Introduce a helper to report full size of underlying allocation of a
vmalloc'ed address.
Suggested-by: Uladzislau Rezki <urezki@xxxxxxxxx>
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
Cc: Uladzislau Rezki <urezki@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
---
include/linux/vmalloc.h | 1 +
mm/vmalloc.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+)
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 096d48a..7fbd390 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -297,4 +297,5 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
static inline bool vmalloc_dump_obj(void *object) { return false; }
#endif
+size_t vsize(void *addr);
#endif /* _LINUX_VMALLOC_H */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ca71de7..8499eba 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4057,6 +4057,23 @@ bool vmalloc_dump_obj(void *object)
}
#endif
+/* Report full size of underlying allocation of a vmalloc'ed addr */
+size_t vsize(void *addr)
+{
+ struct vmap_area *va;
+ size_t va_size = 0;
+
+ if (!addr)
+ return 0;
+
+ spin_lock(&vmap_area_lock);
+ va = __find_vmap_area((unsigned long)addr, &vmap_area_root);
+ if (va && va->vm)
+ va_size = va->vm->size;
+ spin_unlock(&vmap_area_lock);
+ return va_size;
+}
+
#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)
__acquires(&vmap_purge_lock)
--
1.8.3.1
