From b20732900e4636a467c0183a47f7396700f5f743 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 7 Aug 2024 15:11:22 +0200 Subject: Adding upstream version 6.9.7. Signed-off-by: Daniel Baumann --- arch/s390/kernel/nmi.c | 168 ++++++++++++++----------------------------------- 1 file changed, 48 insertions(+), 120 deletions(-) (limited to 'arch/s390/kernel/nmi.c') diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index 9ad44c26d1..c77382a673 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -23,16 +23,14 @@ #include #include #include +#include #include #include #include #include #include -#include #include #include -#include -#include struct mcck_struct { unsigned int kill_task : 1; @@ -204,133 +202,63 @@ void s390_handle_mcck(void) } } -/* - * returns 0 if register contents could be validated - * returns 1 otherwise +/** + * nmi_registers_valid - verify if registers are valid + * @mci: machine check interruption code + * + * Inspect a machine check interruption code and verify if all required + * registers are valid. For some registers the corresponding validity bit is + * ignored and the registers are set to the expected value. + * Returns true if all registers are valid, otherwise false. */ -static int notrace s390_validate_registers(union mci mci) +static bool notrace nmi_registers_valid(union mci mci) { - struct mcesa *mcesa; - void *fpt_save_area; union ctlreg2 cr2; - int kill_task; - u64 zero; - - kill_task = 0; - zero = 0; - - if (!mci.gr || !mci.fp) - kill_task = 1; - fpt_save_area = &S390_lowcore.floating_pt_save_area; - if (!mci.fc) { - kill_task = 1; - asm volatile( - " lfpc %0\n" - : - : "Q" (zero)); - } else { - asm volatile( - " lfpc %0\n" - : - : "Q" (S390_lowcore.fpt_creg_save_area)); - } - mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK); - if (!cpu_has_vx()) { - /* Validate floating point registers */ - asm volatile( - " ld 0,0(%0)\n" - " ld 1,8(%0)\n" - " ld 2,16(%0)\n" - " ld 3,24(%0)\n" - " ld 4,32(%0)\n" - " ld 5,40(%0)\n" - " ld 6,48(%0)\n" - " ld 7,56(%0)\n" - " ld 8,64(%0)\n" - " ld 9,72(%0)\n" - " ld 10,80(%0)\n" - " ld 11,88(%0)\n" - " ld 12,96(%0)\n" - " ld 13,104(%0)\n" - " ld 14,112(%0)\n" - " ld 15,120(%0)\n" - : - : "a" (fpt_save_area) - : "memory"); - } else { - /* Validate vector registers */ - union ctlreg0 cr0; - - /* - * The vector validity must only be checked if not running a - * KVM guest. For KVM guests the machine check is forwarded by - * KVM and it is the responsibility of the guest to take - * appropriate actions. The host vector or FPU values have been - * saved by KVM and will be restored by KVM. - */ - if (!mci.vr && !test_cpu_flag(CIF_MCCK_GUEST)) - kill_task = 1; - cr0.reg = S390_lowcore.cregs_save_area[0]; - cr0.afp = cr0.vx = 1; - local_ctl_load(0, &cr0.reg); - asm volatile( - " la 1,%0\n" - " VLM 0,15,0,1\n" - " VLM 16,31,256,1\n" - : - : "Q" (*(struct vx_array *)mcesa->vector_save_area) - : "1"); - local_ctl_load(0, &S390_lowcore.cregs_save_area[0]); - } - /* Validate access registers */ - asm volatile( - " lam 0,15,0(%0)\n" - : - : "a" (&S390_lowcore.access_regs_save_area) - : "memory"); - if (!mci.ar) - kill_task = 1; - /* Validate guarded storage registers */ - cr2.reg = S390_lowcore.cregs_save_area[2]; - if (cr2.gse) { - if (!mci.gs) { - /* - * 2 cases: - * - machine check in kernel or userspace - * - machine check while running SIE (KVM guest) - * For kernel or userspace the userspace values of - * guarded storage control can not be recreated, the - * process must be terminated. - * For SIE the guest values of guarded storage can not - * be recreated. This is either due to a bug or due to - * GS being disabled in the guest. The guest will be - * notified by KVM code and the guests machine check - * handling must take care of this. The host values - * are saved by KVM and are not affected. - */ - if (!test_cpu_flag(CIF_MCCK_GUEST)) - kill_task = 1; - } else { - load_gs_cb((struct gs_cb *)mcesa->guarded_storage_save_area); - } - } /* - * The getcpu vdso syscall reads CPU number from the programmable + * The getcpu vdso syscall reads the CPU number from the programmable * field of the TOD clock. Disregard the TOD programmable register - * validity bit and load the CPU number into the TOD programmable - * field unconditionally. + * validity bit and load the CPU number into the TOD programmable field + * unconditionally. */ set_tod_programmable_field(raw_smp_processor_id()); - /* Validate clock comparator register */ + /* + * Set the clock comparator register to the next expected value. + */ set_clock_comparator(S390_lowcore.clock_comparator); - + if (!mci.gr || !mci.fp || !mci.fc) + return false; + /* + * The vector validity must only be checked if not running a + * KVM guest. For KVM guests the machine check is forwarded by + * KVM and it is the responsibility of the guest to take + * appropriate actions. The host vector or FPU values have been + * saved by KVM and will be restored by KVM. + */ + if (!mci.vr && !test_cpu_flag(CIF_MCCK_GUEST)) + return false; + if (!mci.ar) + return false; + /* + * Two cases for guarded storage registers: + * - machine check in kernel or userspace + * - machine check while running SIE (KVM guest) + * For kernel or userspace the userspace values of guarded storage + * control can not be recreated, the process must be terminated. + * For SIE the guest values of guarded storage can not be recreated. + * This is either due to a bug or due to GS being disabled in the + * guest. The guest will be notified by KVM code and the guests machine + * check handling must take care of this. The host values are saved by + * KVM and are not affected. + */ + cr2.reg = S390_lowcore.cregs_save_area[2]; + if (cr2.gse && !mci.gs && !test_cpu_flag(CIF_MCCK_GUEST)) + return false; if (!mci.ms || !mci.pm || !mci.ia) - kill_task = 1; - - return kill_task; + return false; + return true; } -NOKPROBE_SYMBOL(s390_validate_registers); +NOKPROBE_SYMBOL(nmi_registers_valid); /* * Backup the guest's machine check info to its description block @@ -428,7 +356,7 @@ void notrace s390_do_machine_check(struct pt_regs *regs) s390_handle_damage(); } } - if (s390_validate_registers(mci)) { + if (!nmi_registers_valid(mci)) { if (!user_mode(regs)) s390_handle_damage(); /* -- cgit v1.2.3