[PATCH 2/2] uprobes: make arch_uprobe_exception_notify as weak

[Yipeng Zou]

The function implementation under some arch does nothing.
We can mark it with weak attributes to improve.

Signed-off-by: Yipeng Zou <zouyipeng at huawei.com>
---
 arch/arm/probes/uprobes/core.c     | 6 ------
 arch/arm64/kernel/probes/uprobes.c | 6 ------
 arch/csky/kernel/probes/uprobes.c  | 6 ------
 arch/riscv/kernel/probes/uprobes.c | 6 ------
 kernel/events/uprobes.c            | 6 ++++++
 5 files changed, 6 insertions(+), 24 deletions(-)

diff --git a/arch/arm/probes/uprobes/core.c b/arch/arm/probes/uprobes/core.c
index f5f790c6e5f8..535ea1b355ed 100644
--- a/arch/arm/probes/uprobes/core.c
+++ b/arch/arm/probes/uprobes/core.c
@@ -175,12 +175,6 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
 	instruction_pointer_set(regs, utask->vaddr);
 }
 
-int arch_uprobe_exception_notify(struct notifier_block *self,
-				 unsigned long val, void *data)
-{
-	return NOTIFY_DONE;
-}
-
 static int uprobe_trap_handler(struct pt_regs *regs, unsigned int instr)
 {
 	unsigned long flags;
diff --git a/arch/arm64/kernel/probes/uprobes.c b/arch/arm64/kernel/probes/uprobes.c
index d49aef2657cd..687ede3375a6 100644
--- a/arch/arm64/kernel/probes/uprobes.c
+++ b/arch/arm64/kernel/probes/uprobes.c
@@ -159,12 +159,6 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
 	return orig_ret_vaddr;
 }
 
-int arch_uprobe_exception_notify(struct notifier_block *self,
-				 unsigned long val, void *data)
-{
-	return NOTIFY_DONE;
-}
-
 static int uprobe_breakpoint_handler(struct pt_regs *regs,
 				     unsigned long esr)
 {
diff --git a/arch/csky/kernel/probes/uprobes.c b/arch/csky/kernel/probes/uprobes.c
index 2d31a12e46cf..67ff13d960e8 100644
--- a/arch/csky/kernel/probes/uprobes.c
+++ b/arch/csky/kernel/probes/uprobes.c
@@ -132,12 +132,6 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
 	return ra;
 }
 
-int arch_uprobe_exception_notify(struct notifier_block *self,
-				 unsigned long val, void *data)
-{
-	return NOTIFY_DONE;
-}
-
 int uprobe_breakpoint_handler(struct pt_regs *regs)
 {
 	if (uprobe_pre_sstep_notifier(regs))
diff --git a/arch/riscv/kernel/probes/uprobes.c b/arch/riscv/kernel/probes/uprobes.c
index c976a21cd4bd..770f16c6e00f 100644
--- a/arch/riscv/kernel/probes/uprobes.c
+++ b/arch/riscv/kernel/probes/uprobes.c
@@ -131,12 +131,6 @@ arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
 	return ra;
 }
 
-int arch_uprobe_exception_notify(struct notifier_block *self,
-				 unsigned long val, void *data)
-{
-	return NOTIFY_DONE;
-}
-
 bool uprobe_breakpoint_handler(struct pt_regs *regs)
 {
 	if (uprobe_pre_sstep_notifier(regs))
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index d9e357b7e17c..33e637f7a202 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -2343,6 +2343,12 @@ int uprobe_post_sstep_notifier(struct pt_regs *regs)
 	return 1;
 }
 
+int __weak arch_uprobe_exception_notify(struct notifier_block *self,
+				 unsigned long val, void *data)
+{
+	return NOTIFY_DONE;
+}
+
 static struct notifier_block uprobe_exception_nb = {
 	.notifier_call		= arch_uprobe_exception_notify,
 	.priority		= INT_MAX-1,	/* notified after kprobes, kgdb */
-- 
2.17.1