[PATCH v2 08/11] arm64: vdso: Simplify pagelist allocation

[Mark Brown]

Currently we allocate a single array for the struct page * for the vDSO
and then do the lookup for code and data in slightly different ways. Make
this more regular by factoring out the array allocation and struct page *
lookup into a function and using it for both. We don't currently rely on
everything being in one array so there should be no functional change.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
 arch/arm64/kernel/vdso.c | 42 ++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 032249f70460..f78349faa6c4 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -88,12 +88,23 @@ static int __vdso_remap(enum vdso_abi abi,
 	return 0;
 }
 
-static int __vdso_init(enum vdso_abi abi)
+static struct page **vdso_get_pages(unsigned long pfn, size_t pages)
 {
+	struct page **pagelist;
 	int i;
-	struct page **vdso_pagelist;
-	unsigned long pfn;
 
+	pagelist = kcalloc(pages, sizeof(struct page *), GFP_KERNEL);
+	if (!pagelist)
+		return NULL;
+
+	for (i = 0; i < pages; i++)
+		pagelist[i] = pfn_to_page(pfn + i);
+
+	return pagelist;
+}
+
+static int __vdso_init(enum vdso_abi abi)
+{
 	if (memcmp(vdso_info[abi].vdso_code_start, "\177ELF", 4)) {
 		pr_err("vDSO is not a valid ELF object!\n");
 		return -EINVAL;
@@ -113,25 +124,14 @@ static int __vdso_init(enum vdso_abi abi)
 			vdso_info[abi].vdso_code_start) >>
 			PAGE_SHIFT;
 
-	/* Allocate the vDSO pagelist, plus a page for the data. */
-	vdso_pagelist = kcalloc(vdso_info[abi].vdso_text_pages + 1,
-				sizeof(struct page *),
-				GFP_KERNEL);
-	if (vdso_pagelist == NULL)
-		return -ENOMEM;
-
-	/* Grab the vDSO data page. */
-	vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data));
-
+	vdso_info[abi].dm->pages =
+		vdso_get_pages(sym_to_pfn(vdso_data), 1);
+	vdso_info[abi].cm->pages =
+		vdso_get_pages(sym_to_pfn(vdso_info[abi].vdso_code_start),
+			       vdso_info[abi].vdso_text_pages);
 
-	/* Grab the vDSO code pages. */
-	pfn = sym_to_pfn(vdso_info[abi].vdso_code_start);
-
-	for (i = 0; i < vdso_info[abi].vdso_text_pages; i++)
-		vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
-
-	vdso_info[abi].dm->pages = &vdso_pagelist[0];
-	vdso_info[abi].cm->pages = &vdso_pagelist[1];
+	if (!vdso_info[abi].cm->pages || !vdso_info[abi].dm->pages)
+		return -ENOMEM;
 
 	return 0;
 }
-- 
2.20.1