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 --- arch/mips/cobalt/lcd.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 arch/mips/cobalt/lcd.c (limited to 'arch/mips/cobalt/lcd.c') diff --git a/arch/mips/cobalt/lcd.c b/arch/mips/cobalt/lcd.c new file mode 100644 index 000000000..7d43b5ec3 --- /dev/null +++ b/arch/mips/cobalt/lcd.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Registration of Cobalt LCD platform device. + * + * Copyright (C) 2008 Yoichi Yuasa + */ +#include +#include +#include +#include + +static struct resource cobalt_lcd_resource __initdata = { + .start = 0x1f000000, + .end = 0x1f00001f, + .flags = IORESOURCE_MEM, +}; + +static __init int cobalt_lcd_add(void) +{ + struct platform_device *pdev; + int retval; + + pdev = platform_device_alloc("cobalt-lcd", -1); + if (!pdev) + return -ENOMEM; + + retval = platform_device_add_resources(pdev, &cobalt_lcd_resource, 1); + if (retval) + goto err_free_device; + + retval = platform_device_add(pdev); + if (retval) + goto err_free_device; + + return 0; + +err_free_device: + platform_device_put(pdev); + + return retval; +} +device_initcall(cobalt_lcd_add); -- cgit v1.3.1