x86, ds: add leakage warning
Add a warning in case a debug store context is not removed before
the task it is attached to is freed.
Remove the old warning at thread exit. It is too early.
Declare the debug store context field in thread_struct unconditionally.
Remove ds_copy_thread() and ds_exit_thread() and do the work directly
in process*.c.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: oleg@redhat.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144601.254472000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index 21a3852..71cab3b 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -1352,16 +1352,6 @@
update_debugctlmsr(debugctlmsr);
}
-void ds_copy_thread(struct task_struct *tsk, struct task_struct *father)
-{
- clear_tsk_thread_flag(tsk, TIF_DS_AREA_MSR);
- tsk->thread.ds_ctx = NULL;
-}
-
-void ds_exit_thread(struct task_struct *tsk)
-{
-}
-
static __init int ds_selftest(void)
{
if (ds_cfg.sizeof_rec[ds_bts]) {
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index ca98915..fb5dfb8 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -14,6 +14,7 @@
#include <asm/idle.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
+#include <asm/ds.h>
unsigned long idle_halt;
EXPORT_SYMBOL(idle_halt);
@@ -45,6 +46,8 @@
kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
tsk->thread.xstate = NULL;
}
+
+ WARN(tsk->thread.ds_ctx, "leaking DS context\n");
}
void free_thread_info(struct thread_info *ti)
@@ -83,8 +86,6 @@
put_cpu();
kfree(bp);
}
-
- ds_exit_thread(current);
}
void flush_thread(void)
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 76f8f84..b5e4bfe 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -290,7 +290,8 @@
p->thread.io_bitmap_max = 0;
}
- ds_copy_thread(p, current);
+ clear_tsk_thread_flag(p, TIF_DS_AREA_MSR);
+ p->thread.ds_ctx = NULL;
clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
p->thread.debugctlmsr = 0;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index b751a41..5a1a1de 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -335,7 +335,8 @@
goto out;
}
- ds_copy_thread(p, me);
+ clear_tsk_thread_flag(p, TIF_DS_AREA_MSR);
+ p->thread.ds_ctx = NULL;
clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
p->thread.debugctlmsr = 0;