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 --- drivers/fpga/xilinx-selectmap.c | 94 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 drivers/fpga/xilinx-selectmap.c (limited to 'drivers/fpga/xilinx-selectmap.c') diff --git a/drivers/fpga/xilinx-selectmap.c b/drivers/fpga/xilinx-selectmap.c new file mode 100644 index 000000000..d0cbb5fdf --- /dev/null +++ b/drivers/fpga/xilinx-selectmap.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Xilinx Spartan6 and 7 Series SelectMAP interface driver + * + * (C) 2024 Charles Perry + * + * Manage Xilinx FPGA firmware loaded over the SelectMAP configuration + * interface. + */ + +#include "xilinx-core.h" + +#include +#include +#include +#include +#include + +struct xilinx_selectmap_conf { + struct xilinx_fpga_core core; + void __iomem *base; +}; + +#define to_xilinx_selectmap_conf(obj) \ + container_of(obj, struct xilinx_selectmap_conf, core) + +static int xilinx_selectmap_write(struct xilinx_fpga_core *core, + const char *buf, size_t count) +{ + struct xilinx_selectmap_conf *conf = to_xilinx_selectmap_conf(core); + size_t i; + + for (i = 0; i < count; ++i) + writeb(buf[i], conf->base); + + return 0; +} + +static int xilinx_selectmap_probe(struct platform_device *pdev) +{ + struct xilinx_selectmap_conf *conf; + struct gpio_desc *gpio; + void __iomem *base; + + conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL); + if (!conf) + return -ENOMEM; + + conf->core.dev = &pdev->dev; + conf->core.write = xilinx_selectmap_write; + + base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); + if (IS_ERR(base)) + return dev_err_probe(&pdev->dev, PTR_ERR(base), + "ioremap error\n"); + conf->base = base; + + /* CSI_B is active low */ + gpio = devm_gpiod_get_optional(&pdev->dev, "csi", GPIOD_OUT_HIGH); + if (IS_ERR(gpio)) + return dev_err_probe(&pdev->dev, PTR_ERR(gpio), + "Failed to get CSI_B gpio\n"); + + /* RDWR_B is active low */ + gpio = devm_gpiod_get_optional(&pdev->dev, "rdwr", GPIOD_OUT_HIGH); + if (IS_ERR(gpio)) + return dev_err_probe(&pdev->dev, PTR_ERR(gpio), + "Failed to get RDWR_B gpio\n"); + + return xilinx_core_probe(&conf->core); +} + +static const struct of_device_id xlnx_selectmap_of_match[] = { + { .compatible = "xlnx,fpga-xc7s-selectmap", }, // Spartan-7 + { .compatible = "xlnx,fpga-xc7a-selectmap", }, // Artix-7 + { .compatible = "xlnx,fpga-xc7k-selectmap", }, // Kintex-7 + { .compatible = "xlnx,fpga-xc7v-selectmap", }, // Virtex-7 + {}, +}; +MODULE_DEVICE_TABLE(of, xlnx_selectmap_of_match); + +static struct platform_driver xilinx_selectmap_driver = { + .driver = { + .name = "xilinx-selectmap", + .of_match_table = xlnx_selectmap_of_match, + }, + .probe = xilinx_selectmap_probe, +}; + +module_platform_driver(xilinx_selectmap_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Charles Perry "); +MODULE_DESCRIPTION("Load Xilinx FPGA firmware over SelectMap"); -- cgit v1.3.1