On Fri, 2020-05-15 at 10:28 +0900, Nobuhiro Iwamatsu wrote: > From: "wuxu.wu" <wuxu.wu@xxxxxxxxxx> > > commit 19b61392c5a852b4e8a0bf35aecb969983c5932d upstream. Queued up for 3.16, thanks. Ben. > 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@xxxxxxxxxx> > Link: https://lore.kernel.org/r/1577849981-31489-1-git-send-email-wuxu.wu@xxxxxxxxxx > Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> > [iwamatsu: Backported to 3.16: adjut context] > Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@xxxxxxxxxxxxx> > --- > drivers/spi/spi-dw.c | 14 ++++++++++++-- > drivers/spi/spi-dw.h | 1 + > 2 files changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c > index 66e9e5196c8c5..b3e697d5b5966 100644 > --- a/drivers/spi/spi-dw.c > +++ b/drivers/spi/spi-dw.c > @@ -182,9 +182,11 @@ 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) { > @@ -196,13 +198,16 @@ static void dw_writer(struct dw_spi *dws) > dw_writew(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_readw(dws, DW_SPI_DR); > /* Care rx only if the transfer's original "rx" is not null */ > @@ -214,6 +219,7 @@ static void dw_reader(struct dw_spi *dws) > } > dws->rx += dws->n_bytes; > } > + spin_unlock(&dws->buf_lock); > } > > static void *next_transfer(struct dw_spi *dws) > @@ -368,6 +374,7 @@ static void pump_transfers(unsigned long data) > struct spi_transfer *previous = NULL; > struct spi_device *spi = NULL; > struct chip_data *chip = NULL; > + unsigned long flags; > u8 bits = 0; > u8 imask = 0; > u8 cs_change = 0; > @@ -406,6 +413,7 @@ static void pump_transfers(unsigned long data) > dws->dma_width = chip->dma_width; > dws->cs_control = chip->cs_control; > > + spin_lock_irqsave(&dws->buf_lock, flags); > dws->rx_dma = transfer->rx_dma; > dws->tx_dma = transfer->tx_dma; > dws->tx = (void *)transfer->tx_buf; > @@ -415,6 +423,7 @@ static void pump_transfers(unsigned long data) > dws->len = dws->cur_transfer->len; > if (chip != dws->prev_chip) > cs_change = 1; > + spin_unlock_irqrestore(&dws->buf_lock, flags); > > cr0 = chip->cr0; > > @@ -651,6 +660,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws) > dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60); > 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, dws); > if (ret < 0) { > diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h > index 6d2acad34f64f..be4119a2159bf 100644 > --- a/drivers/spi/spi-dw.h > +++ b/drivers/spi/spi-dw.h > @@ -116,6 +116,7 @@ struct dw_spi { > size_t len; > void *tx; > void *tx_end; > + spinlock_t buf_lock; > void *rx; > void *rx_end; > int dma_mapped; -- Ben Hutchings The two most common things in the universe are hydrogen and stupidity.
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