dracut, initcpio: make libgcc_s search universal

Closes: #427.

Update zfsbootmenu-core.sh

Update mkinitcpio.conf

Update zfsbootmenu-core.sh

Update docs/man/zfsbootmenu.7.rst

Co-authored-by: Andrew J. Hesford <[email protected]>

Update docs/man/zfsbootmenu.7.rst

Co-authored-by: Andrew J. Hesford <[email protected]>

docs/man/dist/man7/zfsbootmenu.7

@@ -27,7 +27,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .\" new: \\n[rst2man-indent\\n[rst2man-indent-level]]
 .in \\n[rst2man-indent\\n[rst2man-indent-level]]u
 ..
-.TH "ZFSBOOTMENU" "7" "2023-05-21" "" "ZFSBootMenu"
+.TH "ZFSBOOTMENU" "7" "2023-07-17" "" "ZFSBootMenu"
 .SH NAME
 zfsbootmenu \- System Integration
 .SH SYNOPSIS
@@ -436,6 +436,13 @@ kexec \-\-unload
 should be sufficient to return to the main menu. Likewise, the hook may construct and execute its own \fIkexec\fP command to alter boot\-time parameters. This may be useful, for example, to allow ZFSBootMenu to select a boot environment and then restructure the boot process to launch a Xen kernel with the selected environment configured as dom0.
 .UNINDENT
 .UNINDENT
+.sp
+\fBzfsbootmenu_skip_gcc_s=yes\fP
+.INDENT 0.0
+.INDENT 3.5
+The ZFSBootMenu module attempts to detect and install a copy of the library \fBlibgcc_s.so\fP in its initramfs image on glibc systems. Because several executables may have latent dependencies on this library via a \fBdlopen\fP call in glibc itself, a failure to detect and install the library will cause initramfs generation to fail. If the host system has no dependencies on \fBlibgcc_s.so\fP, set \fBzfsbootmenu_skip_gcc_s=yes\fP to avoid this failure. Alternatively, if \fBlibgcc_s.so\fP is present in an undetected location, set this option and configure Dracut to explicitly install the library.
+.UNINDENT
+.UNINDENT
 .SH OPTIONS FOR MKINITCPIO
 .sp
 The \fBdracut\fP options specified above may also be specified in a mkinitcpio configuration file when \fBgenerate\-zbm\fP is configured to create images using \fBmkinitcpio\fP\&. However, whereas the \fB<executable\-list>\fP values in the dracut configuration should be specified as a single, space\-separated string; in the mkinitcpio configuration, each \fB<executable\-list>\fP value must be specified as a Bash array like the standard mkinitcpio arguments.

docs/man/zfsbootmenu.7.rst

@@ -233,6 +233,15 @@ In addition to standard dracut configuration options, the ZFSBootMenu dracut mod
 
   Any installed hooks are run right before the ZFSBootMenu menu will be presented; ZFS pools will generally have been imported and the default boot environment will be available in the *BOOTFS* environment variable. Hooks will not be run if the countdown timer expires (or was set to zero) and the default boot environment is automatically selected. **Note:** The hooks may be run multiple times if the menu is invoked multiple times, e.g., by dropping to an emergency shell and then returning to the menu. If a script should only run once, the script is responsible for keeping track of this.
 
+<<<<<<< HEAD
+=======
+**zfsbootmenu_load_key=<executable-list>**
+
+  An optional variable specifying a space-separated list of paths to load-key hooks that will be installed in the ZFSBootMenu initramfs. Any path in the list **<executable-list>** that exists and is executable will be installed.
+
+  Any installed hooks are run immediately before ZFSBootMenu menu attempts to load a key for the encryption root of a locked filesystem. Each hook will be run with the name of the encryption root as its sole argument. If any hook exits with a non-zero return code, the load attempt will be aborted and the encryption root will not be unlocked. Hooks can be used to prepare keys needed to unlock the encryption root or may even attempt to unlock the root directly; a filesystem that is unlocked after the hooks have run will be considered to have had its keys successfully loaded. **Note:** The hooks may be run multiple times if keys for a given encryption root need to be loaded multiple times, e.g., by triggering a re-import of the pool. If a script should only run once, the script is responsible for keeping track of this.
+
+>>>>>>> f2ddbec (Update docs/man/zfsbootmenu.7.rst)
 **zfsbootmenu_teardown=<executable-list>**
 
   An optional variable specifying a space-separated list of paths to teardown hooks that will be installed in the ZFSBootMenu initramfs. Any path in the list **<executable-list>** that exists and is executable will be installed.
@@ -261,6 +270,10 @@ In addition to standard dracut configuration options, the ZFSBootMenu dracut mod
 
   should be sufficient to return to the main menu. Likewise, the hook may construct and execute its own *kexec* command to alter boot-time parameters. This may be useful, for example, to allow ZFSBootMenu to select a boot environment and then restructure the boot process to launch a Xen kernel with the selected environment configured as dom0.
 
+**zfsbootmenu_skip_gcc_s=yes**
+
+  The ZFSBootMenu module attempts to detect and install a copy of the library **libgcc_s.so** in its initramfs image on glibc systems. Because several executables may have latent dependencies on this library via a **dlopen** call in glibc itself, a failure to detect and install the library will cause initramfs generation to fail. If the host system has no dependencies on **libgcc_s.so**, set **zfsbootmenu_skip_gcc_s=yes** to avoid this failure. Alternatively, if **libgcc_s.so** is present in an undetected location, set this option and configure Dracut to explicitly install the library.
+
 .. _zbm-mkinitcpio-options:
 
 Options for mkinitcpio

dracut/module-setup.sh

@@ -68,27 +68,22 @@ install() {
     fi
   done
 
-  # Workaround for zfsonlinux/zfs#4749 by ensuring libgcc_s.so(.1) is included
-  _ret=0
-  # If zpool requires libgcc_s.so*, dracut will track and include it
-  if ! ldd "$( command -v zpool )" | grep -qF 'libgcc_s.so'; then
-    # On systems with gcc-config (Gentoo, Funtoo, etc.), use it to find libgcc_s
-    if command -v gcc-config >/dev/null 2>&1; then
-      dracut_install "/usr/lib/gcc/$(s=$(gcc-config -c); echo "${s%-*}/${s##*-}")/libgcc_s.so.1"
-      _ret=$?
-    # Otherwise, use dracut's library installation function to find the right one
-    elif ! inst_libdir_file "libgcc_s.so*"; then
-      # If all else fails, just try looking for some gcc arch directory
-      dracut_install /usr/lib/gcc/*/*/libgcc_s.so*
-      _ret=$?
-    fi
-  fi
-
-  if [ ${_ret} -ne 0 ]; then
-    dfatal "Unable to install libgcc_s.so"
+  # Add libgcc_s as appropriate
+  local _libgcc_s
+  if ! _libgcc_s="$( find_libgcc_s )"; then
+    dfatal "Unable to locate libgcc_s.so"
     exit 1
   fi
 
+  local _lib
+  while read -r _lib ; do
+    [ -n "${_lib}" ] || continue
+    if ! dracut_install "${_lib}"; then
+      dfatal "Failed to install '${_lib}'"
+      exit 1
+    fi
+  done <<< "${_libgcc_s}"
+
   # shellcheck disable=SC2154
   while read -r doc ; do
     relative="${doc//${zfsbootmenu_module_root}\//}"

etc/zfsbootmenu/mkinitcpio.conf

@@ -90,14 +90,14 @@ HOOKS=(base udev autodetect modconf block filesystems keyboard zfsbootmenu)
 # 'zfsbootmenu_setup' hooks are run after pools are imported and right before
 # the menu is presented.
 #
+# 'zfsbootmenu_load_key' hooks are run immediately before attempting to load an
+# encryption key and unlock a locked filesystem. Each hook is called with a
+# single argument: the name of an encryption root that should be unlocked.
+#
 # 'zfsbootmenu_teardown' hooks are run immediately before a chosen boot
 # environment is about to be launched. Any writable ZFS pools will have been
 # exported, but read-only pools will generally still be available.
 #
-# 'zfsbootmenu_load_key' hooks are run immediately before attempting to load an
-# encryption key and unlocked a locked filesystem. Each hook is called with a
-# single argument: the name of an encryption root that should be unlocked.
-#
 #zfsbootmenu_early_setup=()
 #zfsbootmenu_setup=()
 #zfsbootmenu_load_key=()

initcpio/install/zfsbootmenu

@@ -138,6 +138,22 @@ build() {
     # Binaries required for ZBM operation
     add_zbm_binaries
 
+    # Add libgcc_s as appropriate
+    local _libgcc_s
+    if ! _libgcc_s="$( find_libgcc_s )"; then
+        error "unable to locate libgcc_s.so"
+        exit 1
+    fi
+
+    local _lib
+    while read -r _lib ; do
+        [ -n "${_lib}" ] || continue
+        if ! add_binary "${_lib}"; then
+            error "Failed to install '${_lib}'"
+            exit 1
+        fi
+    done <<< "${_libgcc_s}"
+
     # On-line documentation
     while read -r doc; do
         relative="${doc#"${zfsbootmenu_module_root}/"}"

zfsbootmenu/install-helpers.sh

@@ -184,3 +184,73 @@ create_zbm_traceconf() {
 	export zfsbootmenu_trace_baud=${zfsbootmenu_trace_baud}
 	EOF
 }
+
+find_libgcc_s() {
+  local f libdirs libbase ldir zlibs matched
+
+  # Skip detection if desired
+  # shellcheck disable=SC2154
+  case "${zfsbootmenu_skip_gcc_s,,}" in
+    yes|on|1) return 0 ;;
+  esac
+
+  # This is only required on glibc systems due to a dlopen in pthread_cancel
+  # https://github.com/openzfs/zfs/commit/24554082bd93cb90400c4cb751275debda229009
+  ldconfig -p 2>/dev/null | grep -qF 'libc.so.6' || return 0
+
+  # Build a list of libraries linked by zpool
+  zlibs="$( ldd "$( command -v zpool 2>/dev/null )" )" || zlibs=
+
+  # If zpool links libgcc_s overtly, there is no need for further action
+  if grep -qF 'libgcc_s.so' <<< "${zlibs}"; then
+    return 0
+  fi
+
+  # Query gcc-config for a current runtime profile if possible
+  if command -v gcc-config >/dev/null 2>&1; then
+    local gver
+    if gver="$( gcc-config -c )"; then
+      for f in "/usr/lib/gcc/${gver%-*}/${gver##*-}"/libgcc_s.so*; do
+        [ -e "${f}" ] || continue
+        echo "${f}"
+        matched="yes"
+      done
+      [ -n "${matched}" ] && return 0
+    fi
+  fi
+
+  # Try walking library paths to find libgcc_s
+
+  # Search the system cache (adapted from dracut)
+  libdirs="$( ldconfig -pN 2>/dev/null \
+              | grep -E -v '/(lib|lib64|usr/lib|usr/lib64)/[^/]*$' \
+              | sed -n 's,.* => \(.*\)/.*,\1,p' | sort | uniq )" || libdirs=""
+
+  # Search zpool dependencies to figure out system libdirs
+  if [[ "${zlibs}" == */lib64/* ]]; then
+    libbase="lib64"
+  else
+    libbase="lib"
+  fi
+
+  # Look in all possible system library directories
+  libdirs="/${libbase} /usr/${libbase} ${libdirs}"
+  for ldir in ${libdirs}; do
+    for f in "${ldir}"/libgcc_s.so*; do
+      [ -e "${f}" ] || continue
+      echo "${f}"
+      matched="yes"
+    done
+  done
+  [ -n "${matched}" ] && return 0
+
+  # As a final fallback, just try to grab *any* libgcc_s from GCC
+  for f in /usr/lib/gcc/*/*/libgcc_s.so*; do
+    [ -f "${f}" ] || continue
+    echo "${f}"
+    matched="yes"
+  done
+
+  [ -n "${matched}" ] && return 0
+  return 1
+}

zfsbootmenu/lib/zfsbootmenu-core.sh

@@ -1679,7 +1679,7 @@ load_key() {
       zinfo "Processing hook: ${_hook}"
       [ -x "${_hook}" ] || continue
       if ! "${_hook}" "${encroot}"; then
-        zwarn "load-key hook failed for '${encroot}', aborting load attempt"
+        zwarn "load-key hook '${_hook}' failed for '${encroot}', aborting load attempt"
         return 1
       fi
     done