From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: [PATCH v8 03/14] x86/cet/ibt: Handle signals for end branch Date: Tue, 13 Aug 2019 13:53:48 -0700 Message-ID: <20190813205359.12196-4-yu-cheng.yu@intel.com> References: <20190813205359.12196-1-yu-cheng.yu@intel.com> Return-path: In-Reply-To: <20190813205359.12196-1-yu-cheng.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org 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 Cc: Yu-cheng Yu List-Id: linux-api@vger.kernel.org Restore end branch tracking setting from thread header. Signed-off-by: Yu-cheng Yu --- arch/x86/kernel/cet.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/arch/x86/kernel/cet.c b/arch/x86/kernel/cet.c index 505a69f476e1..db542bd423cc 100644 --- a/arch/x86/kernel/cet.c +++ b/arch/x86/kernel/cet.c @@ -281,6 +281,15 @@ int cet_restore_signal(bool ia32, struct sc_ext *sc_ext) msr_ia32_u_cet |= MSR_IA32_CET_SHSTK_EN; } + if (current->thread.cet.ibt_enabled) { + if (current->thread.cet.ibt_bitmap_used) + msr_ia32_u_cet |= (IBT_BITMAP_ADDR | + MSR_IA32_CET_LEG_IW_EN); + + msr_ia32_u_cet |= (MSR_IA32_CET_ENDBR_EN | + MSR_IA32_CET_NO_TRACK_EN); + } + wrmsrl(MSR_IA32_PL3_SSP, new_ssp); wrmsrl(MSR_IA32_U_CET, msr_ia32_u_cet); return 0; @@ -321,6 +330,15 @@ int cet_setup_signal(bool ia32, unsigned long rstor_addr, struct sc_ext *sc_ext) sc_ext->ssp = new_ssp; } + if (current->thread.cet.ibt_enabled) { + if (current->thread.cet.ibt_bitmap_used) + msr_ia32_u_cet |= (IBT_BITMAP_ADDR | + MSR_IA32_CET_LEG_IW_EN); + + msr_ia32_u_cet |= (MSR_IA32_CET_ENDBR_EN | + MSR_IA32_CET_NO_TRACK_EN); + } + modify_fpu_regs_begin(); wrmsrl(MSR_IA32_PL3_SSP, ssp); wrmsrl(MSR_IA32_U_CET, msr_ia32_u_cet); -- 2.17.1