Re: [PATCH] powerpc: Only pad struct pt_regs when needed

[Michael Ellerman]

On Thu, 6 May 2021 13:30:51 + (UTC), Christophe Leroy wrote:
> 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.

Applied to powerpc/next.

[1/1] powerpc: Only pad struct pt_regs when needed
  https://git.kernel.org/powerpc/c/b09049c516af90d4b6643b5d0d2549cd01539086

cheers

[PATCH] powerpc: Only pad struct pt_regs when needed

[Christophe Leroy]

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 
---
 arch/powerpc/include/asm/ptrace.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/ptrace.h 
b/arch/powerpc/include/asm/ptrace.h
index 9c9ab2746168..4fd3a3bd5272 100644
--- 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
 
-- 
2.25.0