ia64: Add unwcheck.sh script contributed by Harish Patil. It checks

	the unwind info for consistency (well, just the obvious
	stuff, but it's a start).
	Fix the couple of bugs that this script uncovered (and work
	around one false positive).

arch/ia64/Makefile

@@ -58,6 +58,9 @@ all compressed: vmlinux.gz
 vmlinux.gz: vmlinux
 	$(call makeboot,vmlinux.gz)
 
+check: vmlinux
+	arch/ia64/scripts/unwcheck.sh vmlinux
+
 archmrproper:
 archclean:
 	$(Q)$(MAKE) -f scripts/Makefile.clean obj=arch/ia64/boot

arch/ia64/ia32/ia32_entry.S

@@ -95,12 +95,19 @@ END(sys32_sigsuspend)
 GLOBAL_ENTRY(ia32_ret_from_clone)
 	PT_REGS_UNWIND_INFO(0)
 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
+{	/*
+	 * Some versions of gas generate bad unwind info if the first instruction of a
+	 * procedure doesn't go into the first slot of a bundle.  This is a workaround.
+	 */
+	nop.m 0
+	nop.i 0
 	/*
 	 * We need to call schedule_tail() to complete the scheduling process.
 	 * Called by ia64_switch_to after do_fork()->copy_thread().  r8 contains the
 	 * address of the previously executing task.
 	 */
 	br.call.sptk.many rp=ia64_invoke_schedule_tail
+}
 .ret1:
 #endif
 	adds r2=TI_FLAGS+IA64_TASK_SIZE,r13

arch/ia64/kernel/entry.S

@@ -507,7 +507,14 @@ END(invoke_syscall_trace)
 
 GLOBAL_ENTRY(ia64_trace_syscall)
 	PT_REGS_UNWIND_INFO(0)
+{	/*
+	 * Some versions of gas generate bad unwind info if the first instruction of a
+	 * procedure doesn't go into the first slot of a bundle.  This is a workaround.
+	 */
+	nop.m 0
+	nop.i 0
 	br.call.sptk.many rp=invoke_syscall_trace // give parent a chance to catch syscall args
+}
 .ret6:	br.call.sptk.many rp=b6			// do the syscall
 strace_check_retval:
 	cmp.lt p6,p0=r8,r0			// syscall failed?
@@ -537,12 +544,19 @@ END(ia64_trace_syscall)
 
 GLOBAL_ENTRY(ia64_ret_from_clone)
 	PT_REGS_UNWIND_INFO(0)
+{	/*
+	 * Some versions of gas generate bad unwind info if the first instruction of a
+	 * procedure doesn't go into the first slot of a bundle.  This is a workaround.
+	 */
+	nop.m 0
+	nop.i 0
 	/*
 	 * We need to call schedule_tail() to complete the scheduling process.
 	 * Called by ia64_switch_to() after do_fork()->copy_thread().  r8 contains the
 	 * address of the previously executing task.
 	 */
 	br.call.sptk.many rp=ia64_invoke_schedule_tail
+}
 .ret8:
 	adds r2=TI_FLAGS+IA64_TASK_SIZE,r13
 	;;
@@ -716,21 +730,9 @@ dont_preserve_current_frame:
 	shr.u loc1=r18,9		// RNaTslots <= dirtySize / (64*8) + 1
 	sub r17=r17,r18			// r17 = (physStackedSize + 8) - dirtySize
 	;;
-#if 1
-	.align 32		// see comment below about gas bug...
-#endif
 	mov ar.rsc=r19			// load ar.rsc to be used for "loadrs"
 	shladd in0=loc1,3,r17
 	mov in1=0
-#if 0
-	// gas-2.12.90 is unable to generate a stop bit after .align, which is bad,
-	// because alloc must be at the beginning of an insn-group.
-	.align 32
-#else
-	nop 0
-	nop 0
-	nop 0
-#endif
 	;;
 rse_clear_invalid:
 #ifdef CONFIG_ITANIUM
@@ -969,17 +971,16 @@ ENTRY(sys_rt_sigreturn)
 END(sys_rt_sigreturn)
 
 GLOBAL_ENTRY(ia64_prepare_handle_unaligned)
-	//
-	// r16 = fake ar.pfs, we simply need to make sure
-	// privilege is still 0
-	//
-	mov r16=r0
 	.prologue
+	/*
+	 * r16 = fake ar.pfs, we simply need to make sure privilege is still 0
+	 */
+	mov r16=r0
 	DO_SAVE_SWITCH_STACK
-	br.call.sptk.many rp=ia64_handle_unaligned // stack frame setup in ivt
+	br.call.sptk.many rp=ia64_handle_unaligned	// stack frame setup in ivt
 .ret21:	.body
 	DO_LOAD_SWITCH_STACK
-	br.cond.sptk.many rp			  // goes to ia64_leave_kernel
+	br.cond.sptk.many rp				// goes to ia64_leave_kernel
 END(ia64_prepare_handle_unaligned)
 
 	//

arch/ia64/kernel/gate.S

@@ -144,15 +144,18 @@ END(fsys_fallback_syscall)
 	 * call stack.
 	 */
 
+#define SIGTRAMP_SAVES										\
+	.unwabi @svr4, 's'		// mark this as a sigtramp handler (saves scratch regs)	\
+	.savesp ar.unat, UNAT_OFF+SIGCONTEXT_OFF						\
+	.savesp ar.fpsr, FPSR_OFF+SIGCONTEXT_OFF						\
+	.savesp pr, PR_OFF+SIGCONTEXT_OFF							\
+	.savesp rp, RP_OFF+SIGCONTEXT_OFF							\
+	.vframesp SP_OFF+SIGCONTEXT_OFF
+
 GLOBAL_ENTRY(ia64_sigtramp)
 	// describe the state that is active when we get here:
 	.prologue
-	.unwabi @svr4, 's'		// mark this as a sigtramp handler (saves scratch regs)
-	.savesp ar.unat, UNAT_OFF+SIGCONTEXT_OFF
-	.savesp ar.fpsr, FPSR_OFF+SIGCONTEXT_OFF
-	.savesp pr, PR_OFF+SIGCONTEXT_OFF
-	.savesp rp, RP_OFF+SIGCONTEXT_OFF
-	.vframesp SP_OFF+SIGCONTEXT_OFF
+	SIGTRAMP_SAVES
 	.body
 
 	.label_state 1
@@ -237,10 +240,11 @@ back_from_restore_rbs:
 	ldf.fill f14=[base0],32
 	ldf.fill f15=[base1],32
 	mov r15=__NR_rt_sigreturn
+	.restore sp				// pop .prologue
 	break __BREAK_SYSCALL
 
-	.body
-	.copy_state 1
+	.prologue
+	SIGTRAMP_SAVES
 setup_rbs:
 	mov ar.rsc=0				// put RSE into enforced lazy mode
 	;;
@@ -252,6 +256,7 @@ setup_rbs:
 	;;
 	.spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF
 	st8 [r14]=r16				// save sc_ar_rnat
+	.body
 	adds r14=(LOADRS_OFF+SIGCONTEXT_OFF),sp
 
 	mov.m r16=ar.bsp			// sc_loadrs <- (new bsp - new bspstore) << 16
@@ -263,10 +268,11 @@ setup_rbs:
 	;;
 	st8 [r14]=r15				// save sc_loadrs
 	mov ar.rsc=0xf				// set RSE into eager mode, pl 3
+	.restore sp				// pop .prologue
 	br.cond.sptk back_from_setup_rbs
 
 	.prologue
-	.copy_state 1
+	SIGTRAMP_SAVES
 	.spillsp ar.rnat, RNAT_OFF+SIGCONTEXT_OFF
 	.body
 restore_rbs:

arch/ia64/lib/memcpy_mck.S

@@ -159,7 +159,7 @@ GLOBAL_ENTRY(__copy_user)
 	mov	ar.ec=2
 (p10)	br.dpnt.few .aligned_src_tail
 	;;
-	.align 32
+//	.align 32
 1:
 EX(.ex_handler, (p16)	ld8	r34=[src0],16)
 EK(.ex_handler, (p16)	ld8	r38=[src1],16)
@@ -316,7 +316,7 @@ EK(.ex_handler,	(p[D])	st8 [dst1] = t15, 4*8)
 (p7)	mov	ar.lc = r21
 (p8)	mov	ar.lc = r0
 	;;
-	.align 32
+//	.align 32
 1:	lfetch.fault	  [src_pre_mem], 128
 	lfetch.fault.excl [dst_pre_mem], 128
 	br.cloop.dptk.few 1b
@@ -522,7 +522,7 @@ EK(.ex_handler,  (p17)	st8	[dst1]=r39,8);						\
 		 shrp	r21=r22,r38,shift;	/* speculative work */			\
 		 br.sptk.few .unaligned_src_tail /* branch out of jump table */		\
 		 ;;
-	.align 32
+//	.align 32
 .jump_table:
 	COPYU(8)	// unaligned cases
 .jmp1:

arch/ia64/lib/memset.S

@@ -125,7 +125,7 @@ GLOBAL_ENTRY(memset)
 (p_zr)	br.cond.dptk.many .l1b			// Jump to use stf.spill
 ;; }
 
-	.align 32 // -------------------------- //  L1A: store ahead into cache lines; fill later
+//	.align 32 // -------------------------- //  L1A: store ahead into cache lines; fill later
 { .mmi
 	and	tmp = -(LINE_SIZE), cnt		// compute end of range
 	mov	ptr9 = ptr1			// used for prefetching
@@ -194,7 +194,7 @@ GLOBAL_ENTRY(memset)
 	br.cond.dpnt.many  .move_bytes_from_alignment	// Branch no. 3
 ;; }
 
-	.align 32
+//	.align 32
 .l1b:	// ------------------------------------ //  L1B: store ahead into cache lines; fill later
 { .mmi
 	and	tmp = -(LINE_SIZE), cnt		// compute end of range
@@ -261,7 +261,7 @@ GLOBAL_ENTRY(memset)
 	and	cnt = 0x1f, cnt			// compute the remaining cnt
 	mov.i   ar.lc = loopcnt
 ;; }
-	.align 32
+//	.align 32
 .l2:	// ------------------------------------ //  L2A:  store 32B in 2 cycles
 { .mmb
 	stf8	[ptr1] = fvalue, 8

arch/ia64/scripts/unwcheck.sh

+#!/bin/sh
+#   Usage: unwcheck.sh <executable_file_name>
+#   Pre-requisite: readelf [from Gnu binutils package]
+#   Purpose: Check the following invariant
+#       For each code range in the input binary:
+#          Sum[ lengths of unwind regions] = Number of slots in code range.
+#   Author : Harish Patil
+#   First version: January 2002
+#   Modified : 2/13/2002
+#   Modified : 3/15/2002: duplicate detection
+readelf -u $1 | gawk '\
+ function todec(hexstr){
+    dec = 0;
+    l = length(hexstr);
+    for (i = 1; i <= l; i++)
+    {
+        c = substr(hexstr, i, 1);
+        if (c == "A")
+            dec = dec*16 + 10;
+        else if (c == "B")
+            dec = dec*16 + 11;
+        else if (c == "C")
+            dec = dec*16 + 12;
+        else if (c == "D")
+            dec = dec*16 + 13;
+        else if (c == "E")
+            dec = dec*16 + 14;
+        else if (c == "F")
+            dec = dec*16 + 15;
+        else
+            dec = dec*16 + c;
+    }
+    return dec;
+ }
+ BEGIN { first = 1; sum_rlen = 0; no_slots = 0; errors=0; no_code_ranges=0; }
+ {
+   if (NF==5 && $3=="info")
+   {
+      no_code_ranges += 1;
+      if (first == 0)
+      {
+         if (sum_rlen != no_slots)
+         {
+            print full_code_range;
+            print "       ", "lo = ", lo, " hi =", hi;
+            print "       ", "sum_rlen = ", sum_rlen, "no_slots = " no_slots;
+            print "       ","   ", "*******ERROR ***********";
+            print "       ","   ", "sum_rlen:", sum_rlen, " != no_slots:" no_slots;
+            errors += 1;
+         }
+         sum_rlen = 0;
+      }
+      full_code_range =  $0;
+      code_range =  $2;
+      gsub("..$", "", code_range);
+      gsub("^.", "", code_range);
+      split(code_range, addr, "-");
+      lo = toupper(addr[1]);
+
+      code_range_lo[no_code_ranges] = addr[1];
+      occurs[addr[1]] += 1;
+      full_range[addr[1]] = $0;
+
+      gsub("0X.[0]*", "", lo);
+      hi = toupper(addr[2]);
+      gsub("0X.[0]*", "", hi);
+      no_slots = (todec(hi) - todec(lo))/ 16*3
+      first = 0;
+   }
+   if (index($0,"rlen") > 0 )
+   {
+    rlen_str =  substr($0, index($0,"rlen"));
+    rlen = rlen_str;
+    gsub("rlen=", "", rlen);
+    gsub(")", "", rlen);
+    sum_rlen = sum_rlen +  rlen;
+   }
+  }
+  END {
+      if (first == 0)
+      {
+         if (sum_rlen != no_slots)
+         {
+            print "code_range=", code_range;
+            print "       ", "lo = ", lo, " hi =", hi;
+            print "       ", "sum_rlen = ", sum_rlen, "no_slots = " no_slots;
+            print "       ","   ", "*******ERROR ***********";
+            print "       ","   ", "sum_rlen:", sum_rlen, " != no_slots:" no_slots;
+            errors += 1;
+         }
+      }
+    no_duplicates = 0;
+    for (i=1; i<=no_code_ranges; i++)
+    {
+        cr = code_range_lo[i];
+        if (reported_cr[cr]==1) continue;
+        if ( occurs[cr] > 1)
+        {
+            reported_cr[cr] = 1;
+            print "Code range low ", code_range_lo[i], ":", full_range[cr], " occurs: ", occurs[cr], " times.";
+            print " ";
+            no_duplicates++;
+        }
+    }
+    print "======================================"
+    print "Total errors:", errors, "/", no_code_ranges, " duplicates:", no_duplicates;
+    print "======================================"
+  }
+  '