diff options
author | wuxu.wu <wuxu.wu@huawei.com> | 2020-01-01 11:39:41 +0800 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2020-05-22 21:19:11 +0100 |
commit | f358118d34cdd7e898685205bb62e41e9a3246aa (patch) | |
tree | d277c5ffe678c5670b56ed042ec6a5b48c1495c0 | |
parent | 42f443179444258caf10b7f4f9f4e75201150918 (diff) | |
download | linux-stable-f358118d34cdd7e898685205bb62e41e9a3246aa.tar.gz |
spi: spi-dw: Add lock protect dw_spi rx/tx to prevent concurrent calls
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.com
Signed-off-by: Mark Brown <broonie@kernel.org>
[iwamatsu: Backported to 3.16: adjut context]
Signed-off-by: Nobuhiro Iwamatsu (CIP) <nobuhiro1.iwamatsu@toshiba.co.jp>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r-- | drivers/spi/spi-dw.c | 14 | ||||
-rw-r--r-- | 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 66e9e5196c8c5e..b3e697d5b5966b 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 6d2acad34f64f5..be4119a2159bf3 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; |