| author |  Jakub Konka <kubkon@jakubkonka.com> 2021-08-02 11:10:07+02:00 |
| committer |  Andrew Kelley <andrew@ziglang.org> 2021-08-02 13:40:53-04:00 |
| log | 68e26a2ceea85a149cb23286504cbdcec1ae814e |
| tree | 7d7baf8c489b53b21df872efd3c10463b29ab65e |
| parent | 871f6343f4d36c5c048f3307e2a38d184e248826 |
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.
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 files changed, 6 insertions(+), 1 deletions(-)
lib
std
lib/std/debug.zig+6-1
| ... | ... | @@ -438,7 +438,12 @@ pub fn writeCurrentStackTrace( |
| 438 | 438 | } |
| 439 | 439 | var it = StackIterator.init(start_addr, null); |
| 440 | 440 | while (it.next()) |return_address| { |
| 441 | try printSourceAtAddress(debug_info, out_stream, return_address - 1, tty_config); | |
| 441 | // On arm64 macOS, the address of the last frame is 0x0 rather than 0x1 as on x86_64 macOS, | |
| 442 | // therefore, we do a check for `return_address == 0` before subtracting 1 from it to avoid | |
| 443 | // an overflow. We do not need to signal `StackIterator` as it will correctly detect this | |
| 444 | // condition on the subsequent iteration and return `null` thus terminating the loop. | |
| 445 | const address = if (return_address == 0) return_address else return_address - 1; | |
| 446 | try printSourceAtAddress(debug_info, out_stream, address, tty_config); | |
| 442 | 447 | } |
| 443 | 448 | } |
| 444 | 449 |