lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 27 Mar 2019 14:10:14 -0400 From: Sasha Levin <sashal@...nel.org> To: linux-kernel@...r.kernel.org, stable@...r.kernel.org Cc: Rafael Ávila de Espíndola <rafael@...indo.la>, Nick Desaulniers <ndesaulniers@...gle.com>, Borislav Petkov <bp@...e.de>, "H. Peter Anvin" <hpa@...or.com>, Andy Lutomirski <luto@...nel.org>, Brijesh Singh <brijesh.singh@....com>, Cao Jin <caoj.fnst@...fujitsu.com>, Ingo Molnar <mingo@...hat.com>, Joerg Roedel <jroedel@...e.de>, Masahiro Yamada <yamada.masahiro@...ionext.com>, Masami Hiramatsu <mhiramat@...nel.org>, Thomas Gleixner <tglx@...utronix.de>, Tri Vo <trong@...roid.com>, dima@...ovin.in, morbo@...gle.com, x86-ml <x86@...nel.org>, Sasha Levin <sashal@...nel.org> Subject: [PATCH AUTOSEL 4.19 182/192] x86/build: Mark per-CPU symbols as absolute explicitly for LLD From: Rafael Ávila de Espíndola <rafael@...indo.la> [ Upstream commit d071ae09a4a1414c1433d5ae9908959a7325b0ad ] Accessing per-CPU variables is done by finding the offset of the variable in the per-CPU block and adding it to the address of the respective CPU's block. Section 3.10.8 of ld.bfd's documentation states: For expressions involving numbers, relative addresses and absolute addresses, ld follows these rules to evaluate terms: Other binary operations, that is, between two relative addresses not in the same section, or between a relative address and an absolute address, first convert any non-absolute term to an absolute address before applying the operator." Note that LLVM's linker does not adhere to the GNU ld's implementation and as such requires implicitly-absolute terms to be explicitly marked as absolute in the linker script. If not, it fails currently with: ld.lld: error: ./arch/x86/kernel/vmlinux.lds:153: at least one side of the expression must be absolute ld.lld: error: ./arch/x86/kernel/vmlinux.lds:154: at least one side of the expression must be absolute Makefile:1040: recipe for target 'vmlinux' failed This is not a functional change for ld.bfd which converts the term to an absolute symbol anyways as specified above. Based on a previous submission by Tri Vo <trong@...roid.com>. Reported-by: Dmitry Golovin <dima@...ovin.in> Signed-off-by: Rafael Ávila de Espíndola <rafael@...indo.la> [ Update commit message per Boris' and Michael's suggestions. ] Signed-off-by: Nick Desaulniers <ndesaulniers@...gle.com> [ Massage commit message more, fix typos. ] Signed-off-by: Borislav Petkov <bp@...e.de> Tested-by: Dmitry Golovin <dima@...ovin.in> Cc: "H. Peter Anvin" <hpa@...or.com> Cc: Andy Lutomirski <luto@...nel.org> Cc: Brijesh Singh <brijesh.singh@....com> Cc: Cao Jin <caoj.fnst@...fujitsu.com> Cc: Ingo Molnar <mingo@...hat.com> Cc: Joerg Roedel <jroedel@...e.de> Cc: Masahiro Yamada <yamada.masahiro@...ionext.com> Cc: Masami Hiramatsu <mhiramat@...nel.org> Cc: Thomas Gleixner <tglx@...utronix.de> Cc: Tri Vo <trong@...roid.com> Cc: dima@...ovin.in Cc: morbo@...gle.com Cc: x86-ml <x86@...nel.org> Link: https://lkml.kernel.org/r/20181219190145.252035-1-ndesaulniers@google.com Signed-off-by: Sasha Levin <sashal@...nel.org> --- arch/x86/kernel/vmlinux.lds.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 5dd3317d761f..c63bab98780c 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -411,7 +411,7 @@ SECTIONS * Per-cpu symbols which need to be offset from __per_cpu_load * for the boot processor. */ -#define INIT_PER_CPU(x) init_per_cpu__##x = x + __per_cpu_load +#define INIT_PER_CPU(x) init_per_cpu__##x = ABSOLUTE(x) + __per_cpu_load INIT_PER_CPU(gdt_page); INIT_PER_CPU(irq_stack_union); -- 2.19.1
Powered by blists - more mailing lists