From: Philipp Rudo <prudo@linux.vnet.ibm.com> To: kexec@lists.infradead.org, linux-s390@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eric Biederman <ebiederm@xmission.com>, Vivek Goyal <vgoyal@redhat.com>, Michael Ellerman <mpe@ellerman.id.au>, Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>, Martin Schwidefsky <schwidefsky@de.ibm.com>, Heiko Carstens <heiko.carstens@de.ibm.com>, Andrew Morton <akpm@linux-foundation.org>, x86@kernel.org Subject: [PATCH 17/17] s390/kexec_file: Add ELF loader Date: Mon, 12 Feb 2018 11:07:54 +0100 [thread overview] Message-ID: <20180212100754.55121-18-prudo@linux.vnet.ibm.com> (raw) In-Reply-To: <20180212100754.55121-1-prudo@linux.vnet.ibm.com> Add an ELF loader for kexec_file. The main task here is to do proper sanity checks on the ELF file. Basically all other functionality was already implemented for the image loader. Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> --- arch/s390/include/asm/kexec.h | 1 + arch/s390/kernel/Makefile | 2 +- arch/s390/kernel/kexec_elf.c | 149 ++++++++++++++++++++++++++++++++++ arch/s390/kernel/machine_kexec_file.c | 1 + 4 files changed, 152 insertions(+), 1 deletion(-) create mode 100644 arch/s390/kernel/kexec_elf.c diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h index 532f5e4f198f..e450b82e2716 100644 --- a/arch/s390/include/asm/kexec.h +++ b/arch/s390/include/asm/kexec.h @@ -67,5 +67,6 @@ void kexec_file_update_kernel(struct kimage *iamge, struct s390_load_data *data); extern const struct kexec_file_ops s390_kexec_image_ops; +extern const struct kexec_file_ops s390_kexec_elf_ops; #endif /*_S390_KEXEC_H */ diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 58a590709cc3..66d7b432c2a8 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -60,7 +60,7 @@ obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o als.o obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o -obj-y += machine_kexec_file.o kexec_image.o +obj-y += machine_kexec_file.o kexec_image.o kexec_elf.o extra-y += head.o head64.o vmlinux.lds diff --git a/arch/s390/kernel/kexec_elf.c b/arch/s390/kernel/kexec_elf.c new file mode 100644 index 000000000000..919ab2f1256f --- /dev/null +++ b/arch/s390/kernel/kexec_elf.c @@ -0,0 +1,149 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ELF loader for kexec_file_load system call. + * + * Copyright IBM Corp. 2018 + * + * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> + */ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/kexec.h> +#include <asm/setup.h> + +static int kexec_file_add_elf_kernel(struct kimage *image, + struct s390_load_data *data, + char *kernel, unsigned long kernel_len) +{ + struct kexec_buf buf; + const Elf_Ehdr *ehdr; + const Elf_Phdr *phdr; + int i, ret; + + ehdr = (Elf_Ehdr *)kernel; + buf.image = image; + + phdr = (void *)ehdr + ehdr->e_phoff; + for (i = 0; i < ehdr->e_phnum; i++, phdr++) { + if (phdr->p_type != PT_LOAD) + continue; + + buf.buffer = kernel + phdr->p_offset; + buf.bufsz = phdr->p_filesz; + + buf.mem = ALIGN(phdr->p_paddr, phdr->p_align); + buf.memsz = phdr->p_memsz; + + if (phdr->p_paddr == 0) { + data->kernel_buf = buf.buffer; + data->memsz += STARTUP_NORMAL_OFFSET; + + buf.buffer += STARTUP_NORMAL_OFFSET; + buf.bufsz -= STARTUP_NORMAL_OFFSET; + + buf.mem += STARTUP_NORMAL_OFFSET; + buf.memsz -= STARTUP_NORMAL_OFFSET; + } + + if (image->type == KEXEC_TYPE_CRASH) + buf.mem += crashk_res.start; + + ret = kexec_add_buffer(&buf); + if (ret) + return ret; + + data->memsz += buf.memsz; + } + + return 0; +} + +static void *s390_elf_load(struct kimage *image, + char *kernel, unsigned long kernel_len, + char *initrd, unsigned long initrd_len, + char *cmdline, unsigned long cmdline_len) +{ + struct s390_load_data data = {0}; + const Elf_Ehdr *ehdr; + const Elf_Phdr *phdr; + size_t size; + int i, ret; + + /* image->fobs->probe already checked for valid ELF magic number. */ + ehdr = (Elf_Ehdr *)kernel; + + if (ehdr->e_type != ET_EXEC || + ehdr->e_ident[EI_CLASS] != ELFCLASS64 || + !elf_check_arch(ehdr)) + return ERR_PTR(-EINVAL); + + if (!ehdr->e_phnum || ehdr->e_phentsize != sizeof(Elf_Phdr)) + return ERR_PTR(-EINVAL); + + size = ehdr->e_ehsize + ehdr->e_phoff; + size += ehdr->e_phentsize * ehdr->e_phnum; + if (size > kernel_len) + return ERR_PTR(-EINVAL); + + phdr = (void *)ehdr + ehdr->e_phoff; + size = ALIGN(size, phdr->p_align); + for (i = 0; i < ehdr->e_phnum; i++, phdr++) { + if (phdr->p_type == PT_INTERP) + return ERR_PTR(-EINVAL); + + if (phdr->p_offset > kernel_len) + return ERR_PTR(-EINVAL); + + size += ALIGN(phdr->p_filesz, phdr->p_align); + } + + if (size > kernel_len) + return ERR_PTR(-EINVAL); + + ret = kexec_file_add_elf_kernel(image, &data, kernel, kernel_len); + if (ret) + return ERR_PTR(ret); + + if (!data.memsz) + return ERR_PTR(-EINVAL); + + if (initrd) { + ret = kexec_file_add_initrd(image, &data, initrd, initrd_len); + if (ret) + return ERR_PTR(ret); + } + + ret = kexec_file_add_purgatory(image, &data); + if (ret) + return ERR_PTR(ret); + + kexec_file_update_kernel(image, &data); + + return NULL; +} + +static int s390_elf_probe(const char *buf, unsigned long len) +{ + const Elf_Ehdr *ehdr; + + if (len < sizeof(Elf_Ehdr)) + return -ENOEXEC; + + ehdr = (Elf_Ehdr *)buf; + + /* Only check the ELF magic number here and do proper validity check + * in the loader. Any check here that fails would send the erroneous + * ELF file to the image loader that does not care what it gets. + * (Most likely) causing behavior not intended by the user. + */ + if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) + return -ENOEXEC; + + return 0; +} + +const struct kexec_file_ops s390_kexec_elf_ops = { + .probe = s390_elf_probe, + .load = s390_elf_load, +}; diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index 050ceab746ec..8938e0eca4b0 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -12,6 +12,7 @@ #include <asm/setup.h> const struct kexec_file_ops * const kexec_file_loaders[] = { + &s390_kexec_elf_ops, &s390_kexec_image_ops, NULL, }; -- 2.13.5
WARNING: multiple messages have this Message-ID (diff)
From: Philipp Rudo <prudo@linux.vnet.ibm.com> To: kexec@lists.infradead.org, linux-s390@vger.kernel.org Cc: Michael Ellerman <mpe@ellerman.id.au>, x86@kernel.org, Heiko Carstens <heiko.carstens@de.ibm.com>, linux-kernel@vger.kernel.org, Martin Schwidefsky <schwidefsky@de.ibm.com>, Eric Biederman <ebiederm@xmission.com>, Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>, Andrew Morton <akpm@linux-foundation.org>, Vivek Goyal <vgoyal@redhat.com> Subject: [PATCH 17/17] s390/kexec_file: Add ELF loader Date: Mon, 12 Feb 2018 11:07:54 +0100 [thread overview] Message-ID: <20180212100754.55121-18-prudo@linux.vnet.ibm.com> (raw) In-Reply-To: <20180212100754.55121-1-prudo@linux.vnet.ibm.com> Add an ELF loader for kexec_file. The main task here is to do proper sanity checks on the ELF file. Basically all other functionality was already implemented for the image loader. Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com> --- arch/s390/include/asm/kexec.h | 1 + arch/s390/kernel/Makefile | 2 +- arch/s390/kernel/kexec_elf.c | 149 ++++++++++++++++++++++++++++++++++ arch/s390/kernel/machine_kexec_file.c | 1 + 4 files changed, 152 insertions(+), 1 deletion(-) create mode 100644 arch/s390/kernel/kexec_elf.c diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h index 532f5e4f198f..e450b82e2716 100644 --- a/arch/s390/include/asm/kexec.h +++ b/arch/s390/include/asm/kexec.h @@ -67,5 +67,6 @@ void kexec_file_update_kernel(struct kimage *iamge, struct s390_load_data *data); extern const struct kexec_file_ops s390_kexec_image_ops; +extern const struct kexec_file_ops s390_kexec_elf_ops; #endif /*_S390_KEXEC_H */ diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 58a590709cc3..66d7b432c2a8 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -60,7 +60,7 @@ obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o als.o obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o -obj-y += machine_kexec_file.o kexec_image.o +obj-y += machine_kexec_file.o kexec_image.o kexec_elf.o extra-y += head.o head64.o vmlinux.lds diff --git a/arch/s390/kernel/kexec_elf.c b/arch/s390/kernel/kexec_elf.c new file mode 100644 index 000000000000..919ab2f1256f --- /dev/null +++ b/arch/s390/kernel/kexec_elf.c @@ -0,0 +1,149 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * ELF loader for kexec_file_load system call. + * + * Copyright IBM Corp. 2018 + * + * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> + */ + +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/kexec.h> +#include <asm/setup.h> + +static int kexec_file_add_elf_kernel(struct kimage *image, + struct s390_load_data *data, + char *kernel, unsigned long kernel_len) +{ + struct kexec_buf buf; + const Elf_Ehdr *ehdr; + const Elf_Phdr *phdr; + int i, ret; + + ehdr = (Elf_Ehdr *)kernel; + buf.image = image; + + phdr = (void *)ehdr + ehdr->e_phoff; + for (i = 0; i < ehdr->e_phnum; i++, phdr++) { + if (phdr->p_type != PT_LOAD) + continue; + + buf.buffer = kernel + phdr->p_offset; + buf.bufsz = phdr->p_filesz; + + buf.mem = ALIGN(phdr->p_paddr, phdr->p_align); + buf.memsz = phdr->p_memsz; + + if (phdr->p_paddr == 0) { + data->kernel_buf = buf.buffer; + data->memsz += STARTUP_NORMAL_OFFSET; + + buf.buffer += STARTUP_NORMAL_OFFSET; + buf.bufsz -= STARTUP_NORMAL_OFFSET; + + buf.mem += STARTUP_NORMAL_OFFSET; + buf.memsz -= STARTUP_NORMAL_OFFSET; + } + + if (image->type == KEXEC_TYPE_CRASH) + buf.mem += crashk_res.start; + + ret = kexec_add_buffer(&buf); + if (ret) + return ret; + + data->memsz += buf.memsz; + } + + return 0; +} + +static void *s390_elf_load(struct kimage *image, + char *kernel, unsigned long kernel_len, + char *initrd, unsigned long initrd_len, + char *cmdline, unsigned long cmdline_len) +{ + struct s390_load_data data = {0}; + const Elf_Ehdr *ehdr; + const Elf_Phdr *phdr; + size_t size; + int i, ret; + + /* image->fobs->probe already checked for valid ELF magic number. */ + ehdr = (Elf_Ehdr *)kernel; + + if (ehdr->e_type != ET_EXEC || + ehdr->e_ident[EI_CLASS] != ELFCLASS64 || + !elf_check_arch(ehdr)) + return ERR_PTR(-EINVAL); + + if (!ehdr->e_phnum || ehdr->e_phentsize != sizeof(Elf_Phdr)) + return ERR_PTR(-EINVAL); + + size = ehdr->e_ehsize + ehdr->e_phoff; + size += ehdr->e_phentsize * ehdr->e_phnum; + if (size > kernel_len) + return ERR_PTR(-EINVAL); + + phdr = (void *)ehdr + ehdr->e_phoff; + size = ALIGN(size, phdr->p_align); + for (i = 0; i < ehdr->e_phnum; i++, phdr++) { + if (phdr->p_type == PT_INTERP) + return ERR_PTR(-EINVAL); + + if (phdr->p_offset > kernel_len) + return ERR_PTR(-EINVAL); + + size += ALIGN(phdr->p_filesz, phdr->p_align); + } + + if (size > kernel_len) + return ERR_PTR(-EINVAL); + + ret = kexec_file_add_elf_kernel(image, &data, kernel, kernel_len); + if (ret) + return ERR_PTR(ret); + + if (!data.memsz) + return ERR_PTR(-EINVAL); + + if (initrd) { + ret = kexec_file_add_initrd(image, &data, initrd, initrd_len); + if (ret) + return ERR_PTR(ret); + } + + ret = kexec_file_add_purgatory(image, &data); + if (ret) + return ERR_PTR(ret); + + kexec_file_update_kernel(image, &data); + + return NULL; +} + +static int s390_elf_probe(const char *buf, unsigned long len) +{ + const Elf_Ehdr *ehdr; + + if (len < sizeof(Elf_Ehdr)) + return -ENOEXEC; + + ehdr = (Elf_Ehdr *)buf; + + /* Only check the ELF magic number here and do proper validity check + * in the loader. Any check here that fails would send the erroneous + * ELF file to the image loader that does not care what it gets. + * (Most likely) causing behavior not intended by the user. + */ + if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) + return -ENOEXEC; + + return 0; +} + +const struct kexec_file_ops s390_kexec_elf_ops = { + .probe = s390_elf_probe, + .load = s390_elf_load, +}; diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c index 050ceab746ec..8938e0eca4b0 100644 --- a/arch/s390/kernel/machine_kexec_file.c +++ b/arch/s390/kernel/machine_kexec_file.c @@ -12,6 +12,7 @@ #include <asm/setup.h> const struct kexec_file_ops * const kexec_file_loaders[] = { + &s390_kexec_elf_ops, &s390_kexec_image_ops, NULL, }; -- 2.13.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2018-02-12 10:08 UTC|newest] Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-02-12 10:07 [PATCH 00/17] Add kexec_file_load support to s390 Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 01/17] kexec_file: Silence compile warnings Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 02/17] kexec_file: Remove checks in kexec_purgatory_load Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 03/17] kexec_file: Make purgatory_info->ehdr const Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 04/17] kexec_file: Search symbols in read-only kexec_purgatory Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 05/17] kexec_file: Use read-only sections in arch_kexec_apply_relocations* Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 06/17] kexec_file: Split up __kexec_load_puragory Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 07/17] kexec_file: Simplify kexec_purgatory_setup_sechdrs 1 Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 08/17] kexec_file: Simplify kexec_purgatory_setup_sechdrs 2 Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 09/17] kexec_file: Remove mis-use of sh_offset field Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 10/17] kexec_file: Allow archs to set purgatory load address Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 11/17] kexec_file: Move purgatories sha256 to common code Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 12/17] s390/kexec_file: Prepare setup.h for kexec_file_load Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 13/17] s390/kexec_file: Add purgatory Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 14/17] s390/kexec_file: Add kexec_file_load system call Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:56 ` Philippe Ombredanne 2018-02-12 10:56 ` Philippe Ombredanne 2018-02-12 11:29 ` Philipp Rudo 2018-02-12 11:29 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 15/17] s390/kexec_file: Add image loader Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` [PATCH 16/17] s390/kexec_file: Add crash support to " Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo 2018-02-12 10:07 ` Philipp Rudo [this message] 2018-02-12 10:07 ` [PATCH 17/17] s390/kexec_file: Add ELF loader Philipp Rudo 2018-02-14 7:35 ` [PATCH 00/17] Add kexec_file_load support to s390 Dave Young 2018-02-14 7:35 ` Dave Young 2018-02-14 7:35 ` Dave Young 2018-02-14 9:54 ` Philipp Rudo 2018-02-14 9:54 ` Philipp Rudo 2018-02-15 5:08 ` AKASHI Takahiro 2018-02-15 5:08 ` AKASHI Takahiro 2018-02-23 8:34 ` Dave Young 2018-02-23 8:34 ` Dave Young 2018-02-23 10:01 ` Philipp Rudo 2018-02-23 10:01 ` Philipp Rudo 2018-02-24 1:59 ` Dave Young 2018-02-24 1:59 ` Dave Young 2018-02-26 1:21 ` AKASHI Takahiro 2018-02-26 1:21 ` AKASHI Takahiro 2018-02-26 11:16 ` Philipp Rudo 2018-02-26 11:16 ` Philipp Rudo -- strict thread matches above, loose matches on Subject: below -- 2018-02-02 13:07 Philipp Rudo 2018-02-02 13:07 ` [PATCH 17/17] s390/kexec_file: Add ELF loader Philipp Rudo 2018-02-02 13:07 ` Philipp Rudo
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