From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/dma/hsu/hsu.h | 127 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 drivers/dma/hsu/hsu.h (limited to 'drivers/dma/hsu/hsu.h') diff --git a/drivers/dma/hsu/hsu.h b/drivers/dma/hsu/hsu.h new file mode 100644 index 000000000..3bca577b9 --- /dev/null +++ b/drivers/dma/hsu/hsu.h @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Driver for the High Speed UART DMA + * + * Copyright (C) 2015 Intel Corporation + * + * Partially based on the bits found in drivers/tty/serial/mfd.c. + */ + +#ifndef __DMA_HSU_H__ +#define __DMA_HSU_H__ + +#include +#include +#include +#include + +#include + +#include "../virt-dma.h" + +#define HSU_CH_SR 0x00 /* channel status */ +#define HSU_CH_CR 0x04 /* channel control */ +#define HSU_CH_DCR 0x08 /* descriptor control */ +#define HSU_CH_BSR 0x10 /* FIFO buffer size */ +#define HSU_CH_MTSR 0x14 /* minimum transfer size */ +#define HSU_CH_DxSAR(x) (0x20 + 8 * (x)) /* desc start addr */ +#define HSU_CH_DxTSR(x) (0x24 + 8 * (x)) /* desc transfer size */ +#define HSU_CH_D0SAR 0x20 /* desc 0 start addr */ +#define HSU_CH_D0TSR 0x24 /* desc 0 transfer size */ +#define HSU_CH_D1SAR 0x28 +#define HSU_CH_D1TSR 0x2c +#define HSU_CH_D2SAR 0x30 +#define HSU_CH_D2TSR 0x34 +#define HSU_CH_D3SAR 0x38 +#define HSU_CH_D3TSR 0x3c + +#define HSU_DMA_CHAN_NR_DESC 4 +#define HSU_DMA_CHAN_LENGTH 0x40 + +/* Bits in HSU_CH_SR */ +#define HSU_CH_SR_DESCTO(x) BIT(8 + (x)) +#define HSU_CH_SR_DESCTO_ANY GENMASK(11, 8) +#define HSU_CH_SR_CHE BIT(15) +#define HSU_CH_SR_DESCE(x) BIT(16 + (x)) +#define HSU_CH_SR_DESCE_ANY GENMASK(19, 16) +#define HSU_CH_SR_CDESC_ANY GENMASK(31, 30) + +/* Bits in HSU_CH_CR */ +#define HSU_CH_CR_CHA BIT(0) +#define HSU_CH_CR_CHD BIT(1) + +/* Bits in HSU_CH_DCR */ +#define HSU_CH_DCR_DESCA(x) BIT(0 + (x)) +#define HSU_CH_DCR_CHSOD(x) BIT(8 + (x)) +#define HSU_CH_DCR_CHSOTO BIT(14) +#define HSU_CH_DCR_CHSOE BIT(15) +#define HSU_CH_DCR_CHDI(x) BIT(16 + (x)) +#define HSU_CH_DCR_CHEI BIT(23) +#define HSU_CH_DCR_CHTOI(x) BIT(24 + (x)) + +/* Bits in HSU_CH_DxTSR */ +#define HSU_CH_DxTSR_MASK GENMASK(15, 0) +#define HSU_CH_DxTSR_TSR(x) ((x) & HSU_CH_DxTSR_MASK) + +struct hsu_dma_sg { + dma_addr_t addr; + unsigned int len; +}; + +struct hsu_dma_desc { + struct virt_dma_desc vdesc; + enum dma_transfer_direction direction; + struct hsu_dma_sg *sg; + unsigned int nents; + size_t length; + unsigned int active; + enum dma_status status; +}; + +static inline struct hsu_dma_desc *to_hsu_dma_desc(struct virt_dma_desc *vdesc) +{ + return container_of(vdesc, struct hsu_dma_desc, vdesc); +} + +struct hsu_dma_chan { + struct virt_dma_chan vchan; + + void __iomem *reg; + + /* hardware configuration */ + enum dma_transfer_direction direction; + struct dma_slave_config config; + + struct hsu_dma_desc *desc; +}; + +static inline struct hsu_dma_chan *to_hsu_dma_chan(struct dma_chan *chan) +{ + return container_of(chan, struct hsu_dma_chan, vchan.chan); +} + +static inline u32 hsu_chan_readl(struct hsu_dma_chan *hsuc, int offset) +{ + return readl(hsuc->reg + offset); +} + +static inline void hsu_chan_writel(struct hsu_dma_chan *hsuc, int offset, + u32 value) +{ + writel(value, hsuc->reg + offset); +} + +struct hsu_dma { + struct dma_device dma; + + /* channels */ + struct hsu_dma_chan *chan; + unsigned short nr_channels; +}; + +static inline struct hsu_dma *to_hsu_dma(struct dma_device *ddev) +{ + return container_of(ddev, struct hsu_dma, dma); +} + +#endif /* __DMA_HSU_H__ */ -- cgit v1.3.1