aboutsummaryrefslogtreecommitdiffstats
path: root/features/rt/random-Make-it-work-on-rt.patch
diff options
context:
space:
mode:
Diffstat (limited to 'features/rt/random-Make-it-work-on-rt.patch')
-rw-r--r--features/rt/random-Make-it-work-on-rt.patch185
1 files changed, 185 insertions, 0 deletions
diff --git a/features/rt/random-Make-it-work-on-rt.patch b/features/rt/random-Make-it-work-on-rt.patch
new file mode 100644
index 00000000..1362346f
--- /dev/null
+++ b/features/rt/random-Make-it-work-on-rt.patch
@@ -0,0 +1,185 @@
+From 39bd47e442b4654f824987ebaff05ce1dfaa1af0 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Tue, 21 Aug 2012 20:38:50 +0200
+Subject: [PATCH 149/191] random: Make it work on rt
+
+Delegate the random insertion to the forced threaded interrupt
+handler. Store the return IP of the hard interrupt handler in the irq
+descriptor and feed it into the random generator as a source of
+entropy.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+---
+ arch/x86/kernel/cpu/mshyperv.c | 3 ++-
+ drivers/char/random.c | 11 +++++------
+ drivers/hv/hyperv_vmbus.h | 1 +
+ drivers/hv/vmbus_drv.c | 5 ++++-
+ include/linux/irqdesc.h | 1 +
+ include/linux/random.h | 2 +-
+ kernel/irq/handle.c | 8 +++++++-
+ kernel/irq/manage.c | 6 ++++++
+ 8 files changed, 27 insertions(+), 10 deletions(-)
+
+diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
+index e88bc296afca..73a2494a0b2e 100644
+--- a/arch/x86/kernel/cpu/mshyperv.c
++++ b/arch/x86/kernel/cpu/mshyperv.c
+@@ -85,11 +85,12 @@ EXPORT_SYMBOL_GPL(hv_remove_vmbus_irq);
+ DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0)
+ {
+ struct pt_regs *old_regs = set_irq_regs(regs);
++ u64 ip = regs ? instruction_pointer(regs) : 0;
+
+ inc_irq_stat(hyperv_stimer0_count);
+ if (hv_stimer0_handler)
+ hv_stimer0_handler();
+- add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
++ add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0, ip);
+ ack_APIC_irq();
+
+ set_irq_regs(old_regs);
+diff --git a/drivers/char/random.c b/drivers/char/random.c
+index 0fe9e200e4c8..da0a1ef9615c 100644
+--- a/drivers/char/random.c
++++ b/drivers/char/random.c
+@@ -1252,26 +1252,25 @@ static __u32 get_reg(struct fast_pool *f, struct pt_regs *regs)
+ return *ptr;
+ }
+
+-void add_interrupt_randomness(int irq, int irq_flags)
++void add_interrupt_randomness(int irq, int irq_flags, __u64 ip)
+ {
+ struct entropy_store *r;
+ struct fast_pool *fast_pool = this_cpu_ptr(&irq_randomness);
+- struct pt_regs *regs = get_irq_regs();
+ unsigned long now = jiffies;
+ cycles_t cycles = random_get_entropy();
+ __u32 c_high, j_high;
+- __u64 ip;
+
+ if (cycles == 0)
+- cycles = get_reg(fast_pool, regs);
++ cycles = get_reg(fast_pool, NULL);
+ c_high = (sizeof(cycles) > 4) ? cycles >> 32 : 0;
+ j_high = (sizeof(now) > 4) ? now >> 32 : 0;
+ fast_pool->pool[0] ^= cycles ^ j_high ^ irq;
+ fast_pool->pool[1] ^= now ^ c_high;
+- ip = regs ? instruction_pointer(regs) : _RET_IP_;
++ if (!ip)
++ ip = _RET_IP_;
+ fast_pool->pool[2] ^= ip;
+ fast_pool->pool[3] ^= (sizeof(ip) > 4) ? ip >> 32 :
+- get_reg(fast_pool, regs);
++ get_reg(fast_pool, NULL);
+
+ fast_mix(fast_pool);
+ add_interrupt_bench(cycles);
+diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
+index 9416e09ebd58..4a5767a15544 100644
+--- a/drivers/hv/hyperv_vmbus.h
++++ b/drivers/hv/hyperv_vmbus.h
+@@ -18,6 +18,7 @@
+ #include <linux/atomic.h>
+ #include <linux/hyperv.h>
+ #include <linux/interrupt.h>
++#include <linux/irq.h>
+
+ #include "hv_trace.h"
+
+diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
+index 806950bc3c1d..e0afa5031cc4 100644
+--- a/drivers/hv/vmbus_drv.c
++++ b/drivers/hv/vmbus_drv.c
+@@ -22,6 +22,7 @@
+ #include <linux/clockchips.h>
+ #include <linux/cpu.h>
+ #include <linux/sched/task_stack.h>
++#include <linux/irq.h>
+
+ #include <linux/delay.h>
+ #include <linux/notifier.h>
+@@ -1337,6 +1338,8 @@ static void vmbus_isr(void)
+ void *page_addr = hv_cpu->synic_event_page;
+ struct hv_message *msg;
+ union hv_synic_event_flags *event;
++ struct pt_regs *regs = get_irq_regs();
++ u64 ip = regs ? instruction_pointer(regs) : 0;
+ bool handled = false;
+
+ if (unlikely(page_addr == NULL))
+@@ -1381,7 +1384,7 @@ static void vmbus_isr(void)
+ tasklet_schedule(&hv_cpu->msg_dpc);
+ }
+
+- add_interrupt_randomness(hv_get_vector(), 0);
++ add_interrupt_randomness(hv_get_vector(), 0, ip);
+ }
+
+ /*
+diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
+index 891b323266df..45d8bda8fd53 100644
+--- a/include/linux/irqdesc.h
++++ b/include/linux/irqdesc.h
+@@ -68,6 +68,7 @@ struct irq_desc {
+ unsigned int irqs_unhandled;
+ atomic_t threads_handled;
+ int threads_handled_last;
++ u64 random_ip;
+ raw_spinlock_t lock;
+ struct cpumask *percpu_enabled;
+ const struct cpumask *percpu_affinity;
+diff --git a/include/linux/random.h b/include/linux/random.h
+index f45b8be3e3c4..0e41d0527809 100644
+--- a/include/linux/random.h
++++ b/include/linux/random.h
+@@ -35,7 +35,7 @@ static inline void add_latent_entropy(void) {}
+
+ extern void add_input_randomness(unsigned int type, unsigned int code,
+ unsigned int value) __latent_entropy;
+-extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
++extern void add_interrupt_randomness(int irq, int irq_flags, __u64 ip) __latent_entropy;
+
+ extern void get_random_bytes(void *buf, int nbytes);
+ extern int wait_for_random_bytes(void);
+diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
+index 762a928e18f9..7929fcdb7817 100644
+--- a/kernel/irq/handle.c
++++ b/kernel/irq/handle.c
+@@ -192,10 +192,16 @@ irqreturn_t handle_irq_event_percpu(struct irq_desc *desc)
+ {
+ irqreturn_t retval;
+ unsigned int flags = 0;
++ struct pt_regs *regs = get_irq_regs();
++ u64 ip = regs ? instruction_pointer(regs) : 0;
+
+ retval = __handle_irq_event_percpu(desc, &flags);
+
+- add_interrupt_randomness(desc->irq_data.irq, flags);
++#ifdef CONFIG_PREEMPT_RT
++ desc->random_ip = ip;
++#else
++ add_interrupt_randomness(desc->irq_data.irq, flags, ip);
++#endif
+
+ if (!noirqdebug)
+ note_interrupt(desc, retval);
+diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
+index ac2c57429750..f4d18858d079 100644
+--- a/kernel/irq/manage.c
++++ b/kernel/irq/manage.c
+@@ -1247,6 +1247,12 @@ static int irq_thread(void *data)
+ if (action_ret == IRQ_WAKE_THREAD)
+ irq_wake_secondary(desc, action);
+
++ if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
++ migrate_disable();
++ add_interrupt_randomness(action->irq, 0,
++ desc->random_ip ^ (unsigned long) action);
++ migrate_enable();
++ }
+ wake_threads_waitq(desc);
+ }
+
+--
+2.19.1
+