This reverts commit 116ac378bb3ff844df333e7609e7604651a0db9d.

This commit causes the kernel to oops and reboot when injecting a SLB multihit which causes a MCE.

Before this commit a SLB multihit was corrected by the kernel and the system continued to operate normally.

cc: stable@vger.kernel.org Fixes: 116ac378bb3f ("powerpc/64s: machine check interrupt update NMI accounting") Signed-off-by: Michal Suchanek msuchanek@suse.de --- arch/powerpc/kernel/mce.c | 7 ------- arch/powerpc/kernel/traps.c | 18 +++--------------- 2 files changed, 3 insertions(+), 22 deletions(-)

diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c index ada59f6c4298..2e13528dcc92 100644 --- a/arch/powerpc/kernel/mce.c +++ b/arch/powerpc/kernel/mce.c @@ -591,14 +591,10 @@ EXPORT_SYMBOL_GPL(machine_check_print_event_info); long notrace machine_check_early(struct pt_regs *regs) { long handled = 0; - bool nested = in_nmi(); u8 ftrace_enabled = this_cpu_get_ftrace_enabled();

this_cpu_set_ftrace_enabled(0);

- if (!nested) - nmi_enter(); - hv_nmi_check_nonrecoverable(regs);

/* @@ -607,9 +603,6 @@ long notrace machine_check_early(struct pt_regs *regs) if (ppc_md.machine_check_early) handled = ppc_md.machine_check_early(regs);

- if (!nested) - nmi_exit(); - this_cpu_set_ftrace_enabled(ftrace_enabled);

return handled; diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index d1ebe152f210..7853b770918d 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -827,19 +827,7 @@ void machine_check_exception(struct pt_regs *regs) { int recover = 0;

- /* - * BOOK3S_64 does not call this handler as a non-maskable interrupt - * (it uses its own early real-mode handler to handle the MCE proper - * and then raises irq_work to call this handler when interrupts are - * enabled). - * - * This is silly. The BOOK3S_64 should just call a different function - * rather than expecting semantics to magically change. Something - * like 'non_nmi_machine_check_exception()', perhaps? - */ - const bool nmi = !IS_ENABLED(CONFIG_PPC_BOOK3S_64); - - if (nmi) nmi_enter(); + nmi_enter();

__this_cpu_inc(irq_stat.mce_exceptions);

@@ -865,7 +853,7 @@ void machine_check_exception(struct pt_regs *regs) if (check_io_access(regs)) goto bail;

- if (nmi) nmi_exit(); + nmi_exit();

die("Machine check", regs, SIGBUS);

@@ -876,7 +864,7 @@ void machine_check_exception(struct pt_regs *regs) return;

bail: - if (nmi) nmi_exit(); + nmi_exit(); }

void SMIException(struct pt_regs *regs)