Manos Pitsidianakis <manos.pitsidiana...@linaro.org> writes: > On Tue, Aug 5, 2025 at 7:00 PM Daniel P. Berrangé <berra...@redhat.com> wrote: >> >> On Tue, Aug 05, 2025 at 12:19:26PM +0300, Manos Pitsidianakis wrote: >> > Add a backtrace_on_error meson feature (enabled with >> > --enable-backtrace-on-error) that compiles system binaries with >> > -rdynamic option and prints a function backtrace on error to stderr. >> > >> > Example output by adding an unconditional error_setg on error_abort in >> > hw/arm/boot.c: >> > >> > ./qemu-system-aarch64(+0x13b4a2c) [0x55d015406a2c] >> > ./qemu-system-aarch64(+0x13b4abd) [0x55d015406abd] >> > ./qemu-system-aarch64(+0x13b4d49) [0x55d015406d49] >> > ./qemu-system-aarch64(error_setg_internal+0xe7) [0x55d015406f62] >> > ./qemu-system-aarch64(arm_load_dtb+0xbf) [0x55d014d7686f] >> > ./qemu-system-aarch64(+0xd2f1d8) [0x55d014d811d8] >> > ./qemu-system-aarch64(notifier_list_notify+0x44) [0x55d01540a282] >> > ./qemu-system-aarch64(qdev_machine_creation_done+0xa0) [0x55d01476ae17] >> > ./qemu-system-aarch64(+0xaa691e) [0x55d014af891e] >> > ./qemu-system-aarch64(qmp_x_exit_preconfig+0x72) [0x55d014af8a5d] >> > ./qemu-system-aarch64(qemu_init+0x2a89) [0x55d014afb657] >> > ./qemu-system-aarch64(main+0x2f) [0x55d01521e836] >> > /lib/x86_64-linux-gnu/libc.so.6(+0x29ca8) [0x7f3033d67ca8] >> > /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x85) [0x7f3033d67d65] >> > ./qemu-system-aarch64(_start+0x21) [0x55d0146814f1] >> > >> > Unexpected error in arm_load_dtb() at ../hw/arm/boot.c:529: >> >> From an end-user POV, IMHO the error messages need to be good enough >> that such backtraces aren't needed to understand the problem. For >> developers, GDB can give much better backtraces (file+line numbers, >> plus parameters plus local variables) in the ideally rare cases that >> the error message alone has insufficient info. So I'm not really >> convinced that programs (in general, not just QEMU) should try to >> create backtraces themselves. > > Hi Daniel, > > I don't think there's value in replacing gdb debugging with this, I > agree. I think it has value for "fire and forget" uses, when errors > happen unexpectedly and are hard to replicate and you only end up with > log entries and no easy way to debug it.
Enable core dumps. I doubt that's harder than recompiling and redeploying QEMU with backtraces enabled.
