[binutils-gdb] Support TLS variables on FreeBSD/powerpc.

[John Baldwin <jhb at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=8399425f5f472ad8e630bb30ad2dbefeddbb68b7

commit 8399425f5f472ad8e630bb30ad2dbefeddbb68b7
Author: John Baldwin <jhb@FreeBSD.org>
Date:   Tue Mar 12 13:39:02 2019 -0700

    Support TLS variables on FreeBSD/powerpc.
    
    Derive the pointer to the DTV array from the %r2 register on 32-bit
    powerpc and %r13 on 64-bit powerpc.
    
    gdb/ChangeLog:
    
    	* ppc-fbsd-tdep.c (ppcfbsd_get_thread_local_address): New.
    	(ppcfbsd_init_abi): Install gdbarch
    	"fetch_tls_load_module_address" and "get_thread_local_address"
    	methods.

Diff:
---
 gdb/ChangeLog       |  7 +++++++
 gdb/ppc-fbsd-tdep.c | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 741799d..fe7504c 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,12 @@
 2019-03-12  John Baldwin  <jhb@FreeBSD.org>
 
+	* ppc-fbsd-tdep.c (ppcfbsd_get_thread_local_address): New.
+	(ppcfbsd_init_abi): Install gdbarch
+	"fetch_tls_load_module_address" and "get_thread_local_address"
+	methods.
+
+2019-03-12  John Baldwin  <jhb@FreeBSD.org>
+
 	* riscv-fbsd-tdep.c (riscv_fbsd_get_thread_local_address): New.
 	(riscv_fbsd_init_abi): Install gdbarch
 	"fetch_tls_load_module_address" and "get_thread_local_address"
diff --git a/gdb/ppc-fbsd-tdep.c b/gdb/ppc-fbsd-tdep.c
index c21a52c..290bd1f 100644
--- a/gdb/ppc-fbsd-tdep.c
+++ b/gdb/ppc-fbsd-tdep.c
@@ -279,6 +279,39 @@ ppcfbsd_return_value (struct gdbarch *gdbarch, struct value *function,
 					   regcache, readbuf, writebuf);
 }
 
+/* Implement the "get_thread_local_address" gdbarch method.  */
+
+static CORE_ADDR
+ppcfbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
+				  CORE_ADDR lm_addr, CORE_ADDR offset)
+{
+  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+  struct regcache *regcache;
+  int tp_offset, tp_regnum;
+
+  regcache = get_thread_arch_regcache (ptid, gdbarch);
+
+  if (tdep->wordsize == 4)
+    {
+      tp_offset = 0x7008;
+      tp_regnum = PPC_R0_REGNUM + 2;
+    }
+  else
+    {
+      tp_offset = 0x7010;
+      tp_regnum = PPC_R0_REGNUM + 13;
+    }
+  target_fetch_registers (regcache, tp_regnum);
+
+  ULONGEST tp;
+  if (regcache->cooked_read (tp_regnum, &tp) != REG_VALID)
+    error (_("Unable to fetch tcb pointer"));
+
+  /* tp points to the end of the TCB block.  The first member of the
+     TCB is the pointer to the DTV array.  */
+  CORE_ADDR dtv_addr = tp - tp_offset;
+  return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
+}
 
 static void
 ppcfbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -322,6 +355,8 @@ ppcfbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 					     svr4_fetch_objfile_link_map);
+  set_gdbarch_get_thread_local_address (gdbarch,
+					ppcfbsd_get_thread_local_address);
 }
 
 void