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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /fs/adfs/dir_f.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'fs/adfs/dir_f.c')
| -rw-r--r-- | fs/adfs/dir_f.c | 324 |
1 files changed, 324 insertions, 0 deletions
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, +}; |
