Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM updates from Russell King:
 "Low priority fixes and updates for ARM:

   - add some missing includes

   - efficiency improvements in system call entry code when tracing is
     enabled

   - ensure ARMv6+ is always built as EABI

   - export save_stack_trace_tsk()

   - fix fatal signal handling during mm fault

   - build translation table base address register from scratch

   - appropriately align the .data section to a word boundary where we
     rely on that data being word aligned"

* 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8691/1: Export save_stack_trace_tsk()
  ARM: 8692/1: mm: abort uaccess retries upon fatal signal
  ARM: 8690/1: lpae: build TTB control register value from scratch in v7_ttb_setup
  ARM: align .data section
  ARM: always enable AEABI for ARMv6+
  ARM: avoid saving and restoring registers unnecessarily
  ARM: move PC value into r9
  ARM: obtain thread info structure later
  ARM: use aliases for registers in entry-common
  ARM: 8689/1: scu: add missing errno include
  ARM: 8688/1: pm: add missing types include

arch/arm/kernel/entry-common.S

@@ -27,6 +27,14 @@
 
 #include "entry-header.S"
 
+saved_psr	.req	r8
+#if defined(CONFIG_TRACE_IRQFLAGS) || defined(CONFIG_CONTEXT_TRACKING)
+saved_pc	.req	r9
+#define TRACE(x...) x
+#else
+saved_pc	.req	lr
+#define TRACE(x...)
+#endif
 
 	.align	5
 #if !(IS_ENABLED(CONFIG_TRACE_IRQFLAGS) || IS_ENABLED(CONFIG_CONTEXT_TRACKING))
@@ -146,16 +154,17 @@ ENTRY(vector_swi)
  ARM(	stmdb	r8, {sp, lr}^		)	@ Calling sp, lr
  THUMB(	mov	r8, sp			)
  THUMB(	store_user_sp_lr r8, r10, S_SP	)	@ calling sp, lr
-	mrs	r8, spsr			@ called from non-FIQ mode, so ok.
-	str	lr, [sp, #S_PC]			@ Save calling PC
-	str	r8, [sp, #S_PSR]		@ Save CPSR
+	mrs	saved_psr, spsr			@ called from non-FIQ mode, so ok.
+ TRACE(	mov	saved_pc, lr		)
+	str	saved_pc, [sp, #S_PC]		@ Save calling PC
+	str	saved_psr, [sp, #S_PSR]		@ Save CPSR
 	str	r0, [sp, #S_OLD_R0]		@ Save OLD_R0
 #endif
 	zero_fp
 	alignment_trap r10, ip, __cr_alignment
-	enable_irq
-	ct_user_exit
-	get_thread_info tsk
+	asm_trace_hardirqs_on save=0
+	enable_irq_notrace
+	ct_user_exit save=0
 
 	/*
 	 * Get the system call number.
@@ -168,11 +177,11 @@ ENTRY(vector_swi)
 	 * value to determine if it is an EABI or an old ABI call.
 	 */
 #ifdef CONFIG_ARM_THUMB
-	tst	r8, #PSR_T_BIT
+	tst	saved_psr, #PSR_T_BIT
 	movne	r10, #0				@ no thumb OABI emulation
- USER(	ldreq	r10, [lr, #-4]		)	@ get SWI instruction
+ USER(	ldreq	r10, [saved_pc, #-4]	)	@ get SWI instruction
 #else
- USER(	ldr	r10, [lr, #-4]		)	@ get SWI instruction
+ USER(	ldr	r10, [saved_pc, #-4]	)	@ get SWI instruction
 #endif
  ARM_BE8(rev	r10, r10)			@ little endian instruction
 
@@ -183,15 +192,17 @@ ENTRY(vector_swi)
 	 */
 #elif defined(CONFIG_ARM_THUMB)
 	/* Legacy ABI only, possibly thumb mode. */
-	tst	r8, #PSR_T_BIT			@ this is SPSR from save_user_regs
+	tst	saved_psr, #PSR_T_BIT		@ this is SPSR from save_user_regs
 	addne	scno, r7, #__NR_SYSCALL_BASE	@ put OS number in
- USER(	ldreq	scno, [lr, #-4]		)
+ USER(	ldreq	scno, [saved_pc, #-4]	)
 
 #else
 	/* Legacy ABI only. */
- USER(	ldr	scno, [lr, #-4]		)	@ get SWI instruction
+ USER(	ldr	scno, [saved_pc, #-4]	)	@ get SWI instruction
 #endif
 
+	/* saved_psr and saved_pc are now dead */
+
 	uaccess_disable tbl
 
 	adr	tbl, sys_call_table		@ load syscall table pointer
@@ -210,6 +221,12 @@ ENTRY(vector_swi)
 	bic	scno, scno, #0xff000000		@ mask off SWI op-code
 	eor	scno, scno, #__NR_SYSCALL_BASE	@ check OS number
 #endif
+	get_thread_info tsk
+	/*
+	 * Reload the registers that may have been corrupted on entry to
+	 * the syscall assembly (by tracing or context tracking.)
+	 */
+ TRACE(	ldmia	sp, {r0 - r3}		)
 
 local_restart:
 	ldr	r10, [tsk, #TI_FLAGS]		@ check for syscall tracing
@@ -239,8 +256,9 @@ local_restart:
 	 * current task.
 	 */
 9001:
-	sub	lr, lr, #4
+	sub	lr, saved_pc, #4
 	str	lr, [sp, #S_PC]
+	get_thread_info tsk
 	b	ret_fast_syscall
 #endif
 ENDPROC(vector_swi)