*/
SYM_CODE_START(mcck_int_handler)
BPOFF
- la %r1,4095 # validate r1
- spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # validate cpu timer
- LBEAR __LC_LAST_BREAK_SAVE_AREA-4095(%r1) # validate bear
- lmg %r0,%r15,__LC_GPREGS_SAVE_AREA # validate gprs
lmg %r8,%r9,__LC_MCK_OLD_PSW
TSTMSK __LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE
jo .Lmcck_panic # yes -> rest of mcck code invalid
TSTMSK __LC_MCCK_CODE,MCCK_CODE_CR_VALID
jno .Lmcck_panic # control registers invalid -> panic
- lctlg %c0,%c15,__LC_CREGS_SAVE_AREA # validate ctl regs
ptlb
lghi %r14,__LC_CPU_TIMER_SAVE_AREA
mvc __LC_MCCK_ENTER_TIMER(8),0(%r14)
}
}
-/*
- * 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
s390_handle_damage();
}
}
- if (s390_validate_registers(mci)) {
+ if (!nmi_registers_valid(mci)) {
if (!user_mode(regs))
s390_handle_damage();
/*
projects / users / dwmw2 / linux.git / commitdiff