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 a166563e7ec3
("arm64: mm: support large block mapping when rodata=full"). Therefore,
propagate any error to the caller.

Fixes: a166563e7ec3 ("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>

diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 5135f2d66958d9184ae33a2992339f02bbc96f64..b4ea86cd3a7199dd8a88f867fdb28ad10df2ca77 100644 (file)
--- a/arch/arm64/mm/pageattr.c
+++ b/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;
                }
        }