powerpc: Only pad struct pt_regs when needed

If neither KUAP nor PPC64 is selected, there is nothing in the second
union of struct pt_regs, so the alignment padding is waste of memory.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/d536bbc46094f66b24d3017343be25164f232933.1620307840.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 9c9ab27..4fd3a3b 100644 (file)
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -47,7 +47,7 @@ struct pt_regs
                        unsigned long result;
                };
        };
-
+#if defined(CONFIG_PPC64) || defined(CONFIG_PPC_KUAP)
        union {
                struct {
 #ifdef CONFIG_PPC64
@@ -67,6 +67,7 @@ struct pt_regs
                };
                unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */
        };
+#endif
 };
 #endif