Hi, I've run into a problem with this change.
We (Yocto Project) upgraded to qemu 8.2.0 recently and after that we started seeing errors cross compiling webkitgtk on x86_64 for x86_64 during the introspection code which runs under user mode qemu. The error we see is: qemu-x86_64: QEMU internal SIGSEGV {code=MAPERR, addr=0x20} Segmentation fault e.g. here: https://autobuilder.yoctoproject.org/typhoon/#/builders/40/builds/8488/steps/11/logs/stdio This usually seems to happen on our debian 11 based autobuilder machines. I took one of the broken builds and bisected it to this change (commit 7b7a3366e142d3baeb3fd1d3660a50e7956c19eb). There was a change in output from commit 7dfd3ca8d95f9962cdd2ebdfcdd699279b98fa18, before that it was: ERROR:../git/accel/tcg/cpu-exec.c:532:cpu_exec_longjmp_cleanup: assertion failed: (cpu == current_cpu) Bail out! ERROR:../git/accel/tcg/cpu-exec.c:532:cpu_exec_longjmp_cleanup: assertion failed: (cpu == current_cpu) After digging into the code and trying to work out what is going on, I realised that n is NULL when it fails so this makes the problem "go away": diff --git a/linux-user/syscall.c b/linux-user/syscall.c index e384e14248..2577fb770d 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -8085,6 +8085,9 @@ static int open_self_maps_2(void *opaque, target_ulong guest_start, while (1) { IntervalTreeNode *n = interval_tree_iter_first(d->host_maps, host_start, host_start); + if (!n) { + return 0; + } MapInfo *mi = container_of(n, MapInfo, itree); uintptr_t this_hlast = MIN(host_last, n->last); target_ulong this_gend = h2g(this_hlast) + 1; I'm hoping that might be enough to give you an idea of what is going on and what the correct fix may be? I haven't managed to make an isolated test to reproduce the issue yet. Cheers, Richard