Nicholas Piggin <npig...@gmail.com> writes: > Nicholas Piggin's on January 22, 2019 4:46 pm: >> HV interrupts that use HSRR registers do not clear MSR[RI], but >> NMI entry code is not recoverable early on due to both using HSPRG >> for a scratch register. >> >> This bug means that a system reset or machine check can cause silent >> data corruption (due to loss of r13 register) if it hits in a small >> window when taking an HV interrupt. >> >> Fix this by marking NMIs non-recoverable if they land in HV interrupt >> ranges. > > Hum, I had a v2 that I didn't send properly with a small compile fix, > but I've also just noticed this: > >> +void hv_nmi_check_nonrecoverable(struct pt_regs *regs) >> +{ >> +#ifdef CONFIG_POWERNV >> + unsigned long kbase = (unsigned long)_stext; >> + unsigned long nip = regs->nip; >> + >> + if (!(regs->msr & MSR_RI)) >> + return; >> + if (!(regs->msr & MSR_HV)) >> + return; >> + if (regs->msr & MSR_PR) >> + return; >> +again: >> + if (nip >= 0x500 && nip < 0x600) >> + goto nonrecoverable; >> + if (nip >= 0x980 && nip < 0xa00) >> + goto nonrecoverable; >> + if (nip >= 0xe00 && nip < 0xec0) >> + goto nonrecoverable; >> + if (nip >= 0xf80 && nip < 0xfa0) >> + goto nonrecoverable; >> + /* Trampolines are not relocated. */ >> + if (nip >= real_trampolines_start - kbase && >> + nip < real_trampolines_end - kbase) >> + goto nonrecoverable; >> + if (nip >= virt_trampolines_start - kbase && >> + nip < virt_trampolines_end - kbase) >> + goto nonrecoverable; >> + if (nip >= 0xc000000000000000ULL) { >> + nip -= 0xc000000000000000ULL; >> + goto again; > > Tried to be a bit too clever here. The 0xc... vectors also have a > +0x4000 offset so this won't catch them properly. I'll respin.
Thanks. I'm seeing the same build error as the kbuild robot too. cheers