From 0f326b993712da64329eb7c544d8fd63fde98f7d Mon Sep 17 00:00:00 2001 From: David Woodhouse <dwmw@amazon.co.uk> Date: Thu, 11 Jan 2018 21:46:29 +0000 Subject: [PATCH] x86/retpoline/ftrace: Convert ftrace assembler indirect jumps CVE-2017-5715 (Spectre v2 retpoline) commit 9351803bd803cdbeb9b5a7850b7b6f464806e3db upstream. Convert all indirect jumps in ftrace assembler code to use non-speculative sequences when CONFIG_RETPOLINE is enabled. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: gnomes@lxorguk.ukuu.org.uk Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: thomas.lendacky@amd.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kees Cook <keescook@google.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Link: https://lkml.kernel.org/r/1515707194-20531-8-git-send-email-dwmw@amazon.co.uk Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Razvan Ghitulete <rga@amazon.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (cherry picked from commit f190ccc7f1fdd5eea12cdffc10332d8c715b7919) Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> --- arch/x86/entry/entry_32.S | 5 +++-- arch/x86/kernel/mcount_64.S | 7 ++++--- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 3a333cf85b78..49a8c9f7a379 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -863,7 +863,8 @@ trace: movl 0x4(%ebp), %edx subl $MCOUNT_INSN_SIZE, %eax - call *ftrace_trace_function + movl ftrace_trace_function, %ecx + CALL_NOSPEC %ecx popl %edx popl %ecx @@ -898,7 +899,7 @@ return_to_handler: movl %eax, %ecx popl %edx popl %eax - jmp *%ecx + JMP_NOSPEC %ecx #endif #ifdef CONFIG_TRACING diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S index 5d9afbcb6074..09284cfab86f 100644 --- a/arch/x86/kernel/mcount_64.S +++ b/arch/x86/kernel/mcount_64.S @@ -7,7 +7,7 @@ #include <linux/linkage.h> #include <asm/ptrace.h> #include <asm/ftrace.h> - +#include <asm/nospec-branch.h> .code64 .section .entry.text, "ax" @@ -285,8 +285,9 @@ trace: * ip and parent ip are used and the list function is called when * function tracing is enabled. */ - call *ftrace_trace_function + movq ftrace_trace_function, %r8 + CALL_NOSPEC %r8 restore_mcount_regs jmp fgraph_trace @@ -329,5 +330,5 @@ GLOBAL(return_to_handler) movq 8(%rsp), %rdx movq (%rsp), %rax addq $24, %rsp - jmp *%rdi + JMP_NOSPEC %rdi #endif -- 2.30.9