Commit d69911a6 authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds

x86, build: replace Perl script with Shell script

Commit e6023367 ("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: default avatarKees Cook <keescook@chromium.org>
Reported-by: default avatarRob Landley <rob@landley.net>
Acked-by: default avatarRob Landley <rob@landley.net>
Cc: Anca Emanuel <anca.emanuel@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Junjie Mao <eternal.n08@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9879de73
...@@ -90,7 +90,7 @@ suffix-$(CONFIG_KERNEL_LZO) := lzo ...@@ -90,7 +90,7 @@ suffix-$(CONFIG_KERNEL_LZO) := lzo
suffix-$(CONFIG_KERNEL_LZ4) := lz4 suffix-$(CONFIG_KERNEL_LZ4) := lz4
RUN_SIZE = $(shell $(OBJDUMP) -h vmlinux | \ 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 $@ quiet_cmd_mkpiggy = MKPIGGY $@
cmd_mkpiggy = $(obj)/mkpiggy $< $(RUN_SIZE) > $@ || ( rm -f $@ ; false ) cmd_mkpiggy = $(obj)/mkpiggy $< $(RUN_SIZE) > $@ || ( rm -f $@ ; false )
......
#!/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);
#!/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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