[PATCH 11/14] ARM: kasan: work around LPAE build warning

From: Arnd Bergmann
Date: Tue Sep 28 2021 - 11:42:36 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

pgd_page_vaddr() returns an 'unsigned long' address, causing a warning
with the memcpy() call in kasan_init():

arch/arm/mm/kasan_init.c: In function 'kasan_init':
include/asm-generic/pgtable-nop4d.h:44:50: error: passing argument 2 of '__memcpy' makes pointer from integer without a cast [-Werror=int-conversion]
44 | #define pgd_page_vaddr(pgd) ((unsigned long)(p4d_pgtable((p4d_t){ pgd })))
| ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| |
| long unsigned int
arch/arm/include/asm/string.h:58:45: note: in definition of macro 'memcpy'
58 | #define memcpy(dst, src, len) __memcpy(dst, src, len)
| ^~~
arch/arm/mm/kasan_init.c:229:16: note: in expansion of macro 'pgd_page_vaddr'
229 | pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_START)),
| ^~~~~~~~~~~~~~
arch/arm/include/asm/string.h:21:47: note: expected 'const void *' but argument is of type 'long unsigned int'
21 | extern void *__memcpy(void *dest, const void *src, __kernel_size_t n);
| ~~~~~~~~~~~~^~~

Avoid this by adding an explicit typecast.

Fixes: 5615f69bc209 ("ARM: 9016/2: Initialize the mapping of KASan shadow memory")
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Link: https://lore.kernel.org/all/CACRpkdb3DMvof3-xdtss0Pc6KM36pJA-iy=WhvtNVnsDpeJ24Q@xxxxxxxxxxxxxx/
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/arm/mm/kasan_init.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c
index 9c348042a724..4b1619584b23 100644
--- a/arch/arm/mm/kasan_init.c
+++ b/arch/arm/mm/kasan_init.c
@@ -226,7 +226,7 @@ void __init kasan_init(void)
BUILD_BUG_ON(pgd_index(KASAN_SHADOW_START) !=
pgd_index(KASAN_SHADOW_END));
memcpy(tmp_pmd_table,
- pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_START)),
+ (void*)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_START)),
sizeof(tmp_pmd_table));
set_pgd(&tmp_pgd_table[pgd_index(KASAN_SHADOW_START)],
__pgd(__pa(tmp_pmd_table) | PMD_TYPE_TABLE | L_PGD_SWAPPER));
--
2.29.2