tools/squashfs4/patches/005-Don-t-use-sigwaitinfo-sigtimedwait-if-not-supported.patch

   1 From dbe9747b4f09bd2f4d63af06e55c2c3ed35bfca1 Mon Sep 17 00:00:00 2001
   2 From: Phillip Lougher <phillip@squashfs.org.uk>
   3 Date: Tue, 7 Feb 2023 23:09:30 +0000
   4 Subject: [PATCH] Don't use sigwaitinfo()/sigtimedwait() if not supported
   5
   6 If sigwaitinfo() and sigtimedwait() are not supported,
   7 use sigwait() instead.
   8
   9 This will disable the queue/caches dump if ^\ (SIGQUIT)
  10 is hit twice within a second.
  11
  12 But the queue/caches dump is still available if SIGHUP
  13 is sent to the program.
  14
  15 Currently this check is applied to MAC OS X.  FreeBSD and
  16 NetBSD appear to have these functions.
  17
  18 Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
  19 ---
  20  squashfs-tools/info.c            | 25 ++-------------
  21  squashfs-tools/signals.h         | 54 ++++++++++++++++++++++++++++++++
  22  squashfs-tools/unsquashfs_info.c | 25 ++-------------
  23  3 files changed, 60 insertions(+), 44 deletions(-)
  24  create mode 100644 squashfs-tools/signals.h
  25
  26 --- a/squashfs-tools/info.c
  27 +++ b/squashfs-tools/info.c
  28 @@ -2,7 +2,7 @@
  29   * Create a squashfs filesystem.  This is a highly compressed read only
  30   * filesystem.
  31   *
  32 - * Copyright (c) 2013, 2014, 2019, 2021
  33 + * Copyright (c) 2013, 2014, 2019, 2021, 2022, 2023
  34   * Phillip Lougher <phillip@squashfs.org.uk>
  35   *
  36   * This program is free software; you can redistribute it and/or
  37 @@ -42,6 +42,7 @@
  38  #include "mksquashfs_error.h"
  39  #include "progressbar.h"
  40  #include "caches-queues-lists.h"
  41 +#include "signals.h"
  42
  43  static int silent = 0;
  44  static struct dir_ent *ent = NULL;
  45 @@ -144,7 +145,6 @@ void dump_state()
  46  void *info_thrd(void *arg)
  47  {
  48         sigset_t sigmask;
  49 -       struct timespec timespec = { .tv_sec = 1, .tv_nsec = 0 };
  50         int sig, waiting = 0;
  51
  52         sigemptyset(&sigmask);
  53 @@ -152,26 +152,7 @@ void *info_thrd(void *arg)
  54         sigaddset(&sigmask, SIGHUP);
  55
  56         while(1) {
  57 -               if(waiting)
  58 -                       sig = sigtimedwait(&sigmask, NULL, &timespec);
  59 -               else
  60 -                       sig = sigwaitinfo(&sigmask, NULL);
  61 -
  62 -               if(sig == -1) {
  63 -                       switch(errno) {
  64 -                       case EAGAIN:
  65 -                               /* interval timed out */
  66 -                               waiting = 0;
  67 -                               /* FALLTHROUGH */
  68 -                       case EINTR:
  69 -                               /* if waiting, the wait will be longer, but
  70 -                                  that's OK */
  71 -                               continue;
  72 -                       default:
  73 -                               BAD_ERROR("sigtimedwait/sigwaitinfo failed "
  74 -                                       "because %s\n", strerror(errno));
  75 -                       }
  76 -               }
  77 +               sig = wait_for_signal(&sigmask, &waiting);
  78
  79                 if(sig == SIGQUIT && !waiting) {
  80                         print_filename();
  81 --- /dev/null
  82 +++ b/squashfs-tools/signals.h
  83 @@ -0,0 +1,54 @@
  84 +#ifndef SIGNALS_H
  85 +#define SIGNALS_H
  86 +/*
  87 + * Create a squashfs filesystem.  This is a highly compressed read only
  88 + * filesystem.
  89 + *
  90 + * Copyright (c) 2023
  91 + * Phillip Lougher <phillip@squashfs.org.uk>
  92 + *
  93 + * This program is free software; you can redistribute it and/or
  94 + * modify it under the terms of the GNU General Public License
  95 + * as published by the Free Software Foundation; either version 2,
  96 + * or (at your option) any later version.
  97 + *
  98 + * This program is distributed in the hope that it will be useful,
  99 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
 100 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 101 + * GNU General Public License for more details.
 102 + *
 103 + * You should have received a copy of the GNU General Public License
 104 + * along with this program; if not, write to the Free Software
 105 + * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 106 + *
 107 + * signals.h
 108 + */
 109 +
 110 +static inline int wait_for_signal(sigset_t *sigmask, int *waiting)
 111 +{
 112 +       int sig;
 113 +
 114 +#if defined(__APPLE__) && defined(__MACH__)
 115 +       sigwait(sigmask, &sig);
 116 +       *waiting = 0;
 117 +#else
 118 +       struct timespec timespec = { .tv_sec = 1, .tv_nsec = 0 };
 119 +
 120 +       while(1) {
 121 +               if(*waiting)
 122 +                       sig = sigtimedwait(sigmask, NULL, &timespec);
 123 +               else
 124 +                       sig = sigwaitinfo(sigmask, NULL);
 125 +
 126 +               if(sig != -1)
 127 +                       break;
 128 +
 129 +               if(errno == EAGAIN)
 130 +                       *waiting = 0;
 131 +               else if(errno != EINTR)
 132 +                       BAD_ERROR("sigtimedwait/sigwaitinfo failed because %s\n", strerror(errno));
 133 +       }
 134 +#endif
 135 +       return sig;
 136 +}
 137 +#endif
 138 --- a/squashfs-tools/unsquashfs_info.c
 139 +++ b/squashfs-tools/unsquashfs_info.c
 140 @@ -2,7 +2,7 @@
 141   * Create a squashfs filesystem.  This is a highly compressed read only
 142   * filesystem.
 143   *
 144 - * Copyright (c) 2013, 2021
 145 + * Copyright (c) 2013, 2021, 2023
 146   * Phillip Lougher <phillip@squashfs.org.uk>
 147   *
 148   * This program is free software; you can redistribute it and/or
 149 @@ -40,6 +40,7 @@
 150  #include "squashfs_fs.h"
 151  #include "unsquashfs.h"
 152  #include "unsquashfs_error.h"
 153 +#include "signals.h"
 154
 155  char *pathname = NULL;
 156
 157 @@ -96,7 +97,6 @@ void dump_state()
 158  void *info_thrd(void *arg)
 159  {
 160         sigset_t sigmask;
 161 -       struct timespec timespec = { .tv_sec = 1, .tv_nsec = 0 };
 162         int sig, waiting = 0;
 163
 164         sigemptyset(&sigmask);
 165 @@ -104,26 +104,7 @@ void *info_thrd(void *arg)
 166         sigaddset(&sigmask, SIGHUP);
 167
 168         while(1) {
 169 -               if(waiting)
 170 -                       sig = sigtimedwait(&sigmask, NULL, &timespec);
 171 -               else
 172 -                       sig = sigwaitinfo(&sigmask, NULL);
 173 -
 174 -               if(sig == -1) {
 175 -                       switch(errno) {
 176 -                       case EAGAIN:
 177 -                               /* interval timed out */
 178 -                               waiting = 0;
 179 -                               /* FALLTHROUGH */
 180 -                       case EINTR:
 181 -                               /* if waiting, the wait will be longer, but
 182 -                                  that's OK */
 183 -                               continue;
 184 -                       default:
 185 -                               BAD_ERROR("sigtimedwait/sigwaitinfo failed "
 186 -                                       "because %s\n", strerror(errno));
 187 -                       }
 188 -               }
 189 +               sig = wait_for_signal(&sigmask, &waiting);
 190
 191                 if(sig == SIGQUIT && !waiting) {
 192                         if(pathname)