Kbuild fixes for v5.19

- Make the *.mod build rule portable for POSIX awk
 
  - Fix regression of 'make nsdeps'
 
  - Make scripts/check-local-export working for older bash versions
 
  - Fix scripts/gdb to extract the .config data from vmlinux
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Merge tag 'kbuild-fixes-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Make the *.mod build rule portable for POSIX awk

 - Fix regression of 'make nsdeps'

 - Make scripts/check-local-export working for older bash versions

 - Fix scripts/gdb to extract the .config data from vmlinux

* tag 'kbuild-fixes-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  scripts/gdb: change kernel config dumping method
  scripts/check-local-export: avoid 'wait $!' for process substitution
  scripts/nsdeps: adjust to the format change of *.mod files
  kbuild: avoid regex RS for POSIX awk

Documentation/process/changes.rst

@@ -32,6 +32,7 @@ you probably needn't concern yourself with pcmciautils.
 GNU C                  5.1              gcc --version
 Clang/LLVM (optional)  11.0.0           clang --version
 GNU make               3.81             make --version
+bash                   4.2              bash --version
 binutils               2.23             ld -v
 flex                   2.5.35           flex --version
 bison                  2.0              bison --version
@@ -84,6 +85,12 @@ Make
 
 You will need GNU make 3.81 or later to build the kernel.
 
+Bash
+----
+
+Some bash scripts are used for the kernel build.
+Bash 4.2 or newer is needed.
+
 Binutils
 --------
 
@@ -362,6 +369,11 @@ Make
 
 - <ftp://ftp.gnu.org/gnu/make/>
 
+Bash
+----
+
+- <ftp://ftp.gnu.org/gnu/bash/>
+
 Binutils
 --------
 

scripts/Makefile.build

@@ -251,8 +251,8 @@ $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
 
 # To make this rule robust against "Argument list too long" error,
 # ensure to add $(obj)/ prefix by a shell command.
-cmd_mod = echo $(call real-search, $*.o, .o, -objs -y -m) | \
-	$(AWK) -v RS='( |\n)' '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
+cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
+	$(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
 
 $(obj)/%.mod: FORCE
 	$(call if_changed,mod)

scripts/check-local-export

@@ -8,11 +8,31 @@
 
 set -e
 
+# catch errors from ${NM}
+set -o pipefail
+
+# Run the last element of a pipeline in the current shell.
+# Without this, the while-loop would be executed in a subshell, and
+# the changes made to 'symbol_types' and 'export_symbols' would be lost.
+shopt -s lastpipe
+
 declare -A symbol_types
 declare -a export_symbols
 
 exit_code=0
 
+# If there is no symbol in the object, ${NM} (both GNU nm and llvm-nm) shows
+# 'no symbols' diagnostic (but exits with 0). It is harmless and hidden by
+# '2>/dev/null'. However, it suppresses real error messages as well. Add a
+# hand-crafted error message here.
+#
+# TODO:
+# Use --quiet instead of 2>/dev/null when we upgrade the minimum version of
+# binutils to 2.37, llvm to 13.0.0.
+# Then, the following line will be really simple:
+#   ${NM} --quiet ${1} |
+
+{ ${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; false; } } |
 while read value type name
 do
 	# Skip the line if the number of fields is less than 3.
@@ -37,21 +57,7 @@ do
 	if [[ ${name} == __ksymtab_* ]]; then
 		export_symbols+=(${name#__ksymtab_})
 	fi
-
-	# If there is no symbol in the object, ${NM} (both GNU nm and llvm-nm)
-	# shows 'no symbols' diagnostic (but exits with 0). It is harmless and
-	# hidden by '2>/dev/null'. However, it suppresses real error messages
-	# as well. Add a hand-crafted error message here.
-	#
-	# Use --quiet instead of 2>/dev/null when we upgrade the minimum version
-	# of binutils to 2.37, llvm to 13.0.0.
-	#
-	# Then, the following line will be really simple:
-	#   done < <(${NM} --quiet ${1})
-done < <(${NM} ${1} 2>/dev/null || { echo "${0}: ${NM} failed" >&2; false; } )
-
-# Catch error in the process substitution
-wait $!
+done
 
 for name in "${export_symbols[@]}"
 do

scripts/gdb/linux/config.py

@@ -24,9 +24,9 @@ class LxConfigDump(gdb.Command):
             filename = arg
 
         try:
-            py_config_ptr = gdb.parse_and_eval("kernel_config_data + 8")
-            py_config_size = gdb.parse_and_eval(
-                    "sizeof(kernel_config_data) - 1 - 8 * 2")
+            py_config_ptr = gdb.parse_and_eval("&kernel_config_data")
+            py_config_ptr_end = gdb.parse_and_eval("&kernel_config_data_end")
+            py_config_size = py_config_ptr_end - py_config_ptr
         except gdb.error as e:
             raise gdb.GdbError("Can't find config, enable CONFIG_IKCONFIG?")
 

scripts/nsdeps

@@ -34,9 +34,8 @@ generate_deps() {
 	local mod=${1%.ko:}
 	shift
 	local namespaces="$*"
-	local mod_source_files="`cat $mod.mod | sed -n 1p                      \
-					      | sed -e 's/\.o/\.c/g'           \
-					      | sed "s|[^ ]* *|${src_prefix}&|g"`"
+	local mod_source_files=$(sed "s|^\(.*\)\.o$|${src_prefix}\1.c|" $mod.mod)
+
 	for ns in $namespaces; do
 		echo "Adding namespace $ns to module $mod.ko."
 		generate_deps_for_ns $ns "$mod_source_files"