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/bcm63xx/dev-wdt.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 arch/mips/bcm63xx/dev-wdt.c (limited to 'arch/mips/bcm63xx/dev-wdt.c') diff --git a/arch/mips/bcm63xx/dev-wdt.c b/arch/mips/bcm63xx/dev-wdt.c new file mode 100644 index 000000000..302bf7ed5 --- /dev/null +++ b/arch/mips/bcm63xx/dev-wdt.c @@ -0,0 +1,45 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2008 Florian Fainelli + */ + +#include +#include +#include +#include +#include + +static struct resource wdt_resources[] = { + { + .start = -1, /* filled at runtime */ + .end = -1, /* filled at runtime */ + .flags = IORESOURCE_MEM, + }, +}; + +static struct bcm7038_wdt_platform_data bcm63xx_wdt_pdata = { + .clk_name = "periph", +}; + +static struct platform_device bcm63xx_wdt_device = { + .name = "bcm63xx-wdt", + .id = -1, + .num_resources = ARRAY_SIZE(wdt_resources), + .resource = wdt_resources, + .dev = { + .platform_data = &bcm63xx_wdt_pdata, + }, +}; + +static int __init bcm63xx_wdt_register(void) +{ + wdt_resources[0].start = bcm63xx_regset_address(RSET_WDT); + wdt_resources[0].end = wdt_resources[0].start; + wdt_resources[0].end += RSET_WDT_SIZE - 1; + + return platform_device_register(&bcm63xx_wdt_device); +} +arch_initcall(bcm63xx_wdt_register); -- cgit v1.3.1