From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from cantor2.suse.de ([195.135.220.15] helo=mx2.suse.de) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WTUX9-00011h-TA for kexec@lists.infradead.org; Fri, 28 Mar 2014 11:01:12 +0000 Date: Fri, 28 Mar 2014 12:00:47 +0100 From: Petr Tesarik Subject: Re: [PATCH 2/2] makedumpfile: Use max_pfn from mem_map array Message-ID: <20140328120047.24a056ea@hananiah.suse.cz> In-Reply-To: <20140327145441.4c956989@holzheu> References: <20140325171420.6b558576@holzheu> <20140326.105507.429853525.d.hatayama@jp.fujitsu.com> <20140326185426.5e2e5fc4@holzheu> <0910DD04CBD6DE4193FCF86B9C00BE971FA0EC@BPXM01GP.gisp.nec.co.jp> <20140327145441.4c956989@holzheu> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Michael Holzheu Cc: "kexec@lists.infradead.org" , "d.hatayama@jp.fujitsu.com" , Atsushi Kumagai On Thu, 27 Mar 2014 14:54:41 +0100 Michael Holzheu wrote: > On Thu, 27 Mar 2014 05:19:06 +0000 > Atsushi Kumagai wrote: > > > Hello Michael, > > > > >On Wed, 26 Mar 2014 10:55:07 +0100 (a/T) > > >HATAYAMA Daisuke wrote: > > > > > >> From: Michael Holzheu > > >> Subject: [PATCH 2/2] makedumpfile: Use max_pfn from mem_map array > > >> Date: Tue, 25 Mar 2014 17:14:20 +0100 > > > > > >[snip] > > > > > >> > With this patch makedumpfile gets the maximum page frame number from > > >> > the mem_map array and adjusts info->max_mapnr if this value is smaller > > >> > than the value calculated from the ELF header. > > >> > > > >> > Signed-off-by: Michael Holzheu > > >> > --- > > >> > makedumpfile.c | 14 +++++++++++++- > > >> > 1 file changed, 13 insertions(+), 1 deletion(-) > > >> > > > >> > --- a/makedumpfile.c > > >> > +++ b/makedumpfile.c > > >> > @@ -2829,7 +2829,8 @@ get_mem_map_without_mm(void) > > >> > int > > >> > get_mem_map(void) > > >> > { > > >> > - int ret; > > >> > + unsigned long max_pfn = 0; > > >> > + int ret, i; > > >> > > >> Please define max_pfn as unsigned long long. > > > > > >Ok done. > > > > > >> > > >> And for i, > > >> > > >> > > > >> > switch (get_mem_type()) { > > >> > case SPARSEMEM: > > >> > @@ -2861,6 +2862,17 @@ get_mem_map(void) > > >> > ret = FALSE; > > >> > break; > > >> > } > > >> > + /* > > >> > + * Adjust "max_mapnr" for the case that Linux uses less memory > > >> > + * than is dumped. For example when "mem=" has been used for the > > >> > + * dumped system. > > >> > + */ > > >> > + for (i = 0; i < info->num_mem_map; i++) { > > >> > > >> info->num_mem_map is defined as unsigned int. I guess some warning > > >> about comparison with different signedness occurs. > > > > > >Ah ok... > > > > > >With the default CFLAGS for makedumpfile-1.5.5 tarball I do not get > > >any warning. When I add "-W" to CFLAGS, I get lots of warnings > > >including the one you mentioned. > > > > > >Here the fixed patch: > > > > Thanks, I'll merge the fixed version into v1.5.6. > > Great! I'm sorry to spoil the party, but this patch broke Xen dumps for me. I'm getting an long series of these messages: set_bitmap: Can't read the bitmap(/tmp/kdump_bitmap91pbsO). Invalid argument set_bitmap: Can't read the bitmap(/tmp/kdump_bitmap91pbsO). Invalid argument set_bitmap: Can't read the bitmap(/tmp/kdump_bitmap91pbsO). Invalid argument ... In fact, it most likely broke all non-cyclic dumps. That's because the bitmap length is calculated in prepare_bitmap_buffer using info->max_mapnr, but create_1st_bitmap() still loops over all PT_LOAD segments, calling set_bit_on_1st_bitmap() for each PFN. The offset may easily fall beyond the bitmap size. Petr T _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec