| 1 | |
| 2 | |
| 3 | * Cryptographic API.
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| 4 | *
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| 5 | * Copyright (c) 2017-present, Facebook, Inc.
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| 6 |
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| 7 | #include <linux/crypto.h>
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| 8 | #include <linux/init.h>
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| 9 | #include <linux/interrupt.h>
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| 10 | #include <linux/mm.h>
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| 11 | #include <linux/module.h>
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| 12 | #include <linux/net.h>
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| 13 | #include <linux/overflow.h>
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| 14 | #include <linux/vmalloc.h>
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| 15 | #include <linux/zstd.h>
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| 16 | #include <crypto/internal/acompress.h>
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| 17 | #include <crypto/scatterwalk.h>
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| 18 |
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| 19 |
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| 20 | #define ZSTD_DEF_LEVEL 3
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| 21 | #define ZSTD_MAX_WINDOWLOG 18
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| 22 | #define ZSTD_MAX_SIZE BIT(ZSTD_MAX_WINDOWLOG)
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| 23 |
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| 24 | struct zstd_ctx {
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| 25 | zstd_cctx *cctx;
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| 26 | zstd_dctx *dctx;
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| 27 | size_t wksp_size;
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| 28 | zstd_parameters params;
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| 29 | u8 wksp[] __aligned(8) __counted_by(wksp_size);
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| 30 | };
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| 31 |
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| 32 | static DEFINE_MUTEX(zstd_stream_lock);
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| 33 |
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| 34 | static void *zstd_alloc_stream(void)
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| 35 | {
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| 36 | zstd_parameters params;
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| 37 | struct zstd_ctx *ctx;
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| 38 | size_t wksp_size;
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| 39 |
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| 40 | params = zstd_get_params(ZSTD_DEF_LEVEL, ZSTD_MAX_SIZE);
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| 41 |
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| 42 | wksp_size = max(zstd_cstream_workspace_bound(¶ms.cParams),
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| 43 | zstd_dstream_workspace_bound(ZSTD_MAX_SIZE));
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| 44 | if (!wksp_size)
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| 45 | return ERR_PTR(-EINVAL);
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| 46 |
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| 47 | ctx = kvmalloc_flex(*ctx, wksp, wksp_size);
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| 48 | if (!ctx)
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| 49 | return ERR_PTR(-ENOMEM);
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| 50 |
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| 51 | ctx->params = params;
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| 52 | ctx->wksp_size = wksp_size;
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| 53 |
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| 54 | return ctx;
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| 55 | }
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| 56 |
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| 57 | static void zstd_free_stream(void *ctx)
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| 58 | {
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| 59 | kvfree(ctx);
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| 60 | }
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| 61 |
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| 62 | static struct crypto_acomp_streams zstd_streams = {
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| 63 | .alloc_ctx = zstd_alloc_stream,
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| 64 | .free_ctx = zstd_free_stream,
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| 65 | };
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| 66 |
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| 67 | static int zstd_init(struct crypto_acomp *acomp_tfm)
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| 68 | {
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| 69 | int ret = 0;
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| 70 |
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| 71 | mutex_lock(&zstd_stream_lock);
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| 72 | ret = crypto_acomp_alloc_streams(&zstd_streams);
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| 73 | mutex_unlock(&zstd_stream_lock);
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| 74 |
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| 75 | return ret;
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| 76 | }
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| 77 |
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| 78 | static int zstd_compress_one(struct acomp_req *req, struct zstd_ctx *ctx,
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| 79 | const void *src, void *dst, unsigned int *dlen)
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| 80 | {
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| 81 | size_t out_len;
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| 82 |
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| 83 | ctx->cctx = zstd_init_cctx(ctx->wksp, ctx->wksp_size);
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| 84 | if (!ctx->cctx)
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| 85 | return -EINVAL;
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| 86 |
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| 87 | out_len = zstd_compress_cctx(ctx->cctx, dst, req->dlen, src, req->slen,
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| 88 | &ctx->params);
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| 89 | if (zstd_is_error(out_len))
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| 90 | return -EINVAL;
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| 91 |
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| 92 | *dlen = out_len;
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| 93 |
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| 94 | return 0;
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| 95 | }
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| 96 |
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| 97 | static int zstd_compress(struct acomp_req *req)
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| 98 | {
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| 99 | struct crypto_acomp_stream *s;
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| 100 | unsigned int pos, scur, dcur;
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| 101 | unsigned int total_out = 0;
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| 102 | bool data_available = true;
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| 103 | zstd_out_buffer outbuf;
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| 104 | struct acomp_walk walk;
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| 105 | zstd_in_buffer inbuf;
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| 106 | struct zstd_ctx *ctx;
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| 107 | size_t pending_bytes;
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| 108 | size_t num_bytes;
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| 109 | int ret;
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| 110 |
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| 111 | s = crypto_acomp_lock_stream_bh(&zstd_streams);
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| 112 | ctx = s->ctx;
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| 113 |
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| 114 | ret = acomp_walk_virt(&walk, req, true);
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| 115 | if (ret)
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| 116 | goto out;
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| 117 |
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| 118 | ctx->cctx = zstd_init_cstream(&ctx->params, 0, ctx->wksp, ctx->wksp_size);
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| 119 | if (!ctx->cctx) {
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| 120 | ret = -EINVAL;
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| 121 | goto out;
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| 122 | }
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| 123 |
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| 124 | do {
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| 125 | dcur = acomp_walk_next_dst(&walk);
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| 126 | if (!dcur) {
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| 127 | ret = -ENOSPC;
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| 128 | goto out;
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| 129 | }
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| 130 |
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| 131 | outbuf.pos = 0;
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| 132 | outbuf.dst = (u8 *)walk.dst.virt.addr;
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| 133 | outbuf.size = dcur;
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| 134 |
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| 135 | do {
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| 136 | scur = acomp_walk_next_src(&walk);
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| 137 | if (dcur == req->dlen && scur == req->slen) {
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| 138 | ret = zstd_compress_one(req, ctx, walk.src.virt.addr,
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| 139 | walk.dst.virt.addr, &total_out);
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| 140 | acomp_walk_done_src(&walk, scur);
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| 141 | acomp_walk_done_dst(&walk, dcur);
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| 142 | goto out;
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| 143 | }
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| 144 |
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| 145 | if (scur) {
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| 146 | inbuf.pos = 0;
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| 147 | inbuf.src = walk.src.virt.addr;
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| 148 | inbuf.size = scur;
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| 149 | } else {
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| 150 | data_available = false;
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| 151 | break;
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| 152 | }
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| 153 |
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| 154 | num_bytes = zstd_compress_stream(ctx->cctx, &outbuf, &inbuf);
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| 155 | if (ZSTD_isError(num_bytes)) {
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| 156 | ret = -EIO;
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| 157 | goto out;
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| 158 | }
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| 159 |
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| 160 | pending_bytes = zstd_flush_stream(ctx->cctx, &outbuf);
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| 161 | if (ZSTD_isError(pending_bytes)) {
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| 162 | ret = -EIO;
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| 163 | goto out;
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| 164 | }
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| 165 | acomp_walk_done_src(&walk, inbuf.pos);
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| 166 | } while (dcur != outbuf.pos);
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| 167 |
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| 168 | total_out += outbuf.pos;
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| 169 | acomp_walk_done_dst(&walk, dcur);
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| 170 | } while (data_available);
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| 171 |
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| 172 | pos = outbuf.pos;
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| 173 | num_bytes = zstd_end_stream(ctx->cctx, &outbuf);
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| 174 | if (ZSTD_isError(num_bytes))
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| 175 | ret = -EIO;
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| 176 | else
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| 177 | total_out += (outbuf.pos - pos);
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| 178 |
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| 179 | out:
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| 180 | if (ret)
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| 181 | req->dlen = 0;
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| 182 | else
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| 183 | req->dlen = total_out;
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| 184 |
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| 185 | crypto_acomp_unlock_stream_bh(s);
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| 186 |
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| 187 | return ret;
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| 188 | }
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| 189 |
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| 190 | static int zstd_decompress_one(struct acomp_req *req, struct zstd_ctx *ctx,
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| 191 | const void *src, void *dst, unsigned int *dlen)
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| 192 | {
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| 193 | size_t out_len;
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| 194 |
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| 195 | ctx->dctx = zstd_init_dctx(ctx->wksp, ctx->wksp_size);
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| 196 | if (!ctx->dctx)
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| 197 | return -EINVAL;
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| 198 |
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| 199 | out_len = zstd_decompress_dctx(ctx->dctx, dst, req->dlen, src, req->slen);
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| 200 | if (zstd_is_error(out_len))
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| 201 | return -EINVAL;
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| 202 |
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| 203 | *dlen = out_len;
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| 204 |
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| 205 | return 0;
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| 206 | }
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| 207 |
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| 208 | static int zstd_decompress(struct acomp_req *req)
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| 209 | {
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| 210 | struct crypto_acomp_stream *s;
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| 211 | unsigned int total_out = 0;
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| 212 | unsigned int scur, dcur;
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| 213 | zstd_out_buffer outbuf;
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| 214 | struct acomp_walk walk;
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| 215 | zstd_in_buffer inbuf;
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| 216 | struct zstd_ctx *ctx;
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| 217 | size_t pending_bytes;
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| 218 | int ret;
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| 219 |
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| 220 | s = crypto_acomp_lock_stream_bh(&zstd_streams);
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| 221 | ctx = s->ctx;
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| 222 |
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| 223 | ret = acomp_walk_virt(&walk, req, true);
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| 224 | if (ret)
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| 225 | goto out;
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| 226 |
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| 227 | ctx->dctx = zstd_init_dstream(ZSTD_MAX_SIZE, ctx->wksp, ctx->wksp_size);
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| 228 | if (!ctx->dctx) {
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| 229 | ret = -EINVAL;
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| 230 | goto out;
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| 231 | }
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| 232 |
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| 233 | do {
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| 234 | scur = acomp_walk_next_src(&walk);
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| 235 | if (scur) {
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| 236 | inbuf.pos = 0;
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| 237 | inbuf.size = scur;
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| 238 | inbuf.src = walk.src.virt.addr;
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| 239 | } else {
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| 240 | break;
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| 241 | }
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| 242 |
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| 243 | do {
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| 244 | dcur = acomp_walk_next_dst(&walk);
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| 245 | if (dcur == req->dlen && scur == req->slen) {
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| 246 | ret = zstd_decompress_one(req, ctx, walk.src.virt.addr,
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| 247 | walk.dst.virt.addr, &total_out);
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| 248 | acomp_walk_done_dst(&walk, dcur);
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| 249 | acomp_walk_done_src(&walk, scur);
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| 250 | goto out;
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| 251 | }
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| 252 |
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| 253 | if (!dcur) {
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| 254 | ret = -ENOSPC;
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| 255 | goto out;
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| 256 | }
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| 257 |
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| 258 | outbuf.pos = 0;
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| 259 | outbuf.dst = (u8 *)walk.dst.virt.addr;
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| 260 | outbuf.size = dcur;
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| 261 |
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| 262 | pending_bytes = zstd_decompress_stream(ctx->dctx, &outbuf, &inbuf);
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| 263 | if (ZSTD_isError(pending_bytes)) {
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| 264 | ret = -EIO;
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| 265 | goto out;
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| 266 | }
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| 267 |
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| 268 | total_out += outbuf.pos;
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| 269 |
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| 270 | acomp_walk_done_dst(&walk, outbuf.pos);
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| 271 | } while (inbuf.pos != scur);
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| 272 |
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| 273 | acomp_walk_done_src(&walk, scur);
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| 274 | } while (ret == 0);
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| 275 |
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| 276 | out:
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| 277 | if (ret)
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| 278 | req->dlen = 0;
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| 279 | else
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| 280 | req->dlen = total_out;
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| 281 |
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| 282 | crypto_acomp_unlock_stream_bh(s);
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| 283 |
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| 284 | return ret;
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| 285 | }
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| 286 |
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| 287 | static struct acomp_alg zstd_acomp = {
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| 288 | .base = {
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| 289 | .cra_name = "zstd",
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| 290 | .cra_driver_name = "zstd-generic",
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| 291 | .cra_flags = CRYPTO_ALG_REQ_VIRT,
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| 292 | .cra_module = THIS_MODULE,
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| 293 | },
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| 294 | .init = zstd_init,
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| 295 | .compress = zstd_compress,
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| 296 | .decompress = zstd_decompress,
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| 297 | };
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| 298 |
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| 299 | static int __init zstd_mod_init(void)
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| 300 | {
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| 301 | return crypto_register_acomp(&zstd_acomp);
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| 302 | }
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| 303 |
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| 304 | static void __exit zstd_mod_fini(void)
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| 305 | {
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| 306 | crypto_unregister_acomp(&zstd_acomp);
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| 307 | crypto_acomp_free_streams(&zstd_streams);
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| 308 | }
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| 309 |
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| 310 | module_init(zstd_mod_init);
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| 311 | module_exit(zstd_mod_fini);
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| 312 |
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| 313 | MODULE_LICENSE("GPL");
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| 314 | MODULE_DESCRIPTION("Zstd Compression Algorithm");
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| 315 | MODULE_ALIAS_CRYPTO("zstd");
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