On Wed, Mar 07, 2007 at 05:06:39PM +0800, Zou, Nanhai wrote: > > -----Original Message----- > > From: Horms [mailto:horms@xxxxxxxxxxxx] > > Sent: 2007年3月7日 15:55 > > To: Zou, Nanhai > > Cc: Linux-IA64; fastboot@xxxxxxxxxxxxxx; Luck, Tony; Magnus Damm > > Subject: Re: [patch 3/3] IA64: verify the base address of crashkernel > > > > On Wed, Mar 07, 2007 at 12:50:12PM +0800, Zou, Nanhai wrote: > > > On Wed, Mar 07, 2007 at 11:46, Horms wrote: > > > > > > > > I think that the manual option is also important because it > > > > maintains feature-compatibility with other architectures. I don't > > > > consider it a hack that might work purely for the purposes of > > > > debugging. > > > > > > I don't understand why we need to maintain compatibility with other > > > architectures here. Manfully choose may confuse user, XXX@16M may work > > > on one arch,but not on another arch. Other architectures need manually > > > choose crash kernel region simply because they do not support kernel > > > automatically choose feature. > > > > > > I keep the XXX@YYY format to just make kdump script compatible, do > > > that distributions does not need to maintain different kdump scripts > > > for different arches. > > > > > From my point of view, what you say in the paragraph immediately above > > Thanks, is this logic better? > > > Don't write code to improve a "no user will use" feature. > Let's keep kernel code clean. I think we could argue about this forever :-) > > kdump_region_verify_rsvd_region (unsigned long base, unsigned long size, > > struct rsvd_region *rsvd_regions, int n) > > { > > int i; > > > > for (i = 0; i < n; i++) { > > /* Assume that start < end && size > 0 */ > > if (__pa(rsvd_regions[i].start) >= base + size && > > __pa(rsvd_regions[i].end) < base) > > continue; > This is much worse. Have you ever tested it? Sorry, I wrote it down wrong :( That should have been: if (__pa(rsvd_regions[i].start) >= base + size || __pa(rsvd_regions[i].end) <= base) continue; I'll do some testing tomorrow. But this was what I was thinking about: s=__pa(rsvd_regions[i].start) e=__pa(rsvd_regions[i].end) base base+size OK: s:bad e:ok | | BAD: s:bad | e:bad | BAD: s:bad | | e:bad BAD: s:bad | e:bad | BAD: | s:bad e:bad | BAD: | s:bad | e:bad OK: | | s:ok e:bad -- Horms H: http://www.vergenet.net/~horms/ W: http://www.valinux.co.jp/en/ - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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