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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/ext4/hash.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/ext4/hash.c')
| -rw-r--r-- | fs/ext4/hash.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/fs/ext4/hash.c b/fs/ext4/hash.c new file mode 100644 index 000000000..978bd92da --- /dev/null +++ b/fs/ext4/hash.c @@ -0,0 +1,347 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/ext4/hash.c + * + * Copyright (C) 2002 by Theodore Ts'o + */ + +#include <linux/fs.h> +#include <linux/unicode.h> +#include <linux/compiler.h> +#include <linux/bitops.h> +#include <linux/unaligned.h> +#include "ext4.h" + +#define DELTA 0x9E3779B9 + +static void TEA_transform(__u32 buf[4], __u32 const in[]) +{ + __u32 sum = 0; + __u32 b0 = buf[0], b1 = buf[1]; + __u32 a = in[0], b = in[1], c = in[2], d = in[3]; + int n = 16; + + do { + sum += DELTA; + b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b); + b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d); + } while (--n); + + buf[0] += b0; + buf[1] += b1; +} + +/* F, G and H are basic MD4 functions: selection, majority, parity */ +#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) +#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z))) +#define H(x, y, z) ((x) ^ (y) ^ (z)) + +/* + * The generic round function. The application is so specific that + * we don't bother protecting all the arguments with parens, as is generally + * good macro practice, in favor of extra legibility. + * Rotation is separate from addition to prevent recomputation + */ +#define ROUND(f, a, b, c, d, x, s) \ + (a += f(b, c, d) + x, a = rol32(a, s)) +#define K1 0 +#define K2 013240474631UL +#define K3 015666365641UL + +/* + * Basic cut-down MD4 transform. Returns only 32 bits of result. + */ +static __u32 half_md4_transform(__u32 buf[4], __u32 const in[8]) +{ + __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3]; + + /* Round 1 */ + ROUND(F, a, b, c, d, in[0] + K1, 3); + ROUND(F, d, a, b, c, in[1] + K1, 7); + ROUND(F, c, d, a, b, in[2] + K1, 11); + ROUND(F, b, c, d, a, in[3] + K1, 19); + ROUND(F, a, b, c, d, in[4] + K1, 3); + ROUND(F, d, a, b, c, in[5] + K1, 7); + ROUND(F, c, d, a, b, in[6] + K1, 11); + ROUND(F, b, c, d, a, in[7] + K1, 19); + + /* Round 2 */ + ROUND(G, a, b, c, d, in[1] + K2, 3); + ROUND(G, d, a, b, c, in[3] + K2, 5); + ROUND(G, c, d, a, b, in[5] + K2, 9); + ROUND(G, b, c, d, a, in[7] + K2, 13); + ROUND(G, a, b, c, d, in[0] + K2, 3); + ROUND(G, d, a, b, c, in[2] + K2, 5); + ROUND(G, c, d, a, b, in[4] + K2, 9); + ROUND(G, b, c, d, a, in[6] + K2, 13); + + /* Round 3 */ + ROUND(H, a, b, c, d, in[3] + K3, 3); + ROUND(H, d, a, b, c, in[7] + K3, 9); + ROUND(H, c, d, a, b, in[2] + K3, 11); + ROUND(H, b, c, d, a, in[6] + K3, 15); + ROUND(H, a, b, c, d, in[1] + K3, 3); + ROUND(H, d, a, b, c, in[5] + K3, 9); + ROUND(H, c, d, a, b, in[0] + K3, 11); + ROUND(H, b, c, d, a, in[4] + K3, 15); + + buf[0] += a; + buf[1] += b; + buf[2] += c; + buf[3] += d; + + return buf[1]; /* "most hashed" word */ +} +#undef ROUND +#undef K1 +#undef K2 +#undef K3 +#undef F +#undef G +#undef H + +/* The old legacy hash */ +static __u32 dx_hack_hash_unsigned(const char *name, int len) +{ + __u32 hash, hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9; + const unsigned char *ucp = (const unsigned char *) name; + + while (len--) { + hash = hash1 + (hash0 ^ (((int) *ucp++) * 7152373)); + + if (hash & 0x80000000) + hash -= 0x7fffffff; + hash1 = hash0; + hash0 = hash; + } + return hash0 << 1; +} + +static __u32 dx_hack_hash_signed(const char *name, int len) +{ + __u32 hash, hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9; + const signed char *scp = (const signed char *) name; + + while (len--) { + hash = hash1 + (hash0 ^ (((int) *scp++) * 7152373)); + + if (hash & 0x80000000) + hash -= 0x7fffffff; + hash1 = hash0; + hash0 = hash; + } + return hash0 << 1; +} + +static void str2hashbuf_signed(const char *msg, int len, __u32 *buf, int num) +{ + __u32 pad, val; + int i; + const signed char *scp = (const signed char *) msg; + + pad = (__u32)len | ((__u32)len << 8); + pad |= pad << 16; + + if (len > num*4) + len = num * 4; + + while (len >= 4) { + val = ((__u32)scp[0] << 24) + ((__u32)scp[1] << 16) + ((__u32)scp[2] << 8) + scp[3]; + *buf++ = val; + scp += 4; + len -= 4; + num--; + } + + val = pad; + + for (i = 0; i < len; i++) + val = scp[i] + (val << 8); + + if (--num >= 0) + *buf++ = val; + + while (--num >= 0) + *buf++ = pad; + +} + +static void str2hashbuf_unsigned(const char *msg, int len, __u32 *buf, int num) +{ + __u32 pad, val; + int i; + const unsigned char *ucp = (const unsigned char *) msg; + + pad = (__u32)len | ((__u32)len << 8); + pad |= pad << 16; + + if (len > num*4) + len = num * 4; + + while (len >= 4) { + val = get_unaligned_be32(ucp); + *buf++ = val; + ucp += 4; + len -= 4; + num--; + } + + val = pad; + + for (i = 0; i < len; i++) + val = ucp[i] + (val << 8); + + if (--num >= 0) + *buf++ = val; + + while (--num >= 0) + *buf++ = pad; + +} + +/* + * Returns the hash of a filename. If len is 0 and name is NULL, then + * this function can be used to test whether or not a hash version is + * supported. + * + * The seed is an 4 longword (32 bits) "secret" which can be used to + * uniquify a hash. If the seed is all zero's, then some default seed + * may be used. + * + * A particular hash version specifies whether or not the seed is + * represented, and whether or not the returned hash is 32 bits or 64 + * bits. 32 bit hashes will return 0 for the minor hash. + */ +static int __ext4fs_dirhash(const struct inode *dir, const char *name, int len, + struct dx_hash_info *hinfo) +{ + __u32 hash; + __u32 minor_hash = 0; + const char *p; + int i; + __u32 in[8], buf[4]; + bool use_unsigned = false; + + /* Initialize the default seed for the hash checksum functions */ + buf[0] = 0x67452301; + buf[1] = 0xefcdab89; + buf[2] = 0x98badcfe; + buf[3] = 0x10325476; + + /* Check to see if the seed is all zero's */ + if (hinfo->seed) { + for (i = 0; i < 4; i++) { + if (hinfo->seed[i]) { + memcpy(buf, hinfo->seed, sizeof(buf)); + break; + } + } + } + + switch (hinfo->hash_version) { + case DX_HASH_LEGACY_UNSIGNED: + hash = dx_hack_hash_unsigned(name, len); + break; + case DX_HASH_LEGACY: + hash = dx_hack_hash_signed(name, len); + break; + case DX_HASH_HALF_MD4_UNSIGNED: + use_unsigned = true; + fallthrough; + case DX_HASH_HALF_MD4: + p = name; + while (len > 0) { + if (use_unsigned) + str2hashbuf_unsigned(p, len, in, 8); + else + str2hashbuf_signed(p, len, in, 8); + half_md4_transform(buf, in); + len -= 32; + p += 32; + } + minor_hash = buf[2]; + hash = buf[1]; + break; + case DX_HASH_TEA_UNSIGNED: + use_unsigned = true; + fallthrough; + case DX_HASH_TEA: + p = name; + while (len > 0) { + if (use_unsigned) + str2hashbuf_unsigned(p, len, in, 4); + else + str2hashbuf_signed(p, len, in, 4); + TEA_transform(buf, in); + len -= 16; + p += 16; + } + hash = buf[0]; + minor_hash = buf[1]; + break; + case DX_HASH_SIPHASH: + { + struct qstr qname = QSTR_INIT(name, len); + __u64 combined_hash; + + if (fscrypt_has_encryption_key(dir)) { + combined_hash = fscrypt_fname_siphash(dir, &qname); + } else { + ext4_warning_inode(dir, "Siphash requires key"); + return -EINVAL; + } + + hash = (__u32)(combined_hash >> 32); + minor_hash = (__u32)combined_hash; + break; + } + default: + hinfo->hash = 0; + hinfo->minor_hash = 0; + ext4_warning(dir->i_sb, + "invalid/unsupported hash tree version %u", + hinfo->hash_version); + return -EINVAL; + } + hash = hash & ~1; + if (hash == (EXT4_HTREE_EOF_32BIT << 1)) + hash = (EXT4_HTREE_EOF_32BIT - 1) << 1; + hinfo->hash = hash; + hinfo->minor_hash = minor_hash; + return 0; +} + +int ext4fs_dirhash(const struct inode *dir, const char *name, int len, + struct dx_hash_info *hinfo) +{ +#if IS_ENABLED(CONFIG_UNICODE) + const struct unicode_map *um = dir->i_sb->s_encoding; + int r, dlen; + unsigned char *buff; + struct qstr qstr = {.name = name, .len = len }; + + if (len && IS_CASEFOLDED(dir) && + (!IS_ENCRYPTED(dir) || fscrypt_has_encryption_key(dir))) { + buff = kzalloc(PATH_MAX, GFP_KERNEL); + if (!buff) + return -ENOMEM; + + dlen = utf8_casefold(um, &qstr, buff, PATH_MAX); + if (dlen < 0) { + kfree(buff); + goto opaque_seq; + } + + r = __ext4fs_dirhash(dir, buff, dlen, hinfo); + + kfree(buff); + return r; + } +opaque_seq: +#endif + return __ext4fs_dirhash(dir, name, len, hinfo); +} + +#if IS_ENABLED(CONFIG_EXT4_KUNIT_TESTS) +EXPORT_SYMBOL_FOR_EXT4_TEST(ext4fs_dirhash); +#endif |
