XArray: Add calls to might_alloc()

Catch bogus GFP flags deterministically, instead of occasionally
when we actually have to allocate memory.
Reported-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

include/linux/xarray.h

@@ -16,6 +16,7 @@
 #include <linux/kconfig.h>
 #include <linux/kernel.h>
 #include <linux/rcupdate.h>
+#include <linux/sched/mm.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
@@ -586,6 +587,7 @@ static inline void *xa_store_bh(struct xarray *xa, unsigned long index,
 {
 	void *curr;
 
+	might_alloc(gfp);
 	xa_lock_bh(xa);
 	curr = __xa_store(xa, index, entry, gfp);
 	xa_unlock_bh(xa);
@@ -612,6 +614,7 @@ static inline void *xa_store_irq(struct xarray *xa, unsigned long index,
 {
 	void *curr;
 
+	might_alloc(gfp);
 	xa_lock_irq(xa);
 	curr = __xa_store(xa, index, entry, gfp);
 	xa_unlock_irq(xa);
@@ -687,6 +690,7 @@ static inline void *xa_cmpxchg(struct xarray *xa, unsigned long index,
 {
 	void *curr;
 
+	might_alloc(gfp);
 	xa_lock(xa);
 	curr = __xa_cmpxchg(xa, index, old, entry, gfp);
 	xa_unlock(xa);
@@ -714,6 +718,7 @@ static inline void *xa_cmpxchg_bh(struct xarray *xa, unsigned long index,
 {
 	void *curr;
 
+	might_alloc(gfp);
 	xa_lock_bh(xa);
 	curr = __xa_cmpxchg(xa, index, old, entry, gfp);
 	xa_unlock_bh(xa);
@@ -741,6 +746,7 @@ static inline void *xa_cmpxchg_irq(struct xarray *xa, unsigned long index,
 {
 	void *curr;
 
+	might_alloc(gfp);
 	xa_lock_irq(xa);
 	curr = __xa_cmpxchg(xa, index, old, entry, gfp);
 	xa_unlock_irq(xa);
@@ -770,6 +776,7 @@ static inline int __must_check xa_insert(struct xarray *xa,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock(xa);
 	err = __xa_insert(xa, index, entry, gfp);
 	xa_unlock(xa);
@@ -799,6 +806,7 @@ static inline int __must_check xa_insert_bh(struct xarray *xa,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock_bh(xa);
 	err = __xa_insert(xa, index, entry, gfp);
 	xa_unlock_bh(xa);
@@ -828,6 +836,7 @@ static inline int __must_check xa_insert_irq(struct xarray *xa,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock_irq(xa);
 	err = __xa_insert(xa, index, entry, gfp);
 	xa_unlock_irq(xa);
@@ -857,6 +866,7 @@ static inline __must_check int xa_alloc(struct xarray *xa, u32 *id,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock(xa);
 	err = __xa_alloc(xa, id, entry, limit, gfp);
 	xa_unlock(xa);
@@ -886,6 +896,7 @@ static inline int __must_check xa_alloc_bh(struct xarray *xa, u32 *id,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock_bh(xa);
 	err = __xa_alloc(xa, id, entry, limit, gfp);
 	xa_unlock_bh(xa);
@@ -915,6 +926,7 @@ static inline int __must_check xa_alloc_irq(struct xarray *xa, u32 *id,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock_irq(xa);
 	err = __xa_alloc(xa, id, entry, limit, gfp);
 	xa_unlock_irq(xa);
@@ -948,6 +960,7 @@ static inline int xa_alloc_cyclic(struct xarray *xa, u32 *id, void *entry,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock(xa);
 	err = __xa_alloc_cyclic(xa, id, entry, limit, next, gfp);
 	xa_unlock(xa);
@@ -981,6 +994,7 @@ static inline int xa_alloc_cyclic_bh(struct xarray *xa, u32 *id, void *entry,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock_bh(xa);
 	err = __xa_alloc_cyclic(xa, id, entry, limit, next, gfp);
 	xa_unlock_bh(xa);
@@ -1014,6 +1028,7 @@ static inline int xa_alloc_cyclic_irq(struct xarray *xa, u32 *id, void *entry,
 {
 	int err;
 
+	might_alloc(gfp);
 	xa_lock_irq(xa);
 	err = __xa_alloc_cyclic(xa, id, entry, limit, next, gfp);
 	xa_unlock_irq(xa);

tools/include/linux/sched/mm.h

 #ifndef _TOOLS_PERF_LINUX_SCHED_MM_H
 #define _TOOLS_PERF_LINUX_SCHED_MM_H
 
+#define might_alloc(gfp)	do { } while (0)
+
 #endif  /* _TOOLS_PERF_LINUX_SCHED_MM_H */