3.16.84-rc1 review patch. If anyone has any objections, please let me know.
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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 [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 --- drivers/spi/spi-dw.c | 14 ++++++++++++-- drivers/spi/spi-dw.h | 1 + 2 files changed, 13 insertions(+), 2 deletions(-)
--- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -182,9 +182,11 @@ static inline u32 rx_max(struct dw_spi *
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 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 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 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, 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) { --- 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;