From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: x86, build: replace Perl script with Shell script
Commit e6023367d779 ("x86, kaslr: Prevent .bss from overlaping initrd")
added Perl to the required build environment. This reimplements in shell
the Perl script used to find the size of the kernel with bss and brk
added.
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reported-by: Rob Landley <rob@xxxxxxxxxxx>
Acked-by: Rob Landley <rob@xxxxxxxxxxx>
Cc: Anca Emanuel <anca.emanuel@xxxxxxxxx>
Cc: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Cc: Junjie Mao <eternal.n08@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/boot/compressed/Makefile | 2 -
arch/x86/tools/calc_run_size.pl | 39 --------------------------
arch/x86/tools/calc_run_size.sh | 42 ++++++++++++++++++++++++++++
3 files changed, 43 insertions(+), 40 deletions(-)
diff -puN arch/x86/boot/compressed/Makefile~x86-build-replace-perl-script-with-shell-script arch/x86/boot/compressed/Makefile
--- a/arch/x86/boot/compressed/Makefile~x86-build-replace-perl-script-with-shell-script
+++ a/arch/x86/boot/compressed/Makefile
@@ -90,7 +90,7 @@ suffix-$(CONFIG_KERNEL_LZO) := lzo
suffix-$(CONFIG_KERNEL_LZ4) := lz4
RUN_SIZE = $(shell $(OBJDUMP) -h vmlinux | \
- perl $(srctree)/arch/x86/tools/calc_run_size.pl)
+ $(CONFIG_SHELL) $(srctree)/arch/x86/tools/calc_run_size.sh)
quiet_cmd_mkpiggy = MKPIGGY $@
cmd_mkpiggy = $(obj)/mkpiggy $< $(RUN_SIZE) > $@ || ( rm -f $@ ; false )
diff -puN arch/x86/tools/calc_run_size.pl~x86-build-replace-perl-script-with-shell-script /dev/null
--- a/arch/x86/tools/calc_run_size.pl
+++ /dev/null
@@ -1,39 +0,0 @@
-#!/usr/bin/perl
-#
-# Calculate the amount of space needed to run the kernel, including room for
-# the .bss and .brk sections.
-#
-# Usage:
-# objdump -h a.out | perl calc_run_size.pl
-use strict;
-
-my $mem_size = 0;
-my $file_offset = 0;
-
-my $sections=" *[0-9]+ \.(?:bss|brk) +";
-while (<>) {
- if (/^$sections([0-9a-f]+) +(?:[0-9a-f]+ +){2}([0-9a-f]+)/) {
- my $size = hex($1);
- my $offset = hex($2);
- $mem_size += $size;
- if ($file_offset == 0) {
- $file_offset = $offset;
- } elsif ($file_offset != $offset) {
- # BFD linker shows the same file offset in ELF.
- # Gold linker shows them as consecutive.
- next if ($file_offset + $mem_size == $offset + $size);
-
- printf STDERR "file_offset: 0x%lx\n", $file_offset;
- printf STDERR "mem_size: 0x%lx\n", $mem_size;
- printf STDERR "offset: 0x%lx\n", $offset;
- printf STDERR "size: 0x%lx\n", $size;
-
- die ".bss and .brk are non-contiguous\n";
- }
- }
-}
-
-if ($file_offset == 0) {
- die "Never found .bss or .brk file offset\n";
-}
-printf("%d\n", $mem_size + $file_offset);
diff -puN /dev/null arch/x86/tools/calc_run_size.sh
--- /dev/null
+++ a/arch/x86/tools/calc_run_size.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+#
+# Calculate the amount of space needed to run the kernel, including room for
+# the .bss and .brk sections.
+#
+# Usage:
+# objdump -h a.out | sh calc_run_size.sh
+
+NUM='\([0-9a-fA-F]*[ \t]*\)'
+OUT=$(sed -n 's/^[ \t0-9]*.b[sr][sk][ \t]*'"$NUM$NUM$NUM$NUM"'.*/\1\4/p')
+if [ -z "$OUT" ] ; then
+ echo "Never found .bss or .brk file offset" >&2
+ exit 1
+fi
+
+OUT=$(echo ${OUT# })
+sizeA=$(printf "%d" 0x${OUT%% *})
+OUT=${OUT#* }
+offsetA=$(printf "%d" 0x${OUT%% *})
+OUT=${OUT#* }
+sizeB=$(printf "%d" 0x${OUT%% *})
+OUT=${OUT#* }
+offsetB=$(printf "%d" 0x${OUT%% *})
+
+run_size=$(( $offsetA + $sizeA + $sizeB ))
+
+# BFD linker shows the same file offset in ELF.
+if [ "$offsetA" -ne "$offsetB" ] ; then
+ # Gold linker shows them as consecutive.
+ endB=$(( $offsetB + $sizeB ))
+ if [ "$endB" != "$run_size" ] ; then
+ printf "sizeA: 0x%x\n" $sizeA >&2
+ printf "offsetA: 0x%x\n" $offsetA >&2
+ printf "sizeB: 0x%x\n" $sizeB >&2
+ printf "offsetB: 0x%x\n" $offsetB >&2
+ echo ".bss and .brk are non-contiguous" >&2
+ exit 1
+ fi
+fi
+
+printf "%d\n" $run_size
+exit 0
_
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