Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751866AbdIVHz6 (ORCPT ); Fri, 22 Sep 2017 03:55:58 -0400 Received: from mail-io0-f171.google.com ([209.85.223.171]:45200 "EHLO mail-io0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751704AbdIVHz4 (ORCPT ); Fri, 22 Sep 2017 03:55:56 -0400 X-Google-Smtp-Source: AOwi7QBeX36ixcEG/CuAWoQkZIzgU/TY54zZUk4VuFI2VydkqraktEGYmZs4AtUHf1/svmgloYgb5Q== Date: Fri, 22 Sep 2017 16:58:09 +0900 From: AKASHI Takahiro To: Dave Young Cc: catalin.marinas@arm.com, will.deacon@arm.com, bauerman@linux.vnet.ibm.com, dhowells@redhat.com, vgoyal@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, akpm@linux-foundation.org, mpe@ellerman.id.au, bhe@redhat.com, arnd@arndb.de, ard.biesheuvel@linaro.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v3 03/10] kexec_file: factor out arch_kexec_kernel_*() from x86, powerpc Message-ID: <20170922075807.GM17186@linaro.org> Mail-Followup-To: AKASHI Takahiro , Dave Young , catalin.marinas@arm.com, will.deacon@arm.com, bauerman@linux.vnet.ibm.com, dhowells@redhat.com, vgoyal@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, akpm@linux-foundation.org, mpe@ellerman.id.au, bhe@redhat.com, arnd@arndb.de, ard.biesheuvel@linaro.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20170915105932.25338-1-takahiro.akashi@linaro.org> <20170915105932.25338-4-takahiro.akashi@linaro.org> <20170921073516.GA6643@dhcp-128-65.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170921073516.GA6643@dhcp-128-65.nay.redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11424 Lines: 334 Hi Dave, On Thu, Sep 21, 2017 at 03:35:16PM +0800, Dave Young wrote: > Hi AKASHI, > On 09/15/17 at 07:59pm, AKASHI Takahiro wrote: > > arch_kexec_kernel_*() and arch_kimage_file_post_load_cleanup can now be > > duplicated among some architectures, so let's factor them out. > > > > Signed-off-by: AKASHI Takahiro > > Cc: Dave Young > > Cc: Vivek Goyal > > Cc: Baoquan He > > Cc: Michael Ellerman > > Cc: Thiago Jung Bauermann > > --- > > arch/powerpc/include/asm/kexec.h | 4 ++ > > arch/powerpc/kernel/machine_kexec_file_64.c | 36 ++---------------- > > arch/x86/kernel/machine_kexec_64.c | 59 +---------------------------- > > include/linux/kexec.h | 26 ++++++++++--- > > kernel/kexec_file.c | 52 +++++++++++++++++++------ > > 5 files changed, 70 insertions(+), 107 deletions(-) > > > > diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h > > index 25668bc8cb2a..50810d24e38f 100644 > > --- a/arch/powerpc/include/asm/kexec.h > > +++ b/arch/powerpc/include/asm/kexec.h > > @@ -94,6 +94,10 @@ static inline bool kdump_in_progress(void) > > #ifdef CONFIG_KEXEC_FILE > > extern struct kexec_file_ops kexec_elf64_ops; > > > > +#define arch_kexec_kernel_image_probe arch_kexec_kernel_image_probe > > +int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > + unsigned long buf_len); > > + > > #ifdef CONFIG_IMA_KEXEC > > #define ARCH_HAS_KIMAGE_ARCH > > > > diff --git a/arch/powerpc/kernel/machine_kexec_file_64.c b/arch/powerpc/kernel/machine_kexec_file_64.c > > index 992c0d258e5d..5b7c4a3fbb50 100644 > > --- a/arch/powerpc/kernel/machine_kexec_file_64.c > > +++ b/arch/powerpc/kernel/machine_kexec_file_64.c > > @@ -31,8 +31,9 @@ > > > > #define SLAVE_CODE_SIZE 256 > > > > -static struct kexec_file_ops *kexec_file_loaders[] = { > > +struct kexec_file_ops *kexec_file_loaders[] = { > > &kexec_elf64_ops, > > + NULL > > }; > > > > int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > @@ -45,38 +46,7 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > if (image->type == KEXEC_TYPE_CRASH) > > return -ENOTSUPP; > > > > - for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) { > > - fops = kexec_file_loaders[i]; > > - if (!fops || !fops->probe) > > - continue; > > - > > - ret = fops->probe(buf, buf_len); > > - if (!ret) { > > - image->fops = fops; > > - return ret; > > - } > > - } > > - > > - return ret; > > -} > > - > > -void *arch_kexec_kernel_image_load(struct kimage *image) > > -{ > > - if (!image->fops || !image->fops->load) > > - return ERR_PTR(-ENOEXEC); > > - > > - return image->fops->load(image, image->kernel_buf, > > - image->kernel_buf_len, image->initrd_buf, > > - image->initrd_buf_len, image->cmdline_buf, > > - image->cmdline_buf_len); > > -} > > - > > -int arch_kimage_file_post_load_cleanup(struct kimage *image) > > -{ > > - if (!image->fops || !image->fops->cleanup) > > - return 0; > > - > > - return image->fops->cleanup(image->image_loader_data); > > + return kexec_kernel_image_probe(image, buf, buf_len); > > } > > > > /** > > diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c > > index cb0a30473c23..f4df8315d001 100644 > > --- a/arch/x86/kernel/machine_kexec_64.c > > +++ b/arch/x86/kernel/machine_kexec_64.c > > @@ -30,8 +30,9 @@ > > #include > > > > #ifdef CONFIG_KEXEC_FILE > > -static struct kexec_file_ops *kexec_file_loaders[] = { > > +struct kexec_file_ops *kexec_file_loaders[] = { > > &kexec_bzImage64_ops, > > + NULL > > }; > > #endif > > > > @@ -361,62 +362,6 @@ void arch_crash_save_vmcoreinfo(void) > > /* arch-dependent functionality related to kexec file-based syscall */ > > > > #ifdef CONFIG_KEXEC_FILE > > -int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > - unsigned long buf_len) > > -{ > > - int i, ret = -ENOEXEC; > > - struct kexec_file_ops *fops; > > - > > - for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) { > > - fops = kexec_file_loaders[i]; > > - if (!fops || !fops->probe) > > - continue; > > - > > - ret = fops->probe(buf, buf_len); > > - if (!ret) { > > - image->fops = fops; > > - return ret; > > - } > > - } > > - > > - return ret; > > -} > > - > > -void *arch_kexec_kernel_image_load(struct kimage *image) > > -{ > > - vfree(image->arch.elf_headers); > > - image->arch.elf_headers = NULL; > > - > > - if (!image->fops || !image->fops->load) > > - return ERR_PTR(-ENOEXEC); > > - > > - return image->fops->load(image, image->kernel_buf, > > - image->kernel_buf_len, image->initrd_buf, > > - image->initrd_buf_len, image->cmdline_buf, > > - image->cmdline_buf_len); > > -} > > - > > -int arch_kimage_file_post_load_cleanup(struct kimage *image) > > -{ > > - if (!image->fops || !image->fops->cleanup) > > - return 0; > > - > > - return image->fops->cleanup(image->image_loader_data); > > -} > > - > > -#ifdef CONFIG_KEXEC_VERIFY_SIG > > -int arch_kexec_kernel_verify_sig(struct kimage *image, void *kernel, > > - unsigned long kernel_len) > > -{ > > - if (!image->fops || !image->fops->verify_sig) { > > - pr_debug("kernel loader does not support signature verification."); > > - return -EKEYREJECTED; > > - } > > - > > - return image->fops->verify_sig(kernel, kernel_len); > > -} > > -#endif > > - > > /* > > * Apply purgatory relocations. > > * > > diff --git a/include/linux/kexec.h b/include/linux/kexec.h > > index dd056fab9e35..4a2b24d94e04 100644 > > --- a/include/linux/kexec.h > > +++ b/include/linux/kexec.h > > @@ -134,6 +134,26 @@ struct kexec_file_ops { > > #endif > > }; > > > > +int kexec_kernel_image_probe(struct kimage *image, void *buf, > > + unsigned long buf_len); > > +void *kexec_kernel_image_load(struct kimage *image); > > +int kexec_kernel_post_load_cleanup(struct kimage *image); > > +int kexec_kernel_verify_sig(struct kimage *image, void *buf, > > + unsigned long buf_len); > > + > > +#ifndef arch_kexec_kernel_image_probe > > +#define arch_kexec_kernel_image_probe kexec_kernel_image_probe > > +#endif > > +#ifndef arch_kexec_kernel_image_load > > +#define arch_kexec_kernel_image_load kexec_kernel_image_load > > +#endif > > +#ifndef arch_kimage_file_post_load_cleanup > > +#define arch_kimage_file_post_load_cleanup kexec_kernel_post_load_cleanup > > +#endif > > +#ifndef arch_kexec_kernel_verify_sig > > +#define arch_kexec_kernel_verify_sig kexec_kernel_verify_sig > > +#endif > > + > > /** > > * struct kexec_buf - parameters for finding a place for a buffer in memory > > * @image: kexec image in which memory to search. > > @@ -276,12 +296,6 @@ int crash_shrink_memory(unsigned long new_size); > > size_t crash_get_memory_size(void); > > void crash_free_reserved_phys_range(unsigned long begin, unsigned long end); > > > > -int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > - unsigned long buf_len); > > -void * __weak arch_kexec_kernel_image_load(struct kimage *image); > > -int __weak arch_kimage_file_post_load_cleanup(struct kimage *image); > > -int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, > > - unsigned long buf_len); > > I thought we can keep using the __weak function in common code and drop > the arch functions, no need the #ifndef arch_kexec_kernel_image_probe > and the function renaming stuff. But I did not notice the powerpc > _probe function checks KEXEC_ON_CRASH, that should be checked earlier > and we can fail out early if not supported, but I have no idea > how to do it gracefully for now. > > Also for x86 _load function it cleanups image->arch.elf_headers, it can > not be dropped simply. Yeah, arm64 post_load_cleanup function also has some extra stuff. See my patch #7/8. > Consider the above two issues, maybe you can keep the powerpc > version of _probe() and x86 version of _load(), and still copy the common code > to kexec_file.c weak functions. It was exactly what I made before submitting v3, but I changed my mind a bit. My intension is to prevent the code being duplicated even though it has only a few lines of code. I agree that '#ifndef arch_kexec_kernel_image_probe' in kexec.h would be quite ugly, but similar usages can be spotted in the kernel source. That said if you don't like it at all, I defer to you. Thanks, -Takahiro AKASHI > I can post patch to cleanup the x86 > _load function in the future. > > int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr, > > Elf_Shdr *sechdrs, unsigned int relsec); > > int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs, > > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c > > index 9f48f4412297..6203b54e04c5 100644 > > --- a/kernel/kexec_file.c > > +++ b/kernel/kexec_file.c > > @@ -26,30 +26,60 @@ > > #include > > #include "kexec_internal.h" > > > > +__weak struct kexec_file_ops *kexec_file_loaders[] = {NULL}; > > + > > static int kexec_calculate_store_digests(struct kimage *image); > > > > -/* Architectures can provide this probe function */ > > -int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf, > > - unsigned long buf_len) > > +int kexec_kernel_image_probe(struct kimage *image, void *buf, > > + unsigned long buf_len) > > { > > - return -ENOEXEC; > > + int i, ret = -ENOEXEC; > > + struct kexec_file_ops *fops; > > + > > + for (i = 0; ; i++) { > > + fops = kexec_file_loaders[i]; > > + if (!fops || !fops->probe) > > + break; > > + > > + ret = fops->probe(buf, buf_len); > > + if (!ret) { > > + image->fops = fops; > > + return ret; > > + } > > + } > > + > > + return ret; > > } > > > > -void * __weak arch_kexec_kernel_image_load(struct kimage *image) > > +void *kexec_kernel_image_load(struct kimage *image) > > { > > - return ERR_PTR(-ENOEXEC); > > + if (!image->fops || !image->fops->load) > > + return ERR_PTR(-ENOEXEC); > > + > > + return image->fops->load(image, image->kernel_buf, > > + image->kernel_buf_len, image->initrd_buf, > > + image->initrd_buf_len, image->cmdline_buf, > > + image->cmdline_buf_len); > > } > > > > -int __weak arch_kimage_file_post_load_cleanup(struct kimage *image) > > +int kexec_kernel_post_load_cleanup(struct kimage *image) > > { > > - return -EINVAL; > > + if (!image->fops || !image->fops->cleanup) > > + return 0; > > + > > + return image->fops->cleanup(image->image_loader_data); > > } > > > > #ifdef CONFIG_KEXEC_VERIFY_SIG > > -int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf, > > - unsigned long buf_len) > > +int kexec_kernel_verify_sig(struct kimage *image, void *buf, > > + unsigned long buf_len) > > { > > - return -EKEYREJECTED; > > + if (!image->fops || !image->fops->verify_sig) { > > + pr_debug("kernel loader does not support signature verification.\n"); > > + return -EKEYREJECTED; > > + } > > + > > + return image->fops->verify_sig(buf, buf_len); > > } > > #endif > > > > -- > > 2.14.1 > > > > > > _______________________________________________ > > kexec mailing list > > kexec@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/kexec > > Thanks > Dave