From patchwork Wed Oct 4 21:20:02 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Garnier X-Patchwork-Id: 9985627 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D642460586 for ; Wed, 4 Oct 2017 21:26:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C66B828B68 for ; Wed, 4 Oct 2017 21:26:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BA40728C2A; Wed, 4 Oct 2017 21:26:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 87C7D28B68 for ; Wed, 4 Oct 2017 21:26:32 +0000 (UTC) Received: (qmail 17600 invoked by uid 550); 4 Oct 2017 21:21:53 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 16345 invoked from network); 4 Oct 2017 21:21:45 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=24jnHp4VljPiYGteQW746Fn83usA8PfLmyfmuL1UQX0=; b=SgpJReqTl3ep3+irbhH7IuWarff/6N0ob5PayLg/6HzmKdq+sxueU/mno4L+tJm87N aUpw6r1mqZONCrqHQHDkulu/OcEUE3tozQBMWHcR1yDonmqkR5bdWDSpvc8pL6edso2K G8QyPpIJ0tqVqOoyP51kbBtyWCfRTL/1J8PLGAqnc8emSJ0SiHrBGEzVF0FKhG9ttvsD Oc+Bn0vZ0vD24sx1sOUVPaaXxwO6pdm39vulm6e5U56qw0M0scEfUNzExnaOCJj1540t D9U4H+sTfOXohfTC0b6gdiJrvdkDcxX808daorThDUucjzpbTkP6psZhWTzpXvcULqMx jnjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=24jnHp4VljPiYGteQW746Fn83usA8PfLmyfmuL1UQX0=; b=GNkday2uLbKGava5c2ZVbI54OP0mtkbrtyca6BaiPMoU45oAqKTyJualxX3B6iQjxk WtJMXPMkf9DfcqKftCH2fLg442vbCgCKiTq65l/j1ebsBpmGej0jeg5KMnyRDT2qXN35 aEOehlSWzbK7WR+MXYEzKwvKyXi9/VtREf9dA4NLCxJsNC7ug1b4VjcPsGsJumHkynMK FVS9GgT96FOkFkc5aFgG+n8OA9m55v37PyYESI7eX30ycNqbHYISp+HAAXYt2jNNN0gH Lq+grbN7fB+oZdljgaQMWEq8J039LdHVRxG6I+30tJc0b6gzxfM7JWuPiSuGVHP4d0j0 OXOA== X-Gm-Message-State: AHPjjUh78A1D4sbpj7U3xejEqf5MyDcjECPDIkdi+GBRyhUye2lvAP1q D1uw+VeHX5XyGV4sxu5h1+1/PQ== X-Google-Smtp-Source: AOwi7QBjMfytId8mzXFMNAl1Aw3rjdm30RagPAs51z+B/izHqHMD+VIt8lZH1BJSYV5G/SP/MvRgqQ== X-Received: by 10.159.204.147 with SMTP id t19mr20921354plo.7.1507152093135; Wed, 04 Oct 2017 14:21:33 -0700 (PDT) From: Thomas Garnier To: Herbert Xu , "David S . Miller" , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Peter Zijlstra , Josh Poimboeuf , Thomas Garnier , Arnd Bergmann , Kees Cook , Matthias Kaehlcke , Tom Lendacky , Andy Lutomirski , "Kirill A . Shutemov" , Borislav Petkov , "Rafael J . Wysocki" , Len Brown , Pavel Machek , Juergen Gross , Chris Wright , Alok Kataria , Rusty Russell , Tejun Heo , Christoph Lameter , Boris Ostrovsky , Alexey Dobriyan , Andrew Morton , Paul Gortmaker , Chris Metcalf , "Paul E . McKenney" , Nicolas Pitre , Borislav Petkov , "Luis R . Rodriguez" , Greg Kroah-Hartman , Christopher Li , Steven Rostedt , Jason Baron , Dou Liyang , "Rafael J . Wysocki" , Mika Westerberg , Lukas Wunner , Masahiro Yamada , Alexei Starovoitov , Daniel Borkmann , Markus Trippelsdorf , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Joerg Roedel , Rik van Riel , David Howells , Ard Biesheuvel , Waiman Long , Kyle Huey , Andrey Ryabinin , Jonathan Corbet , Matthew Wilcox , Michal Hocko , Peter Foley , Paul Bolle , Jiri Kosina , Rob Landley , "H . J . Lu" , Baoquan He , =?UTF-8?q?Jan=20H=20=2E=20Sch=C3=B6nherr?= , Daniel Micay Cc: x86@kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, linux-arch@vger.kernel.org, linux-sparse@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com Date: Wed, 4 Oct 2017 14:20:02 -0700 Message-Id: <20171004212003.28296-27-thgarnie@google.com> X-Mailer: git-send-email 2.14.2.920.gcf0c67979c-goog In-Reply-To: <20171004212003.28296-1-thgarnie@google.com> References: <20171004212003.28296-1-thgarnie@google.com> Subject: [kernel-hardening] [RFC v3 26/27] x86/relocs: Add option to generate 64-bit relocations X-Virus-Scanned: ClamAV using ClamSMTP The x86 relocation tool generates a list of 32-bit signed integers. There was no need to use 64-bit integers because all addresses where above the 2G top of the memory. This change add a large-reloc option to generate 64-bit unsigned integers. It can be used when the kernel plan to go below the top 2G and 32-bit integers are not enough. Signed-off-by: Thomas Garnier --- arch/x86/tools/relocs.c | 60 +++++++++++++++++++++++++++++++++--------- arch/x86/tools/relocs.h | 4 +-- arch/x86/tools/relocs_common.c | 15 +++++++---- 3 files changed, 60 insertions(+), 19 deletions(-) diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index bc032ad88b22..e7497ea1fe76 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -12,8 +12,14 @@ static Elf_Ehdr ehdr; +#if ELF_BITS == 64 +typedef uint64_t rel_off_t; +#else +typedef uint32_t rel_off_t; +#endif + struct relocs { - uint32_t *offset; + rel_off_t *offset; unsigned long count; unsigned long size; }; @@ -684,7 +690,7 @@ static void print_absolute_relocs(void) printf("\n"); } -static void add_reloc(struct relocs *r, uint32_t offset) +static void add_reloc(struct relocs *r, rel_off_t offset) { if (r->count == r->size) { unsigned long newsize = r->size + 50000; @@ -1058,26 +1064,48 @@ static void sort_relocs(struct relocs *r) qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs); } -static int write32(uint32_t v, FILE *f) +static int write32(rel_off_t rel, FILE *f) { - unsigned char buf[4]; + unsigned char buf[sizeof(uint32_t)]; + uint32_t v = (uint32_t)rel; put_unaligned_le32(v, buf); - return fwrite(buf, 1, 4, f) == 4 ? 0 : -1; + return fwrite(buf, 1, sizeof(buf), f) == sizeof(buf) ? 0 : -1; } -static int write32_as_text(uint32_t v, FILE *f) +static int write32_as_text(rel_off_t rel, FILE *f) { + uint32_t v = (uint32_t)rel; return fprintf(f, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 0 : -1; } -static void emit_relocs(int as_text, int use_real_mode) +static int write64(rel_off_t rel, FILE *f) +{ + unsigned char buf[sizeof(uint64_t)]; + uint64_t v = (uint64_t)rel; + + put_unaligned_le64(v, buf); + return fwrite(buf, 1, sizeof(buf), f) == sizeof(buf) ? 0 : -1; +} + +static int write64_as_text(rel_off_t rel, FILE *f) +{ + uint64_t v = (uint64_t)rel; + return fprintf(f, "\t.quad 0x%016"PRIx64"\n", v) > 0 ? 0 : -1; +} + +static void emit_relocs(int as_text, int use_real_mode, int use_large_reloc) { int i; - int (*write_reloc)(uint32_t, FILE *) = write32; + int (*write_reloc)(rel_off_t, FILE *); int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, const char *symname); + if (use_large_reloc) + write_reloc = write64; + else + write_reloc = write32; + #if ELF_BITS == 64 if (!use_real_mode) do_reloc = do_reloc64; @@ -1088,6 +1116,9 @@ static void emit_relocs(int as_text, int use_real_mode) do_reloc = do_reloc32; else do_reloc = do_reloc_real; + + /* Large relocations only for 64-bit */ + use_large_reloc = 0; #endif /* Collect up the relocations */ @@ -1111,8 +1142,13 @@ static void emit_relocs(int as_text, int use_real_mode) * gas will like. */ printf(".section \".data.reloc\",\"a\"\n"); - printf(".balign 4\n"); - write_reloc = write32_as_text; + if (use_large_reloc) { + printf(".balign 8\n"); + write_reloc = write64_as_text; + } else { + printf(".balign 4\n"); + write_reloc = write32_as_text; + } } if (use_real_mode) { @@ -1180,7 +1216,7 @@ static void print_reloc_info(void) void process(FILE *fp, int use_real_mode, int as_text, int show_absolute_syms, int show_absolute_relocs, - int show_reloc_info) + int show_reloc_info, int use_large_reloc) { regex_init(use_real_mode); read_ehdr(fp); @@ -1203,5 +1239,5 @@ void process(FILE *fp, int use_real_mode, int as_text, print_reloc_info(); return; } - emit_relocs(as_text, use_real_mode); + emit_relocs(as_text, use_real_mode, use_large_reloc); } diff --git a/arch/x86/tools/relocs.h b/arch/x86/tools/relocs.h index 1d23bf953a4a..cb771cc4412d 100644 --- a/arch/x86/tools/relocs.h +++ b/arch/x86/tools/relocs.h @@ -30,8 +30,8 @@ enum symtype { void process_32(FILE *fp, int use_real_mode, int as_text, int show_absolute_syms, int show_absolute_relocs, - int show_reloc_info); + int show_reloc_info, int use_large_reloc); void process_64(FILE *fp, int use_real_mode, int as_text, int show_absolute_syms, int show_absolute_relocs, - int show_reloc_info); + int show_reloc_info, int use_large_reloc); #endif /* RELOCS_H */ diff --git a/arch/x86/tools/relocs_common.c b/arch/x86/tools/relocs_common.c index acab636bcb34..9cf1391af50a 100644 --- a/arch/x86/tools/relocs_common.c +++ b/arch/x86/tools/relocs_common.c @@ -11,14 +11,14 @@ void die(char *fmt, ...) static void usage(void) { - die("relocs [--abs-syms|--abs-relocs|--reloc-info|--text|--realmode]" \ - " vmlinux\n"); + die("relocs [--abs-syms|--abs-relocs|--reloc-info|--text|--realmode|" \ + "--large-reloc] vmlinux\n"); } int main(int argc, char **argv) { int show_absolute_syms, show_absolute_relocs, show_reloc_info; - int as_text, use_real_mode; + int as_text, use_real_mode, use_large_reloc; const char *fname; FILE *fp; int i; @@ -29,6 +29,7 @@ int main(int argc, char **argv) show_reloc_info = 0; as_text = 0; use_real_mode = 0; + use_large_reloc = 0; fname = NULL; for (i = 1; i < argc; i++) { char *arg = argv[i]; @@ -53,6 +54,10 @@ int main(int argc, char **argv) use_real_mode = 1; continue; } + if (strcmp(arg, "--large-reloc") == 0) { + use_large_reloc = 1; + continue; + } } else if (!fname) { fname = arg; @@ -74,11 +79,11 @@ int main(int argc, char **argv) if (e_ident[EI_CLASS] == ELFCLASS64) process_64(fp, use_real_mode, as_text, show_absolute_syms, show_absolute_relocs, - show_reloc_info); + show_reloc_info, use_large_reloc); else process_32(fp, use_real_mode, as_text, show_absolute_syms, show_absolute_relocs, - show_reloc_info); + show_reloc_info, use_large_reloc); fclose(fp); return 0; }