93b83005ea
[ Upstream commit 33d6e0ff68af74be0c846c8e042e84a9a1a0561e ]
If a memsetXX implementation is completely broken and fails in the first
iteration, when i, j, and k are all zero, the failure is masked as zero
is returned. Failing in the first iteration is perhaps the most likely
failure, so this makes the tests pretty much useless. Avoid the
situation by always setting a random unused bit in the result on
failure.
Link: http://lkml.kernel.org/r/20190506124634.6807-3-peda@axentia.se
Fixes: 03270c13c5 ("lib/string.c: add testcases for memset16/32/64")
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
141 lines
2.4 KiB
C
141 lines
2.4 KiB
C
#include <linux/module.h>
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#include <linux/printk.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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static __init int memset16_selftest(void)
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{
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unsigned i, j, k;
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u16 v, *p;
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p = kmalloc(256 * 2 * 2, GFP_KERNEL);
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if (!p)
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return -1;
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for (i = 0; i < 256; i++) {
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for (j = 0; j < 256; j++) {
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memset(p, 0xa1, 256 * 2 * sizeof(v));
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memset16(p + i, 0xb1b2, j);
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for (k = 0; k < 512; k++) {
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v = p[k];
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if (k < i) {
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if (v != 0xa1a1)
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goto fail;
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} else if (k < i + j) {
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if (v != 0xb1b2)
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goto fail;
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} else {
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if (v != 0xa1a1)
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goto fail;
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}
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}
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}
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}
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fail:
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kfree(p);
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if (i < 256)
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return (i << 24) | (j << 16) | k | 0x8000;
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return 0;
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}
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static __init int memset32_selftest(void)
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{
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unsigned i, j, k;
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u32 v, *p;
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p = kmalloc(256 * 2 * 4, GFP_KERNEL);
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if (!p)
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return -1;
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for (i = 0; i < 256; i++) {
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for (j = 0; j < 256; j++) {
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memset(p, 0xa1, 256 * 2 * sizeof(v));
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memset32(p + i, 0xb1b2b3b4, j);
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for (k = 0; k < 512; k++) {
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v = p[k];
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if (k < i) {
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if (v != 0xa1a1a1a1)
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goto fail;
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} else if (k < i + j) {
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if (v != 0xb1b2b3b4)
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goto fail;
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} else {
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if (v != 0xa1a1a1a1)
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goto fail;
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}
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}
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}
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}
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fail:
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kfree(p);
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if (i < 256)
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return (i << 24) | (j << 16) | k | 0x8000;
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return 0;
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}
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static __init int memset64_selftest(void)
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{
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unsigned i, j, k;
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u64 v, *p;
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p = kmalloc(256 * 2 * 8, GFP_KERNEL);
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if (!p)
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return -1;
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for (i = 0; i < 256; i++) {
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for (j = 0; j < 256; j++) {
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memset(p, 0xa1, 256 * 2 * sizeof(v));
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memset64(p + i, 0xb1b2b3b4b5b6b7b8ULL, j);
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for (k = 0; k < 512; k++) {
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v = p[k];
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if (k < i) {
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if (v != 0xa1a1a1a1a1a1a1a1ULL)
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goto fail;
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} else if (k < i + j) {
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if (v != 0xb1b2b3b4b5b6b7b8ULL)
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goto fail;
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} else {
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if (v != 0xa1a1a1a1a1a1a1a1ULL)
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goto fail;
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}
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}
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}
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}
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fail:
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kfree(p);
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if (i < 256)
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return (i << 24) | (j << 16) | k | 0x8000;
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return 0;
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}
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static __init int string_selftest_init(void)
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{
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int test, subtest;
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test = 1;
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subtest = memset16_selftest();
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if (subtest)
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goto fail;
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test = 2;
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subtest = memset32_selftest();
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if (subtest)
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goto fail;
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test = 3;
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subtest = memset64_selftest();
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if (subtest)
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goto fail;
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pr_info("String selftests succeeded\n");
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return 0;
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fail:
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pr_crit("String selftest failure %d.%08x\n", test, subtest);
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return 0;
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}
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module_init(string_selftest_init);
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MODULE_LICENSE("GPL v2");
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