From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
x86@kernel.org, Dave Hansen <dave.hansen@linux.intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org,
Andy Lutomirski <luto@amacapital.net>,
Josh Triplett <josh@joshtriplett.org>,
Haitao Huang <haitao.huang@linux.intel.com>,
Jethro Beekman <jethro@fortanix.com>,
"Dr . Greg Wettstein" <greg@enjellic.com>
Subject: [RFC PATCH v5 2/5] x86/fault: Add helper function to sanitize error code
Date: Fri, 14 Dec 2018 13:57:26 -0800 [thread overview]
Message-ID: <20181214215729.4221-3-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20181214215729.4221-1-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. squashes
the signal when fixup is successful.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/mm/fault.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 7e8a7558ca07..fefeb745d21d 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -719,18 +719,22 @@ pgtable_bad(struct pt_regs *regs, unsigned long error_code,
oops_end(flags, regs, sig);
}
-static void set_signal_archinfo(unsigned long address,
- unsigned long error_code)
+static void sanitize_error_code(unsigned long address,
+ unsigned long *error_code)
{
- struct task_struct *tsk = current;
-
/*
* 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;
+ *error_code |= X86_PF_PROT;
+}
+
+static void set_signal_archinfo(unsigned long address,
+ unsigned long error_code)
+{
+ struct task_struct *tsk = current;
tsk->thread.trap_nr = X86_TRAP_PF;
tsk->thread.error_code = error_code | X86_PF_USER;
@@ -771,6 +775,8 @@ 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 +926,7 @@ __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 +1045,8 @@ 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
--
2.19.2
next prev parent reply other threads:[~2018-12-14 21:58 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-14 21:57 [RFC PATCH v5 0/5] x86: Add vDSO exception fixup for SGX Sean Christopherson
2018-12-14 21:57 ` [RFC PATCH v5 1/5] x86/vdso: Add support for exception fixup in vDSO functions Sean Christopherson
2018-12-14 21:57 ` Sean Christopherson [this message]
2018-12-14 21:57 ` [RFC PATCH v5 3/5] x86/fault: Attempt to fixup unhandled #PF on ENCLU before signaling Sean Christopherson
2018-12-14 21:57 ` [RFC PATCH v5 4/5] x86/traps: Attempt to fixup exceptions in vDSO " Sean Christopherson
2018-12-14 21:57 ` [RFC PATCH v5 5/5] x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave transitions Sean Christopherson
2018-12-19 9:21 ` Jarkko Sakkinen
2018-12-18 4:18 ` [RFC PATCH v5 0/5] x86: Add vDSO exception fixup for SGX Jarkko Sakkinen
2018-12-18 15:08 ` Sean Christopherson
2018-12-19 4:43 ` Jarkko Sakkinen
2018-12-19 5:03 ` Jarkko Sakkinen
2018-12-19 7:58 ` x86/sgx: uapi change proposal Jarkko Sakkinen
2018-12-19 8:41 ` Jethro Beekman
2018-12-19 9:11 ` Jarkko Sakkinen
2018-12-19 9:36 ` Jethro Beekman
2018-12-19 10:43 ` Jarkko Sakkinen
2018-12-19 14:45 ` Sean Christopherson
2018-12-20 2:58 ` Andy Lutomirski
2018-12-20 10:32 ` Jarkko Sakkinen
2018-12-20 13:12 ` Jarkko Sakkinen
2018-12-20 13:19 ` Jarkko Sakkinen
2018-12-22 8:16 ` Jarkko Sakkinen
[not found] ` <20181222082502.GA13275@linux.intel.com>
2018-12-23 12:52 ` Jarkko Sakkinen
2018-12-23 20:42 ` Andy Lutomirski
2018-12-24 11:52 ` Jarkko Sakkinen
2019-01-02 20:47 ` Sean Christopherson
2019-01-03 15:02 ` Jarkko Sakkinen
[not found] ` <20190103162634.GA8610@linux.intel.com>
2019-01-09 14:45 ` Jarkko Sakkinen
2018-12-21 16:28 ` Sean Christopherson
2018-12-21 17:12 ` Andy Lutomirski
2018-12-21 18:24 ` Sean Christopherson
2018-12-21 23:41 ` Jarkko Sakkinen
2018-12-23 20:41 ` Andy Lutomirski
2018-12-24 12:01 ` Jarkko Sakkinen
2018-12-21 23:37 ` Jarkko Sakkinen
2018-12-22 6:32 ` Jarkko Sakkinen
2019-01-08 19:27 ` Huang, Kai
2019-01-08 22:09 ` Sean Christopherson
2019-01-08 22:54 ` Andy Lutomirski
2019-01-09 16:31 ` Sean Christopherson
2019-01-10 21:34 ` Andy Lutomirski
2019-01-10 22:22 ` Huang, Kai
2019-01-10 23:54 ` Sean Christopherson
2019-01-11 0:30 ` Andy Lutomirski
2019-01-11 1:32 ` Sean Christopherson
2019-01-11 12:58 ` Jarkko Sakkinen
2019-01-11 13:00 ` Jarkko Sakkinen
2019-01-11 23:19 ` Sean Christopherson
2019-01-18 14:37 ` Jarkko Sakkinen
2019-01-10 17:45 ` Jarkko Sakkinen
2019-01-10 21:36 ` Andy Lutomirski
2019-01-11 16:07 ` Jarkko Sakkinen
2019-01-09 5:24 ` Huang, Kai
2019-01-09 17:16 ` Sean Christopherson
2019-01-10 0:21 ` Huang, Kai
2019-01-10 0:40 ` Sean Christopherson
2019-01-10 17:43 ` Jarkko Sakkinen
2018-12-20 10:30 ` Jarkko Sakkinen
2018-12-19 14:43 ` Dr. Greg
2018-12-20 10:34 ` Jarkko Sakkinen
2018-12-20 22:06 ` Dr. Greg
2018-12-21 13:48 ` Jarkko Sakkinen
2018-12-20 12:08 ` Arnd Bergmann
2018-12-20 12:49 ` 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=20181214215729.4221-3-sean.j.christopherson@intel.com \
--to=sean.j.christopherson@intel.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=greg@enjellic.com \
--cc=haitao.huang@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jethro@fortanix.com \
--cc=josh@joshtriplett.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sgx@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--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 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).