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

Pull x86 asm changes from Ingo Molnar:
 "There were lots of changes in this development cycle:

   - over 100 separate cleanups, restructuring changes, speedups and
     fixes in the x86 system call, irq, trap and other entry code, part
     of a heroic effort to deobfuscate a decade old spaghetti asm code
     and its C code dependencies (Denys Vlasenko, Andy Lutomirski)

   - alternatives code fixes and enhancements (Borislav Petkov)

   - simplifications and cleanups to the compat code (Brian Gerst)

   - signal handling fixes and new x86 testcases (Andy Lutomirski)

   - various other fixes and cleanups

  By their nature many of these changes are risky - we tried to test
  them well on many different x86 systems (there are no known
  regressions), and they are split up finely to help bisection - but
  there's still a fair bit of residual risk left so caveat emptor"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (148 commits)
  perf/x86/64: Report regs_user->ax too in get_regs_user()
  perf/x86/64: Simplify regs_user->abi setting code in get_regs_user()
  perf/x86/64: Do report user_regs->cx while we are in syscall, in get_regs_user()
  perf/x86/64: Do not guess user_regs->cs, ss, sp in get_regs_user()
  x86/asm/entry/32: Tidy up JNZ instructions after TESTs
  x86/asm/entry/64: Reduce padding in execve stubs
  x86/asm/entry/64: Remove GET_THREAD_INFO() in ret_from_fork
  x86/asm/entry/64: Simplify jumps in ret_from_fork
  x86/asm/entry/64: Remove a redundant jump
  x86/asm/entry/64: Optimize [v]fork/clone stubs
  x86/asm/entry: Zero EXTRA_REGS for stub32_execve() too
  x86/asm/entry/64: Move stub_x32_execvecloser() to stub_execveat()
  x86/asm/entry/64: Use common code for rt_sigreturn() epilogue
  x86/asm/entry/64: Add forgotten CFI annotation
  x86/asm/entry/irq: Simplify interrupt dispatch table (IDT) layout
  x86/asm/entry/64: Move opportunistic sysret code to syscall code path
  x86, selftests: Add sigreturn selftest
  x86/alternatives: Guard NOPs optimization
  x86/asm/entry: Clear EXTRA_REGS for all executable formats
  x86/signal: Remove pax argument from restore_sigcontext
  ...

1 files changed, 31 insertions, 62 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 31e2d5bf3e38..1c309763e321 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -395,10 +395,13 @@ sysenter_past_esp:
 	/*CFI_REL_OFFSET cs, 0*/
 	/*
 	 * Push current_thread_info()->sysenter_return to the stack.
-	 * A tiny bit of offset fixup is necessary - 4*4 means the 4 words
-	 * pushed above; +8 corresponds to copy_thread's esp0 setting.
+	 * A tiny bit of offset fixup is necessary: TI_sysenter_return
+	 * is relative to thread_info, which is at the bottom of the
+	 * kernel stack page.  4*4 means the 4 words pushed above;
+	 * TOP_OF_KERNEL_STACK_PADDING takes us to the top of the stack;
+	 * and THREAD_SIZE takes us to the bottom.
 	 */
-	pushl_cfi ((TI_sysenter_return)-THREAD_SIZE+8+4*4)(%esp)
+	pushl_cfi ((TI_sysenter_return) - THREAD_SIZE + TOP_OF_KERNEL_STACK_PADDING + 4*4)(%esp)
 	CFI_REL_OFFSET eip, 0
 
 	pushl_cfi %eax
@@ -432,7 +435,7 @@ sysenter_after_call:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $_TIF_ALLWORK_MASK, %ecx
-	jne sysexit_audit
+	jnz sysexit_audit
 sysenter_exit:
 /* if something modifies registers it must also disable sysexit */
 	movl PT_EIP(%esp), %edx
@@ -460,7 +463,7 @@ sysenter_audit:
 
 sysexit_audit:
 	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
-	jne syscall_exit_work
+	jnz syscall_exit_work
 	TRACE_IRQS_ON
 	ENABLE_INTERRUPTS(CLBR_ANY)
 	movl %eax,%edx		/* second arg, syscall return value */
@@ -472,7 +475,7 @@ sysexit_audit:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $(_TIF_ALLWORK_MASK & ~_TIF_SYSCALL_AUDIT), %ecx
-	jne syscall_exit_work
+	jnz syscall_exit_work
 	movl PT_EAX(%esp),%eax	/* reload syscall return value */
 	jmp sysenter_exit
 #endif
@@ -510,7 +513,7 @@ syscall_exit:
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testl $_TIF_ALLWORK_MASK, %ecx	# current->work
-	jne syscall_exit_work
+	jnz syscall_exit_work
 
 restore_all:
 	TRACE_IRQS_IRET
@@ -612,7 +615,7 @@ work_notifysig:				# deal with pending signals and
 #ifdef CONFIG_VM86
 	testl $X86_EFLAGS_VM, PT_EFLAGS(%esp)
 	movl %esp, %eax
-	jne work_notifysig_v86		# returning to kernel-space or
+	jnz work_notifysig_v86		# returning to kernel-space or
 					# vm86-space
 1:
 #else
@@ -720,43 +723,22 @@ END(sysenter_badsys)
 .endm
 
 /*
- * Build the entry stubs and pointer table with some assembler magic.
- * We pack 7 stubs into a single 32-byte chunk, which will fit in a
- * single cache line on all modern x86 implementations.
+ * Build the entry stubs with some assembler magic.
+ * We pack 1 stub into every 8-byte block.
  */
-.section .init.rodata,"a"
-ENTRY(interrupt)
-.section .entry.text, "ax"
-	.p2align 5
-	.p2align CONFIG_X86_L1_CACHE_SHIFT
+	.align 8
 ENTRY(irq_entries_start)
 	RING0_INT_FRAME
-vector=FIRST_EXTERNAL_VECTOR
-.rept (FIRST_SYSTEM_VECTOR-FIRST_EXTERNAL_VECTOR+6)/7
-	.balign 32
-  .rept	7
-    .if vector < FIRST_SYSTEM_VECTOR
-      .if vector <> FIRST_EXTERNAL_VECTOR
+    vector=FIRST_EXTERNAL_VECTOR
+    .rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
+	pushl_cfi $(~vector+0x80)	/* Note: always in signed byte range */
+    vector=vector+1
+	jmp	common_interrupt
 	CFI_ADJUST_CFA_OFFSET -4
-      .endif
-1:	pushl_cfi $(~vector+0x80)	/* Note: always in signed byte range */
-      .if ((vector-FIRST_EXTERNAL_VECTOR)%7) <> 6
-	jmp 2f
-      .endif
-      .previous
-	.long 1b
-      .section .entry.text, "ax"
-vector=vector+1
-    .endif
-  .endr
-2:	jmp common_interrupt
-.endr
+	.align	8
+    .endr
 END(irq_entries_start)
 
-.previous
-END(interrupt)
-.previous
-
 /*
  * the CPU automatically disables interrupts when executing an IRQ vector,
  * so IRQ-flags tracing has to follow that:
@@ -816,15 +798,9 @@ ENTRY(simd_coprocessor_error)
 	pushl_cfi $0
 #ifdef CONFIG_X86_INVD_BUG
 	/* AMD 486 bug: invd from userspace calls exception 19 instead of #GP */
-661:	pushl_cfi $do_general_protection
-662:
-.section .altinstructions,"a"
-	altinstruction_entry 661b, 663f, X86_FEATURE_XMM, 662b-661b, 664f-663f
-.previous
-.section .altinstr_replacement,"ax"
-663:	pushl $do_simd_coprocessor_error
-664:
-.previous
+	ALTERNATIVE "pushl_cfi $do_general_protection",	\
+		    "pushl $do_simd_coprocessor_error", \
+		    X86_FEATURE_XMM
 #else
 	pushl_cfi $do_simd_coprocessor_error
 #endif
@@ -1240,20 +1216,13 @@ error_code:
 	/*CFI_REL_OFFSET es, 0*/
 	pushl_cfi %ds
 	/*CFI_REL_OFFSET ds, 0*/
-	pushl_cfi %eax
-	CFI_REL_OFFSET eax, 0
-	pushl_cfi %ebp
-	CFI_REL_OFFSET ebp, 0
-	pushl_cfi %edi
-	CFI_REL_OFFSET edi, 0
-	pushl_cfi %esi
-	CFI_REL_OFFSET esi, 0
-	pushl_cfi %edx
-	CFI_REL_OFFSET edx, 0
-	pushl_cfi %ecx
-	CFI_REL_OFFSET ecx, 0
-	pushl_cfi %ebx
-	CFI_REL_OFFSET ebx, 0
+	pushl_cfi_reg eax
+	pushl_cfi_reg ebp
+	pushl_cfi_reg edi
+	pushl_cfi_reg esi
+	pushl_cfi_reg edx
+	pushl_cfi_reg ecx
+	pushl_cfi_reg ebx
 	cld
 	movl $(__KERNEL_PERCPU), %ecx
 	movl %ecx, %fs