tester malloc3 causes kernel panic on QEMU 7.2/8.0 (amd64)

[Jiří Zárevúcky]

This happens at least with QEMU 7.2 and QEMU 8.0,
as of commit d4643dba… and also going several years back, so it's not a recent regression, but seems to be some kind of interaction with newer QEMU versions, as QEMU 6.2.0 built from source does not trigger this.

Should be worth investigating.

Thread 75 waiting for 1 frames 3145847 available.

######> Kernel panic on cpu0 due to a bad memory access while storing to address 0x0000000000000008. <######

CURRENT=0xffffffff81fd4000: pe=0 thread=0xffffffff81efc510 task=0xffffffff81efb4a0 cpu=0xffffffff8188c810 as=0xffffffff8173f8f0 magic=0xfacefeed
thread="uinit"
task="/srv/klog"
cs =0x0000000000000008	rip=0xffffffff80143bbb	rfl=0x0000000000210286	err=0x0000000000000002
rax=0x0000000000000010	rbx=0x0000000000001000	rcx=0xffffffff8188c810	rdx=0x0000000000000000
rsi=0x0000000000000001	rdi=0xffffffff801605c0	rbp=0xffffffff81fd4e50	rsp=0xffffffff81fd4e10
r8 =0xffffffff80174080	r9 =0x00000000000019fd	r10=0x0000000000000001	r11=0xffffffff8173c10f
r12=0x000000000000000b	r13=0x0000000000000000	r14=0x000000000050dee8	r15=0x0000000000000000

0xffffffff81fd4bd0: kernel/libnoninstrumentables.a.p/generic_src_debug_stacktrace.c()+0x0000000000000119
0xffffffff81fd4c70: kernel/libnoninstrumentables.a.p/generic_src_debug_panic.c.o:.t()+0x00000000000001ae
0xffffffff81fd4cf0: kernel/libinstrumentables.a.p/generic_src_mm_as.c.o:.text()+0x0000000000002869
0xffffffff81fd4d50: kernel/libinstrumentables.a.p/generic_src_interrupt_interrupt.c()+0x0000000000000406
0xffffffff81fd4de0: kernel/libnoninstrumentables.a.p/arch_amd64_src_asm.S.o:int_14()+0x00000000000000b2
0xffffffff81fd4e50: kernel/libnoninstrumentables.a.p/generic_src_mm_malloc.c.o:.tex()+0x0000000000000310
0xffffffff81fd4eb0: kernel/libnoninstrumentables.a.p/generic_src_log_log.c.o:.text()+0x0000000000000866
0xffffffff81fd4f30: kernel/libnoninstrumentables.a.p/generic_src_syscall_syscall.c.()+0x00000000000000bd
0xffffffff81fd4fc0: kernel/libnoninstrumentables.a.p/arch_amd64_src_asm.S.o:syscall()+0x00000000000000bc
cpu0: halted

[Jiří Zárevúcky]

Also happens with QEMU 8.0 built from source.
Doesn't happen with ia32.