From 2b97956af60810cd382b86b9ce9aea421b889861 Mon Sep 17 00:00:00 2001 From: Nuoqi Gui Date: Fri, 4 Sep 2026 12:41:55 +0200 Subject: selftests/bpf: Test rhtab kptr cancellation semantics Resizable hash-map updates and deletions must not perform full special-field destruction in their caller context. In particular, a referenced kptr must remain attached to the allocation until the memory allocator destructor can release it safely. Add separate coverage for both affected paths. The update test stores a task kptr, replaces the ordinary value bytes with BPF_EXIST, and verifies that the kptr survived. The delete test removes an element and exchanges its kptr through the still-valid map-value pointer before the allocation is reclaimed. Both cases observe a NULL kptr when rhtab uses bpf_obj_free_fields(). They recover and release the reference after rhtab switches to cancellation semantics. Signed-off-by: Nuoqi Gui [ kkd: Split update and delete coverage and rewrote the commit log ] Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904104203.345917-5-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/clocksource/timer-versatile.c | 40 +++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 drivers/clocksource/timer-versatile.c (limited to 'drivers/clocksource/timer-versatile.c') diff --git a/drivers/clocksource/timer-versatile.c b/drivers/clocksource/timer-versatile.c new file mode 100644 index 000000000..f5d017b31 --- /dev/null +++ b/drivers/clocksource/timer-versatile.c @@ -0,0 +1,40 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * + * Copyright (C) 2014 ARM Limited + */ + +#include +#include +#include +#include +#include + +#define SYS_24MHZ 0x05c + +static void __iomem *versatile_sys_24mhz; + +static u64 notrace versatile_sys_24mhz_read(void) +{ + return readl(versatile_sys_24mhz); +} + +static int __init versatile_sched_clock_init(struct device_node *node) +{ + void __iomem *base = of_iomap(node, 0); + + of_node_clear_flag(node, OF_POPULATED); + + if (!base) + return -ENXIO; + + versatile_sys_24mhz = base + SYS_24MHZ; + + sched_clock_register(versatile_sys_24mhz_read, 32, 24000000); + + return 0; +} +TIMER_OF_DECLARE(vexpress, "arm,vexpress-sysreg", + versatile_sched_clock_init); +TIMER_OF_DECLARE(versatile, "arm,versatile-sysreg", + versatile_sched_clock_init); -- cgit v1.3.1