7fa3ef5203
[ Upstream commit 837ba18dfcd4db21ad58107c65bfe89753aa56d7 ]
The "tx/rx-transfer - crossing PAGE_SIZE" test always fails when
len=131071 and rx_offset >= 5:
spi-loopback-test spi0.0: Running test tx/rx-transfer - crossing PAGE_SIZE
...
with iteration values: len = 131071, tx_off = 0, rx_off = 3
with iteration values: len = 131071, tx_off = 0, rx_off = 4
with iteration values: len = 131071, tx_off = 0, rx_off = 5
loopback strangeness - rx changed outside of allowed range at: ...a4321000
spi_msg@ffffffd5a4157690
frame_length: 131071
actual_length: 131071
spi_transfer@ffffffd5a41576f8
len: 131071
tx_buf: ffffffd5a4340ffc
Note that rx_offset > 3 can only occur if the SPI controller driver sets
->dma_alignment to a higher value than 4, so most SPI controller drivers
are not affect.
The allocated Rx buffer is of size SPI_TEST_MAX_SIZE_PLUS, which is 132
KiB (assuming 4 KiB pages). This test uses an initial offset into the
rx_buf of PAGE_SIZE - 4, and a len of 131071, so the range expected to
be written in this transfer ends at (4096 - 4) + 5 + 131071 == 132 KiB,
which is also the end of the allocated buffer. But the code which
verifies the content of the buffer reads a byte beyond the allocated
buffer and spuriously fails because this out-of-bounds read doesn't
return the expected value.
Fix this by using ITERATE_LEN instead of ITERATE_MAX_LEN to avoid
testing sizes which cause out-of-bounds reads.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Link: https://lore.kernel.org/r/20200902132341.7079-1-vincent.whitchurch@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.