Linus,
Please pull the latest x86-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
x86-urgent-for-linus
# HEAD: da6139e49c7cb0f4251265cb5243b8d220adb48d x86: Add check for number
of available vectors before CPU down
Two leftover fixes that did not make it into v3.13.
Thanks,
Ingo
------------------>
Borislav Petkov (1):
x86, cpu, amd: Add workaround for family 16h, erratum 793
Prarit Bhargava (1):
x86: Add check for number of available vectors before CPU down
arch/x86/include/asm/irq.h | 1 +
arch/x86/include/uapi/asm/msr-index.h | 1 +
arch/x86/kernel/cpu/amd.c | 10 +++++
arch/x86/kernel/irq.c | 70 +++++++++++++++++++++++++++++++++++
arch/x86/kernel/smpboot.c | 6 +++
5 files changed, 88 insertions(+)
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 0ea10f27..cb6cfcd 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -25,6 +25,7 @@ extern void irq_ctx_init(int cpu);
#ifdef CONFIG_HOTPLUG_CPU
#include <linux/cpumask.h>
+extern int check_irq_vectors_for_cpu_disable(void);
extern void fixup_irqs(void);
extern void irq_force_complete_move(int);
#endif
diff --git a/arch/x86/include/uapi/asm/msr-index.h
b/arch/x86/include/uapi/asm/msr-index.h
index 37813b5..59cea18 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -184,6 +184,7 @@
#define MSR_AMD64_PATCH_LOADER 0xc0010020
#define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140
#define MSR_AMD64_OSVW_STATUS 0xc0010141
+#define MSR_AMD64_LS_CFG 0xc0011020
#define MSR_AMD64_DC_CFG 0xc0011022
#define MSR_AMD64_BU_CFG2 0xc001102a
#define MSR_AMD64_IBSFETCHCTL 0xc0011030
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index bca023b..59bfebc 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -508,6 +508,16 @@ static void early_init_amd(struct cpuinfo_x86 *c)
set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
}
#endif
+
+ /* F16h erratum 793, CVE-2013-6885 */
+ if (c->x86 == 0x16 && c->x86_model <= 0xf) {
+ u64 val;
+
+ rdmsrl(MSR_AMD64_LS_CFG, val);
+ if (!(val & BIT(15)))
+ wrmsrl(MSR_AMD64_LS_CFG, val | BIT(15));
+ }
+
}
static const int amd_erratum_383[];
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 22d0687..4207e8d 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -262,6 +262,76 @@ __visible void smp_trace_x86_platform_ipi(struct pt_regs
*regs)
EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);
#ifdef CONFIG_HOTPLUG_CPU
+/*
+ * This cpu is going to be removed and its vectors migrated to the remaining
+ * online cpus. Check to see if there are enough vectors in the remaining
cpus.
+ * This function is protected by stop_machine().
+ */
+int check_irq_vectors_for_cpu_disable(void)
+{
+ int irq, cpu;
+ unsigned int this_cpu, vector, this_count, count;
+ struct irq_desc *desc;
+ struct irq_data *data;
+ struct cpumask affinity_new, online_new;
+
+ this_cpu = smp_processor_id();
+ cpumask_copy(&online_new, cpu_online_mask);
+ cpu_clear(this_cpu, online_new);
+
+ this_count = 0;
+ for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
+ irq = __this_cpu_read(vector_irq[vector]);
+ if (irq >= 0) {
+ desc = irq_to_desc(irq);
+ data = irq_desc_get_irq_data(desc);
+ cpumask_copy(&affinity_new, data->affinity);
+ cpu_clear(this_cpu, affinity_new);
+
+ /* Do not count inactive or per-cpu irqs. */
+ if (!irq_has_action(irq) || irqd_is_per_cpu(data))
+ continue;
+
+ /*
+ * A single irq may be mapped to multiple
+ * cpu's vector_irq[] (for example IOAPIC cluster
+ * mode). In this case we have two
+ * possibilities:
+ *
+ * 1) the resulting affinity mask is empty; that is
+ * this the down'd cpu is the last cpu in the irq's
+ * affinity mask, or
+ *
+ * 2) the resulting affinity mask is no longer
+ * a subset of the online cpus but the affinity
+ * mask is not zero; that is the down'd cpu is the
+ * last online cpu in a user set affinity mask.
+ */
+ if (cpumask_empty(&affinity_new) ||
+ !cpumask_subset(&affinity_new, &online_new))
+ this_count++;
+ }
+ }
+
+ count = 0;
+ for_each_online_cpu(cpu) {
+ if (cpu == this_cpu)
+ continue;
+ for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS;
+ vector++) {
+ if (per_cpu(vector_irq, cpu)[vector] < 0)
+ count++;
+ }
+ }
+
+ if (count < this_count) {
+ pr_warn("CPU %d disable failed: CPU has %u vectors assigned and
there are only %u available.\n",
+ this_cpu, this_count, count);
+ return -ERANGE;
+ }
+ return 0;
+}
+
/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
void fixup_irqs(void)
{
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 85dc05a..391ea52 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1312,6 +1312,12 @@ void cpu_disable_common(void)
int native_cpu_disable(void)
{
+ int ret;
+
+ ret = check_irq_vectors_for_cpu_disable();
+ if (ret)
+ return ret;
+
clear_local_APIC();
cpu_disable_common();
--
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