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/dw/internal.h | 101 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 drivers/dma/dw/internal.h (limited to 'drivers/dma/dw/internal.h') diff --git a/drivers/dma/dw/internal.h b/drivers/dma/dw/internal.h new file mode 100644 index 000000000..f1bd06a20 --- /dev/null +++ b/drivers/dma/dw/internal.h @@ -0,0 +1,101 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Driver for the Synopsys DesignWare DMA Controller + * + * Copyright (C) 2013 Intel Corporation + */ + +#ifndef _DMA_DW_INTERNAL_H +#define _DMA_DW_INTERNAL_H + +#include + +#include "regs.h" + +int do_dma_probe(struct dw_dma_chip *chip); +int do_dma_remove(struct dw_dma_chip *chip); + +void do_dw_dma_on(struct dw_dma *dw); +void do_dw_dma_off(struct dw_dma *dw); + +int do_dw_dma_disable(struct dw_dma_chip *chip); +int do_dw_dma_enable(struct dw_dma_chip *chip); + +extern bool dw_dma_filter(struct dma_chan *chan, void *param); + +#ifdef CONFIG_ACPI +void dw_dma_acpi_controller_register(struct dw_dma *dw); +void dw_dma_acpi_controller_free(struct dw_dma *dw); +#else /* !CONFIG_ACPI */ +static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {} +static inline void dw_dma_acpi_controller_free(struct dw_dma *dw) {} +#endif /* !CONFIG_ACPI */ + +struct platform_device; + +#ifdef CONFIG_OF +struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev); +void dw_dma_of_controller_register(struct dw_dma *dw); +void dw_dma_of_controller_free(struct dw_dma *dw); +#else +static inline struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev) +{ + return NULL; +} +static inline void dw_dma_of_controller_register(struct dw_dma *dw) {} +static inline void dw_dma_of_controller_free(struct dw_dma *dw) {} +#endif + +struct dw_dma_chip_pdata { + const struct dw_dma_platform_data *pdata; + int (*probe)(struct dw_dma_chip *chip); + int (*remove)(struct dw_dma_chip *chip); + struct dw_dma_chip *chip; + u8 m_master; + u8 p_master; +}; + +static __maybe_unused const struct dw_dma_chip_pdata dw_dma_chip_pdata = { + .probe = dw_dma_probe, + .remove = dw_dma_remove, + .m_master = 0, + .p_master = 1, +}; + +static const struct dw_dma_platform_data idma32_pdata = { + .nr_channels = 8, + .chan_allocation_order = CHAN_ALLOCATION_ASCENDING, + .chan_priority = CHAN_PRIORITY_ASCENDING, + .block_size = 131071, + .nr_masters = 1, + .data_width = {4}, + .multi_block = {1, 1, 1, 1, 1, 1, 1, 1}, +}; + +static __maybe_unused const struct dw_dma_chip_pdata idma32_chip_pdata = { + .pdata = &idma32_pdata, + .probe = idma32_dma_probe, + .remove = idma32_dma_remove, + .m_master = 0, + .p_master = 0, +}; + +static const struct dw_dma_platform_data xbar_pdata = { + .nr_channels = 8, + .chan_allocation_order = CHAN_ALLOCATION_ASCENDING, + .chan_priority = CHAN_PRIORITY_ASCENDING, + .block_size = 131071, + .nr_masters = 1, + .data_width = {4}, + .quirks = DW_DMA_QUIRK_XBAR_PRESENT, +}; + +static __maybe_unused const struct dw_dma_chip_pdata xbar_chip_pdata = { + .pdata = &xbar_pdata, + .probe = idma32_dma_probe, + .remove = idma32_dma_remove, + .m_master = 0, + .p_master = 0, +}; + +#endif /* _DMA_DW_INTERNAL_H */ -- cgit v1.3.1