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authorKees Cook <keescook@chromium.org>2018-04-11 02:32:54 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-11 20:28:35 +0300
commitf6f66c1bf53079ce1f0789c8b482fba35b81617d (patch)
treef6660b3a670c905f8f49e68ba6625c39be3bae56
parent5f00ae0d3ef8d36041d8d40ec71ab31b22764cba (diff)
downloadlinux-f6f66c1bf53079ce1f0789c8b482fba35b81617d.tar.xz
lib/test_bitmap.c: do not accidentally use stack VLA
This avoids an accidental stack VLA (since the compiler thinks the value of "len" can change, even when marked "const"). This just replaces it with a #define so it will DTRT. Seen with -Wvla. Fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621 Link: http://lkml.kernel.org/r/20180307212555.GA17927@beast Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Yury Norov <ynorov@caviumnetworks.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--lib/test_bitmap.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index 413367cf569e..de16f7869fb1 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -296,15 +296,17 @@ static void __init test_bitmap_parselist(void)
}
}
+#define EXP_BYTES (sizeof(exp) * 8)
+
static void __init test_bitmap_arr32(void)
{
- unsigned int nbits, next_bit, len = sizeof(exp) * 8;
+ unsigned int nbits, next_bit;
u32 arr[sizeof(exp) / 4];
- DECLARE_BITMAP(bmap2, len);
+ DECLARE_BITMAP(bmap2, EXP_BYTES);
memset(arr, 0xa5, sizeof(arr));
- for (nbits = 0; nbits < len; ++nbits) {
+ for (nbits = 0; nbits < EXP_BYTES; ++nbits) {
bitmap_to_arr32(arr, exp, nbits);
bitmap_from_arr32(bmap2, arr, nbits);
expect_eq_bitmap(bmap2, exp, nbits);
@@ -316,7 +318,7 @@ static void __init test_bitmap_arr32(void)
" tail is not safely cleared: %d\n",
nbits, next_bit);
- if (nbits < len - 32)
+ if (nbits < EXP_BYTES - 32)
expect_eq_uint(arr[DIV_ROUND_UP(nbits, 32)],
0xa5a5a5a5);
}