From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752185AbaKDTpq (ORCPT ); Tue, 4 Nov 2014 14:45:46 -0500 Received: from terminus.zytor.com ([198.137.202.10]:60928 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118AbaKDTpo (ORCPT ); Tue, 4 Nov 2014 14:45:44 -0500 Date: Tue, 4 Nov 2014 11:45:28 -0800 From: tip-bot for Jan Beulich Message-ID: Cc: jbeulich@suse.com, hpa@zytor.com, tglx@linutronix.de, linux-kernel@vger.kernel.org, JBeulich@suse.com, mingo@kernel.org Reply-To: hpa@zytor.com, jbeulich@suse.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@kernel.org, JBeulich@suse.com In-Reply-To: <5458A15A0200007800044A9A@mail.emea.novell.com> References: <5458A15A0200007800044A9A@mail.emea.novell.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/boot] x86-64: Handle PC-relative relocations on per-CPU data Git-Commit-ID: 6d24c5f72dfb26e5fa7f02fa9266dfdbae41adba X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 6d24c5f72dfb26e5fa7f02fa9266dfdbae41adba Gitweb: http://git.kernel.org/tip/6d24c5f72dfb26e5fa7f02fa9266dfdbae41adba Author: Jan Beulich AuthorDate: Tue, 4 Nov 2014 08:50:18 +0000 Committer: Thomas Gleixner CommitDate: Tue, 4 Nov 2014 20:43:14 +0100 x86-64: Handle PC-relative relocations on per-CPU data This is in preparation of using RIP-relative addressing in many of the per-CPU accesses. Signed-off-by: Jan Beulich Link: http://lkml.kernel.org/r/5458A15A0200007800044A9A@mail.emea.novell.com Signed-off-by: Thomas Gleixner --- arch/x86/boot/compressed/misc.c | 14 +++++++++++++- arch/x86/tools/relocs.c | 36 +++++++++++++++++++++++++++--------- 2 files changed, 40 insertions(+), 10 deletions(-) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 57ab74d..644abd7 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -260,7 +260,7 @@ static void handle_relocations(void *output, unsigned long output_len) /* * Process relocations: 32 bit relocations first then 64 bit after. - * Two sets of binary relocations are added to the end of the kernel + * Three sets of binary relocations are added to the end of the kernel * before compression. Each relocation table entry is the kernel * address of the location which needs to be updated stored as a * 32-bit value which is sign extended to 64 bits. @@ -270,6 +270,8 @@ static void handle_relocations(void *output, unsigned long output_len) * kernel bits... * 0 - zero terminator for 64 bit relocations * 64 bit relocation repeated + * 0 - zero terminator for inverse 32 bit relocations + * 32 bit inverse relocation repeated * 0 - zero terminator for 32 bit relocations * 32 bit relocation repeated * @@ -286,6 +288,16 @@ static void handle_relocations(void *output, unsigned long output_len) *(uint32_t *)ptr += delta; } #ifdef CONFIG_X86_64 + while (*--reloc) { + long extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("inverse 32-bit relocation outside of kernel!\n"); + + *(int32_t *)ptr -= delta; + } for (reloc--; *reloc; reloc--) { long extended = *reloc; extended += map; diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index a5efb21..0c2fae8 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -20,7 +20,10 @@ struct relocs { static struct relocs relocs16; static struct relocs relocs32; +#if ELF_BITS == 64 +static struct relocs relocs32neg; static struct relocs relocs64; +#endif struct section { Elf_Shdr shdr; @@ -762,11 +765,16 @@ static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, switch (r_type) { case R_X86_64_NONE: + /* NONE can be ignored. */ + break; + case R_X86_64_PC32: /* - * NONE can be ignored and PC relative relocations don't - * need to be adjusted. + * PC relative relocations don't need to be adjusted unless + * referencing a percpu symbol. */ + if (is_percpu_sym(sym, symname)) + add_reloc(&relocs32neg, offset); break; case R_X86_64_32: @@ -986,7 +994,10 @@ static void emit_relocs(int as_text, int use_real_mode) /* Order the relocations for more efficient processing */ sort_relocs(&relocs16); sort_relocs(&relocs32); +#if ELF_BITS == 64 + sort_relocs(&relocs32neg); sort_relocs(&relocs64); +#endif /* Print the relocations */ if (as_text) { @@ -1007,14 +1018,21 @@ static void emit_relocs(int as_text, int use_real_mode) for (i = 0; i < relocs32.count; i++) write_reloc(relocs32.offset[i], stdout); } else { - if (ELF_BITS == 64) { - /* Print a stop */ - write_reloc(0, stdout); +#if ELF_BITS == 64 + /* Print a stop */ + write_reloc(0, stdout); - /* Now print each relocation */ - for (i = 0; i < relocs64.count; i++) - write_reloc(relocs64.offset[i], stdout); - } + /* Now print each relocation */ + for (i = 0; i < relocs64.count; i++) + write_reloc(relocs64.offset[i], stdout); + + /* Print a stop */ + write_reloc(0, stdout); + + /* Now print each inverse 32-bit relocation */ + for (i = 0; i < relocs32neg.count; i++) + write_reloc(relocs32neg.offset[i], stdout); +#endif /* Print a stop */ write_reloc(0, stdout);