[PATCH 9/9] Support TLS variables on FreeBSD/powerpc.

John Baldwin
2019-01-22T18:43:50Z

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

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5d228614db..938fa83ca8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2019-01-22 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.
+
2019-01-22 John Baldwin <jhb@FreeBSD.org>

* riscv-fbsd-tdep.c (riscv_fbsd_get_thread_local_address): New.
diff --git a/gdb/ppc-fbsd-tdep.c b/gdb/ppc-fbsd-tdep.c
index c21a52c898..290bd1fd88 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
--
2.19.2