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 --- rust/helpers/io.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 161 insertions(+) create mode 100644 rust/helpers/io.c (limited to 'rust/helpers/io.c') diff --git a/rust/helpers/io.c b/rust/helpers/io.c new file mode 100644 index 000000000..308950aae --- /dev/null +++ b/rust/helpers/io.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +#ifdef CONFIG_HAS_IOMEM +__rust_helper void __iomem *rust_helper_ioremap(phys_addr_t offset, size_t size) +{ + return ioremap(offset, size); +} + +__rust_helper void __iomem *rust_helper_ioremap_np(phys_addr_t offset, + size_t size) +{ + return ioremap_np(offset, size); +} + +__rust_helper void rust_helper_iounmap(void __iomem *addr) +{ + iounmap(addr); +} +#endif /* CONFIG_HAS_IOMEM */ + +__rust_helper void rust_helper_memcpy_fromio(void *dst, + const volatile void __iomem *src, + size_t count) +{ + memcpy_fromio(dst, src, count); +} + +__rust_helper void rust_helper_memcpy_toio(volatile void __iomem *dst, + const void *src, size_t count) +{ + memcpy_toio(dst, src, count); +} + +__rust_helper u8 rust_helper_readb(const void __iomem *addr) +{ + return readb(addr); +} + +__rust_helper u16 rust_helper_readw(const void __iomem *addr) +{ + return readw(addr); +} + +__rust_helper u32 rust_helper_readl(const void __iomem *addr) +{ + return readl(addr); +} + +#ifdef CONFIG_64BIT +__rust_helper u64 rust_helper_readq(const void __iomem *addr) +{ + return readq(addr); +} +#endif + +__rust_helper void rust_helper_writeb(u8 value, void __iomem *addr) +{ + writeb(value, addr); +} + +__rust_helper void rust_helper_writew(u16 value, void __iomem *addr) +{ + writew(value, addr); +} + +__rust_helper void rust_helper_writel(u32 value, void __iomem *addr) +{ + writel(value, addr); +} + +#ifdef CONFIG_64BIT +__rust_helper void rust_helper_writeq(u64 value, void __iomem *addr) +{ + writeq(value, addr); +} +#endif + +__rust_helper u8 rust_helper_readb_relaxed(const void __iomem *addr) +{ + return readb_relaxed(addr); +} + +__rust_helper u16 rust_helper_readw_relaxed(const void __iomem *addr) +{ + return readw_relaxed(addr); +} + +__rust_helper u32 rust_helper_readl_relaxed(const void __iomem *addr) +{ + return readl_relaxed(addr); +} + +#ifdef CONFIG_64BIT +__rust_helper u64 rust_helper_readq_relaxed(const void __iomem *addr) +{ + return readq_relaxed(addr); +} +#endif + +__rust_helper void rust_helper_writeb_relaxed(u8 value, void __iomem *addr) +{ + writeb_relaxed(value, addr); +} + +__rust_helper void rust_helper_writew_relaxed(u16 value, void __iomem *addr) +{ + writew_relaxed(value, addr); +} + +__rust_helper void rust_helper_writel_relaxed(u32 value, void __iomem *addr) +{ + writel_relaxed(value, addr); +} + +#ifdef CONFIG_64BIT +__rust_helper void rust_helper_writeq_relaxed(u64 value, void __iomem *addr) +{ + writeq_relaxed(value, addr); +} +#endif + +__rust_helper resource_size_t rust_helper_resource_size(struct resource *res) +{ + return resource_size(res); +} + +__rust_helper struct resource * +rust_helper_request_mem_region(resource_size_t start, resource_size_t n, + const char *name) +{ + return request_mem_region(start, n, name); +} + +__rust_helper void rust_helper_release_mem_region(resource_size_t start, + resource_size_t n) +{ + release_mem_region(start, n); +} + +__rust_helper struct resource *rust_helper_request_region(resource_size_t start, + resource_size_t n, + const char *name) +{ + return request_region(start, n, name); +} + +__rust_helper struct resource * +rust_helper_request_muxed_region(resource_size_t start, resource_size_t n, + const char *name) +{ + return request_muxed_region(start, n, name); +} + +__rust_helper void rust_helper_release_region(resource_size_t start, + resource_size_t n) +{ + release_region(start, n); +} -- cgit v1.3.1