From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Fleming Subject: Re: [PATCH v4 07/12] efi: passing kexec necessary efi data via setup_data Date: Wed, 27 Nov 2013 10:17:47 +0000 Message-ID: <20131127101747.GC18170@console-pimps.org> References: <1385445477-9665-1-git-send-email-dyoung@redhat.com> <1385445477-9665-8-git-send-email-dyoung@redhat.com> <20131126220448.GB18170@console-pimps.org> <20131127045237.GC11852@dhcp-16-126.nay.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20131127045237.GC11852-je1gSBvt1TcFLmT5oZ11vB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dave Young Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mjg59-1xO5oi07KQx4cg9Nei1l7Q@public.gmane.org, hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org, James.Bottomley-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org, vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org, horms-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org, kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org, greg-U8xfFu+wG4EAvxtiuMwx3w@public.gmane.org, toshi.kani-VXdhtT5mjnY@public.gmane.org List-Id: linux-efi@vger.kernel.org On Wed, 27 Nov, at 12:52:37PM, Dave Young wrote: > To make it more readable, I will change them like below: > > p = efi_runtime_map; > md = efi_setup->map; > for (i = 0; i < nr_efi_runtime_map; i++) { > [...] > md += 1; > } Actually, md++ is the canonical way to write this. > > > > > + efi_map_region_fixed(md); > > > + size = md->num_pages << PAGE_SHIFT; > > > + end = md->phys_addr + size; > > > + > > > + systab = (u64) (unsigned long) efi_phys.systab; > > > + if (md->phys_addr <= systab && systab < end) { > > > + systab += md->virt_addr - md->phys_addr; > > > + efi.systab = > > > + (efi_system_table_t *) (unsigned long) systab; > > > + } > > > + if (efi_runtime_map) { > > > + memcpy(p, md, memmap.desc_size); > > > + p += memmap.desc_size; > > > + } > > > > Is this if () needed? Is it possible to enter the loop and have > > 'efi_runtime_map' be NULL? > > Yes, it is needed. if efi_runtime_map kmalloc fails I only print error, do not > return so kernel can still boot, just kexec on efi will not work that has been > put in the error message. OK. On second thought, is there any way to turn the above code into a call to efi_save_runtime_map()? Because you've basically duplicated that code and I can definitely envisage the two code paths fragmenting over time, e.g. when someone makes changes to one but not the other. -- Matt Fleming, Intel Open Source Technology Center