Commit 23e212a9d0

Xavier Bouchoux <xavierb@gmail.com>
2022-10-15 16:58:29
std: check for overflow in dumpStackTraceFromBase
same change as [68e26a2ceea85a1] "std: check for overflow in writeCurrentStackTrace" On arm64 macOS, the address of the last frame is 0x0 rather than a positive value like 0x1 on x86_64 macOS, therefore, we overflow an integer trying to subtract 1 when printing the stack trace. This patch fixes it by first checking for this condition before trying to subtract 1. Same behaviour on i386-windows-msvc. Note that we do not need to signal the `SignalIterator` about this as it will correctly detect this condition on the subsequent iteration and return `null`, thus terminating the loop.
1 parent bd0dd22
Changed files (1)
lib
lib/std/debug.zig
@@ -187,7 +187,13 @@ pub fn dumpStackTraceFromBase(bp: usize, ip: usize) void {
         printSourceAtAddress(debug_info, stderr, ip, tty_config) catch return;
         var it = StackIterator.init(null, bp);
         while (it.next()) |return_address| {
-            printSourceAtAddress(debug_info, stderr, return_address - 1, tty_config) catch return;
+            // On arm64 macOS, the address of the last frame is 0x0 rather than 0x1 as on x86_64 macOS,
+            // therefore, we do a check for `return_address == 0` before subtracting 1 from it to avoid
+            // an overflow. We do not need to signal `StackIterator` as it will correctly detect this
+            // condition on the subsequent iteration and return `null` thus terminating the loop.
+            // same behaviour for i386-windows-msvc
+            const address = if (return_address == 0) return_address else return_address - 1;
+            printSourceAtAddress(debug_info, stderr, address, tty_config) catch return;
         }
     }
 }
@@ -563,6 +569,7 @@ pub fn writeCurrentStackTrace(
         // therefore, we do a check for `return_address == 0` before subtracting 1 from it to avoid
         // an overflow. We do not need to signal `StackIterator` as it will correctly detect this
         // condition on the subsequent iteration and return `null` thus terminating the loop.
+        // same behaviour for i386-windows-msvc
         const address = if (return_address == 0) return_address else return_address - 1;
         try printSourceAtAddress(debug_info, out_stream, address, tty_config);
     }