Hi Matthias, a big thank you for giving all the informations! I used your mka/llvm/v4.14_ext Git tree... https://chromium.googlesource.com/chromiumos/third_party/kernel/+log/sandbox/mka/llvm/v4.14_ext ...and was able to compile with clang-6.0 from Debian/buster64 with... ...reverting the clang-3/clang-4 patches... user$ for p in 69e44656ae43 222b88977a00 cdfcf1e45537 26f14c9225a6 0385a18e9995 68dab143c9b4 ; do echo [ $p ] ; LC_ALL=C git revert --no-edit $p ; done 0001-Revert-CLANG3-core-clang-work-around-x86-regparm-int.patch 0002-Revert-CLANG4-futex-don-t-optimize-futex_detect_cmpx.patch 0003-Revert-CLANG4-Disable-lkdtm-when-ftrace-is-enabled.patch 0004-Revert-CLANG4-arm64-prefetch-Use-__builtin_arm_prefe.patch 0005-Revert-CLANG4-kbuild-Add-meabi-gnu-to-the-clang-para.patch 0006-Revert-CLANG4-crypto-arm64-aes-ce-Explicitly-pass-th.patch ...and needed two additional patches from upstream: 0007-kbuild-clang-remove-crufty-HOSTCFLAGS.patch <--- Label with BACKPORT (XXX: Backported; Required when using HOSTCC in make-line, see below) 0008-x86-xen-remove-the-use-of-VLAIS.patch <--- Label with UPSTREAM (XXX: cherry-picked) These 3 patches in your Git branch are in Linux v4.14.36... 9af5ddf981ed BACKPORT: kbuild: disable clang's default use of -fmerge-all-constants f24088a3842c BACKPORT: kbuild: Set KBUILD_CFLAGS before incl. arch Makefile d4dfe384346d UPSTREAM: kbuild: fix linker feature test macros when cross compiling with Clang ...and can be dropped. I do not know your work-flow/policy: Maybe you want to keep your patch-stack against vanilla Linux v4.14 - without stables from linux-stable-4.14.y. For easy switching "mycompiler" I use a wrapper-script: root# cat /usr/bin/mycompiler #!/bin/bash clang-6.0 "$@" - EOF - user$ cp -v /boot/config-4.14.35-1-iniza-amd64 .config user$ MAKE="make V=1" ; COMPILER="mycompiler" ; MAKE_OPTS="CC=$COMPILER HOSTCC=$COMPILER" user$ yes "" | $MAKE $MAKE_OPTS oldconfig && $MAKE $MAKE_OPTS silentoldconfig < /dev/null The diffconfig to my current kernel-config-4.14 looks like this... user$ ./scripts/diffconfig /boot/config-4.14.35-1-iniza-amd64 .config -ARCH_HAS_REFCOUNT y -BPF_JIT_ALWAYS_ON n -EXOFS_DEBUG n -EXOFS_FS m -GENERIC_CPU_VULNERABILITIES y -KASAN n -ORE m -PAGE_TABLE_ISOLATION y -RETPOLINE y -UNWINDER_FRAME_POINTER n -UNWINDER_GUESS n -UNWINDER_ORC y +FRAME_POINTER y +FRAME_POINTER_UNWINDER y +GUESS_UNWINDER n +HAVE_ARCH_KMEMCHECK y +HAVE_RELIABLE_STACKTRACE y +ORC_UNWINDER n Unfortunately, I cannot boot into the generated kernel on bare metal. Checking with QEMU (version: 2.12~rc3) and catching earlyprintk, I see this... user$ echo $KPATH $HOME/src/linux-kernel/important-files user$ ls -al insgesamt 344916 drwxr-xr-x 2 sdi sdi 4096 Apr 24 13:15 . drwxr-xr-x 20 sdi sdi 4096 Apr 24 13:13 .. -rw-r--r-- 1 sdi sdi 4528416 Apr 24 12:42 bzImage lrwxrwxrwx 1 sdi sdi 35 Apr 24 13:15 initrd.img -> initrd.img-4.14.0-1-iniza-llvmlinux -rw-r--r-- 1 sdi sdi 25572955 Apr 24 13:08 initrd.img-4.14.0-1-iniza-llvmlinux -rw-r--r-- 1 sdi sdi 2887195 Apr 24 12:42 System.map -rwxr-xr-x 1 sdi sdi 326116744 Apr 24 12:42 vmlinux user$ sudo qemu-system-x86_64 -enable-kvm -M pc -kernel $KPATH/bzImage -initrd $KPATH/initrd.img -m 512 -net none -serial stdio -append "root=/dev/ram0 console=ttyS0 hung_task_panic=1 earlyprintk=ttyS0,115200" Probing EDD (edd=off to disable)... ok [ 0.000000] Linux version 4.14.0-1-iniza-llvmlinux (sedat.dilek@gmail.com@iniza) (clang version 6.0.0-1 (tags/RELEASE_600/final)) #1 SMP Tue Apr 24 12:42:21 CEST 2018 [ 0.000000] Command line: root=/dev/ram0 console=ttyS0 hung_task_panic=1 earlyprintk=ttyS0,115200 [ 0.000000] x86/fpu: x87 FPU will use FXSAVE [ 0.000000] e820: BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable [ 0.000000] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000001ffdffff] usable [ 0.000000] BIOS-e820: [mem 0x000000001ffe0000-0x000000001fffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000feffc000-0x00000000feffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved [ 0.000000] bootconsole [earlyser0] enabled [ 0.000000] NX (Execute Disable) protection: active [ 0.000000] random: fast init done [ 0.000000] SMBIOS 2.8 present. [ 0.000000] DMI: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014 [ 0.000000] Hypervisor detected: KVM [ 0.000000] tsc: Fast TSC calibration using PIT [ 0.000000] e820: last_pfn = 0x1ffe0 max_arch_pfn = 0x400000000 [ 0.000000] x86/PAT: PAT not supported by CPU. [ 0.000000] x86/PAT: Configuration [0-7]: WB WT UC- UC WB WT UC- UC Memory KASLR using RDTSC... [ 0.000000] found SMP MP-table at [mem 0x000f5d60-0x000f5d6f] mapped at [ffffffffff000d60] [ 0.000000] RAMDISK: [mem 0x1e77c000-0x1ffdffff] [ 0.000000] ACPI: Early table checksum verification disabled [ 0.000000] ACPI: RSDP 0x00000000000F5B90 000014 (v00 BOCHS ) [ 0.000000] ACPI: RSDT 0x000000001FFE157C 000030 (v01 BOCHS BXPCRSDT 00000001 BXPC 00000001) [ 0.000000] ACPI: FACP 0x000000001FFE1458 000074 (v01 BOCHS BXPCFACP 00000001 BXPC 00000001) [ 0.000000] ACPI: DSDT 0x000000001FFE0040 001418 (v01 BOCHS BXPCDSDT 00000001 BXPC 00000001) [ 0.000000] ACPI: FACS 0x000000001FFE0000 000040 [ 0.000000] ACPI: APIC 0x000000001FFE14CC 000078 (v01 BOCHS BXPCAPIC 00000001 BXPC 00000001) [ 0.000000] ACPI: HPET 0x000000001FFE1544 000038 (v01 BOCHS BXPCHPET 00000001 BXPC 00000001) [ 0.000000] No NUMA configuration found [ 0.000000] Faking a node at [mem 0x0000000000000000-0x000000001ffdffff] [ 0.000000] NODE_DATA(0) allocated [mem 0x1e777000-0x1e77bfff] [ 0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00 [ 0.000000] kvm-clock: cpu 0, msr 0:1e76f001, primary cpu clock [ 0.000000] kvm-clock: using sched offset of 528742140 cycles [ 0.000000] clocksource: kvm-clock: mask: 0xffffffffffffffff max_cycles: 0x1cd42e4dffb, max_idle_ns: 881590591483 ns [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x0000000000001000-0x0000000000ffffff] [ 0.000000] DMA32 [mem 0x0000000001000000-0x000000001ffdffff] [ 0.000000] Normal empty [ 0.000000] Device empty [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000001000-0x000000000009efff] [ 0.000000] node 0: [mem 0x0000000000100000-0x000000001ffdffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000001000-0x000000001ffdffff] [ 0.000000] ACPI: PM-Timer IO Port: 0x608 [ 0.000000] ACPI: LAPIC_NMI (acpi_id[0xff] dfl dfl lint[0x1]) [ 0.000000] IOAPIC[0]: apic_id 0, version 17, address 0xfec00000, GSI 0-23 [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 0 global_irq 2 dfl dfl) [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 5 global_irq 5 high level) [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 high level) [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 10 global_irq 10 high level) [ 0.000000] ACPI: INT_SRC_OVR (bus 0 bus_irq 11 global_irq 11 high level) [ 0.000000] Using ACPI (MADT) for SMP configuration information [ 0.000000] ACPI: HPET id: 0x8086a201 base: 0xfed00000 [ 0.000000] smpboot: Allowing 1 CPUs, 0 hotplug CPUs [ 0.000000] PM: Registered nosave memory: [mem 0x00000000-0x00000fff] [ 0.000000] PM: Registered nosave memory: [mem 0x0009f000-0x0009ffff] [ 0.000000] PM: Registered nosave memory: [mem 0x000a0000-0x000effff] [ 0.000000] PM: Registered nosave memory: [mem 0x000f0000-0x000fffff] [ 0.000000] e820: [mem 0x20000000-0xfeffbfff] available for PCI devices [ 0.000000] Booting paravirtualized kernel on KVM [ 0.000000] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645519600211568 ns [ 0.000000] setup_percpu: NR_CPUS:512 nr_cpumask_bits:512 nr_cpu_ids:1 nr_node_ids:1 [ 0.000000] percpu: Embedded 37 pages/cpu @ffff96dd9e400000 s114392 r8192 d28968 u2097152 [ 0.000000] KVM setup async PF for cpu 0 [ 0.000000] kvm-stealtime: cpu 0, msr 1e40d900 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 128872 [ 0.000000] Policy zone: DMA32 [ 0.000000] Kernel command line: root=/dev/ram0 console=ttyS0 hung_task_panic=1 earlyprintk=ttyS0,115200 [ 0.000000] PID hash table entries: 2048 (order: 2, 16384 bytes) [ 0.000000] Memory: 474480K/523768K available (7639K kernel code, 1005K rwdata, 2936K rodata, 1636K init, 688K bss, 49288K reserved, 0K cma-reserved) [ 0.000000] ftrace: allocating 27586 entries in 108 pages [ 0.004000] Hierarchical RCU implementation. [ 0.004000] RCU restricting CPUs from NR_CPUS=512 to nr_cpu_ids=1. [ 0.004000] RCU: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1 [ 0.004000] NR_IRQS: 33024, nr_irqs: 256, preallocated irqs: 16 [ 0.004000] Console: colour VGA+ 80x25 [ 0.004000] console [ttyS0] enabled [ 0.004000] console [ttyS0] enabled [ 0.004000] bootconsole [earlyser0] disabled [ 0.004000] bootconsole [earlyser0] disabled [ 0.004000] clocksource: hpet: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604467 ns [ 0.004000] general protection fault: 0000 [#1] SMP [ 0.004000] Modules linked in: [ 0.004000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-1-iniza-llvmlinux #1 [ 0.004000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014 [ 0.004000] task: ffffffffaa610480 task.stack: ffffffffaa600000 [ 0.004000] RIP: 0010:irq_work_tick+0x9d/0x110 [ 0.004000] RSP: 0000:ffff96dd9e403e58 EFLAGS: 00010046 [ 0.004000] RAX: 0000000000000082 RBX: ffff96dd9e411d80 RCX: adecc9cc04e2ca00 [ 0.004000] RDX: 000000000001ba00 RSI: fffffffffffffed4 RDI: ffff96dd9e41ba38 [ 0.004000] RBP: ffff96dd9e403e78 R08: 0000000000000000 R09: 0000000000000018 [ 0.004000] R10: 0000000000000000 R11: 0000000000000018 R12: ffffffffaa61bd40 [ 0.004000] R13: 0000000000000000 R14: ffffffffaa610480 R15: 0000000000000000 [ 0.004000] FS: 0000000000000000(0000) GS:ffff96dd9e400000(0000) knlGS:0000000000000000 [ 0.004000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.004000] CR2: 00000000ffffffff CR3: 0000000008a09000 CR4: 00000000000006b0 [ 0.004000] Call Trace: [ 0.004000] [ 0.004000] update_process_times+0x6e/0xa0 [ 0.004000] tick_periodic+0x78/0x90 [ 0.004000] tick_handle_periodic+0x26/0x80 [ 0.004000] timer_interrupt+0x13/0x20 [ 0.004000] __handle_irq_event_percpu+0x106/0x230 [ 0.004000] handle_irq_event+0x5a/0xc0 [ 0.004000] handle_level_irq+0x11a/0x190 [ 0.004000] handle_irq+0x1f/0x30 [ 0.004000] do_IRQ+0x4b/0xd0 [ 0.004000] common_interrupt+0x93/0x93 [ 0.004000] [ 0.004000] RIP: 0010:native_restore_fl+0x12/0x20 [ 0.004000] RSP: 0000:ffffffffaa603e10 EFLAGS: 00000286 ORIG_RAX: ffffffffffffffcf [ 0.004000] RAX: 0000000000000001 RBX: ffff96dd9d0c0608 RCX: 0000000000000000 [ 0.004000] RDX: ffff96dd9d0c0400 RSI: 0000000000000286 RDI: 0000000000000286 [ 0.004000] RBP: ffffffffaa603e18 R08: 0000000000000001 R09: 000000000000003f [ 0.004000] R10: 0000000000000286 R11: 0000000000000007 R12: ffff96dd9d0c0514 [ 0.004000] R13: ffff96dd9d0c04e0 R14: ffffffffaa61bd40 R15: ffff96dd9d0c0400 [ 0.004000] _raw_spin_unlock_irqrestore+0x1a/0x20 [ 0.004000] __setup_irq+0x5d9/0x780 [ 0.004000] setup_irq+0x5c/0x90 [ 0.004000] hpet_time_init+0x32/0x40 [ 0.004000] x86_late_time_init+0x10/0x20 [ 0.004000] start_kernel+0x45d/0x580 [ 0.004000] x86_64_start_kernel+0x30f/0x320 [ 0.004000] secondary_startup_64+0xa5/0xa5 [ 0.004000] Code: f0 f0 4c 0f b1 7b f8 4c 89 e3 4d 85 e4 75 cf 48 c7 c1 88 5b 01 00 65 48 03 0c 25 d8 a1 00 00 ff 14 25 10 08 62 aa f6 c4 02 75 4d <48> 83 39 00 74 3e 31 db 48 87 19 48 85 db 74 34 0f 1f 00 48 8d [ 0.004000] RIP: irq_work_tick+0x9d/0x110 RSP: ffff96dd9e403e58 [ 0.004000] ---[ end trace 8c7851007fbc6b6f ]--- [ 0.004000] Kernel panic - not syncing: Fatal exception in interrupt [ 0.004000] ---[ end Kernel panic - not syncing: Fatal exception in interrupt Is this saying someting to you? I am attaching my kernel-config file and the two additional patches. Do you need further informations? Thanks. Regards, - Sedat -