ARM: 9142/1: kasan: work around LPAE build warning
authorArnd Bergmann <arnd@arndb.de>
Mon, 18 Oct 2021 14:30:38 +0000 (15:30 +0100)
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>
Mon, 25 Oct 2021 12:12:35 +0000 (13:12 +0100)
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.

Link: https://lore.kernel.org/all/CACRpkdb3DMvof3-xdtss0Pc6KM36pJA-iy=WhvtNVnsDpeJ24Q@mail.gmail.com/
Fixes: 5615f69bc209 ("ARM: 9016/2: Initialize the mapping of KASan shadow memory")
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
arch/arm/mm/kasan_init.c

index 9c34804..4b16195 100644 (file)
@@ -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));