From b6f7ffb699c08a8ecd0ff97bf828cf55831e2be0 Mon Sep 17 00:00:00 2001
From: Stan Cox <scox@redhat.com>
Date: Fri, 8 Oct 2021 09:42:47 -0400
Subject: [PATCH] Add support for s390 floating point registers

Add float registers.  Add move from float register to general
register.  Allow an sdt argument to be a float register.
---
 includes/sys/sdt.h                     |  2 ++
 runtime/loc2c-runtime.h                |  7 +++++--
 tapsets.cxx                            | 18 +++++++++++++++++-
 testsuite/systemtap.base/sdt_notes.exp |  5 ++++-
 4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/includes/sys/sdt.h b/includes/sys/sdt.h
index f757a46a1..9ecb1cb6f 100644
--- a/includes/sys/sdt.h
+++ b/includes/sys/sdt.h
@@ -104,6 +104,8 @@
 # define STAP_SDT_ARG_CONSTRAINT norfxy
 # elif defined __aarch64__
 # define STAP_SDT_ARG_CONSTRAINT norw
+# elif defined __s390__ || defined __s390x__
+# define STAP_SDT_ARG_CONSTRAINT        norf
 # else
 # define STAP_SDT_ARG_CONSTRAINT        nor
 # endif
diff --git a/runtime/loc2c-runtime.h b/runtime/loc2c-runtime.h
index 163954e01..e6c624d37 100644
--- a/runtime/loc2c-runtime.h
+++ b/runtime/loc2c-runtime.h
@@ -306,13 +306,16 @@
   
 #elif defined (__s390__) || defined (__s390x__)
 
+#define _fetch_float_register(regno) \
+  ({unsigned long v;  __asm__ __volatile__("lgdr %[_DEST],%%f%n[_REGNO]" : [_DEST] "=r" (v): [_REGNO] "n" (-(regno-16))) ; v;})
+
 #undef pt_regs_fetch_register
 #undef pt_regs_store_register
 #define pt_regs_fetch_register(pt_regs,regno) \
-  ((intptr_t) pt_regs->gprs[regno])
+  (regno < 16 ? ((intptr_t) pt_regs->gprs[regno]) : (_fetch_float_register(regno)))
 #define pt_regs_store_register(pt_regs,regno,value) \
   (pt_regs->gprs[regno] = (value))
-#define pt_regs_maxno 16 /* NUM_GPRS */
+#define pt_regs_maxno 32 /* NUM_GPRS */
   
 #endif
 
diff --git a/tapsets.cxx b/tapsets.cxx
index 30352a7e9..1c82aaf69 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -6707,7 +6707,23 @@ sdt_uprobe_var_expanding_visitor::build_dwarf_registers ()
     DRI ("%r13", 13, DI);
     DRI ("%r14", 14, DI);
     DRI ("%r15", 15, DI);
-  } else if (elf_machine == EM_ARM) {
+    DRI ("%f0", 16, DI);
+    DRI ("%f1", 17, DI);
+    DRI ("%f2", 18, DI);
+    DRI ("%f3", 19, DI);
+    DRI ("%f4", 20, DI);
+    DRI ("%f5", 21, DI);
+    DRI ("%f6", 22, DI);
+    DRI ("%f7", 23, DI);
+    DRI ("%f8", 24, DI);
+    DRI ("%f9", 25, DI);
+    DRI ("%f10", 26, DI);
+    DRI ("%f11", 27, DI);
+    DRI ("%f12", 28, DI);
+    DRI ("%f13", 29, DI);
+    DRI ("%f14", 30, DI);
+    DRI ("%f15", 31, DI);
+} else if (elf_machine == EM_ARM) {
     DRI ("r0", 0, SI);
     DRI ("r1", 1, SI);
     DRI ("r2", 2, SI);
diff --git a/testsuite/systemtap.base/sdt_notes.exp b/testsuite/systemtap.base/sdt_notes.exp
index 5fbb2abe0..bbb9175f0 100644
--- a/testsuite/systemtap.base/sdt_notes.exp
+++ b/testsuite/systemtap.base/sdt_notes.exp
@@ -2,8 +2,11 @@ set test "sdt_notes"
 
 # Test layout of .note.stapsdt section and interaction with eu-readelf and gdb
 
+set exeflags [sdt_includes]
+set exeflags "$exeflags additional_flags=-O2"
+
 set res [target_compile $srcdir/$subdir/sdt_types.c \
-	     sdt_types.x executable additional_flags=-O2]
+	     sdt_types.x executable $exeflags]
 if { $res != "" } {
     verbose "target_compile failed: $res" 2
     untested "$test compiling types"
-- 
2.43.5