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/clk/imgtec/Kconfig | 10 ++++ drivers/clk/imgtec/Makefile | 2 + drivers/clk/imgtec/clk-boston.c | 110 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 122 insertions(+) create mode 100644 drivers/clk/imgtec/Kconfig create mode 100644 drivers/clk/imgtec/Makefile create mode 100644 drivers/clk/imgtec/clk-boston.c (limited to 'drivers/clk/imgtec') diff --git a/drivers/clk/imgtec/Kconfig b/drivers/clk/imgtec/Kconfig new file mode 100644 index 000000000..c965fd091 --- /dev/null +++ b/drivers/clk/imgtec/Kconfig @@ -0,0 +1,10 @@ +# SPDX-License-Identifier: GPL-2.0-only +config COMMON_CLK_BOSTON + bool "Clock driver for MIPS Boston boards" + depends on MIPS || COMPILE_TEST + select MFD_SYSCON + help + Enable this to support the system & CPU clocks on the MIPS Boston + development board from Imagination Technologies. These are simple + fixed rate clocks whose rate is determined by reading a platform + provided register. diff --git a/drivers/clk/imgtec/Makefile b/drivers/clk/imgtec/Makefile new file mode 100644 index 000000000..d2e81426c --- /dev/null +++ b/drivers/clk/imgtec/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_COMMON_CLK_BOSTON) += clk-boston.o diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c new file mode 100644 index 000000000..f28c3ab93 --- /dev/null +++ b/drivers/clk/imgtec/clk-boston.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2016-2017 Imagination Technologies + * Author: Paul Burton + */ + +#define pr_fmt(fmt) "clk-boston: " fmt + +#include +#include +#include +#include +#include +#include + +#include + +#define BOSTON_PLAT_MMCMDIV 0x30 +# define BOSTON_PLAT_MMCMDIV_CLK0DIV (0xff << 0) +# define BOSTON_PLAT_MMCMDIV_INPUT (0xff << 8) +# define BOSTON_PLAT_MMCMDIV_MUL (0xff << 16) +# define BOSTON_PLAT_MMCMDIV_CLK1DIV (0xff << 24) + +#define BOSTON_CLK_COUNT 3 + +static u32 ext_field(u32 val, u32 mask) +{ + return (val & mask) >> (ffs(mask) - 1); +} + +static void __init clk_boston_setup(struct device_node *np) +{ + unsigned long in_freq, cpu_freq, sys_freq; + uint mmcmdiv, mul, cpu_div, sys_div; + struct clk_hw_onecell_data *onecell; + struct regmap *regmap; + struct clk_hw *hw; + int err; + + regmap = syscon_node_to_regmap(np->parent); + if (IS_ERR(regmap)) { + pr_err("failed to find regmap\n"); + return; + } + + err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv); + if (err) { + pr_err("failed to read mmcm_div register: %d\n", err); + return; + } + + in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000; + mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL); + + sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV); + sys_freq = mult_frac(in_freq, mul, sys_div); + + cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV); + cpu_freq = mult_frac(in_freq, mul, cpu_div); + + onecell = kzalloc_flex(*onecell, hws, BOSTON_CLK_COUNT); + if (!onecell) + return; + + onecell->num = BOSTON_CLK_COUNT; + + hw = clk_hw_register_fixed_rate(NULL, "input", NULL, 0, in_freq); + if (IS_ERR(hw)) { + pr_err("failed to register input clock: %pe\n", hw); + goto fail_input; + } + onecell->hws[BOSTON_CLK_INPUT] = hw; + + hw = clk_hw_register_fixed_rate(NULL, "sys", "input", 0, sys_freq); + if (IS_ERR(hw)) { + pr_err("failed to register sys clock: %pe\n", hw); + goto fail_sys; + } + onecell->hws[BOSTON_CLK_SYS] = hw; + + hw = clk_hw_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq); + if (IS_ERR(hw)) { + pr_err("failed to register cpu clock: %pe\n", hw); + goto fail_cpu; + } + onecell->hws[BOSTON_CLK_CPU] = hw; + + err = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, onecell); + if (err) { + pr_err("failed to add DT provider: %d\n", err); + goto fail_clk_add; + } + + return; + +fail_clk_add: + clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_CPU]); +fail_cpu: + clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_SYS]); +fail_sys: + clk_hw_unregister_fixed_rate(onecell->hws[BOSTON_CLK_INPUT]); +fail_input: + kfree(onecell); +} + +/* + * Use CLK_OF_DECLARE so that this driver is probed early enough to provide the + * CPU frequency for use with the GIC or cop0 counters/timers. + */ +CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup); -- cgit v1.3.1