From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- drivers/mtd/devices/phram.c | 445 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 445 insertions(+) create mode 100644 drivers/mtd/devices/phram.c (limited to 'drivers/mtd/devices/phram.c') diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c new file mode 100644 index 000000000..b42cadcd7 --- /dev/null +++ b/drivers/mtd/devices/phram.c @@ -0,0 +1,445 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) ???? Jochen Schäuble + * Copyright (c) 2003-2004 Joern Engel + * + * Usage: + * + * one commend line parameter per device, each in the form: + * phram=,,[,] + * may be up to 63 characters. + * , , and can be octal, decimal or hexadecimal. If followed + * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or + * gigabytes. is optional and defaults to PAGE_SIZE. + * + * Example: + * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct phram_mtd_list { + struct mtd_info mtd; + struct list_head list; + bool cached; +}; + +static LIST_HEAD(phram_list); + +static int phram_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + u_char *start = mtd->priv; + + memset(start + instr->addr, 0xff, instr->len); + + return 0; +} + +static int phram_point(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, void **virt, resource_size_t *phys) +{ + *virt = mtd->priv + from; + *retlen = len; + return 0; +} + +static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) +{ + return 0; +} + +static int phram_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, u_char *buf) +{ + u_char *start = mtd->priv; + + memcpy(buf, start + from, len); + *retlen = len; + return 0; +} + +static int phram_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const u_char *buf) +{ + u_char *start = mtd->priv; + + memcpy(start + to, buf, len); + *retlen = len; + return 0; +} + +static int phram_map(struct phram_mtd_list *phram, phys_addr_t start, size_t len) +{ + void *addr = NULL; + + if (phram->cached) + addr = memremap(start, len, MEMREMAP_WB); + else + addr = (void __force *)ioremap(start, len); + if (!addr) + return -EIO; + + phram->mtd.priv = addr; + + return 0; +} + +static void phram_unmap(struct phram_mtd_list *phram) +{ + void *addr = phram->mtd.priv; + + if (phram->cached) { + memunmap(addr); + return; + } + + iounmap((void __iomem *)addr); +} + +static void unregister_devices(void) +{ + struct phram_mtd_list *this, *safe; + + list_for_each_entry_safe(this, safe, &phram_list, list) { + mtd_device_unregister(&this->mtd); + phram_unmap(this); + kfree(this->mtd.name); + kfree(this); + } +} + +static int register_device(struct platform_device *pdev, const char *name, + phys_addr_t start, size_t len, uint32_t erasesize) +{ + struct device_node *np = pdev ? pdev->dev.of_node : NULL; + bool cached = np ? !of_property_read_bool(np, "no-map") : false; + struct phram_mtd_list *new; + int ret = -ENOMEM; + + new = kzalloc_obj(*new); + if (!new) + goto out0; + + new->cached = cached; + + ret = phram_map(new, start, len); + if (ret) { + pr_err("ioremap failed\n"); + goto out1; + } + + + new->mtd.name = name; + new->mtd.size = len; + new->mtd.flags = MTD_CAP_RAM; + new->mtd._erase = phram_erase; + new->mtd._point = phram_point; + new->mtd._unpoint = phram_unpoint; + new->mtd._read = phram_read; + new->mtd._write = phram_write; + new->mtd.owner = THIS_MODULE; + new->mtd.type = MTD_RAM; + new->mtd.erasesize = erasesize; + new->mtd.writesize = 1; + + mtd_set_of_node(&new->mtd, np); + + ret = -EAGAIN; + if (mtd_device_register(&new->mtd, NULL, 0)) { + pr_err("Failed to register new device\n"); + goto out2; + } + + if (pdev) + platform_set_drvdata(pdev, new); + else + list_add_tail(&new->list, &phram_list); + + return 0; + +out2: + phram_unmap(new); +out1: + kfree(new); +out0: + return ret; +} + +static int parse_num64(uint64_t *num64, char *token) +{ + size_t len; + int shift = 0; + int ret; + + len = strlen(token); + /* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */ + if (len > 2) { + if (token[len - 1] == 'i') { + switch (token[len - 2]) { + case 'G': + shift += 10; + fallthrough; + case 'M': + shift += 10; + fallthrough; + case 'k': + shift += 10; + token[len - 2] = 0; + break; + default: + return -EINVAL; + } + } + } + + ret = kstrtou64(token, 0, num64); + *num64 <<= shift; + + return ret; +} + +static int parse_name(char **pname, const char *token) +{ + size_t len; + char *name; + + len = strlen(token) + 1; + if (len > 64) + return -ENOSPC; + + name = kstrdup(token, GFP_KERNEL); + if (!name) + return -ENOMEM; + + *pname = name; + return 0; +} + + +static inline void kill_final_newline(char *str) +{ + char *newline = strrchr(str, '\n'); + + if (newline && !newline[1]) + *newline = 0; +} + + +#define parse_err(fmt, args...) do { \ + pr_err(fmt , ## args); \ + return 1; \ +} while (0) + +#ifndef MODULE +static int phram_init_called; +/* + * This shall contain the module parameter if any. It is of the form: + * - phram=,
,[,] for module case + * - phram.phram=,
,[,] for built-in case + * We leave 64 bytes for the device name, 20 for the address , 20 for the + * size and 20 for the erasesize. + * Example: phram.phram=rootfs,0xa0000000,512Mi,65536 + */ +static char phram_paramline[64 + 20 + 20 + 20]; +#endif + +static int phram_setup(const char *val) +{ + char buf[64 + 20 + 20 + 20], *str = buf; + char *token[4]; + char *name; + uint64_t start; + uint64_t len; + uint64_t erasesize = PAGE_SIZE; + uint32_t rem; + int i, ret; + + if (strnlen(val, sizeof(buf)) >= sizeof(buf)) + parse_err("parameter too long\n"); + + strcpy(str, val); + kill_final_newline(str); + + for (i = 0; i < 4; i++) + token[i] = strsep(&str, ","); + + if (str) + parse_err("too many arguments\n"); + + if (!token[2]) + parse_err("not enough arguments\n"); + + ret = parse_name(&name, token[0]); + if (ret) + return ret; + + ret = parse_num64(&start, token[1]); + if (ret) { + parse_err("illegal start address\n"); + goto error; + } + + ret = parse_num64(&len, token[2]); + if (ret) { + parse_err("illegal device length\n"); + goto error; + } + + if (token[3]) { + ret = parse_num64(&erasesize, token[3]); + if (ret) { + parse_err("illegal erasesize\n"); + goto error; + } + } + + if (len == 0 || erasesize == 0 || erasesize > len + || erasesize > UINT_MAX) { + parse_err("illegal erasesize or len\n"); + ret = -EINVAL; + goto error; + } + + div_u64_rem(len, (uint32_t)erasesize, &rem); + if (rem) { + parse_err("len is not multiple of erasesize\n"); + ret = -EINVAL; + goto error; + } + + ret = register_device(NULL, name, start, len, (uint32_t)erasesize); + if (ret) + goto error; + + pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len, start, erasesize); + return 0; + +error: + kfree(name); + return ret; +} + +static int phram_param_call(const char *val, const struct kernel_param *kp) +{ +#ifdef MODULE + return phram_setup(val); +#else + /* + * If more parameters are later passed in via + * /sys/module/phram/parameters/phram + * and init_phram() has already been called, + * we can parse the argument now. + */ + + if (phram_init_called) + return phram_setup(val); + + /* + * During early boot stage, we only save the parameters + * here. We must parse them later: if the param passed + * from kernel boot command line, phram_param_call() is + * called so early that it is not possible to resolve + * the device (even kmalloc() fails). Defer that work to + * phram_setup(). + */ + + if (strlen(val) >= sizeof(phram_paramline)) + return -ENOSPC; + strcpy(phram_paramline, val); + + return 0; +#endif +} + +module_param_call(phram, phram_param_call, NULL, NULL, 0200); +MODULE_PARM_DESC(phram, "Memory region to map. \"phram=,,[,]\""); + +#ifdef CONFIG_OF +static const struct of_device_id phram_of_match[] = { + { .compatible = "phram" }, + {} +}; +MODULE_DEVICE_TABLE(of, phram_of_match); +#endif + +static int phram_probe(struct platform_device *pdev) +{ + struct resource *res; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENOMEM; + + /* mtd_set_of_node() reads name from "label" */ + return register_device(pdev, NULL, res->start, resource_size(res), + PAGE_SIZE); +} + +static void phram_remove(struct platform_device *pdev) +{ + struct phram_mtd_list *phram = platform_get_drvdata(pdev); + + mtd_device_unregister(&phram->mtd); + phram_unmap(phram); + kfree(phram); +} + +static struct platform_driver phram_driver = { + .probe = phram_probe, + .remove = phram_remove, + .driver = { + .name = "phram", + .of_match_table = of_match_ptr(phram_of_match), + }, +}; + +static int __init init_phram(void) +{ + int ret; + + ret = security_locked_down(LOCKDOWN_DEV_MEM); + if (ret) + return ret; + + ret = platform_driver_register(&phram_driver); + if (ret) + return ret; + +#ifndef MODULE + if (phram_paramline[0]) { + ret = phram_setup(phram_paramline); + if (ret) + platform_driver_unregister(&phram_driver); + } + phram_init_called = 1; +#endif + + return ret; +} + +static void __exit cleanup_phram(void) +{ + unregister_devices(); + platform_driver_unregister(&phram_driver); +} + +module_init(init_phram); +module_exit(cleanup_phram); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Joern Engel "); +MODULE_DESCRIPTION("MTD driver for physical RAM"); -- cgit v1.3.1