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, 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,
cedric.xing@intel.com, puiterwijk@redhat.com,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Subject: [PATCH v25 17/21] x86/fault: Add helper function to sanitize error code
Date: Tue, 4 Feb 2020 08:05:41 +0200 [thread overview]
Message-ID: <20200204060545.31729-18-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20200204060545.31729-1-jarkko.sakkinen@linux.intel.com>
From: Sean Christopherson <sean.j.christopherson@intel.com>
Add helper function to sanitize error code 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>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.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 dee9504cde79..6b662d272af6 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -682,6 +682,18 @@ 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)
{
@@ -738,6 +750,8 @@ 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. */
@@ -886,13 +900,7 @@ __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);
@@ -1009,6 +1017,8 @@ 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
--
2.20.1
next prev parent reply other threads:[~2020-02-04 6:07 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-04 6:05 [PATCH v25 00/21] Intel SGX foundations Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 01/21] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 02/21] x86/cpufeatures: x86/msr: Intel SGX Launch Control " Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 03/21] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 04/21] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 05/21] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 06/21] x86/cpu/intel: Detect SGX supprt Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 07/21] x86/sgx: Enumerate and track EPC sections Jarkko Sakkinen
2020-02-05 19:57 ` Sean Christopherson
2020-02-05 23:11 ` Jarkko Sakkinen
2020-02-06 15:34 ` Jarkko Sakkinen
2020-02-06 15:35 ` Jarkko Sakkinen
2020-02-06 15:55 ` Sean Christopherson
2020-02-04 6:05 ` [PATCH v25 08/21] x86/sgx: Add functions to allocate and free EPC pages Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 09/21] mm: Introduce vm_ops->may_mprotect() Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 10/21] x86/sgx: Linux Enclave Driver Jarkko Sakkinen
2020-02-04 6:18 ` Jarkko Sakkinen
2020-02-05 15:58 ` Haitao Huang
2020-02-07 17:03 ` Haitao Huang
2020-02-04 6:05 ` [PATCH v25 11/21] selftests/x86: Recurse into subdirectories Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 12/21] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 13/21] x86/sgx: Add provisioning Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 14/21] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 15/21] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 16/21] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-02-04 6:05 ` Jarkko Sakkinen [this message]
2020-02-04 6:05 ` [PATCH v25 18/21] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 19/21] x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave transitions Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 20/21] selftests/x86: Add vDSO selftest for SGX Jarkko Sakkinen
2020-02-04 6:05 ` [PATCH v25 21/21] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-02-05 17:54 ` Randy Dunlap
2020-02-05 23:07 ` Jarkko Sakkinen
2020-02-05 23:10 ` Randy Dunlap
2020-02-06 14:50 ` Jarkko Sakkinen
2020-02-04 15:11 ` [PATCH v25 00/21] Intel SGX foundations Sean Christopherson
2020-02-05 21:59 ` Jarkko Sakkinen
2020-02-05 23:09 ` Jarkko Sakkinen
2020-02-05 16:01 ` Haitao Huang
2020-02-05 22:01 ` Jarkko Sakkinen
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