motiejus/zig

commit 3e2ddbfdd7e43788de51b3166e3dbc523c6b7b88 (tree)
parent 6f39ce93ce358743df0abe1acdac75f3fd6a2eab
Author: Jakub Konka <kubkon@jakubkonka.com>
Date:   Sun, 11 Dec 2022 08:49:20 +0100

Remove incorrect assertion in readMachODebugInfo panicking during panic

This fixes a class of bugs on macOS where a segfault happening in
a loaded dylib with no debug info would cause a panic in the panic
handler instead of simply noting that the dylib has no valid debug
info via `error.MissingDebugInfo`. An example could be code linking
some system dylib and causing some routine to segfault on say invalid
pointer value, which should normally cause Zig to print an incomplete
stack trace anchored at the currently loaded image and backtrace all
the way back to the Zig binary with valid debug info. Currently, in
a situation like this we would trigger a panic within a panic.

Diffstat:
M
lib/std/debug.zig
 | 
7
++++++-

1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/lib/std/debug.zig b/lib/std/debug.zig
@@ -1110,7 +1110,12 @@ fn readMachODebugInfo(allocator: mem.Allocator, macho_file: File) !ModuleDebugIn
             else => {},
         }
     }
-    assert(state == .oso_close);
+
+    switch (state) {
+        .init => return error.MissingDebugInfo,
+        .oso_close => {},
+        else => return error.InvalidDebugInfo,
+    }
 
     const symbols = allocator.shrink(symbols_buf, symbol_index);