From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Salter Subject: Re: [PATCH] arm64/efi: handle potential failure to remap memory map Date: Thu, 15 Jan 2015 11:50:47 -0500 Message-ID: <1421340647.22837.2.camel@deneb.redhat.com> References: <1421323266-30973-1-git-send-email-ard.biesheuvel@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1421323266-30973-1-git-send-email-ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ard Biesheuvel Cc: mark.rutland-5wv7dgnIgG8@public.gmane.org, matt.fleming-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, leif.lindholm-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-efi@vger.kernel.org On Thu, 2015-01-15 at 12:01 +0000, Ard Biesheuvel wrote: > When remapping the UEFI memory map using ioremap_cache(), we > have to deal with potential failure. Note that, even if the > common case is for ioremap_cache() to return the existing linear > mapping of the memory map, we cannot rely on that to be always the > case, e.g., in the presence of a mem= kernel parameter. > > At the same time, remove a stale comment and move the memmap code > together. > > Signed-off-by: Ard Biesheuvel > --- > arch/arm64/kernel/efi.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c > index a98415b5979c..c9cb0fbe7aa4 100644 > --- a/arch/arm64/kernel/efi.c > +++ b/arch/arm64/kernel/efi.c > @@ -229,19 +229,21 @@ static int __init arm64_enable_runtime_services(void) > return -1; > } > > - mapsize = memmap.map_end - memmap.map; > - > if (efi_runtime_disabled()) { > pr_info("EFI runtime services will be disabled.\n"); > return -1; > } > > pr_info("Remapping and enabling EFI services.\n"); > - /* replace early memmap mapping with permanent mapping */ > + > + mapsize = memmap.map_end - memmap.map; > memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map, > mapsize); > + if (!memmap.map) { > + pr_err("Failed to remap EFI memory map\n"); > + return -1; > + } > memmap.map_end = memmap.map + mapsize; > - > efi.memmap = &memmap; > > efi.systab = (__force void *)ioremap_cache(efi_system_table, Somewhat unrelated but we should unmap memmap.map if the efi.systab mapping fails. Acked-by: Mark Salter