Subject: Re: linux-next: build failure after merge of the powerpc tree

From: Nicholas Piggin <[email-masked]>
Date: Wed, 10 Feb 2021 18:20:54 +1000

Excerpts from Stephen Rothwell's message of February 9, 2021 8:19 pm:
> Hi all,
> 
> After merging the powerpc tree, today's linux-next build (powerpc
> allyesconfig) failed like this:
> 
> arch/powerpc/kernel/head_64.o:(__ftr_alt_97+0x0): relocation truncated to fit: R_PPC64_REL24 (OPD) against symbol `do_page_fault' defined in .opd section in arch/powerpc/mm/fault.o
> arch/powerpc/kernel/head_64.o:(__ftr_alt_97+0x8): relocation truncated to fit: R_PPC64_REL24 (OPD) against symbol `do_page_fault' defined in .opd section in arch/powerpc/mm/fault.o
> arch/powerpc/kernel/head_64.o:(__ftr_alt_97+0x28): relocation truncated to fit: R_PPC64_REL24 (OPD) against symbol `unknown_exception' defined in .opd section in arch/powerpc/kernel/traps.o
> 
> Not sure exactly which commit caused this, but it is most likkely part
> of a series in the powerpc tree.
> 
> I have left the allyesconfig build broken for today.

Hey Stephen,

Thanks for that, it's due to .noinstr section being put on the other 
side of .text, so all our interrupt handler asm code can't reach them 
directly anymore since the ppc interrupt wrappers patch added noinstr
attribute.

That's not strictly required though, we've used NOKPROBE_SYMBOL okay
until now. If you can take this patch for now, it should get 
allyesconfig to build again. I'll fix it in the powerpc tree before the 
merge window.

Thanks,
Nick
--

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 4badb3e51c19..fee1e4dd1e84 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -172,6 +172,8 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
 #define DECLARE_INTERRUPT_HANDLER_RAW(func)				\
 	__visible long func(struct pt_regs *regs)
 
+#define ppc_noinstr         noinline notrace __no_kcsan __no_sanitize_address
+
 /**
  * DEFINE_INTERRUPT_HANDLER_RAW - Define raw interrupt handler function
  * @func:	Function name of the entry point
@@ -198,7 +200,7 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
 #define DEFINE_INTERRUPT_HANDLER_RAW(func)				\
 static __always_inline long ____##func(struct pt_regs *regs);		\
 									\
-__visible noinstr long func(struct pt_regs *regs)			\
+__visible ppc_noinstr long func(struct pt_regs *regs)			\
 {									\
 	long ret;							\
 									\
@@ -228,7 +230,7 @@ static __always_inline long ____##func(struct pt_regs *regs)
 #define DEFINE_INTERRUPT_HANDLER(func)					\
 static __always_inline void ____##func(struct pt_regs *regs);		\
 									\
-__visible noinstr void func(struct pt_regs *regs)			\
+__visible ppc_noinstr void func(struct pt_regs *regs)			\
 {									\
 	struct interrupt_state state;					\
 									\
@@ -262,7 +264,7 @@ static __always_inline void ____##func(struct pt_regs *regs)
 #define DEFINE_INTERRUPT_HANDLER_RET(func)				\
 static __always_inline long ____##func(struct pt_regs *regs);		\
 									\
-__visible noinstr long func(struct pt_regs *regs)			\
+__visible ppc_noinstr long func(struct pt_regs *regs)			\
 {									\
 	struct interrupt_state state;					\
 	long ret;							\
@@ -297,7 +299,7 @@ static __always_inline long ____##func(struct pt_regs *regs)
 #define DEFINE_INTERRUPT_HANDLER_ASYNC(func)				\
 static __always_inline void ____##func(struct pt_regs *regs);		\
 									\
-__visible noinstr void func(struct pt_regs *regs)			\
+__visible ppc_noinstr void func(struct pt_regs *regs)			\
 {									\
 	struct interrupt_state state;					\
 									\
@@ -331,7 +333,7 @@ static __always_inline void ____##func(struct pt_regs *regs)
 #define DEFINE_INTERRUPT_HANDLER_NMI(func)				\
 static __always_inline long ____##func(struct pt_regs *regs);		\
 									\
-__visible noinstr long func(struct pt_regs *regs)			\
+__visible ppc_noinstr long func(struct pt_regs *regs)			\
 {									\
 	struct interrupt_nmi_state state;				\
 	long ret;							\