[RFC PATCH 2/3] percpu: Assorted fixes found by strict percpu address space checks

[Uros Bizjak]

Assorted fixes to prevent defconfig build failures when
strict percpu address space checks will be enabled.

These show effeciveness of strict percpu address space checks.

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
 arch/x86/kernel/head64.c      | 3 ++-
 drivers/base/devres.c         | 2 +-
 fs/aio.c                      | 2 +-
 include/linux/cleanup.h       | 4 ++--
 include/linux/prandom.h       | 1 +
 kernel/events/hw_breakpoint.c | 4 ++--
 kernel/workqueue.c            | 2 +-
 lib/percpu_counter.c          | 2 +-
 net/core/dev.c                | 2 +-
 9 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index a817ed0724d1..f5d6ad351cc4 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -560,9 +560,10 @@ void early_setup_idt(void)
 void __head startup_64_setup_gdt_idt(void)
 {
 	void *handler = NULL;
+	struct desc_struct *gdt = (struct desc_struct *)(uintptr_t)init_per_cpu_var(gdt_page.gdt);
 
 	struct desc_ptr startup_gdt_descr = {
-		.address = (unsigned long)&RIP_REL_REF(init_per_cpu_var(gdt_page.gdt)),
+		.address = (unsigned long)&RIP_REL_REF(*gdt),
 		.size    = GDT_SIZE - 1,
 	};
 
diff --git a/drivers/base/devres.c b/drivers/base/devres.c
index a2ce0ead06a6..894f5a1e6d18 100644
--- a/drivers/base/devres.c
+++ b/drivers/base/devres.c
@@ -1231,6 +1231,6 @@ void devm_free_percpu(struct device *dev, void __percpu *pdata)
 	 * devm_free_pages() does.
 	 */
 	WARN_ON(devres_release(dev, devm_percpu_release, devm_percpu_match,
-			       (__force void *)pdata));
+			       (__force void *)(uintptr_t)pdata));
 }
 EXPORT_SYMBOL_GPL(devm_free_percpu);
diff --git a/fs/aio.c b/fs/aio.c
index 6066f64967b3..e8920178b50f 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -100,7 +100,7 @@ struct kioctx {
 
 	unsigned long		user_id;
 
-	struct __percpu kioctx_cpu *cpu;
+	struct kioctx_cpu __percpu *cpu;
 
 	/*
 	 * For percpu reqs_available, number of slots we move to/from global
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h
index d9e613803df1..f7e1158cbacf 100644
--- a/include/linux/cleanup.h
+++ b/include/linux/cleanup.h
@@ -154,7 +154,7 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \
 #define DEFINE_GUARD(_name, _type, _lock, _unlock) \
 	DEFINE_CLASS(_name, _type, if (_T) { _unlock; }, ({ _lock; _T; }), _type _T); \
 	static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \
-	{ return *_T; }
+	{ return (void *)(uintptr_t)*_T; }
 
 #define DEFINE_GUARD_COND(_name, _ext, _condlock) \
 	EXTEND_CLASS(_name, _ext, \
@@ -211,7 +211,7 @@ static inline void class_##_name##_destructor(class_##_name##_t *_T)	\
 									\
 static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T)	\
 {									\
-	return _T->lock;						\
+	return (void *)(uintptr_t)_T->lock;				\
 }
 
 
diff --git a/include/linux/prandom.h b/include/linux/prandom.h
index f7f1e5251c67..f2ed5b72b3d6 100644
--- a/include/linux/prandom.h
+++ b/include/linux/prandom.h
@@ -10,6 +10,7 @@
 
 #include <linux/types.h>
 #include <linux/once.h>
+#include <linux/percpu.h>
 #include <linux/random.h>
 
 struct rnd_state {
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 6c2cb4e4f48d..d82fe78f0658 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -849,7 +849,7 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
 
 	cpu_events = alloc_percpu(typeof(*cpu_events));
 	if (!cpu_events)
-		return (void __percpu __force *)ERR_PTR(-ENOMEM);
+		return (void __percpu __force *)(uintptr_t)ERR_PTR(-ENOMEM);
 
 	cpus_read_lock();
 	for_each_online_cpu(cpu) {
@@ -868,7 +868,7 @@ register_wide_hw_breakpoint(struct perf_event_attr *attr,
 		return cpu_events;
 
 	unregister_wide_hw_breakpoint(cpu_events);
-	return (void __percpu __force *)ERR_PTR(err);
+	return (void __percpu __force *)(uintptr_t)ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint);
 
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1745ca788ede..32729a2e93af 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -377,7 +377,7 @@ struct workqueue_struct {
 
 	/* hot fields used during command issue, aligned to cacheline */
 	unsigned int		flags ____cacheline_aligned; /* WQ: WQ_* flags */
-	struct pool_workqueue __percpu __rcu **cpu_pwq; /* I: per-cpu pwqs */
+	struct pool_workqueue __rcu * __percpu *cpu_pwq; /* I: per-cpu pwqs */
 	struct wq_node_nr_active *node_nr_active[]; /* I: per-node nr_active */
 };
 
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index 51bc5246986d..3d0613ac7e73 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -209,7 +209,7 @@ int __percpu_counter_init_many(struct percpu_counter *fbc, s64 amount,
 		INIT_LIST_HEAD(&fbc[i].list);
 #endif
 		fbc[i].count = amount;
-		fbc[i].counters = (void *)counters + (i * counter_size);
+		fbc[i].counters = (void __percpu *)counters + (i * counter_size);
 
 		debug_percpu_counter_activate(&fbc[i]);
 	}
diff --git a/net/core/dev.c b/net/core/dev.c
index 751d9b70e6ad..5cad88cf029c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10860,7 +10860,7 @@ noinline void netdev_core_stats_inc(struct net_device *dev, u32 offset)
 			return;
 	}
 
-	field = (__force unsigned long __percpu *)((__force void *)p + offset);
+	field = (unsigned long __percpu *)(void __percpu *)(p + offset);
 	this_cpu_inc(*field);
 }
 EXPORT_SYMBOL_GPL(netdev_core_stats_inc);
-- 
2.45.2