Message ID | 8dc754989a103805d8f47d87255d1044c040da01.1529365441.git.joseph.salisbury@canonical.com |
---|---|
State | New |
Headers | show |
Series | Fixes for LP:1777194 | expand |
On 06/22/2018 12:08 PM, Joseph Salisbury wrote: > From: Nicholas Piggin <npiggin@gmail.com> > > BugLink: http://bugs.launchpad.net/bugs/1777194 > > Use the NMI IPI rather than smp_call_function for smp_send_stop. > Have stopped CPUs hard disable interrupts rather than just soft > disable. > > This function is used in crash/panic/shutdown paths to bring other > CPUs down as quickly and reliably as possible, and minimizing their > potential to cause trouble. > > Avoiding the Linux smp_call_function infrastructure and (if supported) > using true NMI IPIs makes this more robust. > > Signed-off-by: Nicholas Piggin <npiggin@gmail.com> > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> > (cherry picked from commit 6bed3237624e3faad1592543952907cd01a42c83) > Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com> > --- > arch/powerpc/kernel/smp.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c > index bbe7634..378112c 100644 > --- a/arch/powerpc/kernel/smp.c > +++ b/arch/powerpc/kernel/smp.c > @@ -565,7 +565,11 @@ void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *)) > } > #endif > > +#ifdef CONFIG_NMI_IPI > +static void stop_this_cpu(struct pt_regs *regs) > +#else > static void stop_this_cpu(void *dummy) > +#endif > { > /* Remove this CPU */ > set_cpu_online(smp_processor_id(), false); > @@ -577,7 +581,11 @@ static void stop_this_cpu(void *dummy) > > void smp_send_stop(void) > { > +#ifdef CONFIG_NMI_IPI > + smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, stop_this_cpu, 1000000); > +#else > smp_call_function(stop_this_cpu, NULL, 0); > +#endif > } > > struct thread_info *current_set[NR_CPUS]; The subject of this mail should also contain: [SRU][Bionic]
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index bbe7634..378112c 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -565,7 +565,11 @@ void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *)) } #endif +#ifdef CONFIG_NMI_IPI +static void stop_this_cpu(struct pt_regs *regs) +#else static void stop_this_cpu(void *dummy) +#endif { /* Remove this CPU */ set_cpu_online(smp_processor_id(), false); @@ -577,7 +581,11 @@ static void stop_this_cpu(void *dummy) void smp_send_stop(void) { +#ifdef CONFIG_NMI_IPI + smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, stop_this_cpu, 1000000); +#else smp_call_function(stop_this_cpu, NULL, 0); +#endif } struct thread_info *current_set[NR_CPUS];