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>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v10 04/26] x86/cet: Add control-protection fault handler
Date: Wed, 29 Apr 2020 15:07:10 -0700 [thread overview]
Message-ID: <20200429220732.31602-5-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20200429220732.31602-1-yu-cheng.yu@intel.com>
A control-protection fault is triggered when a control-flow transfer
attempt violates Shadow Stack or Indirect Branch Tracking constraints.
For example, the return address for a RET instruction differs from the copy
on the Shadow Stack; or an indirect JMP instruction, without the NOTRACK
prefix, arrives at a non-ENDBR opcode.
The control-protection fault handler works in a similar way as the general
protection fault handler. It provides the si_code SEGV_CPERR to the signal
handler.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
---
v10:
- Change CONFIG_X86_64 to CONFIG_X86_INTEL_CET.
v9:
- Add Shadow Stack pointer to the fault printout.
arch/x86/entry/entry_64.S | 2 +-
arch/x86/include/asm/traps.h | 5 +++
arch/x86/kernel/idt.c | 4 ++
arch/x86/kernel/signal_compat.c | 2 +-
arch/x86/kernel/traps.c | 59 ++++++++++++++++++++++++++++++
include/uapi/asm-generic/siginfo.h | 3 +-
6 files changed, 72 insertions(+), 3 deletions(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 0e9504fabe52..f42780922387 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1034,7 +1034,7 @@ idtentry spurious_interrupt_bug do_spurious_interrupt_bug has_error_code=0
idtentry coprocessor_error do_coprocessor_error has_error_code=0
idtentry alignment_check do_alignment_check has_error_code=1
idtentry simd_coprocessor_error do_simd_coprocessor_error has_error_code=0
-
+idtentry control_protection do_control_protection has_error_code=1
/*
* Reload gs selector with exception handling
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index c26a7e1d8a2c..9bf804709ee6 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -35,6 +35,9 @@ asmlinkage void alignment_check(void);
asmlinkage void machine_check(void);
#endif /* CONFIG_X86_MCE */
asmlinkage void simd_coprocessor_error(void);
+#ifdef CONFIG_X86_INTEL_CET
+asmlinkage void control_protection(void);
+#endif
#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
asmlinkage void xen_divide_error(void);
@@ -86,6 +89,7 @@ dotraplinkage void do_simd_coprocessor_error(struct pt_regs *regs, long error_co
dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code);
#endif
dotraplinkage void do_mce(struct pt_regs *regs, long error_code);
+dotraplinkage void do_control_protection(struct pt_regs *regs, long error_code);
#ifdef CONFIG_X86_64
asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs);
@@ -151,6 +155,7 @@ enum {
X86_TRAP_AC, /* 17, Alignment Check */
X86_TRAP_MC, /* 18, Machine Check */
X86_TRAP_XF, /* 19, SIMD Floating-Point Exception */
+ X86_TRAP_CP = 21, /* 21 Control Protection Fault */
X86_TRAP_IRET = 32, /* 32, IRET Exception */
};
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 87ef69a72c52..19160c8d734f 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -102,6 +102,10 @@ static const __initconst struct idt_data def_idts[] = {
#elif defined(CONFIG_X86_32)
SYSG(IA32_SYSCALL_VECTOR, entry_INT80_32),
#endif
+
+#ifdef CONFIG_X86_INTEL_CET
+ INTG(X86_TRAP_CP, control_protection),
+#endif
};
/*
diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index 9ccbf0576cd0..c572a3de1037 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -27,7 +27,7 @@ static inline void signal_compat_build_tests(void)
*/
BUILD_BUG_ON(NSIGILL != 11);
BUILD_BUG_ON(NSIGFPE != 15);
- BUILD_BUG_ON(NSIGSEGV != 7);
+ BUILD_BUG_ON(NSIGSEGV != 8);
BUILD_BUG_ON(NSIGBUS != 5);
BUILD_BUG_ON(NSIGTRAP != 5);
BUILD_BUG_ON(NSIGCHLD != 6);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index d54cffdc7cac..d2515dfbc178 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -586,6 +586,65 @@ dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code)
}
NOKPROBE_SYMBOL(do_general_protection);
+static const char * const control_protection_err[] = {
+ "unknown",
+ "near-ret",
+ "far-ret/iret",
+ "endbranch",
+ "rstorssp",
+ "setssbsy",
+};
+
+/*
+ * When a control protection exception occurs, send a signal
+ * to the responsible application. Currently, control
+ * protection is only enabled for the user mode. This
+ * exception should not come from the kernel mode.
+ */
+dotraplinkage void
+do_control_protection(struct pt_regs *regs, long error_code)
+{
+ struct task_struct *tsk;
+
+ RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
+ if (notify_die(DIE_TRAP, "control protection fault", regs,
+ error_code, X86_TRAP_CP, SIGSEGV) == NOTIFY_STOP)
+ return;
+ cond_local_irq_enable(regs);
+
+ if (!user_mode(regs))
+ die("kernel control protection fault", regs, error_code);
+
+ if (!static_cpu_has(X86_FEATURE_SHSTK) &&
+ !static_cpu_has(X86_FEATURE_IBT))
+ WARN_ONCE(1, "CET is disabled but got control protection fault\n");
+
+ tsk = current;
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_nr = X86_TRAP_CP;
+
+ if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
+ printk_ratelimit()) {
+ unsigned int max_err;
+ unsigned long ssp;
+
+ max_err = ARRAY_SIZE(control_protection_err) - 1;
+ if ((error_code < 0) || (error_code > max_err))
+ error_code = 0;
+ rdmsrl(MSR_IA32_PL3_SSP, ssp);
+ pr_info("%s[%d] control protection ip:%lx sp:%lx ssp:%lx error:%lx(%s)",
+ tsk->comm, task_pid_nr(tsk),
+ regs->ip, regs->sp, ssp, error_code,
+ control_protection_err[error_code]);
+ print_vma_addr(KERN_CONT " in ", regs->ip);
+ pr_cont("\n");
+ }
+
+ force_sig_fault(SIGSEGV, SEGV_CPERR,
+ (void __user *)uprobe_get_trap_addr(regs));
+}
+NOKPROBE_SYMBOL(do_control_protection);
+
dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
{
if (poke_int3_handler(regs))
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index cb3d6c267181..693071dbe641 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -229,7 +229,8 @@ typedef struct siginfo {
#define SEGV_ACCADI 5 /* ADI not enabled for mapped object */
#define SEGV_ADIDERR 6 /* Disrupting MCD error */
#define SEGV_ADIPERR 7 /* Precise MCD exception */
-#define NSIGSEGV 7
+#define SEGV_CPERR 8
+#define NSIGSEGV 8
/*
* SIGBUS si_codes
--
2.21.0
next prev parent reply other threads:[~2020-04-29 22:10 UTC|newest]
Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-29 22:07 [PATCH v10 00/26] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 01/26] Documentation/x86: Add CET description Yu-cheng Yu
2020-04-29 22:53 ` Dave Hansen
2020-04-29 23:02 ` Yu-cheng Yu
2020-05-12 23:20 ` Yu-cheng Yu
2020-05-15 18:39 ` Dave Hansen
2020-05-15 21:33 ` Yu-cheng Yu
2020-05-15 22:43 ` Dave Hansen
2020-05-15 23:29 ` Yu-cheng Yu
2020-05-15 23:56 ` Dave Hansen
2020-05-16 2:51 ` H.J. Lu
2020-05-17 23:09 ` Dave Hansen
2020-05-16 2:53 ` Yu-cheng Yu
2020-05-18 13:41 ` Dave Hansen
2020-05-18 14:01 ` H.J. Lu
2020-05-18 14:26 ` Dave Hansen
2020-05-18 14:21 ` Yu-cheng Yu
2020-05-18 23:47 ` Yu-cheng Yu
2020-05-19 0:38 ` Dave Hansen
2020-05-19 1:35 ` Andy Lutomirski
2020-05-20 1:04 ` Andy Lutomirski
2020-05-29 2:08 ` Yu-cheng Yu
2020-05-16 0:13 ` Andrew Cooper
2020-05-16 2:37 ` H.J. Lu
2020-05-16 14:09 ` Andrew Cooper
2020-05-22 16:49 ` Peter Zijlstra
2020-05-22 17:48 ` Andrew Cooper
2020-04-29 22:07 ` [PATCH v10 02/26] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 03/26] x86/fpu/xstate: Introduce CET MSR XSAVES supervisor states Yu-cheng Yu
2020-07-23 16:10 ` Sean Christopherson
2020-07-23 16:21 ` Yu-cheng Yu
2020-04-29 22:07 ` Yu-cheng Yu [this message]
2020-04-29 22:07 ` [PATCH v10 05/26] x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack Yu-cheng Yu
2020-05-07 15:55 ` Dave Hansen
2020-05-07 16:59 ` Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 06/26] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 07/26] x86/mm: Remove _PAGE_DIRTY_HW from kernel RO pages Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 08/26] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 09/26] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 10/26] x86/mm: Update pte_modify for _PAGE_COW Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 11/26] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY_HW to _PAGE_COW Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 12/26] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 13/26] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 14/26] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 15/26] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 16/26] mm: Add guard pages around a shadow stack Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 17/26] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 18/26] mm: Update can_follow_write_pte() for shadow stack Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 19/26] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 20/26] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 21/26] ELF: UAPI and Kconfig additions for ELF program properties Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 22/26] ELF: Add ELF program property parsing support Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 23/26] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 24/26] x86/cet/shstk: ELF header parsing for shadow stack Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 25/26] x86/cet/shstk: Handle thread " Yu-cheng Yu
2020-04-29 22:07 ` [PATCH v10 26/26] x86/cet/shstk: Add arch_prctl functions for " Yu-cheng Yu
2020-05-21 22:42 ` Kees Cook
2020-05-22 17:17 ` Yu-cheng Yu
2020-05-22 17:29 ` Eugene Syromiatnikov
2020-05-22 18:13 ` Yu-cheng Yu
2020-05-21 15:15 ` [PATCH v10 00/26] Control-flow Enforcement: Shadow Stack Josh Poimboeuf
2020-05-21 15:57 ` Yu-cheng Yu
2020-05-21 18:50 ` Josh Poimboeuf
2020-05-21 19:08 ` Yu-cheng Yu
2020-07-23 16:25 ` Sean Christopherson
2020-07-23 16:41 ` Dave Hansen
2020-07-23 16:56 ` Sean Christopherson
2020-07-23 18:41 ` Dave Hansen
2020-07-24 3:40 ` Yu-cheng Yu
2020-07-24 4:50 ` Sean Christopherson
2020-07-24 4:59 ` Sean Christopherson
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200429220732.31602-5-yu-cheng.yu@intel.com \
--to=yu-cheng.yu@intel.com \
--cc=Dave.Martin@arm.com \
--cc=arnd@arndb.de \
--cc=bp@alien8.de \
--cc=bsingharora@gmail.com \
--cc=corbet@lwn.net \
--cc=dave.hansen@linux.intel.com \
--cc=esyr@redhat.com \
--cc=fweimer@redhat.com \
--cc=gorcunov@gmail.com \
--cc=hjl.tools@gmail.com \
--cc=hpa@zytor.com \
--cc=jannh@google.com \
--cc=keescook@chromium.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mike.kravetz@oracle.com \
--cc=mingo@redhat.com \
--cc=nadav.amit@gmail.com \
--cc=oleg@redhat.com \
--cc=pavel@ucw.cz \
--cc=peterz@infradead.org \
--cc=ravi.v.shankar@intel.com \
--cc=rdunlap@infradead.org \
--cc=tglx@linutronix.de \
--cc=vedvyas.shanbhogue@intel.com \
--cc=weijiang.yang@intel.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).