[PATCH v2 08/13] gdb/linux-record: Fix [gs]etgroups16 syscall

["Marcin Kościelnicki" <koriakin@0x04.net>]

Memory size for getgroups16 needs to be multiplied by entry count, and only
needs recording if the pointer is non-NULL.  setgroups16, on the other hand,
doesn't write to user memory and doesn't need special handling at all.

gdb/ChangeLog:

	* linux-record.c (record_linux_system_call): Fix [gs]etgroups16.
---
 gdb/ChangeLog      |  4 ++++
 gdb/linux-record.c | 17 ++++++++++-------
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index ce717ae..1c3cc04 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,9 @@
 2015-10-22  Marcin Kościelnicki  <koriakin@0x04.net>
 
+	* linux-record.c (record_linux_system_call): Fix [gs]etgroups16.
+
+2015-10-22  Marcin Kościelnicki  <koriakin@0x04.net>
+
 	* aarch64-linux-tdep.c (aarch64_linux_init_abi): Add size_time_t.
 	* amd64-linux-tdep.c (amd64_linux_init_abi): Add size_time_t.
 	(amd64_x32_linux_init_abi): Add size_time_t.
diff --git a/gdb/linux-record.c b/gdb/linux-record.c
index dbd8f14..25cbda1 100644
--- a/gdb/linux-record.c
+++ b/gdb/linux-record.c
@@ -628,16 +628,19 @@ record_linux_system_call (enum gdb_syscall syscall,
 
     case gdb_sys_getgroups16:
       regcache_raw_read_unsigned (regcache, tdep->arg2, &tmpulongest);
-      if (record_full_arch_list_add_mem ((CORE_ADDR) tmpulongest,
-					 tdep->size_old_gid_t))
-        return -1;
+      if (tmpulongest)
+        {
+          ULONGEST gidsetsize;
+
+          regcache_raw_read_unsigned (regcache, tdep->arg1,
+                                      &gidsetsize);
+          tmpint = tdep->size_old_gid_t * (int) gidsetsize;
+          if (record_full_arch_list_add_mem ((CORE_ADDR) tmpulongest, tmpint))
+            return -1;
+        }
       break;
 
     case gdb_sys_setgroups16:
-      regcache_raw_read_unsigned (regcache, tdep->arg2, &tmpulongest);
-      if (record_full_arch_list_add_mem ((CORE_ADDR) tmpulongest,
-					 tdep->size_old_gid_t))
-        return -1;
       break;
 
     case gdb_old_select:
-- 
2.6.1