lib/test_meminit.c: fix -Wmaybe-uninitialized false positive (d3a81161) · Commits · 戴 / test

The conditional logic is too complicated for the compiler to fully comprehend: lib/test_meminit.c: In function 'test_meminit_init': lib/test_meminit.c:236:5: error: 'buf_copy' may be used uninitialized in this function [-Werror=maybe-uninitialized] kfree(buf_copy); ^~~~~~~~~~~~~~~ lib/test_meminit.c:201:14: note: 'buf_copy' was declared here Simplify it by splitting out the non-rcu section. Link: http://lkml.kernel.org/r/20190617131210.2190280-1-arnd@arndb.de Fixes: af734ee6ec85 ("lib: introduce test_meminit module") Signed-off-by:

Arnd Bergmann <arnd@arndb.de> Acked-by:

Alexander Potapenko <glider@google.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

lib/test_meminit.c

+26 −24

Original line number	Diff line number	Diff line
		@@ -208,11 +208,16 @@ static int __init do_kmem_cache_size(size_t size, bool want_ctor,
		/* Check that buf is zeroed, if it must be. */
		fail = check_buf(buf, size, want_ctor, want_rcu, want_zero);
		fill_with_garbage_skip(buf, size, want_ctor ? CTOR_BYTES : 0);

		if (!want_rcu) {
		kmem_cache_free(c, buf);
		continue;
		}

		/*
		* If this is an RCU cache, use a critical section to ensure we
		* can touch objects after they're freed.
		*/
		if (want_rcu) {
		rcu_read_lock();
		/*
		* Copy the buffer to check that it's not wiped on
		@@ -221,9 +226,7 @@ static int __init do_kmem_cache_size(size_t size, bool want_ctor,
		buf_copy = kmalloc(size, GFP_KERNEL);
		if (buf_copy)
		memcpy(buf_copy, buf, size);
		}
		kmem_cache_free(c, buf);
		if (want_rcu) {

		/*
		* Check that \|buf\| is intact after kmem_cache_free().
		* \|want_zero\| is false, because we wrote garbage to
		@@ -237,7 +240,6 @@ static int __init do_kmem_cache_size(size_t size, bool want_ctor,
		}
		rcu_read_unlock();
		}
		}
		kmem_cache_destroy(c);

		*total_failures += fail;

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