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spi: spi-dw: Add lock protect dw_spi rx/tx to prevent concurrent calls 

[ Upstream commit 19b61392c5 ]

dw_spi_irq() and dw_spi_transfer_one concurrent calls.

I find a panic in dw_writer(): txw = *(u8 *)(dws->tx), when dw->tx==null,
dw->len==4, and dw->tx_end==1.

When tpm driver's message overtime dw_spi_irq() and dw_spi_transfer_one
may concurrent visit dw_spi, so I think dw_spi structure lack of protection.

Otherwise dw_spi_transfer_one set dw rx/tx buffer and then open irq,
store dw rx/tx instructions and other cores handle irq load dw rx/tx
instructions may out of order.

	[ 1025.321302] Call trace:
	...
	[ 1025.321319]  __crash_kexec+0x98/0x148
	[ 1025.321323]  panic+0x17c/0x314
	[ 1025.321329]  die+0x29c/0x2e8
	[ 1025.321334]  die_kernel_fault+0x68/0x78
	[ 1025.321337]  __do_kernel_fault+0x90/0xb0
	[ 1025.321346]  do_page_fault+0x88/0x500
	[ 1025.321347]  do_translation_fault+0xa8/0xb8
	[ 1025.321349]  do_mem_abort+0x68/0x118
	[ 1025.321351]  el1_da+0x20/0x8c
	[ 1025.321362]  dw_writer+0xc8/0xd0
	[ 1025.321364]  interrupt_transfer+0x60/0x110
	[ 1025.321365]  dw_spi_irq+0x48/0x70
	...

Signed-off-by: wuxu.wu <wuxu.wu@huawei.com>
Link: https://lore.kernel.org/r/1577849981-31489-1-git-send-email-wuxu.wu@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5.4-rM2-2.2.x-imx-squashed
wuxu.wu 2020-01-01 11:39:41 +08:00 committed by Greg Kroah-Hartman
parent db10c64764
commit 7db4e6c728
2 changed files with 13 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
drivers/spi/spi-dw.c
View File

@ -172,9 +172,11 @@ static inline u32 rx_max(struct dw_spi *dws)
static void dw_writer(struct dw_spi *dws)
{
u32 max = tx_max(dws);
u32 max;
u16 txw = 0;
spin_lock(&dws->buf_lock);
max = tx_max(dws);
while (max--) {
/* Set the tx word if the transfer's original "tx" is not null */
if (dws->tx_end - dws->len) {
@ -186,13 +188,16 @@ static void dw_writer(struct dw_spi *dws)
dw_write_io_reg(dws, DW_SPI_DR, txw);
dws->tx += dws->n_bytes;
}
spin_unlock(&dws->buf_lock);
}
static void dw_reader(struct dw_spi *dws)
{
u32 max = rx_max(dws);
u32 max;
u16 rxw;
spin_lock(&dws->buf_lock);
max = rx_max(dws);
while (max--) {
rxw = dw_read_io_reg(dws, DW_SPI_DR);
/* Care rx only if the transfer's original "rx" is not null */
@ -204,6 +209,7 @@ static void dw_reader(struct dw_spi *dws)
}
dws->rx += dws->n_bytes;
}
spin_unlock(&dws->buf_lock);
}
static void int_error_stop(struct dw_spi *dws, const char *msg)
@ -276,18 +282,20 @@ static int dw_spi_transfer_one(struct spi_controller *master,
{
struct dw_spi *dws = spi_controller_get_devdata(master);
struct chip_data *chip = spi_get_ctldata(spi);
unsigned long flags;
u8 imask = 0;
u16 txlevel = 0;
u32 cr0;
int ret;
dws->dma_mapped = 0;
spin_lock_irqsave(&dws->buf_lock, flags);
dws->tx = (void *)transfer->tx_buf;
dws->tx_end = dws->tx + transfer->len;
dws->rx = transfer->rx_buf;
dws->rx_end = dws->rx + transfer->len;
dws->len = transfer->len;
spin_unlock_irqrestore(&dws->buf_lock, flags);
spi_enable_chip(dws, 0);
@ -471,6 +479,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
dws->type = SSI_MOTO_SPI;
dws->dma_inited = 0;
dws->dma_addr = (dma_addr_t)(dws->paddr + DW_SPI_DR);
spin_lock_init(&dws->buf_lock);
spi_controller_set_devdata(master, dws);

1
drivers/spi/spi-dw.h
View File

@ -120,6 +120,7 @@ struct dw_spi {
size_t len;
void *tx;
void *tx_end;
spinlock_t buf_lock;
void *rx;
void *rx_end;
int dma_mapped;