[PATCH v2] init: consolidate trap_init()

* [PATCH v2] init: consolidate trap_init()
       [not found] <20210414165808.458a3d11@xhacker.debian>
@ 2021-04-14 10:00 ` Jisheng Zhang
  2021-08-22 19:48   ` Helge Deller
  0 siblings, 1 reply; 2+ messages in thread
From: Jisheng Zhang @ 2021-04-14 10:00 UTC (permalink / raw)
  To: Vineet Gupta, Russell King, Yoshinori Sato, Brian Cain, Nick Hu,
	Greentime Hu, Vincent Chen, Ley Foon Tan, Jonas Bonn,
	Stefan Kristiansson, Stafford Horne, James E.J. Bottomley,
	Helge Deller, Michael Ellerman, Benjamin Herrenschmidt,
	Paul Mackerras, Paul Walmsley, Palmer Dabbelt, Albert Ou,
	Jeff Dike, Richard Weinberger, Anton Ivanov, Richard Henderson,
	Ivan Kokshaysky, Matt Turner, Michal Simek, David S. Miller,
	Christophe Leroy
  Cc: linux-snps-arc, linux-kernel, linux-arm-kernel, uclinux-h8-devel,
	linux-hexagon, openrisc, linux-parisc, linuxppc-dev, linux-riscv,
	linux-um, Anup Patel, linux-alpha, sparclinux

Many architectures implement the trap_init() as NOP, since there is
no such default for trap_init(), this empty stub is duplicated among
these architectures. Provide a generic but weak NOP implementation
to drop the empty stubs of trap_init() in these architectures.

The alpha, microblaze and sparc32 have real trap_init() implementation
but the __init marker is missing, so add it to these three platforms.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
---
Since v1:
 - add __init marker to trap_init() for alpha, microblaze and sparc32
 - adjust the generic weak NOP trap_init() location to make it sits with
   other NOP implementations together

 arch/alpha/kernel/traps.c      |  2 +-
 arch/arc/kernel/traps.c        |  5 -----
 arch/arm/kernel/traps.c        |  5 -----
 arch/h8300/kernel/traps.c      | 13 -------------
 arch/hexagon/kernel/traps.c    |  4 ----
 arch/microblaze/kernel/traps.c |  2 +-
 arch/nds32/kernel/traps.c      |  5 -----
 arch/nios2/kernel/traps.c      |  5 -----
 arch/openrisc/kernel/traps.c   |  5 -----
 arch/parisc/kernel/traps.c     |  4 ----
 arch/powerpc/kernel/traps.c    |  5 -----
 arch/riscv/kernel/traps.c      |  5 -----
 arch/sparc/kernel/traps_32.c   |  2 +-
 arch/um/kernel/trap.c          |  4 ----
 init/main.c                    |  2 ++
 15 files changed, 5 insertions(+), 63 deletions(-)

diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c
index 921d4b6e4d95..96b203199c6c 100644
--- a/arch/alpha/kernel/traps.c
+++ b/arch/alpha/kernel/traps.c
@@ -973,7 +973,7 @@ do_entUnaUser(void __user * va, unsigned long opcode,
 	return;
 }
 
-void
+void __init
 trap_init(void)
 {
 	/* Tell PAL-code what global pointer we want in the kernel.  */
diff --git a/arch/arc/kernel/traps.c b/arch/arc/kernel/traps.c
index 57235e5c0cea..6b83e3f2b41c 100644
--- a/arch/arc/kernel/traps.c
+++ b/arch/arc/kernel/traps.c
@@ -20,11 +20,6 @@
 #include <asm/unaligned.h>
 #include <asm/kprobes.h>
 
-void __init trap_init(void)
-{
-	return;
-}
-
 void die(const char *str, struct pt_regs *regs, unsigned long address)
 {
 	show_kernel_fault_diag(str, regs, address);
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 17d5a785df28..9baccef20392 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -780,11 +780,6 @@ void abort(void)
 	panic("Oops failed to kill thread");
 }
 
-void __init trap_init(void)
-{
-	return;
-}
-
 #ifdef CONFIG_KUSER_HELPERS
 static void __init kuser_init(void *vectors)
 {
diff --git a/arch/h8300/kernel/traps.c b/arch/h8300/kernel/traps.c
index 5d8b969cd8f3..c3a3ebf77fbb 100644
--- a/arch/h8300/kernel/traps.c
+++ b/arch/h8300/kernel/traps.c
@@ -30,19 +30,6 @@
 
 static DEFINE_SPINLOCK(die_lock);
 
-/*
- * this must be called very early as the kernel might
- * use some instruction that are emulated on the 060
- */
-
-void __init base_trap_init(void)
-{
-}
-
-void __init trap_init(void)
-{
-}
-
 asmlinkage void set_esp0(unsigned long ssp)
 {
 	current->thread.esp0 = ssp;
diff --git a/arch/hexagon/kernel/traps.c b/arch/hexagon/kernel/traps.c
index 904134b37232..edfc35dafeb1 100644
--- a/arch/hexagon/kernel/traps.c
+++ b/arch/hexagon/kernel/traps.c
@@ -28,10 +28,6 @@
 #define TRAP_SYSCALL	1
 #define TRAP_DEBUG	0xdb
 
-void __init trap_init(void)
-{
-}
-
 #ifdef CONFIG_GENERIC_BUG
 /* Maybe should resemble arch/sh/kernel/traps.c ?? */
 int is_valid_bugaddr(unsigned long addr)
diff --git a/arch/microblaze/kernel/traps.c b/arch/microblaze/kernel/traps.c
index 94b6fe93147d..7c15704fe56e 100644
--- a/arch/microblaze/kernel/traps.c
+++ b/arch/microblaze/kernel/traps.c
@@ -18,7 +18,7 @@
 #include <asm/exceptions.h>
 #include <asm/unwind.h>
 
-void trap_init(void)
+void __init trap_init(void)
 {
 	__enable_hw_exceptions();
 }
diff --git a/arch/nds32/kernel/traps.c b/arch/nds32/kernel/traps.c
index ee0d9ae192a5..f06421c645af 100644
--- a/arch/nds32/kernel/traps.c
+++ b/arch/nds32/kernel/traps.c
@@ -183,11 +183,6 @@ void __pgd_error(const char *file, int line, unsigned long val)
 }
 
 extern char *exception_vector, *exception_vector_end;
-void __init trap_init(void)
-{
-	return;
-}
-
 void __init early_trap_init(void)
 {
 	unsigned long ivb = 0;
diff --git a/arch/nios2/kernel/traps.c b/arch/nios2/kernel/traps.c
index b172da4eb1a9..596986a74a26 100644
--- a/arch/nios2/kernel/traps.c
+++ b/arch/nios2/kernel/traps.c
@@ -105,11 +105,6 @@ void show_stack(struct task_struct *task, unsigned long *stack,
 	printk("%s\n", loglvl);
 }
 
-void __init trap_init(void)
-{
-	/* Nothing to do here */
-}
-
 /* Breakpoint handler */
 asmlinkage void breakpoint_c(struct pt_regs *fp)
 {
diff --git a/arch/openrisc/kernel/traps.c b/arch/openrisc/kernel/traps.c
index 4d61333c2623..aa1e709405ac 100644
--- a/arch/openrisc/kernel/traps.c
+++ b/arch/openrisc/kernel/traps.c
@@ -231,11 +231,6 @@ void unhandled_exception(struct pt_regs *regs, int ea, int vector)
 	die("Oops", regs, 9);
 }
 
-void __init trap_init(void)
-{
-	/* Nothing needs to be done */
-}
-
 asmlinkage void do_trap(struct pt_regs *regs, unsigned long address)
 {
 	force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c
index 8d8441d4562a..747c328fb886 100644
--- a/arch/parisc/kernel/traps.c
+++ b/arch/parisc/kernel/traps.c
@@ -859,7 +859,3 @@ void  __init early_trap_init(void)
 
 	initialize_ivt(&fault_vector_20);
 }
-
-void __init trap_init(void)
-{
-}
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index a44a30b0688c..e952bee89684 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -2207,11 +2207,6 @@ DEFINE_INTERRUPT_HANDLER(kernel_bad_stack)
 	die("Bad kernel stack pointer", regs, SIGABRT);
 }
 
-void __init trap_init(void)
-{
-}
-
-
 #ifdef CONFIG_PPC_EMULATED_STATS
 
 #define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index 0879b5df11b9..b3f3d84de779 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -194,8 +194,3 @@ int is_valid_bugaddr(unsigned long pc)
 		return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
 }
 #endif /* CONFIG_GENERIC_BUG */
-
-/* stvec & scratch is already set from head.S */
-void trap_init(void)
-{
-}
diff --git a/arch/sparc/kernel/traps_32.c b/arch/sparc/kernel/traps_32.c
index 247a0d9683b2..c4df20ec01e2 100644
--- a/arch/sparc/kernel/traps_32.c
+++ b/arch/sparc/kernel/traps_32.c
@@ -365,7 +365,7 @@ EXPORT_SYMBOL(do_BUG);
  * up here so that timer interrupts work during initialization.
  */
 
-void trap_init(void)
+void __init trap_init(void)
 {
 	extern void thread_info_offsets_are_bolixed_pete(void);
 
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index ad12f78bda7e..3198c4767387 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -311,7 +311,3 @@ void winch(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 {
 	do_IRQ(WINCH_IRQ, regs);
 }
-
-void trap_init(void)
-{
-}
diff --git a/init/main.c b/init/main.c
index 53b278845b88..8d14674c4e00 100644
--- a/init/main.c
+++ b/init/main.c
@@ -779,6 +779,8 @@ void __init __weak poking_init(void) { }
 
 void __init __weak pgtable_cache_init(void) { }
 
+void __init __weak trap_init(void) { }
+
 bool initcall_debug;
 core_param(initcall_debug, initcall_debug, bool, 0644);
 
-- 
2.31.0


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