We are going to use sleeping lock for freeing vmap. However some
vfree() users want to free memory from atomic (but not from interrupt)
context. For this we add vfree_atomic() - deferred variation of vfree()
which can be used in any atomic context (except NMIs).
Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Joel Fernandes <joelaf@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Jisheng Zhang <jszhang@xxxxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: John Dias <joaodias@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
---
include/linux/vmalloc.h | 1 +
mm/vmalloc.c | 36 ++++++++++++++++++++++++++++++------
2 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 3d9d786..d68edff 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -82,6 +82,7 @@ extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
const void *caller);
extern void vfree(const void *addr);
+extern void vfree_atomic(const void *addr);
extern void *vmap(struct page **pages, unsigned int count,
unsigned long flags, pgprot_t prot);
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 719ced3..b0edc67 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1471,7 +1471,33 @@ static void __vunmap(const void *addr, int deallocate_pages)
kfree(area);
return;
}
-
+
+static inline void __vfree_deferred(const void *addr)
+{
+ struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
+
+ if (llist_add((struct llist_node *)addr, &p->list))
+ schedule_work(&p->wq);
+}
+
+/**
+ * vfree_atomic - release memory allocated by vmalloc()
+ * @addr: memory base address
+ *
+ * This one is just like vfree() but can be called in any atomic context
+ * except NMIs.
+ */
+void vfree_atomic(const void *addr)
+{
+ BUG_ON(in_nmi());
+
+ kmemleak_free(addr);
+
+ if (!addr)
+ return;
+ __vfree_deferred(addr);
+}
+
/**
* vfree - release memory allocated by vmalloc()
* @addr: memory base address
@@ -1494,11 +1520,9 @@ void vfree(const void *addr)
if (!addr)
return;
- if (unlikely(in_interrupt())) {
- struct vfree_deferred *p = this_cpu_ptr(&vfree_deferred);
- if (llist_add((struct llist_node *)addr, &p->list))
- schedule_work(&p->wq);
- } else
+ if (unlikely(in_interrupt()))
+ __vfree_deferred(addr);
+ else
__vunmap(addr, 1);
}
EXPORT_SYMBOL(vfree);
--
2.7.3
--
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