Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751578AbbGaJ7R (ORCPT ); Fri, 31 Jul 2015 05:59:17 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:55696 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752270AbbGaJ7N (ORCPT ); Fri, 31 Jul 2015 05:59:13 -0400 Date: Fri, 31 Jul 2015 17:58:54 +0800 From: joeyli To: Pavel Machek Cc: "Lee, Chun-Yi" , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-pm@vger.kernel.org, "Rafael J. Wysocki" , Matthew Garrett , Len Brown , Josh Boyer , Vojtech Pavlik , Matt Fleming , Jiri Kosina , "H. Peter Anvin" Subject: Re: [RFC PATCH 05/16] x86/efi: Get entropy through EFI random number generator protocol Message-ID: <20150731095854.GC13113@linux-rxt1.site> References: <1437056730-15247-1-git-send-email-jlee@suse.com> <1437056730-15247-6-git-send-email-jlee@suse.com> <20150728122853.GB12681@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150728122853.GB12681@amd> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4877 Lines: 158 On Tue, Jul 28, 2015 at 02:28:53PM +0200, Pavel Machek wrote: > On Thu 2015-07-16 22:25:19, Lee, Chun-Yi wrote: > > To grab random numbers through EFI protocol as one of the entropies > > source of swsusp key, this patch adds the logic for accessing EFI RNG > > (random number generator) protocol that's introduced since UEFI 2.4. > > > > Signed-off-by: Lee, Chun-Yi > > --- > > arch/x86/boot/compressed/efi_random.c | 193 ++++++++++++++++++++++++++++++++++ > > include/linux/efi.h | 46 ++++++++ > > 2 files changed, 239 insertions(+) > > > > diff --git a/arch/x86/boot/compressed/efi_random.c b/arch/x86/boot/compressed/efi_random.c > > index bdb2d46..1f5c63d 100644 > > --- a/arch/x86/boot/compressed/efi_random.c > > +++ b/arch/x86/boot/compressed/efi_random.c > > @@ -2,6 +2,191 @@ > > > > #include > > #include > > +#include > > + > > +static efi_status_t efi_locate_rng(efi_system_table_t *sys_table, > > + void ***rng_handle) > > +{ > > + efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID; > > + unsigned long size = 0; > > + efi_status_t status; > > + > > + status = efi_call_early(locate_handle, > > + EFI_LOCATE_BY_PROTOCOL, > > + &rng_proto, NULL, &size, *rng_handle); > > + > > + if (status == EFI_BUFFER_TOO_SMALL) { > > + status = efi_call_early(allocate_pool, > > + EFI_LOADER_DATA, > > + size, (void **)rng_handle); > > + > > + if (status != EFI_SUCCESS) { > > + efi_printk(sys_table, " Failed to alloc mem for rng_handle"); > > + return status; > > + } > > + > > + status = efi_call_early(locate_handle, > > + EFI_LOCATE_BY_PROTOCOL, &rng_proto, > > + NULL, &size, *rng_handle); > > + } > > + > > + if (status != EFI_SUCCESS) { > > + efi_printk(sys_table, " Failed to locateEFI_RNG_PROTOCOL"); > > missing \n? > Originally those logs just follow a "EFI random" as a complete line. After removed "EFI random", I will add "\n" back to those log. > > + goto free_handle; > > You use that label exactly once, no need for goto > OK, I will remove free_handle label. > > +static bool efi_rng_supported32(efi_system_table_t *sys_table, void **rng_handle) > > +{ > > + const struct efi_config *efi_early = __efi_early(); > > + efi_rng_protocol_32 *rng = NULL; > ...> +static bool efi_rng_supported64(efi_system_table_t *sys_table, void **rng_handle) > > +{ > > + const struct efi_config *efi_early = __efi_early(); > > + efi_rng_protocol_64 *rng = NULL; > > + efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID; > ... > > +static unsigned long efi_get_rng32(efi_system_table_t *sys_table, > > + void **rng_handle) > > +{ > > + const struct efi_config *efi_early = __efi_early(); > > + efi_rng_protocol_32 *rng = NULL; > > + efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID; > ... > > +static unsigned long efi_get_rng64(efi_system_table_t *sys_table, > > + void **rng_handle) > > +{ > > + const struct efi_config *efi_early = __efi_early(); > > + efi_rng_protocol_64 *rng = NULL; > > + efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID; > > Can you do something to avoid each function having two very similar > versions of these functions? > They are similar but I want follow the style in eboot.c. On the other hand, it's earlier to locate problem on 32-bit or 64-bit EFI. So, I will keep the above codes. > > + if (status != EFI_SUCCESS) { > > + efi_printk(sys_table, " Failed to get RNG value "); > > + efi_printk(sys_table, efi_status_to_str(status)); > > Yep. You definitely have \n problems here. Thanks, I will add \n here also. > > > --- a/include/linux/efi.h > > +++ b/include/linux/efi.h > > @@ -427,6 +427,16 @@ typedef struct { > > #define EFI_PCI_IO_ATTRIBUTE_VGA_PALETTE_IO_16 0x20000 > > #define EFI_PCI_IO_ATTRIBUTE_VGA_IO_16 0x40000 > > > > +typedef struct { > > + u32 get_info; > > + u32 get_rng; > > +} efi_rng_protocol_32; > > + > > +typedef struct { > > + u64 get_info; > > + u64 get_rng; > > +} efi_rng_protocol_64; > > We don't typedef structs usually... > > Make it union so you can have just one > I want to follow the style as efi_pci_io_protocolxxx in efi.h. So I will keep it. > > +static inline char *efi_status_to_str(efi_status_t status) > > +{ > > + char *str; > > + > > Are you sure you want this inlined? > It's inlined because in header file. Currently it's only used by efi_random.c, I will move it to efi_random. > > + switch (status) { > > + case EFI_SUCCESS: > > + str = "EFI_SUCCESS"; > > + break; > > Can you use macros to reduce code duplication here? > Pavel I will try to reduce duplicate code. Thanks Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/