From: "wuxu.wu" wuxu.wu@huawei.com

commit 19b61392c5a852b4e8a0bf35aecb969983c5932d upstream.

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.c... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Nobuhiro Iwamatsu (CIP) nobuhiro1.iwamatsu@toshiba.co.jp --- drivers/spi/spi-dw.c | 15 ++++++++++++--- drivers/spi/spi-dw.h | 1 + 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index 87a0e47eeae64..4edd38d03b939 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -180,9 +180,11 @@ 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) { @@ -194,13 +196,16 @@ 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 */ @@ -212,6 +217,7 @@ 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) @@ -284,6 +290,7 @@ static int dw_spi_transfer_one(struct spi_master *master, { struct dw_spi *dws = spi_master_get_devdata(master); struct chip_data *chip = spi_get_ctldata(spi); + unsigned long flags; u8 imask = 0; u16 txlevel = 0; u16 clk_div; @@ -291,12 +298,13 @@ static int dw_spi_transfer_one(struct spi_master *master, 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);

@@ -488,6 +496,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws) dws->dma_inited = 0; dws->dma_addr = (dma_addr_t)(dws->paddr + DW_SPI_DR); snprintf(dws->name, sizeof(dws->name), "dw_spi%d", dws->bus_num); + spin_lock_init(&dws->buf_lock);

ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED, dws->name, master); if (ret < 0) { diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h index 35589a270468d..d05b216ea3f87 100644 --- a/drivers/spi/spi-dw.h +++ b/drivers/spi/spi-dw.h @@ -117,6 +117,7 @@ struct dw_spi { size_t len; void *tx; void *tx_end; + spinlock_t buf_lock; void *rx; void *rx_end; int dma_mapped;