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/block/z2ram.c | 411 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 411 insertions(+) create mode 100644 drivers/block/z2ram.c (limited to 'drivers/block/z2ram.c') diff --git a/drivers/block/z2ram.c b/drivers/block/z2ram.c new file mode 100644 index 000000000..b216cba1c --- /dev/null +++ b/drivers/block/z2ram.c @@ -0,0 +1,411 @@ +/* +** z2ram - Amiga pseudo-driver to access 16bit-RAM in ZorroII space +** as a block device, to be used as a RAM disk or swap space +** +** Copyright (C) 1994 by Ingo Wilken (Ingo.Wilken@informatik.uni-oldenburg.de) +** +** ++Geert: support for zorro_unused_z2ram, better range checking +** ++roman: translate accesses via an array +** ++Milan: support for ChipRAM usage +** ++yambo: converted to 2.0 kernel +** ++yambo: modularized and support added for 3 minor devices including: +** MAJOR MINOR DESCRIPTION +** ----- ----- ---------------------------------------------- +** 37 0 Use Zorro II and Chip ram +** 37 1 Use only Zorro II ram +** 37 2 Use only Chip ram +** 37 4-7 Use memory list entry 1-4 (first is 0) +** ++jskov: support for 1-4th memory list entry. +** +** Permission to use, copy, modify, and distribute this software and its +** documentation for any purpose and without fee is hereby granted, provided +** that the above copyright notice appear in all copies and that both that +** copyright notice and this permission notice appear in supporting +** documentation. This software is provided "as is" without express or +** implied warranty. +*/ + +#define DEVICE_NAME "Z2RAM" + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include + +#define Z2MINOR_COMBINED (0) +#define Z2MINOR_Z2ONLY (1) +#define Z2MINOR_CHIPONLY (2) +#define Z2MINOR_MEMLIST1 (4) +#define Z2MINOR_MEMLIST2 (5) +#define Z2MINOR_MEMLIST3 (6) +#define Z2MINOR_MEMLIST4 (7) +#define Z2MINOR_COUNT (8) /* Move this down when adding a new minor */ + +#define Z2RAM_CHUNK1024 ( Z2RAM_CHUNKSIZE >> 10 ) + +static DEFINE_MUTEX(z2ram_mutex); +static u_long *z2ram_map = NULL; +static u_long z2ram_size = 0; +static int z2_count = 0; +static int chip_count = 0; +static int list_count = 0; +static int current_device = -1; + +static DEFINE_SPINLOCK(z2ram_lock); + +static struct gendisk *z2ram_gendisk[Z2MINOR_COUNT]; + +static blk_status_t z2_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) +{ + struct request *req = bd->rq; + unsigned long start = blk_rq_pos(req) << 9; + unsigned long len = blk_rq_cur_bytes(req); + + blk_mq_start_request(req); + + if (start + len > z2ram_size) { + pr_err(DEVICE_NAME ": bad access: block=%llu, " + "count=%u\n", + (unsigned long long)blk_rq_pos(req), + blk_rq_cur_sectors(req)); + return BLK_STS_IOERR; + } + + spin_lock_irq(&z2ram_lock); + + while (len) { + unsigned long addr = start & Z2RAM_CHUNKMASK; + unsigned long size = Z2RAM_CHUNKSIZE - addr; + void *buffer = bio_data(req->bio); + + if (len < size) + size = len; + addr += z2ram_map[start >> Z2RAM_CHUNKSHIFT]; + if (rq_data_dir(req) == READ) + memcpy(buffer, (char *)addr, size); + else + memcpy((char *)addr, buffer, size); + start += size; + len -= size; + } + + spin_unlock_irq(&z2ram_lock); + blk_mq_end_request(req, BLK_STS_OK); + return BLK_STS_OK; +} + +static void get_z2ram(void) +{ + int i; + + for (i = 0; i < Z2RAM_SIZE / Z2RAM_CHUNKSIZE; i++) { + if (test_bit(i, zorro_unused_z2ram)) { + z2_count++; + z2ram_map[z2ram_size++] = + (unsigned long)ZTWO_VADDR(Z2RAM_START) + + (i << Z2RAM_CHUNKSHIFT); + clear_bit(i, zorro_unused_z2ram); + } + } + + return; +} + +static void get_chipram(void) +{ + + while (amiga_chip_avail() > (Z2RAM_CHUNKSIZE * 4)) { + chip_count++; + z2ram_map[z2ram_size] = + (u_long) amiga_chip_alloc(Z2RAM_CHUNKSIZE, "z2ram"); + + if (z2ram_map[z2ram_size] == 0) { + break; + } + + z2ram_size++; + } + + return; +} + +static int z2_open(struct gendisk *disk, blk_mode_t mode) +{ + int device = disk->first_minor; + int max_z2_map = (Z2RAM_SIZE / Z2RAM_CHUNKSIZE) * sizeof(z2ram_map[0]); + int max_chip_map = (amiga_chip_size / Z2RAM_CHUNKSIZE) * + sizeof(z2ram_map[0]); + int rc = -ENOMEM; + + mutex_lock(&z2ram_mutex); + if (current_device != -1 && current_device != device) { + rc = -EBUSY; + goto err_out; + } + + if (current_device == -1) { + z2_count = 0; + chip_count = 0; + list_count = 0; + z2ram_size = 0; + + /* Use a specific list entry. */ + if (device >= Z2MINOR_MEMLIST1 && device <= Z2MINOR_MEMLIST4) { + int index = device - Z2MINOR_MEMLIST1 + 1; + unsigned long size, paddr, vaddr; + + if (index >= m68k_realnum_memory) { + printk(KERN_ERR DEVICE_NAME + ": no such entry in z2ram_map\n"); + goto err_out; + } + + paddr = m68k_memory[index].addr; + size = m68k_memory[index].size & ~(Z2RAM_CHUNKSIZE - 1); + +#ifdef __powerpc__ + /* FIXME: ioremap doesn't build correct memory tables. */ + { + vfree(vmalloc(size)); + } + + vaddr = (unsigned long)ioremap_wt(paddr, size); + +#else + vaddr = + (unsigned long)z_remap_nocache_nonser(paddr, size); +#endif + z2ram_map = + kmalloc_objs(z2ram_map[0], size / Z2RAM_CHUNKSIZE); + if (z2ram_map == NULL) { + printk(KERN_ERR DEVICE_NAME + ": cannot get mem for z2ram_map\n"); + goto err_out; + } + + while (size) { + z2ram_map[z2ram_size++] = vaddr; + size -= Z2RAM_CHUNKSIZE; + vaddr += Z2RAM_CHUNKSIZE; + list_count++; + } + + if (z2ram_size != 0) + printk(KERN_INFO DEVICE_NAME + ": using %iK List Entry %d Memory\n", + list_count * Z2RAM_CHUNK1024, index); + } else + switch (device) { + case Z2MINOR_COMBINED: + + z2ram_map = + kmalloc(max_z2_map + max_chip_map, + GFP_KERNEL); + if (z2ram_map == NULL) { + printk(KERN_ERR DEVICE_NAME + ": cannot get mem for z2ram_map\n"); + goto err_out; + } + + get_z2ram(); + get_chipram(); + + if (z2ram_size != 0) + printk(KERN_INFO DEVICE_NAME + ": using %iK Zorro II RAM and %iK Chip RAM (Total %dK)\n", + z2_count * Z2RAM_CHUNK1024, + chip_count * Z2RAM_CHUNK1024, + (z2_count + + chip_count) * Z2RAM_CHUNK1024); + + break; + + case Z2MINOR_Z2ONLY: + z2ram_map = kmalloc(max_z2_map, GFP_KERNEL); + if (!z2ram_map) + goto err_out; + + get_z2ram(); + + if (z2ram_size != 0) + printk(KERN_INFO DEVICE_NAME + ": using %iK of Zorro II RAM\n", + z2_count * Z2RAM_CHUNK1024); + + break; + + case Z2MINOR_CHIPONLY: + z2ram_map = kmalloc(max_chip_map, GFP_KERNEL); + if (!z2ram_map) + goto err_out; + + get_chipram(); + + if (z2ram_size != 0) + printk(KERN_INFO DEVICE_NAME + ": using %iK Chip RAM\n", + chip_count * Z2RAM_CHUNK1024); + + break; + + default: + rc = -ENODEV; + goto err_out; + + break; + } + + if (z2ram_size == 0) { + printk(KERN_NOTICE DEVICE_NAME + ": no unused ZII/Chip RAM found\n"); + goto err_out_kfree; + } + + current_device = device; + z2ram_size <<= Z2RAM_CHUNKSHIFT; + set_capacity(z2ram_gendisk[device], z2ram_size >> 9); + } + + mutex_unlock(&z2ram_mutex); + return 0; + +err_out_kfree: + kfree(z2ram_map); +err_out: + mutex_unlock(&z2ram_mutex); + return rc; +} + +static void z2_release(struct gendisk *disk) +{ + mutex_lock(&z2ram_mutex); + if (current_device == -1) { + mutex_unlock(&z2ram_mutex); + return; + } + mutex_unlock(&z2ram_mutex); + /* + * FIXME: unmap memory + */ +} + +static const struct block_device_operations z2_fops = { + .owner = THIS_MODULE, + .open = z2_open, + .release = z2_release, +}; + +static struct blk_mq_tag_set tag_set; + +static const struct blk_mq_ops z2_mq_ops = { + .queue_rq = z2_queue_rq, +}; + +static int z2ram_register_disk(int minor) +{ + struct gendisk *disk; + int err; + + disk = blk_mq_alloc_disk(&tag_set, NULL, NULL); + if (IS_ERR(disk)) + return PTR_ERR(disk); + + disk->major = Z2RAM_MAJOR; + disk->first_minor = minor; + disk->minors = 1; + disk->flags |= GENHD_FL_NO_PART; + disk->fops = &z2_fops; + if (minor) + sprintf(disk->disk_name, "z2ram%d", minor); + else + sprintf(disk->disk_name, "z2ram"); + + z2ram_gendisk[minor] = disk; + err = add_disk(disk); + if (err) + put_disk(disk); + return err; +} + +static int __init z2_init(void) +{ + int ret, i; + + if (!MACH_IS_AMIGA) + return -ENODEV; + + if (register_blkdev(Z2RAM_MAJOR, DEVICE_NAME)) + return -EBUSY; + + tag_set.ops = &z2_mq_ops; + tag_set.nr_hw_queues = 1; + tag_set.nr_maps = 1; + tag_set.queue_depth = 16; + tag_set.numa_node = NUMA_NO_NODE; + ret = blk_mq_alloc_tag_set(&tag_set); + if (ret) + goto out_unregister_blkdev; + + for (i = 0; i < Z2MINOR_COUNT; i++) { + ret = z2ram_register_disk(i); + if (ret && i == 0) + goto out_free_tagset; + } + + return 0; + +out_free_tagset: + blk_mq_free_tag_set(&tag_set); +out_unregister_blkdev: + unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME); + return ret; +} + +static void __exit z2_exit(void) +{ + int i, j; + + unregister_blkdev(Z2RAM_MAJOR, DEVICE_NAME); + + for (i = 0; i < Z2MINOR_COUNT; i++) { + del_gendisk(z2ram_gendisk[i]); + put_disk(z2ram_gendisk[i]); + } + blk_mq_free_tag_set(&tag_set); + + if (current_device != -1) { + i = 0; + + for (j = 0; j < z2_count; j++) { + set_bit(i++, zorro_unused_z2ram); + } + + for (j = 0; j < chip_count; j++) { + if (z2ram_map[i]) { + amiga_chip_free((void *)z2ram_map[i++]); + } + } + + if (z2ram_map != NULL) { + kfree(z2ram_map); + } + } + + return; +} + +module_init(z2_init); +module_exit(z2_exit); +MODULE_DESCRIPTION("Amiga Zorro II ramdisk driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1