| author |  LemonBoy <thatlemon@gmail.com> 2020-11-23 12:00:12+01:00 |
| committer | LemonBoy <thatlemon@gmail.com> 2020-11-23 12:00:12+01:00 |
| log | 560043dadfa8bf3a6c15d7f09bfbc60e48e0084c |
| tree | 035eaee95973b7387dd56b4ef6226d5f6d983dbf |
| parent | c7170e4a5480581db5f30913eebd9ad4f7cd121e |
Fix logic for detecting _DYNAMIC symbol
Prevent spurious crashes for non-PIE executables.2 files changed, 5 insertions(+), 15 deletions(-)
lib/std/dynamic_library.zig+3-15
| ... | ... | @@ -59,24 +59,12 @@ const RDebug = extern struct { |
| 59 | 59 | r_ldbase: usize, |
| 60 | 60 | }; |
| 61 | 61 | |
| 62 | // TODO: This should be weak (#1917) | |
| 63 | extern var _DYNAMIC: [128]elf.Dyn; | |
| 64 | ||
| 65 | comptime { | |
| 66 | if (std.Target.current.os.tag == .linux) { | |
| 67 | asm ( | |
| 68 | \\ .weak _DYNAMIC | |
| 69 | \\ .hidden _DYNAMIC | |
| 70 | ); | |
| 71 | } | |
| 72 | } | |
| 73 | ||
| 74 | 62 | pub fn linkmap_iterator(phdrs: []elf.Phdr) !LinkMap.Iterator { |
| 75 | if (@ptrToInt(&_DYNAMIC[0]) == 0) { | |
| 63 | const _DYNAMIC = @extern([*]elf.Dyn, .{ .name = "_DYNAMIC", .linkage = .Weak }) orelse { | |
| 76 | 64 | // No PT_DYNAMIC means this is either a statically-linked program or a |
| 77 | // badly corrupted one | |
| 65 | // badly corrupted dynamically-linked one. | |
| 78 | 66 | return LinkMap.Iterator{ .current = null }; |
| 79 | } | |
| 67 | }; | |
| 80 | 68 | |
| 81 | 69 | const link_map_ptr = init: { |
| 82 | 70 | var i: usize = 0; |
lib/std/process.zig+2
| ... | ... | @@ -686,6 +686,8 @@ pub fn getBaseAddress() usize { |
| 686 | 686 | if (base != 0) { |
| 687 | 687 | return base; |
| 688 | 688 | } |
| 689 | // XXX: Wrong for PIE executables, it should look at the difference | |
| 690 | // between _DYNAMIC and the PT_DYNAMIC phdr instead. | |
| 689 | 691 | const phdr = os.system.getauxval(std.elf.AT_PHDR); |
| 690 | 692 | return phdr - @sizeOf(std.elf.Ehdr); |
| 691 | 693 | }, |