On Tue, 15 Nov 2016 11:55:26 +1100 Michael Ellerman <m...@ellerman.id.au> wrote:
> Nicholas Piggin <npig...@gmail.com> writes: > > > diff --git a/arch/powerpc/Makefile.postlink b/arch/powerpc/Makefile.postlink > > index 1725e64..b8fe12b 100644 > > --- a/arch/powerpc/Makefile.postlink > > +++ b/arch/powerpc/Makefile.postlink > > @@ -24,6 +27,9 @@ endif > > > > vmlinux: FORCE > > @true > > +ifeq ($(CONFIG_PPC64),y) > > You can just use: > > ifdef CONFIG_PPC64 Okay. The same applies to other parts of this file added earlier. I'll fix. > > + $(call cmd,head_check) > > +endif > > ifeq ($(CONFIG_RELOCATABLE),y) > > $(call if_changed,relocs_check) > > endif > > @@ -32,6 +38,7 @@ endif > > @true > > > > clean: > > + rm -f .tmp_symbols.txt > > @true > > We shouldn't need the true anymore should we? True. > > diff --git a/arch/powerpc/tools/head_check.sh > > b/arch/powerpc/tools/head_check.sh > > new file mode 100755 > > index 0000000..9635fe7 > > --- /dev/null > > +++ b/arch/powerpc/tools/head_check.sh > > @@ -0,0 +1,69 @@ > > +#!/bin/sh > > We run this explicitly via $(CONFIG_SHELL), so having a shebang here is > redundant and also a little confusing. I added "-x" here, to turn on > tracing, but it doesn't take effect, so I think better to just drop the > line. If anyone wants to run it manually they can just pass it to sh. Okay. How about relocs_check.sh? I just started by copying that. > > > +# Copyright © 2016 IBM Corporation > > + > > +# This program is free software; you can redistribute it and/or > > +# modify it under the terms of the GNU General Public License > > +# as published by the Free Software Foundation; either version > > +# 2 of the License, or (at your option) any later version. > > + > > +# This script checks the head of a vmlinux for linker stubs that > > +# break our placement of fixed-location code for 64-bit. > > + > > +# based on relocs_check.pl > > +# Copyright © 2009 IBM Corporation > > + > > +# READ THIS > > +# > > +# If the build dies here, it's likely code in head_64.S or nearby is > > +# referencing labels it can't reach, which results in the linker inserting > > +# stubs without the assembler's knowledge. This can move code around in > > ways > > +# that break the fixed location placement stuff (head-64.h). To debug, > > +# disassemble the vmlinux and look for branch stubs (long_branch, > > plt_branch > > +# etc) in the fixed section region (0 - 0x8000ish). Check what places are > > +# calling those stubs. > > +# > > +# Linker stubs use the TOC pointer, so even if fixed section code could > > +# tolerate them being inserted into head code, they can't be allowed in low > > +# level entry code (boot, interrupt vectors, etc) until r2 is set up. This > > +# could cause the kernel to die in early boot. > > Can you add: > > # Turn this on if you want more debug output: > # set -x Can do, same question applies for relocs_check.sh > > > + > > +if [ $# -lt 2 ]; then > > + echo "$0 [path to nm] [path to vmlinux]" 1>&2 > > + exit 1 > > +fi > > + > > +# Have Kbuild supply the path to nm so we handle cross compilation. > > +nm="$1" > > +vmlinux="$2" > > + > > +nm "$vmlinux" | grep -e " T _stext$" -e " t start_first_256B$" -e " a > > text_start$" -e " t start_text$" -m4 > .tmp_symbols.txt > > You don't use $nm there. Thanks, good catch. > > + > > + > > +vma=$(cat .tmp_symbols.txt | grep " T _stext$" | cut -d' ' -f1) > > + > > +expected_start_head_addr=$vma > > + > > +start_head_addr=$(cat .tmp_symbols.txt | grep " t start_first_256B$" | cut > > -d' ' -f1) > > + > > +if [ "$start_head_addr" != "$expected_start_head_addr" ]; then > > + echo "ERROR: head code starts at $start_head_addr, should be 0" > > + echo "ERROR: see comments in arch/powerpc/tools/head_check.sh" > > This is blowing up for me with ppc64e_defconfig. > > It says: > > ERROR: start_text address is c000000000001100, should be c000000000000200 I must have forgotten to test e. I'll fix that. Thanks, Nick
