[PR gdb/13808] gdb.trace: Pass tdesc selected in gdbserver to IPA.

If gdbserver and IPA are using different tdesc, they will disagree
about 'R' trace packet size.  This results in mangled traces.

To make sure they pick the same tdesc, gdbserver pokes the tdesc
(specified as an index in a target-specific list) into a global
variable in IPA.  In theory, IPA could find out the tdesc on its
own, but that may be complex (in particular, I don't know how to
tell whether we have LAST_BREAK on s390 without messing with ptrace),
and we'd have to duplicate the logic.

Tested on i386 and x86_64.  On i386, it fixes two FAILs in ftrace.exp.
On x86_64, these failures have been KFAILed - one of them works now,
but the other now fails due to an unrelated reason (ugh).

gdb/gdbserver/ChangeLog:

	PR gdb/13808
	* Makefile.in: Add i386-*-linux-ipa.o and amd64-*-linux-ipa.o.
	* configure.srv: Ditto.
	* linux-aarch64-ipa.c (get_ipa_tdesc): New function.
	(initialize_low_tracepoint): Remove ipa_tdesc assignment.
	* linux-amd64-ipa.c: Add "linux-x86-tdesc.h" include.
	(init_registers_amd64_linux): Remove prototype.
	(tdesc_amd64_linux): Remove declaration.
	(get_ipa_tdesc): New function.
	(initialize_low_tracepoint): Remove ipa_tdesc assignment,
	initialize remaining tdescs.
	* linux-i386-ipa.c: Add "linux-x86-tdesc.h" include.
	(init_registers_i386_linux): Remove prototype.
	(tdesc_i386_linux): Remove declaration.
	(get_ipa_tdesc): New function.
	(initialize_low_tracepoint): Remove ipa_tdesc assignment,
	initialize remaining tdescs.
	* linux-low.c (linux_get_ipa_tdesc_idx): New function.
	(linux_target_ops): wire in linux_get_ipa_tdesc_idx.
	* linux-low.h (struct linux_target_ops): Add get_ipa_tdesc_idx.
	* linux-x86-low.c: Move tdesc declarations to linux-x86-tdesc.h.
	(x86_get_ipa_tdesc_idx): New function.
	(the_low_target): Wire in x86_get_ipa_tdesc_idx.
	* linux-x86-tdesc.h: New file.
	* target.h (struct target_ops): Add get_ipa_tdesc_idx.
	(target_get_ipa_tdesc_idx): New macro.
	* tracepoint.c (ipa_tdesc_idx): New macro.
	(struct ipa_sym_addresses): Add addr_ipa_tdesc_idx.
	(symbol_list): Add ipa_tdesc_idx.
	(cmd_qtstart): Write ipa_tdesc_idx in the target.
	(ipa_tdesc): Remove.
	(ipa_tdesc_idx): New variable.
	(get_context_regcache): Use get_ipa_tdesc.
	(gdb_collect): Ditto.
	(gdb_probe): Ditto.
	* tracepoint.h (get_ipa_tdesc): New prototype.
	(ipa_tdesc): Remove.

gdb/testsuite/ChangeLog:

	PR gdb/13808
	* gdb.trace/ftrace.exp (test_fast_tracepoints): Remove kfail.

1 files changed, 30 insertions, 5 deletions

diff --git a/gdb/gdbserver/linux-i386-ipa.c b/gdb/gdbserver/linux-i386-ipa.c
index 11dc038..4860012 100644
--- a/gdb/gdbserver/linux-i386-ipa.c
+++ b/gdb/gdbserver/linux-i386-ipa.c
@@ -21,6 +21,7 @@
 #include "server.h"
 #include <sys/mman.h>
 #include "tracepoint.h"
+#include "linux-x86-tdesc.h"
 
 /* GDB register numbers.  */
 
@@ -47,10 +48,6 @@ enum i386_gdb_regnum
 
 #define i386_num_regs 16
 
-/* Defined in auto-generated file i386-linux.c.  */
-void init_registers_i386_linux (void);
-extern const struct target_desc *tdesc_i386_linux;
-
 #define FT_CR_EAX 15
 #define FT_CR_ECX 14
 #define FT_CR_EDX 13
@@ -247,10 +244,38 @@ initialize_fast_tracepoint_trampoline_buffer (void)
     }
 }
 
+/* Return target_desc to use for IPA, given the tdesc index passed by
+   gdbserver.  */
+
+const struct target_desc *
+get_ipa_tdesc (int idx)
+{
+  switch (idx)
+    {
+    case X86_TDESC_MMX:
+      return tdesc_i386_mmx_linux;
+    case X86_TDESC_SSE:
+      return tdesc_i386_linux;
+    case X86_TDESC_AVX:
+      return tdesc_i386_avx_linux;
+    case X86_TDESC_MPX:
+      return tdesc_i386_mpx_linux;
+    case X86_TDESC_AVX512:
+      return tdesc_i386_avx512_linux;
+    default:
+      internal_error (__FILE__, __LINE__,
+		      "unknown ipa tdesc index: %d", idx);
+      return tdesc_i386_linux;
+    }
+}
+
 void
 initialize_low_tracepoint (void)
 {
+  init_registers_i386_mmx_linux ();
   init_registers_i386_linux ();
-  ipa_tdesc = tdesc_i386_linux;
+  init_registers_i386_avx_linux ();
+  init_registers_i386_mpx_linux ();
+  init_registers_i386_avx512_linux ();
   initialize_fast_tracepoint_trampoline_buffer ();
 }