diff options
Diffstat (limited to 'features/rt/random-Make-it-work-on-rt.patch')
-rw-r--r-- | features/rt/random-Make-it-work-on-rt.patch | 185 |
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 + |