From: Vivek Goyal <vgoyal@xxxxxxxxxx> Subject: Re: [PATCH v3 01/21] vmcore: reference e_phoff member explicitly to get position of program header table Date: Thu, 21 Mar 2013 10:12:02 -0400 > On Thu, Mar 21, 2013 at 11:50:41AM +0900, HATAYAMA Daisuke wrote: >> From: "Eric W. Biederman" <ebiederm at xmission.com> >> Subject: Re: [PATCH v3 01/21] vmcore: reference e_phoff member explicitly to get position of program header table >> Date: Tue, 19 Mar 2013 14:44:16 -0700 >> >> > HATAYAMA Daisuke <d.hatayama at jp.fujitsu.com> writes: >> > >> >> Currently, the code assumes that position of program header table is >> >> next to ELF header. But future change can break the assumption on >> >> kexec-tools and the 1st kernel. To avoid worst case, reference e_phoff >> >> member explicitly to get position of program header table in >> >> file-offset. >> > >> > In principle this looks good. However when I read this it looks like >> > you are going a little too far. >> > >> > You are changing not only the reading of the supplied headers, but >> > you are changing the generation of the new new headers that describe >> > the data provided by /proc/vmcore. >> > >> > I get lost in following this after you mangle merge_note_headers. >> > >> > In principle removing silly assumptions seems reasonable, but I think >> > it is completely orthogonal to the task of maping vmcore mmapable. >> > >> > I think it is fine to claim that the assumptions made here in vmcore are >> > part of the kexec on panic ABI at this point, which would generally make >> > this change unnecessary. >> >> This was suggested by Vivek. He prefers generic one. >> >> Vivek, do you agree to this? Or is it better to re-post this and other >> clean-up patches as another one separately to this patch set? > > Given the fact that current code has been working, I am fine to just > re-post and take care of mmap() related issues. And we can take care > of cleaning up of some assumptions about PT_NOTE headers later. Trying > to club large cleanup with mmap() patches is making it hard to review. > I see. I'll post the clean-up series separately. Thanks. HATAYAMA, Daisuke
