From 70b61e362187b5fccac206506d402f3424e3e749 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 17 Nov 2014 16:16:04 -0800 Subject: [PATCH] x86, kaslr: Handle Gold linker for finding bss/brk When building with the Gold linker, the .bss and .brk areas of vmlinux are shown as consecutive instead of having the same file offset. Allow for either state, as long as things add up correctly. Fixes: e6023367d779 ("x86, kaslr: Prevent .bss from overlaping initrd") Reported-by: Markus Trippelsdorf Signed-off-by: Kees Cook Cc: Junjie Mao Link: http://lkml.kernel.org/r/20141118001604.GA25045@www.outflux.net Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner --- arch/x86/tools/calc_run_size.pl | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/x86/tools/calc_run_size.pl b/arch/x86/tools/calc_run_size.pl index 0b0b124d3ece..23210baade2d 100644 --- a/arch/x86/tools/calc_run_size.pl +++ b/arch/x86/tools/calc_run_size.pl @@ -19,7 +19,16 @@ while (<>) { if ($file_offset == 0) { $file_offset = $offset; } elsif ($file_offset != $offset) { - die ".bss and .brk lack common file offset\n"; + # BFD linker shows the same file offset in ELF. + # Gold linker shows them as consecutive. + next if ($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"; } } }