[PATCH 2/5] arm64: vdso: Remove redundant calls to flush_dcache_page()

[Will Deacon]

flush_dcache_page() ensures that the 'PG_dcache_clean' flag for its
'page' argument is clear so that cache maintenance will be performed
if the page is mapped into userspace with execute permissions.

Newly allocated pages have this flag clear, so there is no need to call
flush_dcache_page() for the compat vdso or signal pages. Remove the
redundant calls.

Signed-off-by: Will Deacon <will at kernel.org>
---
 arch/arm64/kernel/vdso.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 2d057a4dc787..421411981dc3 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -306,7 +306,6 @@ static int aarch32_alloc_kuser_vdso_page(void)
 	memcpy((void *)(vdso_page + 0x1000 - kuser_sz), __kuser_helper_start,
 	       kuser_sz);
 	aarch32_vectors_page = virt_to_page(vdso_page);
-	flush_dcache_page(aarch32_vectors_page);
 	return 0;
 }
 
@@ -322,7 +321,6 @@ static int aarch32_alloc_sigpage(void)
 
 	memcpy((void *)sigpage, __aarch32_sigret_code_start, sigret_sz);
 	aarch32_sig_page = virt_to_page(sigpage);
-	flush_dcache_page(aarch32_sig_page);
 	return 0;
 }
 
-- 
2.31.0.rc2.261.g7f71774620-goog