[PATCH] powerpc/msi: Remove VLA usage
From: Kees Cook <hidden>
Date: 2018-06-29 18:55:06
In the quest to remove all stack VLA usage from the kernel[1], this switches from an unchanging variable to a constant expression to eliminate the VLA generation. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Randy Dunlap <redacted> Cc: Tyrel Datwyler <redacted> Cc: Rob Herring <robh@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Kees Cook <redacted> --- arch/powerpc/sysdev/msi_bitmap.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/sysdev/msi_bitmap.c b/arch/powerpc/sysdev/msi_bitmap.c
index 6243a7e537d0..e64a411d1a00 100644
--- a/arch/powerpc/sysdev/msi_bitmap.c
+++ b/arch/powerpc/sysdev/msi_bitmap.c@@ -225,22 +225,23 @@ static void __init test_of_node(void) struct device_node of_node; struct property prop; struct msi_bitmap bmp; - int size = 256; - DECLARE_BITMAP(expected, size); +#define SIZE_EXPECTED 256 + DECLARE_BITMAP(expected, SIZE_EXPECTED); /* There should really be a struct device_node allocator */ memset(&of_node, 0, sizeof(of_node)); of_node_init(&of_node); of_node.full_name = node_name; - WARN_ON(msi_bitmap_alloc(&bmp, size, &of_node)); + WARN_ON(msi_bitmap_alloc(&bmp, SIZE_EXPECTED, &of_node)); /* No msi-available-ranges, so expect > 0 */ WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp) <= 0); /* Should all still be free */ - WARN_ON(bitmap_find_free_region(bmp.bitmap, size, get_count_order(size))); - bitmap_release_region(bmp.bitmap, 0, get_count_order(size)); + WARN_ON(bitmap_find_free_region(bmp.bitmap, SIZE_EXPECTED, + get_count_order(SIZE_EXPECTED))); + bitmap_release_region(bmp.bitmap, 0, get_count_order(SIZE_EXPECTED)); /* Now create a fake msi-available-ranges property */
@@ -256,8 +257,8 @@ static void __init test_of_node(void) WARN_ON(msi_bitmap_reserve_dt_hwirqs(&bmp)); /* Check we got the expected result */ - WARN_ON(bitmap_parselist(expected_str, expected, size)); - WARN_ON(!bitmap_equal(expected, bmp.bitmap, size)); + WARN_ON(bitmap_parselist(expected_str, expected, SIZE_EXPECTED)); + WARN_ON(!bitmap_equal(expected, bmp.bitmap, SIZE_EXPECTED)); msi_bitmap_free(&bmp); kfree(bmp.bitmap);
--
2.17.1
--
Kees Cook
Pixel Security