arm64/pageattr: Propagate return value from __change_memory_common

The rodata=on security measure requires that any code path which does
vmalloc -> set_memory_ro/set_memory_rox must protect the linear map alias
too. Therefore, if such a call fails, we must abort set_memory_* and caller
must take appropriate action; currently we are suppressing the error, and
there is a real chance of such an error arising post commit a166563
("arm64: mm: support large block mapping when rodata=full"). Therefore,
propagate any error to the caller.

Fixes: a166563 ("arm64: mm: support large block mapping when rodata=full")
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: Dev Jain

arch/arm64/mm/pageattr.c

@@ -148,6 +148,7 @@ static int change_memory_common(unsigned long addr, int numpages,
 	unsigned long size = PAGE_SIZE * numpages;
 	unsigned long end = start + size;
 	struct vm_struct *area;
+	int ret;
 	int i;
 
 	if (!PAGE_ALIGNED(addr)) {
@@ -185,8 +186,10 @@ static int change_memory_common(unsigned long addr, int numpages,
 	if (rodata_full && (pgprot_val(set_mask) == PTE_RDONLY ||
 			    pgprot_val(clear_mask) == PTE_RDONLY)) {
 		for (i = 0; i < area->nr_pages; i++) {
-			__change_memory_common((u64)page_address(area->pages[i]),
+			ret = __change_memory_common((u64)page_address(area->pages[i]),
 					       PAGE_SIZE, set_mask, clear_mask);
+			if (ret)
+				return ret;
 		}
 	}