From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- arch/m68k/virt/ints.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 arch/m68k/virt/ints.c (limited to 'arch/m68k/virt/ints.c') diff --git a/arch/m68k/virt/ints.c b/arch/m68k/virt/ints.c new file mode 100644 index 000000000..896aa6eb8 --- /dev/null +++ b/arch/m68k/virt/ints.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#define GFPIC_REG_IRQ_PENDING 0x04 +#define GFPIC_REG_IRQ_DISABLE_ALL 0x08 +#define GFPIC_REG_IRQ_DISABLE 0x0c +#define GFPIC_REG_IRQ_ENABLE 0x10 + +static struct resource picres[6]; +static const char *picname[6] = { + "goldfish_pic.0", + "goldfish_pic.1", + "goldfish_pic.2", + "goldfish_pic.3", + "goldfish_pic.4", + "goldfish_pic.5" +}; + +/* + * 6 goldfish-pic for CPU IRQ #1 to IRQ #6 + * CPU IRQ #1 -> PIC #1 + * IRQ #1 to IRQ #31 -> unused + * IRQ #32 -> goldfish-tty + * CPU IRQ #2 -> PIC #2 + * IRQ #1 to IRQ #32 -> virtio-mmio from 1 to 32 + * CPU IRQ #3 -> PIC #3 + * IRQ #1 to IRQ #32 -> virtio-mmio from 33 to 64 + * CPU IRQ #4 -> PIC #4 + * IRQ #1 to IRQ #32 -> virtio-mmio from 65 to 96 + * CPU IRQ #5 -> PIC #5 + * IRQ #1 to IRQ #32 -> virtio-mmio from 97 to 128 + * CPU IRQ #6 -> PIC #6 + * IRQ #1 -> goldfish-timer + * IRQ #2 -> goldfish-rtc + * IRQ #3 to IRQ #32 -> unused + * CPU IRQ #7 -> NMI + */ + +static u32 gfpic_read(int pic, int reg) +{ + void __iomem *base = (void __iomem *)(virt_bi_data.pic.mmio + + pic * 0x1000); + + return ioread32be(base + reg); +} + +static void gfpic_write(u32 value, int pic, int reg) +{ + void __iomem *base = (void __iomem *)(virt_bi_data.pic.mmio + + pic * 0x1000); + + iowrite32be(value, base + reg); +} + +#define GF_PIC(irq) ((irq - IRQ_USER) / 32) +#define GF_IRQ(irq) ((irq - IRQ_USER) % 32) + +static void virt_irq_enable(struct irq_data *data) +{ + gfpic_write(BIT(GF_IRQ(data->irq)), GF_PIC(data->irq), + GFPIC_REG_IRQ_ENABLE); +} + +static void virt_irq_disable(struct irq_data *data) +{ + gfpic_write(BIT(GF_IRQ(data->irq)), GF_PIC(data->irq), + GFPIC_REG_IRQ_DISABLE); +} + +static unsigned int virt_irq_startup(struct irq_data *data) +{ + virt_irq_enable(data); + return 0; +} + +static irqreturn_t virt_nmi_handler(int irq, void *dev_id) +{ + static int in_nmi; + + if (READ_ONCE(in_nmi)) + return IRQ_HANDLED; + WRITE_ONCE(in_nmi, 1); + + pr_warn("Non-Maskable Interrupt\n"); + show_registers(get_irq_regs()); + + WRITE_ONCE(in_nmi, 0); + return IRQ_HANDLED; +} + +static struct irq_chip virt_irq_chip = { + .name = "virt", + .irq_enable = virt_irq_enable, + .irq_disable = virt_irq_disable, + .irq_startup = virt_irq_startup, + .irq_shutdown = virt_irq_disable, +}; + +static void goldfish_pic_irq(struct irq_desc *desc) +{ + u32 irq_pending; + unsigned int irq_num; + unsigned int pic = desc->irq_data.irq - 1; + + irq_pending = gfpic_read(pic, GFPIC_REG_IRQ_PENDING); + irq_num = IRQ_USER + pic * 32; + + do { + if (irq_pending & 1) + generic_handle_irq(irq_num); + ++irq_num; + irq_pending >>= 1; + } while (irq_pending); +} + +void __init virt_init_IRQ(void) +{ + unsigned int i; + + m68k_setup_irq_controller(&virt_irq_chip, handle_simple_irq, IRQ_USER, + NUM_VIRT_SOURCES - IRQ_USER); + + for (i = 0; i < 6; i++) { + + picres[i] = (struct resource) + DEFINE_RES_MEM_NAMED(virt_bi_data.pic.mmio + i * 0x1000, + 0x1000, picname[i]); + if (request_resource(&iomem_resource, &picres[i])) { + pr_err("Cannot allocate %s resource\n", picname[i]); + return; + } + + irq_set_chained_handler(virt_bi_data.pic.irq + i, + goldfish_pic_irq); + } + + if (request_irq(IRQ_AUTO_7, virt_nmi_handler, 0, "NMI", + virt_nmi_handler)) + pr_err("Couldn't register NMI\n"); +} -- cgit v1.3.1