GNU bug report logs - #43583
[PATCH 0/4] Fix DFLTCC segfault when compressing or decompressing two files

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Ilya Leoshkevich <iii <at> linux.ibm.com>
To: Jim Meyering <meyering <at> fb.com>, Paul Eggert <eggert <at> cs.ucla.edu>
Cc: Ilya Leoshkevich <iii <at> linux.ibm.com>, bug-gzip <at> gnu.org
Subject: [PATCH 0/4] Fix DFLTCC segfault when compressing or decompressing two
 files
Date: Thu, 24 Sep 2020 00:08:53 +0200

Hi!

We found an issue with IBM Z hardware compression support: gzip
segfaults when processing two files.  This patch series fixes the issue,
adds a test and performs two minor cleanups: fixes clang build and
updates .gitignore files.

Best regards,
Ilya

Ilya Leoshkevich (4):
  Update .gitignore files
  Fix building DFLTCC with clang
  Fix DFLTCC segfault when compressing or decompressing two files
  Add a test for compressing and decompressing two files

 dfltcc.c          | 21 ++++++++++++++-------
 lib/.gitignore    | 14 ++++++++++++++
 m4/.gitignore     |  3 +++
 tests/Makefile.am |  1 +
 tests/two-files   | 31 +++++++++++++++++++++++++++++++
 5 files changed, 63 insertions(+), 7 deletions(-)
 create mode 100755 tests/two-files

-- 
2.25.4

Message #8 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Ilya Leoshkevich <iii <at> linux.ibm.com>
To: Jim Meyering <meyering <at> fb.com>, Paul Eggert <eggert <at> cs.ucla.edu>
Cc: Ilya Leoshkevich <iii <at> linux.ibm.com>, bug-gzip <at> gnu.org
Subject: [PATCH 2/4] Fix building DFLTCC with clang
Date: Thu, 24 Sep 2020 00:08:55 +0200

clang does not support .machinemode, so put it under an #ifdef.
---
 dfltcc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/dfltcc.c b/dfltcc.c
index 432c68c..86aa56e 100644
--- a/dfltcc.c
+++ b/dfltcc.c
@@ -160,10 +160,15 @@ is_dfltcc_enabled (void)
   /* STFLE is supported since z9-109 and only in z/Architecture mode.  When
    * compiling with -m31, gcc defaults to ESA mode, however, since the kernel
    * is 64-bit, it's always z/Architecture mode at runtime.  */
-  __asm__ (".machinemode push\n"
+  __asm__ (
+#ifndef __clang__
+           ".machinemode push\n"
            ".machinemode zarch\n"
+#endif
            "stfle %[facilities]\n"
+#ifndef __clang__
            ".machinemode pop\n"
+#endif
            : [facilities] "=Q"(facilities), [r0] "+r"(r0) :: "cc");
   return is_bit_set (facilities, DFLTCC_FACILITY);
 }
-- 
2.25.4

Message #11 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Ilya Leoshkevich <iii <at> linux.ibm.com>
To: Jim Meyering <meyering <at> fb.com>, Paul Eggert <eggert <at> cs.ucla.edu>
Cc: Ilya Leoshkevich <iii <at> linux.ibm.com>, bug-gzip <at> gnu.org
Subject: [PATCH 4/4] Add a test for compressing and decompressing two files
Date: Thu, 24 Sep 2020 00:08:57 +0200

It ensures that compression and decompression state of the first file
does not affect the second file.
---
 tests/Makefile.am |  1 +
 tests/two-files   | 31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100755 tests/two-files

diff --git a/tests/Makefile.am b/tests/Makefile.am
index a87a594..2f7c9c3 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -27,6 +27,7 @@ TESTS =					\
   reproducible				\
   stdin					\
   timestamp				\
+  two-files				\
   trailing-nul				\
   unpack-invalid			\
   unpack-valid				\
diff --git a/tests/two-files b/tests/two-files
new file mode 100755
index 0000000..efdfb4f
--- /dev/null
+++ b/tests/two-files
@@ -0,0 +1,31 @@
+#!/bin/sh
+# Ensure that gzip can compress more than one file.
+
+# Copyright 2020 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+# limit so don't run it by default.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ..
+
+dd if=/dev/urandom of=a count=5000 bs=1
+dd if=/dev/urandom of=b count=5000 bs=1
+cp a a.exp
+cp b b.exp
+gzip -1 a b || fail=1
+gzip -d a.gz b.gz || fail=1
+compare a.exp a || fail=1
+compare b.exp b || fail=1
+
+Exit $fail
-- 
2.25.4

Message #14 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Ilya Leoshkevich <iii <at> linux.ibm.com>
To: Jim Meyering <meyering <at> fb.com>, Paul Eggert <eggert <at> cs.ucla.edu>
Cc: Ilya Leoshkevich <iii <at> linux.ibm.com>, bug-gzip <at> gnu.org
Subject: [PATCH 3/4] Fix DFLTCC segfault when compressing or decompressing two
 files
Date: Thu, 24 Sep 2020 00:08:56 +0200

The value in total_in global variable from processing the first file
affected processing of the second file.  Fix by making total_in local.
---
 dfltcc.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/dfltcc.c b/dfltcc.c
index 86aa56e..3a5b92d 100644
--- a/dfltcc.c
+++ b/dfltcc.c
@@ -242,10 +242,8 @@ dfltcc_gdht (struct dfltcc_param_v0 *param)
   dfltcc (DFLTCC_GDHT, param, NULL, NULL, &next_in, &avail_in, NULL);
 }
 
-static off_t total_in;
-
 static dfltcc_cc
-dfltcc_cmpr_xpnd (struct dfltcc_param_v0 *param, int fn)
+dfltcc_cmpr_xpnd (struct dfltcc_param_v0 *param, int fn, off_t *total_in)
 {
   uch *next_out = outbuf + outcnt;
   size_t avail_out = OUTBUFSIZ - outcnt;
@@ -257,7 +255,7 @@ dfltcc_cmpr_xpnd (struct dfltcc_param_v0 *param, int fn)
                          window);
   off_t consumed_in = next_in - (inbuf + inptr);
   inptr += consumed_in;
-  total_in += consumed_in;
+  *total_in += consumed_in;
   outcnt += ((OUTBUFSIZ - outcnt) - avail_out);
   return cc;
 }
@@ -349,6 +347,7 @@ dfltcc_deflate (int pack_level)
 
   union aligned_dfltcc_param_v0 ctx_v0;
   struct dfltcc_param_v0 *param = init_param (&ctx_v0);
+  off_t total_in = 0;
 
   /* Compress ifd into ofd in a loop.  */
   while (true)
@@ -398,7 +397,8 @@ dfltcc_deflate (int pack_level)
         }
 
       /* Compress inbuf into outbuf.  */
-      while (dfltcc_cmpr_xpnd (param, DFLTCC_CMPR) == DFLTCC_CC_AGAIN)
+      while (dfltcc_cmpr_xpnd (param, DFLTCC_CMPR, &total_in)
+             == DFLTCC_CC_AGAIN)
         ;
 
       /* Unmask the input data.  */
@@ -427,6 +427,7 @@ dfltcc_inflate (void)
 
   union aligned_dfltcc_param_v0 ctx_v0;
   struct dfltcc_param_v0 *param = init_param (&ctx_v0);
+  off_t total_in = 0;
 
   /* Decompress ifd into ofd in a loop.  */
   while (true)
@@ -446,7 +447,8 @@ dfltcc_inflate (void)
 
         /* Decompress inbuf into outbuf.  */
         dfltcc_cc cc;
-        while ((cc = dfltcc_cmpr_xpnd (param, DFLTCC_XPND)) == DFLTCC_CC_AGAIN)
+        while ((cc = dfltcc_cmpr_xpnd (param, DFLTCC_XPND, &total_in))
+               == DFLTCC_CC_AGAIN)
           ;
         if (cc == DFLTCC_CC_OK)
           {
-- 
2.25.4

Message #17 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Ilya Leoshkevich <iii <at> linux.ibm.com>, Jim Meyering <meyering <at> fb.com>
Cc: bug-gzip <at> gnu.org
Subject: Re: [PATCH 0/4] Fix DFLTCC segfault when compressing or decompressing
 two files
Date: Thu, 24 Sep 2020 16:38:41 -0700

Thanks, I installed those with minor rewording to one commit message.

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