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 --- fs/adfs/dir_f.c | 324 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 324 insertions(+) create mode 100644 fs/adfs/dir_f.c (limited to 'fs/adfs/dir_f.c') diff --git a/fs/adfs/dir_f.c b/fs/adfs/dir_f.c new file mode 100644 index 000000000..05e963402 --- /dev/null +++ b/fs/adfs/dir_f.c @@ -0,0 +1,324 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/fs/adfs/dir_f.c + * + * Copyright (C) 1997-1999 Russell King + * + * E and F format directory handling + */ +#include "adfs.h" +#include "dir_f.h" + +/* + * Read an (unaligned) value of length 1..4 bytes + */ +static inline unsigned int adfs_readval(unsigned char *p, int len) +{ + unsigned int val = 0; + + switch (len) { + case 4: val |= p[3] << 24; + fallthrough; + case 3: val |= p[2] << 16; + fallthrough; + case 2: val |= p[1] << 8; + fallthrough; + default: val |= p[0]; + } + return val; +} + +static inline void adfs_writeval(unsigned char *p, int len, unsigned int val) +{ + switch (len) { + case 4: p[3] = val >> 24; + fallthrough; + case 3: p[2] = val >> 16; + fallthrough; + case 2: p[1] = val >> 8; + fallthrough; + default: p[0] = val; + } +} + +#define ror13(v) ((v >> 13) | (v << 19)) + +#define dir_u8(idx) \ + ({ int _buf = idx >> blocksize_bits; \ + int _off = idx - (_buf << blocksize_bits);\ + *(u8 *)(bh[_buf]->b_data + _off); \ + }) + +#define dir_u32(idx) \ + ({ int _buf = idx >> blocksize_bits; \ + int _off = idx - (_buf << blocksize_bits);\ + *(__le32 *)(bh[_buf]->b_data + _off); \ + }) + +#define bufoff(_bh,_idx) \ + ({ int _buf = _idx >> blocksize_bits; \ + int _off = _idx - (_buf << blocksize_bits);\ + (void *)(_bh[_buf]->b_data + _off); \ + }) + +/* + * There are some algorithms that are nice in + * assembler, but a bitch in C... This is one + * of them. + */ +static u8 +adfs_dir_checkbyte(const struct adfs_dir *dir) +{ + struct buffer_head * const *bh = dir->bh; + const int blocksize_bits = dir->sb->s_blocksize_bits; + union { __le32 *ptr32; u8 *ptr8; } ptr, end; + u32 dircheck = 0; + int last = 5 - 26; + int i = 0; + + /* + * Accumulate each word up to the last whole + * word of the last directory entry. This + * can spread across several buffer heads. + */ + do { + last += 26; + do { + dircheck = le32_to_cpu(dir_u32(i)) ^ ror13(dircheck); + + i += sizeof(u32); + } while (i < (last & ~3)); + } while (dir_u8(last) != 0); + + /* + * Accumulate the last few bytes. These + * bytes will be within the same bh. + */ + if (i != last) { + ptr.ptr8 = bufoff(bh, i); + end.ptr8 = ptr.ptr8 + last - i; + + do { + dircheck = *ptr.ptr8++ ^ ror13(dircheck); + } while (ptr.ptr8 < end.ptr8); + } + + /* + * The directory tail is in the final bh + * Note that contary to the RISC OS PRMs, + * the first few bytes are NOT included + * in the check. All bytes are in the + * same bh. + */ + ptr.ptr8 = bufoff(bh, 2008); + end.ptr8 = ptr.ptr8 + 36; + + do { + __le32 v = *ptr.ptr32++; + dircheck = le32_to_cpu(v) ^ ror13(dircheck); + } while (ptr.ptr32 < end.ptr32); + + return (dircheck ^ (dircheck >> 8) ^ (dircheck >> 16) ^ (dircheck >> 24)) & 0xff; +} + +static int adfs_f_validate(struct adfs_dir *dir) +{ + struct adfs_dirheader *head = dir->dirhead; + struct adfs_newdirtail *tail = dir->newtail; + + if (head->startmasseq != tail->endmasseq || + tail->dirlastmask || tail->reserved[0] || tail->reserved[1] || + (memcmp(&head->startname, "Nick", 4) && + memcmp(&head->startname, "Hugo", 4)) || + memcmp(&head->startname, &tail->endname, 4) || + adfs_dir_checkbyte(dir) != tail->dircheckbyte) + return -EIO; + + return 0; +} + +/* Read and check that a directory is valid */ +static int adfs_f_read(struct super_block *sb, u32 indaddr, unsigned int size, + struct adfs_dir *dir) +{ + const unsigned int blocksize_bits = sb->s_blocksize_bits; + int ret; + + if (size && size != ADFS_NEWDIR_SIZE) + return -EIO; + + ret = adfs_dir_read_buffers(sb, indaddr, ADFS_NEWDIR_SIZE, dir); + if (ret) + return ret; + + dir->dirhead = bufoff(dir->bh, 0); + dir->newtail = bufoff(dir->bh, 2007); + + if (adfs_f_validate(dir)) + goto bad_dir; + + dir->parent_id = adfs_readval(dir->newtail->dirparent, 3); + + return 0; + +bad_dir: + adfs_error(sb, "dir %06x is corrupted", indaddr); + adfs_dir_relse(dir); + + return -EIO; +} + +/* + * convert a disk-based directory entry to a Linux ADFS directory entry + */ +static inline void +adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj, + struct adfs_direntry *de) +{ + unsigned int name_len; + + for (name_len = 0; name_len < ADFS_F_NAME_LEN; name_len++) { + if (de->dirobname[name_len] < ' ') + break; + + obj->name[name_len] = de->dirobname[name_len]; + } + + obj->name_len = name_len; + obj->indaddr = adfs_readval(de->dirinddiscadd, 3); + obj->loadaddr = adfs_readval(de->dirload, 4); + obj->execaddr = adfs_readval(de->direxec, 4); + obj->size = adfs_readval(de->dirlen, 4); + obj->attr = de->newdiratts; + + adfs_object_fixup(dir, obj); +} + +/* + * convert a Linux ADFS directory entry to a disk-based directory entry + */ +static inline void +adfs_obj2dir(struct adfs_direntry *de, struct object_info *obj) +{ + adfs_writeval(de->dirinddiscadd, 3, obj->indaddr); + adfs_writeval(de->dirload, 4, obj->loadaddr); + adfs_writeval(de->direxec, 4, obj->execaddr); + adfs_writeval(de->dirlen, 4, obj->size); + de->newdiratts = obj->attr; +} + +/* + * get a directory entry. Note that the caller is responsible + * for holding the relevant locks. + */ +static int +__adfs_dir_get(struct adfs_dir *dir, int pos, struct object_info *obj) +{ + struct adfs_direntry de; + int ret; + + ret = adfs_dir_copyfrom(&de, dir, pos, 26); + if (ret) + return ret; + + if (!de.dirobname[0]) + return -ENOENT; + + adfs_dir2obj(dir, obj, &de); + + return 0; +} + +static int +adfs_f_setpos(struct adfs_dir *dir, unsigned int fpos) +{ + if (fpos >= ADFS_NUM_DIR_ENTRIES) + return -ENOENT; + + dir->pos = 5 + fpos * 26; + return 0; +} + +static int +adfs_f_getnext(struct adfs_dir *dir, struct object_info *obj) +{ + unsigned int ret; + + ret = __adfs_dir_get(dir, dir->pos, obj); + if (ret == 0) + dir->pos += 26; + + return ret; +} + +static int adfs_f_iterate(struct adfs_dir *dir, struct dir_context *ctx) +{ + struct object_info obj; + int pos = 5 + (ctx->pos - 2) * 26; + + while (ctx->pos < 2 + ADFS_NUM_DIR_ENTRIES) { + if (__adfs_dir_get(dir, pos, &obj)) + break; + if (!dir_emit(ctx, obj.name, obj.name_len, + obj.indaddr, DT_UNKNOWN)) + break; + pos += 26; + ctx->pos++; + } + return 0; +} + +static int adfs_f_update(struct adfs_dir *dir, struct object_info *obj) +{ + struct adfs_direntry de; + int offset, ret; + + offset = 5 - (int)sizeof(de); + + do { + offset += sizeof(de); + ret = adfs_dir_copyfrom(&de, dir, offset, sizeof(de)); + if (ret) { + adfs_error(dir->sb, "error reading directory entry"); + return -ENOENT; + } + if (!de.dirobname[0]) { + adfs_error(dir->sb, "unable to locate entry to update"); + return -ENOENT; + } + } while (adfs_readval(de.dirinddiscadd, 3) != obj->indaddr); + + /* Update the directory entry with the new object state */ + adfs_obj2dir(&de, obj); + + /* Write the directory entry back to the directory */ + return adfs_dir_copyto(dir, offset, &de, 26); +} + +static int adfs_f_commit(struct adfs_dir *dir) +{ + int ret; + + /* Increment directory sequence number */ + dir->dirhead->startmasseq += 1; + dir->newtail->endmasseq += 1; + + /* Update directory check byte */ + dir->newtail->dircheckbyte = adfs_dir_checkbyte(dir); + + /* Make sure the directory still validates correctly */ + ret = adfs_f_validate(dir); + if (ret) + adfs_msg(dir->sb, KERN_ERR, "error: update broke directory"); + + return ret; +} + +const struct adfs_dir_ops adfs_f_dir_ops = { + .read = adfs_f_read, + .iterate = adfs_f_iterate, + .setpos = adfs_f_setpos, + .getnext = adfs_f_getnext, + .update = adfs_f_update, + .commit = adfs_f_commit, +}; -- cgit v1.3.1