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From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org
Cc: akpm@linux-foundation.org, dave.hansen@intel.com,
	sean.j.christopherson@intel.com, nhorman@redhat.com,
	npmccallum@redhat.com, serge.ayoun@intel.com,
	shay.katz-zamir@intel.com, haitao.huang@intel.com,
	andriy.shevchenko@linux.intel.com, tglx@linutronix.de,
	kai.svahn@intel.com, bp@alien8.de, josh@joshtriplett.org,
	luto@kernel.org, kai.huang@intel.com, rientjes@google.com
Subject: [PATCH v19,RESEND 21/27] x86/fault: Add helper function to sanitize error code
Date: Wed, 20 Mar 2019 18:21:13 +0200	[thread overview]
Message-ID: <20190320162119.4469-22-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20190320162119.4469-1-jarkko.sakkinen@linux.intel.com>

From: Sean Christopherson <sean.j.christopherson@intel.com>

...to prepare for vDSO exception fixup, which will expose the error code
to userspace and runs before set_signal_archinfo(), i.e. suppresses the
signal when fixup is successful.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/mm/fault.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 78e2807fbede..5babd515f616 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -719,6 +719,18 @@ pgtable_bad(struct pt_regs *regs, unsigned long error_code,
 	oops_end(flags, regs, sig);
 }
 
+static void sanitize_error_code(unsigned long address,
+				unsigned long *error_code)
+{
+	/*
+	 * To avoid leaking information about the kernel page
+	 * table layout, pretend that user-mode accesses to
+	 * kernel addresses are always protection faults.
+	 */
+	if (address >= TASK_SIZE_MAX)
+		*error_code |= X86_PF_PROT;
+}
+
 static void set_signal_archinfo(unsigned long address,
 				unsigned long error_code)
 {
@@ -771,6 +783,8 @@ no_context(struct pt_regs *regs, unsigned long error_code,
 		 * faulting through the emulate_vsyscall() logic.
 		 */
 		if (current->thread.sig_on_uaccess_err && signal) {
+			sanitize_error_code(address, &error_code);
+
 			set_signal_archinfo(address, error_code);
 
 			/* XXX: hwpoison faults will set the wrong code. */
@@ -920,13 +934,7 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
 		if (is_errata100(regs, address))
 			return;
 
-		/*
-		 * To avoid leaking information about the kernel page table
-		 * layout, pretend that user-mode accesses to kernel addresses
-		 * are always protection faults.
-		 */
-		if (address >= TASK_SIZE_MAX)
-			error_code |= X86_PF_PROT;
+		sanitize_error_code(address, &error_code);
 
 		if (likely(show_unhandled_signals))
 			show_signal_msg(regs, error_code, address, tsk);
@@ -1045,6 +1053,8 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
 	if (is_prefetch(regs, error_code, address))
 		return;
 
+	sanitize_error_code(address, &error_code);
+
 	set_signal_archinfo(address, error_code);
 
 #ifdef CONFIG_MEMORY_FAILURE
-- 
2.19.1


  parent reply	other threads:[~2019-03-20 16:25 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-20 16:20 [PATCH v19,RESEND 00/27] Intel SGX1 support Jarkko Sakkinen
2019-03-20 16:20 ` [PATCH v19,RESEND 01/27] x86/cpufeatures: Add Intel-defined SGX feature bit Jarkko Sakkinen
2019-03-20 19:41   ` Neil Horman
2019-03-21 14:16     ` Jarkko Sakkinen
2019-03-20 16:20 ` [PATCH v19,RESEND 02/27] x86/cpufeatures: Add SGX sub-features (as Linux-defined bits) Jarkko Sakkinen
2019-03-20 16:20 ` [PATCH v19,RESEND 03/27] x86/msr: Add IA32_FEATURE_CONTROL.SGX_ENABLE definition Jarkko Sakkinen
2019-03-20 16:20 ` [PATCH v19,RESEND 04/27] x86/cpufeatures: Add Intel-defined SGX_LC feature bit Jarkko Sakkinen
2019-03-20 16:20 ` [PATCH v19,RESEND 05/27] x86/msr: Add SGX Launch Control MSR definitions Jarkko Sakkinen
2019-03-20 16:20 ` [PATCH v19,RESEND 06/27] x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit Jarkko Sakkinen
2019-03-20 16:20 ` [PATCH v19,RESEND 07/27] x86/mm: x86/sgx: Signal SIGSEGV for userspace #PFs w/ PF_SGX Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 08/27] x86/cpu/intel: Detect SGX support and update caps appropriately Jarkko Sakkinen
2019-03-26 12:17   ` Huang, Kai
2019-03-26 14:27     ` Sean Christopherson
2019-03-26 21:25       ` Huang, Kai
2019-03-26 21:57         ` Sean Christopherson
2019-03-26 23:19           ` Huang, Kai
2019-03-20 16:21 ` [PATCH v19,RESEND 09/27] x86/sgx: Add ENCLS architectural error codes Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 10/27] x86/sgx: Add SGX1 and SGX2 architectural data structures Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 11/27] x86/sgx: Add definitions for SGX's CPUID leaf and variable sub-leafs Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 12/27] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 13/27] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 14/27] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 15/27] x86/sgx: Add sgx_einit() for initializing enclaves Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 16/27] x86/sgx: Add the Linux SGX Enclave Driver Jarkko Sakkinen
2019-03-26 12:01   ` Huang, Kai
2019-03-26 12:40     ` Thomas Gleixner
2019-03-26 14:54       ` Sean Christopherson
2019-03-26 21:11         ` Huang, Kai
2019-03-27  5:02     ` Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 17/27] x86/sgx: Add provisioning Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 18/27] x86/sgx: Add swapping code to the core and SGX driver Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 19/27] x86/sgx: ptrace() support for the " Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 20/27] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2019-03-20 16:21 ` Jarkko Sakkinen [this message]
2019-03-20 16:21 ` [PATCH v19,RESEND 22/27] x86/fault: Attempt to fixup unhandled #PF in vDSO before signaling Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 23/27] x86/traps: Attempt to fixup exceptions " Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 24/27] x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave transitions Jarkko Sakkinen
2019-03-20 18:30   ` Xing, Cedric
2019-03-20 18:52     ` Andy Lutomirski
2019-03-20 19:57       ` Xing, Cedric
2019-03-20 21:03         ` Sean Christopherson
2019-03-21  0:17           ` Xing, Cedric
2019-03-22 21:20             ` Sean Christopherson
2019-03-21 17:17         ` Andy Lutomirski
2019-03-22 20:31           ` Xing, Cedric
2019-03-20 19:02     ` Jethro Beekman
2019-03-20 20:10       ` Xing, Cedric
2019-03-20 19:13     ` Sean Christopherson
2019-03-20 20:38       ` Xing, Cedric
2019-03-22 21:59         ` Sean Christopherson
2019-03-23 17:36           ` Xing, Cedric
2019-03-23 21:38             ` Andy Lutomirski
2019-03-24  8:59               ` Xing, Cedric
2019-03-25 18:03                 ` Sean Christopherson
2019-03-25 23:59                   ` Andy Lutomirski
2019-03-26  4:53                     ` Xing, Cedric
2019-03-26 17:08                       ` Andy Lutomirski
2019-03-28  4:23                         ` Xing, Cedric
2019-03-28 19:18                           ` Andy Lutomirski
2019-03-28 23:19                             ` Xing, Cedric
2019-03-29  9:48                               ` Jarkko Sakkinen
2019-03-31  8:43                                 ` Dr. Greg
2019-04-03 23:03                             ` Sean Christopherson
2019-03-25 23:54                 ` Andy Lutomirski
2019-03-26  4:16                   ` Xing, Cedric
2019-03-20 16:21 ` [PATCH v19,RESEND 25/27] x86/sgx: SGX documentation Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 26/27] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2019-03-20 16:21 ` [PATCH v19,RESEND 27/27] x86/sgx: Update MAINTAINERS Jarkko Sakkinen

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