr_info,
  24     _size: libc::size_t,
  25     vec: *mut libc::c_void,
  26 ) -> libc::c_int {
  27     let info = &*info;
  28     let libs = &mut *(vec as *mut Vec<Library>);
  29     let is_main_prog = info.dlpi_name.is_null() || *info.dlpi_name == 0;
  30     let name = if is_main_prog {
  31         if libs.is_empty() {
  32             env::current_exe().map(|e| e.into()).unwrap_or_default()
  33         } else {
  34             OsString::new()
  35         }
  36     } else {
  37         let bytes = CStr::from_ptr(info.dlpi_name).to_bytes();
  38         OsStr::from_bytes(bytes).to_owned()
  39     };
  40     let headers = slice::from_raw_parts(info.dlpi_phdr, info.dlpi_phnum as usize);
  41     libs.push(Library {
  42         name,
  43         segments: headers
  44             .iter()
  45             .map(|header| LibrarySegment {
  46                 len: (*header).p_memsz as usize,
  47                 stated_virtual_memory_address: (*header).p_vaddr as usize,
  48             })
  49             .collect(),
  50         bias: info.dlpi_addr as usize,
  51     });
  52     0
  53 }