[PATCH] modify acquire_domstatic_pages to take an unsigned int size parameter

[Stefano Stabellini <sstabellini@kernel.org>]

acquire_domstatic_pages currently takes an unsigned long nr_mfns
parameter, but actually it cannot handle anything larger than an
unsigned int nr_mfns. That's because acquire_domstatic_pages is based on
assign_pages which also takes an unsigned int nr parameter.

So modify the nr_mfns parameter of acquire_domstatic_pages to be
unsigned int.

There is only one caller in
xen/arch/arm/domain_build.c:allocate_static_memory. Check that the value
to be passed to acquire_domstatic_pages is no larger than UINT_MAX. If
it is, print an error and goto fail.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
---

Jan, I took your suggestion of moving the check closer to where the
value is read from DT. At that point I also took the opportunity to
change acquire_domstatic_pages to take an unsigned int parameter
instead of unsigned long.


diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 62ab7d0ead..d233d634c1 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -554,6 +554,12 @@ static void __init allocate_static_memory(struct domain *d,
         device_tree_get_reg(&cell, addr_cells, size_cells, &pbase, &psize);
         ASSERT(IS_ALIGNED(pbase, PAGE_SIZE) && IS_ALIGNED(psize, PAGE_SIZE));
 
+        if ( PFN_DOWN(psize) > UINT_MAX )
+        {
+            printk(XENLOG_ERR "%pd: static memory size too large: %#"PRIpaddr,
+                   d, psize);
+            goto fail;
+        }
         smfn = maddr_to_mfn(pbase);
         res = acquire_domstatic_pages(d, smfn, PFN_DOWN(psize), 0);
         if ( res )
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index b9441cb06f..b64c07ae92 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -2714,7 +2714,7 @@ static struct page_info * __init acquire_staticmem_pages(mfn_t smfn,
  * then assign them to one specific domain #d.
  */
 int __init acquire_domstatic_pages(struct domain *d, mfn_t smfn,
-                                   unsigned long nr_mfns, unsigned int memflags)
+                                   unsigned int nr_mfns, unsigned int memflags)
 {
     struct page_info *pg;
 
diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index dd49237e86..5db26ed477 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -89,7 +89,7 @@ bool scrub_free_pages(void);
 /* These functions are for static memory */
 void free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns,
                           bool need_scrub);
-int acquire_domstatic_pages(struct domain *d, mfn_t smfn, unsigned long nr_mfns,
+int acquire_domstatic_pages(struct domain *d, mfn_t smfn, unsigned int nr_mfns,
                             unsigned int memflags);
 #endif