On Wed, Jan 07, 2009 at 05:01:26PM +1100, Michael Ellerman wrote: > Hi all, > > The patch to dynamically allocate memory regions for ppc64 kexec-tools, > ie. "ppc64: kexec memory ranges dynamic allocation" (d182ce5), has never > worked AFAICT. > > Chandru reported it as broken when it was posted: > http://lists.infradead.org/pipermail/kexec/2008-October/002751.html > > Still, it's in now, and I'm trying to work out what's going wrong. > > The symptom is as reported by Chandru, we end up not being able to > allocate any memory (in locate_hole()). This is caused by the list of > memory_ranges being empty. > > The memory_ranges are empty because they have been realloc'ed (by the > dynamic alloc code), and the generic code is still looking at the old > version. > > What I'm not clear on is why the ppc64 code is even calling > setup_memory_ranges() a second time (in elf_ppc64_load()). It's already > been called by get_memory_ranges() from my_load(). Or is there another > route into elf_ppc64_load() that I'm not seeing? > > And in fact if I just remove that call, then everything is peachy. > > The following patch makes it work for me at least. Hi Michael, I must confess that I don't have a complete understanding of this problem. Does Bernhard's recent patch (sorry that I applied it even though it came in after your patch) help this problem? commit 95c74405638c786bc76fbca5e4e8427dfe26e907 Author: Bernhard Walle <bwalle at suse.de> Date: Fri Jan 16 19:11:34 2009 +0100 Subject: Fix memory corruption when using realloc_memory_ranges() > >From 40958d8f957876ca612b666f40bebf28ea335314 Mon Sep 17 00:00:00 2001 > From: Michael Ellerman <michael at ellerman.id.au> > Date: Wed, 7 Jan 2009 16:57:05 +1100 > Subject: [PATCH] Don't call setup_memory_ranges() again > > There's no need to call setup_memory_ranges() again. Furthermore it can > lead to the memory_ranges being realloc'ed, which results in the generic > code (locate_hole() etc.) using the free'd memory_ranges. > > Signed-off-by: Michael Ellerman <michael at ellerman.id.au> > --- > kexec/arch/ppc64/kexec-elf-ppc64.c | 2 -- > 1 files changed, 0 insertions(+), 2 deletions(-) > > diff --git a/kexec/arch/ppc64/kexec-elf-ppc64.c b/kexec/arch/ppc64/kexec-elf-ppc64.c > index 21533cb..1e2d5a3 100644 > --- a/kexec/arch/ppc64/kexec-elf-ppc64.c > +++ b/kexec/arch/ppc64/kexec-elf-ppc64.c > @@ -151,8 +151,6 @@ int elf_ppc64_load(int argc, char **argv, const char *buf, off_t len, > if (ramdisk && reuse_initrd) > die("Can't specify --ramdisk or --initrd with --reuseinitrd\n"); > > - setup_memory_ranges(info->kexec_flags); > - > /* Need to append some command line parameters internally in case of > * taking crash dumps. > */ > -- > 1.5.3.7.1.g4e596e > > -- Simon Horman VA Linux Systems Japan K.K., Sydney, Australia Satellite Office H: www.vergenet.net/~horms/ W: www.valinux.co.jp/en
