soc/nvidia/tegra210: Fix potential NULL pointer dereference

Recent Coverity scan indicated potential NULL deference; if either
spi->dma_in or spi->dma_out are NULL, the fifo_error() check could
dereference a NULL pointer.

Also fixed what appears to be a logic bug for the spi->dma_out case,
where it was using the todo (count) from spi->dma_in.

Found-by: Coverity CID 1241838, 1241854
Change-Id: Icd1412f0956c0a4a75266d1873d5e9848aceee32
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34787
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Tim Wawrzynczak 2019-08-07 20:54:01 -06:00 committed by Martin Roth
parent 98f43a1f75
commit 680027edf6
1 changed files with 25 additions and 21 deletions

View File

@ -286,6 +286,7 @@ static void dump_spi_regs(struct tegra_spi_channel *spi)
static void dump_dma_regs(struct apb_dma_channel *dma)
{
if (dma) {
printk(BIOS_INFO, "DMA regs:\n"
"\tahb_ptr: 0x%08x\n"
"\tapb_ptr: 0x%08x\n"
@ -305,6 +306,7 @@ static void dump_dma_regs(struct apb_dma_channel *dma)
read32(&dma->regs->wcount),
read32(&dma->regs->dma_byte_sta),
read32(&dma->regs->word_transfer));
}
}
static inline unsigned int spi_byte_count(struct tegra_spi_channel *spi)
@ -574,9 +576,9 @@ static int tegra_spi_dma_finish(struct tegra_spi_channel *spi)
struct apb_dma * const apb_dma = (struct apb_dma *)TEGRA_APB_DMA_BASE;
if (spi->dma_in) {
todo = read32(&spi->dma_in->regs->wcount);
if (spi->dma_in) {
while ((read32(&spi->dma_in->regs->dma_byte_sta) < todo) ||
dma_busy(spi->dma_in))
;
@ -589,6 +591,8 @@ static int tegra_spi_dma_finish(struct tegra_spi_channel *spi)
}
if (spi->dma_out) {
todo = read32(&spi->dma_out->regs->wcount);
while ((read32(&spi->dma_out->regs->dma_byte_sta) < todo) ||
dma_busy(spi->dma_out))
;