+ lib-test_string-avoid-masking-memset16-32-64-failures.patch added to -mm tree

[akpm@xxxxxxxxxxxxxxxxxxxx]

The patch titled
     Subject: lib/test_string.c: avoid masking memset16/32/64 failures
has been added to the -mm tree.  Its filename is
     lib-test_string-avoid-masking-memset16-32-64-failures.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/lib-test_string-avoid-masking-memset16-32-64-failures.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/lib-test_string-avoid-masking-memset16-32-64-failures.patch

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------------------------------------------------------
From: Peter Rosin <peda@xxxxxxxxxx>
Subject: lib/test_string.c: avoid masking memset16/32/64 failures

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@xxxxxxxxxx
Fixes: 03270c13c5ff ("lib/string.c: add testcases for memset16/32/64")
Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 lib/test_string.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/lib/test_string.c~lib-test_string-avoid-masking-memset16-32-64-failures
+++ a/lib/test_string.c
@@ -35,7 +35,7 @@ static __init int memset16_selftest(void
 fail:
 	kfree(p);
 	if (i < 256)
-		return (i << 24) | (j << 16) | k;
+		return (i << 24) | (j << 16) | k | 0x8000;
 	return 0;
 }
 
@@ -71,7 +71,7 @@ static __init int memset32_selftest(void
 fail:
 	kfree(p);
 	if (i < 256)
-		return (i << 24) | (j << 16) | k;
+		return (i << 24) | (j << 16) | k | 0x8000;
 	return 0;
 }
 
@@ -107,7 +107,7 @@ static __init int memset64_selftest(void
 fail:
 	kfree(p);
 	if (i < 256)
-		return (i << 24) | (j << 16) | k;
+		return (i << 24) | (j << 16) | k | 0x8000;
 	return 0;
 }
 
_

Patches currently in -mm which might be from peda@xxxxxxxxxx are

lib-string-allow-searching-for-nul-with-strnchr.patch
lib-test_string-avoid-masking-memset16-32-64-failures.patch
lib-test_string-add-some-testcases-for-strchr-and-strnchr.patch