Re: [PATCH] selftests/powerpc/tm: Fix tcheck() reading uninitialised CR value
From: Thibault Ferrante
Date: Wed Sep 09 2026 - 06:09:23 EST
On 09/09/2026 10:56, Christophe Leroy (CS GROUP) wrote:
diff --git a/tools/testing/selftests/powerpc/tm/tm.h b/tools/testing/selftests/powerpc/tm/tm.h
index c03c6e778876..6024ce4ba6ff 100644
--- a/tools/testing/selftests/powerpc/tm/tm.h
+++ b/tools/testing/selftests/powerpc/tm/tm.h
@@ -105,8 +105,12 @@ static inline bool failure_is_nesting(void)
static inline int tcheck(void)
{
long cr;
- asm volatile ("tcheck 0" : "=r"(cr) : : "cr0");
- return (cr >> 28) & 4;
+ asm volatile("tcheck 0;"
Why not use cr7 instead of using cr0 and doing cr >> 28 below ?
That would work, but that's not consistent with other asm in selftest/powerpc: tbegin./tend./tabort. and vas_paste() all target cr0 and shift as needed.