| ... | @@ -19,6 +19,85 @@ pub const DynLib = switch (builtin.os) { | ... | @@ -19,6 +19,85 @@ pub const DynLib = switch (builtin.os) { |
| 19 | else => void, | 19 | else => void, |
| 20 | }; | 20 | }; |
| 21 | | 21 | |
| | 22 | const LinkMap = extern struct { |
| | 23 | l_addr: usize, |
| | 24 | l_name: [*]u8, |
| | 25 | l_ld: [*c]elf.Dyn, |
| | 26 | l_next: [*c]LinkMap, |
| | 27 | l_prev: [*c]LinkMap, |
| | 28 | |
| | 29 | pub const Iterator = struct { |
| | 30 | lm_ptr: [*c]LinkMap, |
| | 31 | |
| | 32 | fn end(self: *const Iterator) bool { |
| | 33 | return self.lm_ptr == 0; |
| | 34 | } |
| | 35 | |
| | 36 | fn next(self: *Iterator) ?*LinkMap { |
| | 37 | if (self.lm_ptr != 0) { |
| | 38 | const ptr = self.lm_ptr; |
| | 39 | self.lm_ptr = self.lm_ptr.*.l_next; |
| | 40 | return ptr; |
| | 41 | } |
| | 42 | return null; |
| | 43 | } |
| | 44 | }; |
| | 45 | }; |
| | 46 | |
| | 47 | const RDebug = extern struct { |
| | 48 | r_version: i32, |
| | 49 | r_map: [*c]LinkMap, |
| | 50 | r_brk: usize, |
| | 51 | r_ldbase: usize, |
| | 52 | }; |
| | 53 | |
| | 54 | fn elf_get_va_offset(phdrs: []elf.Phdr) !usize { |
| | 55 | for (phdrs) |*phdr| { |
| | 56 | if (phdr.p_type == elf.PT_LOAD) { |
| | 57 | return @ptrToInt(phdr) - phdr.p_vaddr; |
| | 58 | } |
| | 59 | } |
| | 60 | return error.InvalidExe; |
| | 61 | } |
| | 62 | |
| | 63 | pub fn linkmap_iterator(phdrs: []elf.Phdr) !LinkMap.Iterator { |
| | 64 | const va_offset = try elf_get_va_offset(phdrs); |
| | 65 | |
| | 66 | const dyn_table = init: { |
| | 67 | for (phdrs) |*phdr| { |
| | 68 | if (phdr.p_type == elf.PT_DYNAMIC) { |
| | 69 | const ptr = @intToPtr([*]elf.Dyn, va_offset + phdr.p_vaddr); |
| | 70 | break :init ptr[0..phdr.p_memsz / @sizeOf(elf.Dyn)]; |
| | 71 | } |
| | 72 | } |
| | 73 | // No PT_DYNAMIC means this is either a statically-linked program or a |
| | 74 | // badly corrupted one |
| | 75 | return LinkMap.Iterator{.lm_ptr = 0}; |
| | 76 | }; |
| | 77 | |
| | 78 | const link_map_ptr = init: { |
| | 79 | for (dyn_table) |*dyn| { |
| | 80 | switch (dyn.d_tag) { |
| | 81 | elf.DT_DEBUG => { |
| | 82 | const r_debug = @intToPtr(*RDebug, dyn.d_un.d_ptr); |
| | 83 | if (r_debug.r_version != 1) return error.InvalidExe; |
| | 84 | break :init r_debug.r_map; |
| | 85 | }, |
| | 86 | elf.DT_PLTGOT => { |
| | 87 | const got_table = @intToPtr([*]usize, dyn.d_un.d_ptr); |
| | 88 | // The address to the link_map structure is stored in the |
| | 89 | // second slot |
| | 90 | break :init @intToPtr([*c]LinkMap, got_table[1]); |
| | 91 | }, |
| | 92 | else => { } |
| | 93 | } |
| | 94 | } |
| | 95 | return error.InvalidExe; |
| | 96 | }; |
| | 97 | |
| | 98 | return LinkMap.Iterator{.lm_ptr = link_map_ptr}; |
| | 99 | } |
| | 100 | |
| 22 | pub const LinuxDynLib = struct { | 101 | pub const LinuxDynLib = struct { |
| 23 | elf_lib: ElfLib, | 102 | elf_lib: ElfLib, |
| 24 | fd: i32, | 103 | fd: i32, |
LemonBoy <thatlemon@gmail.com> 2019-04-24 20:54:17+02:00