LoongArch: Set correct size for vDSO code mapping

The current size of vDSO code mapping is hardcoded to PAGE_SIZE. This
cannot work for 4KB page size after commit 18efd0b ("LoongArch:
vDSO: Wire up getrandom() vDSO implementation") because the code size
increases to 8KB. Thus set the code mapping size to its real size, i.e.
PAGE_ALIGN(vdso_end - vdso_start).

Fixes: 18efd0b ("LoongArch: vDSO: Wire up getrandom() vDSO implementation")
Reviewed-by: Xi Ruoyao <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

Author: chenhuacai

arch/loongarch/kernel/vdso.c

@@ -34,7 +34,6 @@ static union {
 	struct loongarch_vdso_data vdata;
 } loongarch_vdso_data __page_aligned_data;
 
-static struct page *vdso_pages[] = { NULL };
 struct vdso_data *vdso_data = generic_vdso_data.data;
 struct vdso_pcpu_data *vdso_pdata = loongarch_vdso_data.vdata.pdata;
 struct vdso_rng_data *vdso_rng_data = &loongarch_vdso_data.vdata.rng_data;
@@ -85,10 +84,8 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 
 struct loongarch_vdso_info vdso_info = {
 	.vdso = vdso_start,
-	.size = PAGE_SIZE,
 	.code_mapping = {
 		.name = "[vdso]",
-		.pages = vdso_pages,
 		.mremap = vdso_mremap,
 	},
 	.data_mapping = {
@@ -103,11 +100,14 @@ static int __init init_vdso(void)
 	unsigned long i, cpu, pfn;
 
 	BUG_ON(!PAGE_ALIGNED(vdso_info.vdso));
-	BUG_ON(!PAGE_ALIGNED(vdso_info.size));
 
 	for_each_possible_cpu(cpu)
 		vdso_pdata[cpu].node = cpu_to_node(cpu);
 
+	vdso_info.size = PAGE_ALIGN(vdso_end - vdso_start);
+	vdso_info.code_mapping.pages =
+		kcalloc(vdso_info.size / PAGE_SIZE, sizeof(struct page *), GFP_KERNEL);
+
 	pfn = __phys_to_pfn(__pa_symbol(vdso_info.vdso));
 	for (i = 0; i < vdso_info.size / PAGE_SIZE; i++)
 		vdso_info.code_mapping.pages[i] = pfn_to_page(pfn + i);