From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: x86@kernel.org, linux-sgx@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Sean Christopherson <sean.j.christopherson@intel.com>,
Jethro Beekman <jethro@fortanix.com>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com,
asapek@google.com, bp@alien8.de, cedric.xing@intel.com,
chenalexchen@google.com, conradparker@google.com,
cyhanish@google.com, dave.hansen@intel.com,
haitao.huang@intel.com, josh@joshtriplett.org,
kai.huang@intel.com, kai.svahn@intel.com, kmoy@google.com,
ludloff@google.com, luto@kernel.org, nhorman@redhat.com,
npmccallum@redhat.com, puiterwijk@redhat.com,
rientjes@google.com, tglx@linutronix.de, yaozhangx@google.com
Subject: [PATCH v35 19/24] x86/fault: Add helper function to sanitize error code
Date: Tue, 7 Jul 2020 06:37:42 +0300 [thread overview]
Message-ID: <20200707033747.142828-20-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20200707033747.142828-1-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.
Acked-by: Jethro Beekman <jethro@fortanix.com>
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 1db6fbd7af8e..8ba78384ea73 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -556,6 +556,18 @@ 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)
{
@@ -612,6 +624,8 @@ 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. */
@@ -760,13 +774,7 @@ __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);
@@ -885,6 +893,8 @@ 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
--
2.25.1
next prev parent reply other threads:[~2020-07-07 3:42 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 3:37 [PATCH v35 00/24] Intel SGX foundations Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 01/24] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 02/24] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 03/24] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 04/24] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 05/24] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 06/24] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 07/24] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 08/24] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 09/24] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page() Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 10/24] mm: Add vm_ops->mprotect() Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 11/24] x86/sgx: Add SGX enclave driver Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 12/24] x86/sgx: Add SGX_IOC_ENCLAVE_CREATE Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 13/24] x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 14/24] x86/sgx: Add SGX_IOC_ENCLAVE_INIT Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 15/24] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 16/24] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 17/24] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 18/24] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-07-07 3:37 ` Jarkko Sakkinen [this message]
2020-07-07 3:37 ` [PATCH v35 20/24] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 21/24] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-07-14 7:30 ` Jethro Beekman
2020-07-14 9:56 ` Jarkko Sakkinen
2020-07-14 10:07 ` Jethro Beekman
2020-07-14 11:38 ` Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 22/24] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-07-07 3:37 ` [PATCH v35 23/24] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-07-07 4:06 ` Matthew Wilcox
2020-07-07 3:37 ` [PATCH v35 24/24] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
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