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/solutionengine.c | 95 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 drivers/mtd/maps/solutionengine.c (limited to 'drivers/mtd/maps/solutionengine.c') diff --git a/drivers/mtd/maps/solutionengine.c b/drivers/mtd/maps/solutionengine.c new file mode 100644 index 000000000..c07f21b20 --- /dev/null +++ b/drivers/mtd/maps/solutionengine.c @@ -0,0 +1,95 @@ +/* + * Flash and EPROM on Hitachi Solution Engine and similar boards. + * + * (C) 2001 Red Hat, Inc. + * + * GPL'd + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static struct mtd_info *flash_mtd; +static struct mtd_info *eprom_mtd; + +struct map_info soleng_eprom_map = { + .name = "Solution Engine EPROM", + .size = 0x400000, + .bankwidth = 4, +}; + +struct map_info soleng_flash_map = { + .name = "Solution Engine FLASH", + .size = 0x400000, + .bankwidth = 4, +}; + +static const char * const probes[] = { "RedBoot", "cmdlinepart", NULL }; + +static int __init init_soleng_maps(void) +{ + /* First probe at offset 0 */ + soleng_flash_map.phys = 0; + soleng_flash_map.virt = (void __iomem *)P2SEGADDR(0); + soleng_eprom_map.phys = 0x01000000; + soleng_eprom_map.virt = (void __iomem *)P1SEGADDR(0x01000000); + simple_map_init(&soleng_eprom_map); + simple_map_init(&soleng_flash_map); + + printk(KERN_NOTICE "Probing for flash chips at 0x00000000:\n"); + flash_mtd = do_map_probe("cfi_probe", &soleng_flash_map); + if (!flash_mtd) { + /* Not there. Try swapping */ + printk(KERN_NOTICE "Probing for flash chips at 0x01000000:\n"); + soleng_flash_map.phys = 0x01000000; + soleng_flash_map.virt = P2SEGADDR(0x01000000); + soleng_eprom_map.phys = 0; + soleng_eprom_map.virt = P1SEGADDR(0); + flash_mtd = do_map_probe("cfi_probe", &soleng_flash_map); + if (!flash_mtd) { + /* Eep. */ + printk(KERN_NOTICE "Flash chips not detected at either possible location.\n"); + return -ENXIO; + } + } + printk(KERN_NOTICE "Solution Engine: Flash at 0x%pap, EPROM at 0x%pap\n", + &soleng_flash_map.phys, + &soleng_eprom_map.phys); + flash_mtd->owner = THIS_MODULE; + + eprom_mtd = do_map_probe("map_rom", &soleng_eprom_map); + if (eprom_mtd) { + eprom_mtd->owner = THIS_MODULE; + mtd_device_register(eprom_mtd, NULL, 0); + } + + mtd_device_parse_register(flash_mtd, probes, NULL, NULL, 0); + + return 0; +} + +static void __exit cleanup_soleng_maps(void) +{ + if (eprom_mtd) { + mtd_device_unregister(eprom_mtd); + map_destroy(eprom_mtd); + } + + mtd_device_unregister(flash_mtd); + map_destroy(flash_mtd); +} + +module_init(init_soleng_maps); +module_exit(cleanup_soleng_maps); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Woodhouse "); +MODULE_DESCRIPTION("MTD map driver for Hitachi SolutionEngine (and similar) boards"); + -- cgit v1.3.1