From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4435CC35247 for ; Wed, 5 Feb 2020 18:21:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id ED4F621927 for ; Wed, 5 Feb 2020 18:21:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ED4F621927 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 009166B0081; Wed, 5 Feb 2020 13:20:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E236B6B0087; Wed, 5 Feb 2020 13:20:36 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7FD16B0082; Wed, 5 Feb 2020 13:20:36 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0029.hostedemail.com [216.40.44.29]) by kanga.kvack.org (Postfix) with ESMTP id 9AC006B0083 for ; Wed, 5 Feb 2020 13:20:36 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3558D8248D52 for ; Wed, 5 Feb 2020 18:20:36 +0000 (UTC) X-FDA: 76456888872.15.river89_7996de403853d X-HE-Tag: river89_7996de403853d X-Filterd-Recvd-Size: 11033 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by imf09.hostedemail.com (Postfix) with ESMTP for ; Wed, 5 Feb 2020 18:20:35 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2020 10:20:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,406,1574150400"; d="scan'208";a="279447839" Received: from yyu32-desk.sc.intel.com ([143.183.136.146]) by FMSMGA003.fm.intel.com with ESMTP; 05 Feb 2020 10:20:29 -0800 From: Yu-cheng Yu To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin , x86-patch-review@intel.com Cc: Yu-cheng Yu Subject: [RFC PATCH v9 22/27] ELF: Add ELF program property parsing support Date: Wed, 5 Feb 2020 10:19:30 -0800 Message-Id: <20200205181935.3712-23-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200205181935.3712-1-yu-cheng.yu@intel.com> References: <20200205181935.3712-1-yu-cheng.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Dave Martin ELF program properties will be needed for detecting whether to enable optional architecture or ABI features for a new ELF process. For now, there are no generic properties that we care about, so do nothing unless CONFIG_ARCH_USE_GNU_PROPERTY=3Dy. Otherwise, the presence of properties using the PT_PROGRAM_PROPERTY phdrs entry (if any), and notify each property to the arch code. For now, the added code is not used. Signed-off-by: Dave Martin Signed-off-by: Yu-cheng Yu --- fs/binfmt_elf.c | 127 +++++++++++++++++++++++++++++++++++++++ fs/compat_binfmt_elf.c | 4 ++ include/linux/elf.h | 19 ++++++ include/uapi/linux/elf.h | 4 ++ 4 files changed, 154 insertions(+) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index ecd8d2698515..054446f93442 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -39,12 +39,18 @@ #include #include #include +#include +#include #include #include #include #include #include =20 +#ifndef ELF_COMPAT +#define ELF_COMPAT 0 +#endif + #ifndef user_long_t #define user_long_t long #endif @@ -678,6 +684,111 @@ static unsigned long load_elf_interp(struct elfhdr = *interp_elf_ex, * libraries. There is no binary dependent code anywhere else. */ =20 +static int parse_elf_property(const char *data, size_t *off, size_t data= sz, + struct arch_elf_state *arch, + bool have_prev_type, u32 *prev_type) +{ + size_t o, step; + const struct gnu_property *pr; + int ret; + + if (*off =3D=3D datasz) + return -ENOENT; + + if (WARN_ON(*off > datasz || *off % ELF_GNU_PROPERTY_ALIGN)) + return -EIO; + o =3D *off; + datasz -=3D *off; + + if (datasz < sizeof(*pr)) + return -EIO; + pr =3D (const struct gnu_property *)(data + o); + o +=3D sizeof(*pr); + datasz -=3D sizeof(*pr); + + if (pr->pr_datasz > datasz) + return -EIO; + + WARN_ON(o % ELF_GNU_PROPERTY_ALIGN); + step =3D round_up(pr->pr_datasz, ELF_GNU_PROPERTY_ALIGN); + if (step > datasz) + return -EIO; + + /* Properties are supposed to be unique and sorted on pr_type: */ + if (have_prev_type && pr->pr_type <=3D *prev_type) + return -EIO; + *prev_type =3D pr->pr_type; + + ret =3D arch_parse_elf_property(pr->pr_type, data + o, + pr->pr_datasz, ELF_COMPAT, arch); + if (ret) + return ret; + + *off =3D o + step; + return 0; +} + +#define NOTE_DATA_SZ SZ_1K +#define GNU_PROPERTY_TYPE_0_NAME "GNU" +#define NOTE_NAME_SZ (sizeof(GNU_PROPERTY_TYPE_0_NAME)) + +static int parse_elf_properties(struct file *f, const struct elf_phdr *p= hdr, + struct arch_elf_state *arch) +{ + union { + struct elf_note nhdr; + char data[NOTE_DATA_SZ]; + } note; + loff_t pos; + ssize_t n; + size_t off, datasz; + int ret; + bool have_prev_type; + u32 prev_type; + + if (!IS_ENABLED(CONFIG_ARCH_USE_GNU_PROPERTY) || !phdr) + return 0; + + /* load_elf_binary() shouldn't call us unless this is true... */ + if (WARN_ON(phdr->p_type !=3D PT_GNU_PROPERTY)) + return -EIO; + + /* If the properties are crazy large, that's too bad (for now): */ + if (phdr->p_filesz > sizeof(note)) + return -ENOEXEC; + + pos =3D phdr->p_offset; + n =3D kernel_read(f, ¬e, phdr->p_filesz, &pos); + + BUILD_BUG_ON(sizeof(note) < sizeof(note.nhdr) + NOTE_NAME_SZ); + if (n < 0 || n < sizeof(note.nhdr) + NOTE_NAME_SZ) + return -EIO; + + if (note.nhdr.n_type !=3D NT_GNU_PROPERTY_TYPE_0 || + note.nhdr.n_namesz !=3D NOTE_NAME_SZ || + strncmp(note.data + sizeof(note.nhdr), + GNU_PROPERTY_TYPE_0_NAME, n - sizeof(note.nhdr))) + return -EIO; + + off =3D round_up(sizeof(note.nhdr) + NOTE_NAME_SZ, + ELF_GNU_PROPERTY_ALIGN); + if (off > n) + return -EIO; + + if (note.nhdr.n_descsz > n - off) + return -EIO; + datasz =3D off + note.nhdr.n_descsz; + + have_prev_type =3D false; + do { + ret =3D parse_elf_property(note.data, &off, datasz, arch, + have_prev_type, &prev_type); + have_prev_type =3D true; + } while (!ret); + + return ret =3D=3D -ENOENT ? 0 : ret; +} + static int load_elf_binary(struct linux_binprm *bprm) { struct file *interpreter =3D NULL; /* to shut gcc up */ @@ -685,6 +796,7 @@ static int load_elf_binary(struct linux_binprm *bprm) int load_addr_set =3D 0; unsigned long error; struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata =3D NULL; + struct elf_phdr *elf_property_phdata =3D NULL; unsigned long elf_bss, elf_brk; int bss_prot =3D 0; int retval, i; @@ -731,6 +843,11 @@ static int load_elf_binary(struct linux_binprm *bprm= ) for (i =3D 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { char *elf_interpreter; =20 + if (elf_ppnt->p_type =3D=3D PT_GNU_PROPERTY) { + elf_property_phdata =3D elf_ppnt; + continue; + } + if (elf_ppnt->p_type !=3D PT_INTERP) continue; =20 @@ -818,9 +935,14 @@ static int load_elf_binary(struct linux_binprm *bprm= ) goto out_free_dentry; =20 /* Pass PT_LOPROC..PT_HIPROC headers to arch code */ + elf_property_phdata =3D NULL; elf_ppnt =3D interp_elf_phdata; for (i =3D 0; i < loc->interp_elf_ex.e_phnum; i++, elf_ppnt++) switch (elf_ppnt->p_type) { + case PT_GNU_PROPERTY: + elf_property_phdata =3D elf_ppnt; + break; + case PT_LOPROC ... PT_HIPROC: retval =3D arch_elf_pt_proc(&loc->interp_elf_ex, elf_ppnt, interpreter, @@ -831,6 +953,11 @@ static int load_elf_binary(struct linux_binprm *bprm= ) } } =20 + retval =3D parse_elf_properties(interpreter ?: bprm->file, + elf_property_phdata, &arch_state); + if (retval) + goto out_free_dentry; + /* * Allow arch code to reject the ELF at this point, whilst it's * still possible to return an error to the code that invoked diff --git a/fs/compat_binfmt_elf.c b/fs/compat_binfmt_elf.c index aaad4ca1217e..13a087bc816b 100644 --- a/fs/compat_binfmt_elf.c +++ b/fs/compat_binfmt_elf.c @@ -17,6 +17,8 @@ #include #include =20 +#define ELF_COMPAT 1 + /* * Rename the basic ELF layout types to refer to the 32-bit class of fil= es. */ @@ -28,11 +30,13 @@ #undef elf_shdr #undef elf_note #undef elf_addr_t +#undef ELF_GNU_PROPERTY_ALIGN #define elfhdr elf32_hdr #define elf_phdr elf32_phdr #define elf_shdr elf32_shdr #define elf_note elf32_note #define elf_addr_t Elf32_Addr +#define ELF_GNU_PROPERTY_ALIGN ELF32_GNU_PROPERTY_ALIGN =20 /* * Some data types as stored in coredump. diff --git a/include/linux/elf.h b/include/linux/elf.h index 459cddcceaac..7bdc6da160c7 100644 --- a/include/linux/elf.h +++ b/include/linux/elf.h @@ -22,6 +22,9 @@ SET_PERSONALITY(ex) #endif =20 +#define ELF32_GNU_PROPERTY_ALIGN 4 +#define ELF64_GNU_PROPERTY_ALIGN 8 + #if ELF_CLASS =3D=3D ELFCLASS32 =20 extern Elf32_Dyn _DYNAMIC []; @@ -32,6 +35,7 @@ extern Elf32_Dyn _DYNAMIC []; #define elf_addr_t Elf32_Off #define Elf_Half Elf32_Half #define Elf_Word Elf32_Word +#define ELF_GNU_PROPERTY_ALIGN ELF32_GNU_PROPERTY_ALIGN =20 #else =20 @@ -43,6 +47,7 @@ extern Elf64_Dyn _DYNAMIC []; #define elf_addr_t Elf64_Off #define Elf_Half Elf64_Half #define Elf_Word Elf64_Word +#define ELF_GNU_PROPERTY_ALIGN ELF64_GNU_PROPERTY_ALIGN =20 #endif =20 @@ -64,4 +69,18 @@ struct gnu_property { u32 pr_datasz; }; =20 +struct arch_elf_state; + +#ifndef CONFIG_ARCH_USE_GNU_PROPERTY +static inline int arch_parse_elf_property(u32 type, const void *data, + size_t datasz, bool compat, + struct arch_elf_state *arch) +{ + return 0; +} +#else +extern int arch_parse_elf_property(u32 type, const void *data, size_t da= tasz, + bool compat, struct arch_elf_state *arch); +#endif + #endif /* _LINUX_ELF_H */ diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index 61251ecabdd7..518651708d8f 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -368,6 +368,7 @@ typedef struct elf64_shdr { * Notes used in ET_CORE. Architectures export some of the arch register= sets * using the corresponding note types via the PTRACE_GETREGSET and * PTRACE_SETREGSET requests. + * The note name for all these is "LINUX". */ #define NT_PRSTATUS 1 #define NT_PRFPREG 2 @@ -430,6 +431,9 @@ typedef struct elf64_shdr { #define NT_MIPS_FP_MODE 0x801 /* MIPS floating-point mode */ #define NT_MIPS_MSA 0x802 /* MIPS SIMD registers */ =20 +/* Note types with note name "GNU" */ +#define NT_GNU_PROPERTY_TYPE_0 5 + /* Note header in a PT_NOTE section */ typedef struct elf32_note { Elf32_Word n_namesz; /* Name size */ --=20 2.21.0