From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
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 <arnd@arndb.de>,
Andy Lutomirski <luto@kernel.org>,
Balbir Singh <bsingharora@gmail.com>,
Borislav Petkov <bp@alien8.de>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Eugene Syromiatnikov <esyr@redhat.com>,
Florian Weimer <fweimer@redhat.com>,
"H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Kees Cook <keescook@chromium.org>,
Mike Kravetz <mike.kravetz@oracle.com>,
Nadav Amit <nadav.amit@gmail.com>,
Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>,
Peter Zijlstra <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>,
Dave Martin <Dave.Martin@arm.com>,
Weijiang Yang <weijiang.yang@intel.com>,
Pengfei Xu <pengfei.xu@intel.com>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v18 2/7] x86/cet/ibt: User-mode Indirect Branch Tracking support
Date: Wed, 27 Jan 2021 13:30:23 -0800 [thread overview]
Message-ID: <20210127213028.11362-3-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20210127213028.11362-1-yu-cheng.yu@intel.com>
Introduce user-mode Indirect Branch Tracking (IBT) support. Add routines
for the setup/disable of IBT.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
arch/x86/include/asm/cet.h | 3 +++
arch/x86/kernel/cet.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/arch/x86/include/asm/cet.h b/arch/x86/include/asm/cet.h
index 16870e5bc8eb..3a1cba579cb2 100644
--- a/arch/x86/include/asm/cet.h
+++ b/arch/x86/include/asm/cet.h
@@ -15,6 +15,7 @@ struct cet_status {
unsigned long shstk_base;
unsigned long shstk_size;
unsigned int locked:1;
+ unsigned int ibt_enabled:1;
};
#ifdef CONFIG_X86_CET
@@ -26,6 +27,8 @@ void cet_free_shstk(struct task_struct *p);
int cet_verify_rstor_token(bool ia32, unsigned long ssp, unsigned long *new_ssp);
void cet_restore_signal(struct sc_ext *sc);
int cet_setup_signal(bool ia32, unsigned long rstor, struct sc_ext *sc);
+int cet_setup_ibt(void);
+void cet_disable_ibt(void);
#else
static inline int prctl_cet(int option, u64 arg2) { return -EINVAL; }
static inline int cet_setup_thread_shstk(struct task_struct *p,
diff --git a/arch/x86/kernel/cet.c b/arch/x86/kernel/cet.c
index feb466dc2ea8..fff0b35ed0d9 100644
--- a/arch/x86/kernel/cet.c
+++ b/arch/x86/kernel/cet.c
@@ -13,6 +13,8 @@
#include <linux/uaccess.h>
#include <linux/sched/signal.h>
#include <linux/compat.h>
+#include <linux/vmalloc.h>
+#include <linux/bitops.h>
#include <asm/msr.h>
#include <asm/user.h>
#include <asm/fpu/internal.h>
@@ -341,3 +343,34 @@ int cet_setup_signal(bool ia32, unsigned long rstor_addr, struct sc_ext *sc_ext)
return 0;
}
+
+int cet_setup_ibt(void)
+{
+ u64 msr_val;
+
+ if (!static_cpu_has(X86_FEATURE_IBT))
+ return -EOPNOTSUPP;
+
+ start_update_msrs();
+ rdmsrl(MSR_IA32_U_CET, msr_val);
+ msr_val |= (CET_ENDBR_EN | CET_NO_TRACK_EN);
+ wrmsrl(MSR_IA32_U_CET, msr_val);
+ end_update_msrs();
+ current->thread.cet.ibt_enabled = 1;
+ return 0;
+}
+
+void cet_disable_ibt(void)
+{
+ u64 msr_val;
+
+ if (!static_cpu_has(X86_FEATURE_IBT))
+ return;
+
+ start_update_msrs();
+ rdmsrl(MSR_IA32_U_CET, msr_val);
+ msr_val &= ~CET_ENDBR_EN;
+ wrmsrl(MSR_IA32_U_CET, msr_val);
+ end_update_msrs();
+ current->thread.cet.ibt_enabled = 0;
+}
--
2.21.0
next prev parent reply other threads:[~2021-01-27 21:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-27 21:30 [PATCH v18 0/7] Control-flow Enforcement: Indirect Branch Tracking Yu-cheng Yu
2021-01-27 21:30 ` [PATCH v18 1/7] x86/cet/ibt: Update Kconfig for user-mode " Yu-cheng Yu
2021-01-27 21:30 ` Yu-cheng Yu [this message]
2021-01-27 21:30 ` [PATCH v18 3/7] x86/cet/ibt: Handle signals for " Yu-cheng Yu
2021-01-27 21:30 ` [PATCH v18 4/7] x86/cet/ibt: Update ELF header parsing " Yu-cheng Yu
2021-01-27 21:30 ` [PATCH v18 5/7] x86/cet/ibt: Update arch_prctl functions " Yu-cheng Yu
2021-01-27 21:30 ` [PATCH v18 6/7] x86/vdso/32: Add ENDBR32 to __kernel_vsyscall entry point Yu-cheng Yu
2021-01-27 21:30 ` [PATCH v18 7/7] x86/vdso: Insert endbr32/endbr64 to vDSO Yu-cheng Yu
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