Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Misc smaller fixes that missed the v3.17 cycle"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Add arch/x86/purgatory/ make generated files to gitignore
  x86: Fix section conflict for numachip
  x86: Reject x32 executables if x32 ABI not supported
  x86_64, entry: Filter RFLAGS.NT on entry from userspace
  x86, boot, kaslr: Fix nuisance warning on 32-bit builds

1 files changed, 17 insertions, 1 deletions

diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 4299eb05023c..711de084ab57 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -151,6 +151,16 @@ ENTRY(ia32_sysenter_target)
 1:      movl    (%rbp),%ebp
         _ASM_EXTABLE(1b,ia32_badarg)
         ASM_CLAC
+
+        /*
+         * Sysenter doesn't filter flags, so we need to clear NT
+         * ourselves.  To save a few cycles, we can check whether
+         * NT was set instead of doing an unconditional popfq.
+         */
+        testl $X86_EFLAGS_NT,EFLAGS(%rsp)       /* saved EFLAGS match cpu */
+        jnz sysenter_fix_flags
+sysenter_flags_fixed:
+
         orl     $TS_COMPAT,TI_status+THREAD_INFO(%rsp,RIP-ARGOFFSET)
         testl   $_TIF_WORK_SYSCALL_ENTRY,TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)
         CFI_REMEMBER_STATE
@@ -184,6 +194,8 @@ sysexit_from_sys_call:
         TRACE_IRQS_ON
         ENABLE_INTERRUPTS_SYSEXIT32
 
+        CFI_RESTORE_STATE
+
 #ifdef CONFIG_AUDITSYSCALL
         .macro auditsys_entry_common
         movl %esi,%r9d                  /* 6th arg: 4th syscall arg */
@@ -226,7 +238,6 @@ sysexit_from_sys_call:
         .endm
 
 sysenter_auditsys:
-        CFI_RESTORE_STATE
         auditsys_entry_common
         movl %ebp,%r9d                  /* reload 6th syscall arg */
         jmp sysenter_dispatch
@@ -235,6 +246,11 @@ sysexit_audit:
         auditsys_exit sysexit_from_sys_call
 #endif
 
+sysenter_fix_flags:
+        pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_FIXED)
+        popfq_cfi
+        jmp sysenter_flags_fixed
+
 sysenter_tracesys:
 #ifdef CONFIG_AUDITSYSCALL
         testl   $(_TIF_WORK_SYSCALL_ENTRY & ~_TIF_SYSCALL_AUDIT),TI_flags+THREAD_INFO(%rsp,RIP-ARGOFFSET)