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charset="UTF-8" X-Rspamd-Queue-Id: 5C4F9C0030 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: xmfxa4n5ug65maan16o1h53e6iinhnug X-HE-Tag: 1694444816-262216 X-HE-Meta: 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 G8/YcYdm gxrInx0ryrdF1qokspMrGVOsgEexWm6uCRpBbmJIfHrspO0NgFUASkrhzQMVrXUf7wHdCcBBtrijWhSTB62zOqU3jXZVFf3x8Ozv+h3lhDg1CyLBvOPpJoiv/COoVGH05hYj9Z03I5djLN2EpxNtD6SI222o4meamPDITlV+A76hFQUDXVDCKdbo8RfgO4zgrrueVYT6AqiTuuhUmIjEdmEx1sPaTO695q7S1Oc5iLGNxSeYX1+dJME4i8MGrkI+lPGuJLyqAynqx9EpWSpeu68Gn/94Th3stMUznXoO7f39jK1ObfOfimNhmK87saZ4z+Um+QSFhUrmLjwAmXEJS7ko5hytsK1Mopxmf X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 11 Sept 2023 at 16:57, Alexander Potapenko wrote: > > Add a regression test for the special case where memcpy() previously > failed to correctly set the origins: if upon memcpy() four aligned > initialized bytes with a zero origin value ended up split between two > aligned four-byte chunks, one of those chunks could've received the zero > origin value even despite it contained uninitialized bytes from other > writes. > > Signed-off-by: Alexander Potapenko > Suggested-by: Marco Elver Acked-by: Marco Elver > --- > mm/kmsan/kmsan_test.c | 53 +++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 53 insertions(+) > > diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c > index 6eb1e1a4d08f9..07d3a3a5a9c52 100644 > --- a/mm/kmsan/kmsan_test.c > +++ b/mm/kmsan/kmsan_test.c > @@ -486,6 +486,58 @@ static void test_memcpy_aligned_to_unaligned(struct kunit *test) > KUNIT_EXPECT_TRUE(test, report_matches(&expect)); > } > > +/* > + * Test case: ensure that origin slots do not accidentally get overwritten with > + * zeroes during memcpy(). > + * > + * Previously, when copying memory from an aligned buffer to an unaligned one, > + * if there were zero origins corresponding to zero shadow values in the source > + * buffer, they could have ended up being copied to nonzero shadow values in the > + * destination buffer: > + * > + * memcpy(0xffff888080a00000, 0xffff888080900002, 8) > + * > + * src (0xffff888080900002): ..xx .... xx.. > + * src origins: o111 0000 o222 > + * dst (0xffff888080a00000): xx.. ..xx > + * dst origins: o111 0000 > + * (or 0000 o222) > + * > + * (here . stands for an initialized byte, and x for an uninitialized one. > + * > + * Ensure that this does not happen anymore, and for both destination bytes > + * the origin is nonzero (i.e. KMSAN reports an error). > + */ > +static void test_memcpy_initialized_gap(struct kunit *test) > +{ > + EXPECTATION_UNINIT_VALUE_FN(expect, "test_memcpy_initialized_gap"); > + volatile char uninit_src[12]; > + volatile char dst[8] = { 0 }; > + > + kunit_info( > + test, > + "unaligned 4-byte initialized value gets a nonzero origin after memcpy() - (2 UMR reports)\n"); > + > + uninit_src[0] = 42; > + uninit_src[1] = 42; > + uninit_src[4] = 42; > + uninit_src[5] = 42; > + uninit_src[6] = 42; > + uninit_src[7] = 42; > + uninit_src[10] = 42; > + uninit_src[11] = 42; > + memcpy_noinline((void *)&dst[0], (void *)&uninit_src[2], 8); > + > + kmsan_check_memory((void *)&dst[0], 4); > + KUNIT_EXPECT_TRUE(test, report_matches(&expect)); > + report_reset(); > + kmsan_check_memory((void *)&dst[2], 4); > + KUNIT_EXPECT_FALSE(test, report_matches(&expect)); > + report_reset(); > + kmsan_check_memory((void *)&dst[4], 4); > + KUNIT_EXPECT_TRUE(test, report_matches(&expect)); > +} > + > /* Generate test cases for memset16(), memset32(), memset64(). */ > #define DEFINE_TEST_MEMSETXX(size) \ > static void test_memset##size(struct kunit *test) \ > @@ -579,6 +631,7 @@ static struct kunit_case kmsan_test_cases[] = { > KUNIT_CASE(test_init_memcpy), > KUNIT_CASE(test_memcpy_aligned_to_aligned), > KUNIT_CASE(test_memcpy_aligned_to_unaligned), > + KUNIT_CASE(test_memcpy_initialized_gap), > KUNIT_CASE(test_memset16), > KUNIT_CASE(test_memset32), > KUNIT_CASE(test_memset64), > -- > 2.42.0.283.g2d96d420d3-goog >