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/m68k/virt/config.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 arch/m68k/virt/config.c (limited to 'arch/m68k/virt/config.c') diff --git a/arch/m68k/virt/config.c b/arch/m68k/virt/config.c new file mode 100644 index 000000000..b338e2a8d --- /dev/null +++ b/arch/m68k/virt/config.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +struct virt_booter_data virt_bi_data; + +static void virt_get_model(char *str) +{ + /* str is 80 characters long */ + sprintf(str, "QEMU Virtual M68K Machine (%u.%u.%u)", + (u8)(virt_bi_data.qemu_version >> 24), + (u8)(virt_bi_data.qemu_version >> 16), + (u8)(virt_bi_data.qemu_version >> 8)); +} +static void virt_reset(void) +{ + do_kernel_restart(NULL); +} + +/* + * Parse a virtual-m68k-specific record in the bootinfo + */ + +int __init virt_parse_bootinfo(const struct bi_record *record) +{ + int unknown = 0; + const void *data = record->data; + + switch (be16_to_cpu(record->tag)) { + case BI_VIRT_QEMU_VERSION: + virt_bi_data.qemu_version = be32_to_cpup(data); + break; + case BI_VIRT_GF_PIC_BASE: + virt_bi_data.pic.mmio = be32_to_cpup(data); + data += 4; + virt_bi_data.pic.irq = be32_to_cpup(data); + break; + case BI_VIRT_GF_RTC_BASE: + virt_bi_data.rtc.mmio = be32_to_cpup(data); + data += 4; + virt_bi_data.rtc.irq = be32_to_cpup(data); + break; + case BI_VIRT_GF_TTY_BASE: + virt_bi_data.tty.mmio = be32_to_cpup(data); + data += 4; + virt_bi_data.tty.irq = be32_to_cpup(data); + break; + case BI_VIRT_CTRL_BASE: + virt_bi_data.ctrl.mmio = be32_to_cpup(data); + data += 4; + virt_bi_data.ctrl.irq = be32_to_cpup(data); + break; + case BI_VIRT_VIRTIO_BASE: + virt_bi_data.virtio.mmio = be32_to_cpup(data); + data += 4; + virt_bi_data.virtio.irq = be32_to_cpup(data); + break; + default: + unknown = 1; + break; + } + return unknown; +} + +static void __init virt_sched_init(void) +{ + goldfish_timer_init(virt_bi_data.rtc.irq, + (void __iomem *)virt_bi_data.rtc.mmio); +} + +void __init config_virt(void) +{ + char earlycon[24]; + + snprintf(earlycon, sizeof(earlycon), "early_gf_tty,0x%08x", + virt_bi_data.tty.mmio); + setup_earlycon(earlycon); + + mach_init_IRQ = virt_init_IRQ; + mach_sched_init = virt_sched_init; + mach_get_model = virt_get_model; + mach_reset = virt_reset; +} -- cgit v1.3.1