x86, ptrace: support 32bit-cross-64bit BTS recording
Support BTS recording of 32bit and 64bit tasks from 32bit or 64bit tasks.
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 88ed1e7..236528b 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -558,7 +558,7 @@
retval = ds_read_bts((void *)child->thread.ds_area_msr,
bts_index, &ret);
- if (retval)
+ if (retval < 0)
return retval;
if (copy_to_user(out, &ret, sizeof(ret)))