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/mtd/maps/physmap-versatile.c | 242 +++++++++++++++++++++++++++++++++++ 1 file changed, 242 insertions(+) create mode 100644 drivers/mtd/maps/physmap-versatile.c (limited to 'drivers/mtd/maps/physmap-versatile.c') diff --git a/drivers/mtd/maps/physmap-versatile.c b/drivers/mtd/maps/physmap-versatile.c new file mode 100644 index 000000000..2e779111b --- /dev/null +++ b/drivers/mtd/maps/physmap-versatile.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Versatile OF physmap driver add-on + * + * Copyright (c) 2016, Linaro Limited + * Author: Linus Walleij + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "physmap-versatile.h" + +static struct regmap *syscon_regmap; + +enum versatile_flashprot { + INTEGRATOR_AP_FLASHPROT, + INTEGRATOR_CP_FLASHPROT, + VERSATILE_FLASHPROT, + REALVIEW_FLASHPROT, +}; + +static const struct of_device_id syscon_match[] = { + { + .compatible = "arm,integrator-ap-syscon", + .data = (void *)INTEGRATOR_AP_FLASHPROT, + }, + { + .compatible = "arm,integrator-cp-syscon", + .data = (void *)INTEGRATOR_CP_FLASHPROT, + }, + { + .compatible = "arm,core-module-versatile", + .data = (void *)VERSATILE_FLASHPROT, + }, + { + .compatible = "arm,realview-eb-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pb1176-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pb11mp-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pba8-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + { + .compatible = "arm,realview-pbx-syscon", + .data = (void *)REALVIEW_FLASHPROT, + }, + {}, +}; + +/* + * Flash protection handling for the Integrator/AP + */ +#define INTEGRATOR_SC_CTRLS_OFFSET 0x08 +#define INTEGRATOR_SC_CTRLC_OFFSET 0x0C +#define INTEGRATOR_SC_CTRL_FLVPPEN BIT(1) +#define INTEGRATOR_SC_CTRL_FLWP BIT(2) + +#define INTEGRATOR_EBI_CSR1_OFFSET 0x04 +/* The manual says bit 2, the code says bit 3, trust the code */ +#define INTEGRATOR_EBI_WRITE_ENABLE BIT(3) +#define INTEGRATOR_EBI_LOCK_OFFSET 0x20 +#define INTEGRATOR_EBI_LOCK_VAL 0xA05F + +static const struct of_device_id ebi_match[] = { + { .compatible = "arm,external-bus-interface"}, + { }, +}; + +static int ap_flash_init(struct platform_device *pdev) +{ + struct device_node *ebi; + void __iomem *ebi_base; + u32 val; + int ret; + + /* Look up the EBI */ + ebi = of_find_matching_node(NULL, ebi_match); + if (!ebi) { + return -ENODEV; + } + ebi_base = of_iomap(ebi, 0); + of_node_put(ebi); + if (!ebi_base) + return -ENODEV; + + /* Clear VPP and write protection bits */ + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLC_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + dev_err(&pdev->dev, "error clearing Integrator VPP/WP\n"); + + /* Unlock the EBI */ + writel(INTEGRATOR_EBI_LOCK_VAL, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); + + /* Enable write cycles on the EBI, CSR1 (flash) */ + val = readl(ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); + val |= INTEGRATOR_EBI_WRITE_ENABLE; + writel(val, ebi_base + INTEGRATOR_EBI_CSR1_OFFSET); + + /* Lock the EBI again */ + writel(0, ebi_base + INTEGRATOR_EBI_LOCK_OFFSET); + iounmap(ebi_base); + + return 0; +} + +static void ap_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + if (on) { + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLS_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + pr_err("error enabling AP VPP\n"); + } else { + ret = regmap_write(syscon_regmap, + INTEGRATOR_SC_CTRLC_OFFSET, + INTEGRATOR_SC_CTRL_FLVPPEN | INTEGRATOR_SC_CTRL_FLWP); + if (ret) + pr_err("error disabling AP VPP\n"); + } +} + +/* + * Flash protection handling for the Integrator/CP + */ + +#define INTCP_FLASHPROG_OFFSET 0x04 +#define CINTEGRATOR_FLVPPEN BIT(0) +#define CINTEGRATOR_FLWREN BIT(1) +#define CINTEGRATOR_FLMASK BIT(0)|BIT(1) + +static void cp_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + if (on) { + ret = regmap_update_bits(syscon_regmap, + INTCP_FLASHPROG_OFFSET, + CINTEGRATOR_FLMASK, + CINTEGRATOR_FLVPPEN | CINTEGRATOR_FLWREN); + if (ret) + pr_err("error setting CP VPP\n"); + } else { + ret = regmap_update_bits(syscon_regmap, + INTCP_FLASHPROG_OFFSET, + CINTEGRATOR_FLMASK, + 0); + if (ret) + pr_err("error setting CP VPP\n"); + } +} + +/* + * Flash protection handling for the Versatiles and RealViews + */ + +#define VERSATILE_SYS_FLASH_OFFSET 0x4C + +static void versatile_flash_set_vpp(struct map_info *map, int on) +{ + int ret; + + ret = regmap_update_bits(syscon_regmap, VERSATILE_SYS_FLASH_OFFSET, + 0x01, !!on); + if (ret) + pr_err("error setting Versatile VPP\n"); +} + +int of_flash_probe_versatile(struct platform_device *pdev, + struct device_node *np, + struct map_info *map) +{ + struct device_node *sysnp; + const struct of_device_id *devid; + struct regmap *rmap; + static enum versatile_flashprot versatile_flashprot; + int ret; + + /* Not all flash chips use this protection line */ + if (!of_device_is_compatible(np, "arm,versatile-flash")) + return 0; + + /* For first chip probed, look up the syscon regmap */ + if (!syscon_regmap) { + sysnp = of_find_matching_node_and_match(NULL, + syscon_match, + &devid); + if (!sysnp) + return -ENODEV; + + versatile_flashprot = (uintptr_t)devid->data; + rmap = syscon_node_to_regmap(sysnp); + of_node_put(sysnp); + if (IS_ERR(rmap)) + return PTR_ERR(rmap); + + syscon_regmap = rmap; + } + + switch (versatile_flashprot) { + case INTEGRATOR_AP_FLASHPROT: + ret = ap_flash_init(pdev); + if (ret) + return ret; + map->set_vpp = ap_flash_set_vpp; + dev_info(&pdev->dev, "Integrator/AP flash protection\n"); + break; + case INTEGRATOR_CP_FLASHPROT: + map->set_vpp = cp_flash_set_vpp; + dev_info(&pdev->dev, "Integrator/CP flash protection\n"); + break; + case VERSATILE_FLASHPROT: + case REALVIEW_FLASHPROT: + map->set_vpp = versatile_flash_set_vpp; + dev_info(&pdev->dev, "versatile/realview flash protection\n"); + break; + default: + dev_info(&pdev->dev, "device marked as Versatile flash " + "but no system controller was found\n"); + break; + } + + return 0; +} -- cgit v1.3.1