All of lore.kernel.org
 help / color / mirror / Atom feed
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


  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

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=20200204060545.31729-18-jarkko.sakkinen@linux.intel.com \
    --to=jarkko.sakkinen@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=bp@alien8.de \
    --cc=cedric.xing@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=haitao.huang@intel.com \
    --cc=josh@joshtriplett.org \
    --cc=kai.huang@intel.com \
    --cc=kai.svahn@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sgx@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=nhorman@redhat.com \
    --cc=npmccallum@redhat.com \
    --cc=puiterwijk@redhat.com \
    --cc=rientjes@google.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=tglx@linutronix.de \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.