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![Ilya Leoshkevich](/assets/img/avatar_default.png)
Decompressing zlib streams on s390 fails with "incorrect data check"
error.
Userspace zlib checks inflate_state.flags in order to byteswap checksums
only for zlib streams, and s390 hardware inflate code, which was ported
from there, tries to match this behavior. At the same time, kernel zlib
does not use inflate_state.flags, so it contains essentially random
values. For many use cases either zlib stream is zeroed out or checksum
is not used, so this problem is masked, but at least SquashFS is still
affected.
Fix by always passing a checksum to and from the hardware as is, which
matches zlib_inflate()'s expectations.
Link: https://lkml.kernel.org/r/20201215155551.894884-1-iii@linux.ibm.com
Fixes: 1261961000
("lib/zlib: add s390 hardware support for kernel zlib_inflate")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Cc: <stable@vger.kernel.org> [5.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
152 lines
4.4 KiB
C
152 lines
4.4 KiB
C
// SPDX-License-Identifier: Zlib
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#include "../zlib_inflate/inflate.h"
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#include "dfltcc_util.h"
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#include "dfltcc.h"
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#include <asm/setup.h>
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#include <linux/export.h>
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#include <linux/zutil.h>
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/*
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* Expand.
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*/
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int dfltcc_can_inflate(
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z_streamp strm
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)
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{
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struct inflate_state *state = (struct inflate_state *)strm->state;
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struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
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/* Check for kernel dfltcc command line parameter */
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if (zlib_dfltcc_support == ZLIB_DFLTCC_DISABLED ||
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zlib_dfltcc_support == ZLIB_DFLTCC_DEFLATE_ONLY)
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return 0;
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/* Unsupported compression settings */
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if (state->wbits != HB_BITS)
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return 0;
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/* Unsupported hardware */
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return is_bit_set(dfltcc_state->af.fns, DFLTCC_XPND) &&
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is_bit_set(dfltcc_state->af.fmts, DFLTCC_FMT0);
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}
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EXPORT_SYMBOL(dfltcc_can_inflate);
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static int dfltcc_was_inflate_used(
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z_streamp strm
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)
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{
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struct inflate_state *state = (struct inflate_state *)strm->state;
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struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
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return !param->nt;
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}
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static int dfltcc_inflate_disable(
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z_streamp strm
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)
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{
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struct inflate_state *state = (struct inflate_state *)strm->state;
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struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
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if (!dfltcc_can_inflate(strm))
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return 0;
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if (dfltcc_was_inflate_used(strm))
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/* DFLTCC has already decompressed some data. Since there is not
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* enough information to resume decompression in software, the call
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* must fail.
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*/
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return 1;
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/* DFLTCC was not used yet - decompress in software */
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memset(&dfltcc_state->af, 0, sizeof(dfltcc_state->af));
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return 0;
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}
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static dfltcc_cc dfltcc_xpnd(
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z_streamp strm
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)
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{
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struct inflate_state *state = (struct inflate_state *)strm->state;
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struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
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size_t avail_in = strm->avail_in;
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size_t avail_out = strm->avail_out;
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dfltcc_cc cc;
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cc = dfltcc(DFLTCC_XPND | HBT_CIRCULAR,
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param, &strm->next_out, &avail_out,
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&strm->next_in, &avail_in, state->window);
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strm->avail_in = avail_in;
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strm->avail_out = avail_out;
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return cc;
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}
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dfltcc_inflate_action dfltcc_inflate(
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z_streamp strm,
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int flush,
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int *ret
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)
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{
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struct inflate_state *state = (struct inflate_state *)strm->state;
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struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
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struct dfltcc_param_v0 *param = &dfltcc_state->param;
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dfltcc_cc cc;
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if (flush == Z_BLOCK) {
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/* DFLTCC does not support stopping on block boundaries */
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if (dfltcc_inflate_disable(strm)) {
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*ret = Z_STREAM_ERROR;
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return DFLTCC_INFLATE_BREAK;
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} else
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return DFLTCC_INFLATE_SOFTWARE;
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}
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if (state->last) {
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if (state->bits != 0) {
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strm->next_in++;
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strm->avail_in--;
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state->bits = 0;
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}
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state->mode = CHECK;
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return DFLTCC_INFLATE_CONTINUE;
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}
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if (strm->avail_in == 0 && !param->cf)
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return DFLTCC_INFLATE_BREAK;
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if (!state->window || state->wsize == 0) {
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state->mode = MEM;
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return DFLTCC_INFLATE_CONTINUE;
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}
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/* Translate stream to parameter block */
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param->cvt = CVT_ADLER32;
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param->sbb = state->bits;
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param->hl = state->whave; /* Software and hardware history formats match */
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param->ho = (state->write - state->whave) & ((1 << HB_BITS) - 1);
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if (param->hl)
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param->nt = 0; /* Honor history for the first block */
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param->cv = state->check;
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/* Inflate */
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do {
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cc = dfltcc_xpnd(strm);
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} while (cc == DFLTCC_CC_AGAIN);
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/* Translate parameter block to stream */
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strm->msg = oesc_msg(dfltcc_state->msg, param->oesc);
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state->last = cc == DFLTCC_CC_OK;
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state->bits = param->sbb;
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state->whave = param->hl;
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state->write = (param->ho + param->hl) & ((1 << HB_BITS) - 1);
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state->check = param->cv;
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if (cc == DFLTCC_CC_OP2_CORRUPT && param->oesc != 0) {
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/* Report an error if stream is corrupted */
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state->mode = BAD;
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return DFLTCC_INFLATE_CONTINUE;
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}
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state->mode = TYPEDO;
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/* Break if operands are exhausted, otherwise continue looping */
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return (cc == DFLTCC_CC_OP1_TOO_SHORT || cc == DFLTCC_CC_OP2_TOO_SHORT) ?
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DFLTCC_INFLATE_BREAK : DFLTCC_INFLATE_CONTINUE;
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}
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EXPORT_SYMBOL(dfltcc_inflate);
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