lkml.org 
[lkml]   [2018]   [Dec]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH v3 2/4] x86/fault: Attempt to fixup unhandled #PF on ENCLU before signaling
Date
Call fixup_sgx_enclu_exception() in the SIGSEGV and SIGBUS paths of
the page fault handler immediately prior to signaling. If the fault
is fixed, return cleanly and do not generate a signal.

In the SIGSEGV flow, make sure the error code passed to userspace has
been sanitized.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/mm/fault.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 7e8a7558ca07..d3903965334c 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -28,6 +28,7 @@
#include <asm/mmu_context.h> /* vma_pkey() */
#include <asm/efi.h> /* efi_recover_from_page_fault()*/
#include <asm/desc.h> /* store_idt(), ... */
+#include <asm/sgx.h> /* fixup_sgx_enclu_exception() */

#define CREATE_TRACE_POINTS
#include <asm/trace/exceptions.h>
@@ -928,6 +929,9 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
if (address >= TASK_SIZE_MAX)
error_code |= X86_PF_PROT;

+ if (fixup_sgx_enclu_exception(regs, X86_TRAP_PF, error_code, address))
+ return;
+
if (likely(show_unhandled_signals))
show_signal_msg(regs, error_code, address, tsk);

@@ -1045,6 +1049,9 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
if (is_prefetch(regs, error_code, address))
return;

+ if (fixup_sgx_enclu_exception(regs, X86_TRAP_PF, error_code, address))
+ return;
+
set_signal_archinfo(address, error_code);

#ifdef CONFIG_MEMORY_FAILURE
--
2.19.2
\
 
 \ /
  Last update: 2018-12-11 00:22    [W:0.129 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site