LoongArch: Remove unnecessary checks for ORC unwinder

[ Upstream commit 4cd641a79e69270a062777f64a0dd330abb9044a ]

According to the following function definitions, __kernel_text_address()
already checks __module_text_address(), so it should remove the check of
__module_text_address() in bt_address() at least.

int __kernel_text_address(unsigned long addr)
{
	if (kernel_text_address(addr))
		return 1;
	...
	return 0;
}

int kernel_text_address(unsigned long addr)
{
	bool no_rcu;
	int ret = 1;
	...
	if (is_module_text_address(addr))
		goto out;
	...
	return ret;
}

bool is_module_text_address(unsigned long addr)
{
	guard(rcu)();
	return __module_text_address(addr) != NULL;
}

Furthermore, there are two checks of __kernel_text_address(), one is in
bt_address() and the other is after calling bt_address(), it looks like
redundant.

Handle the exception address first and then use __kernel_text_address()
to validate the calculated address for exception or the normal address
in bt_address(), then it can remove the check of __kernel_text_address()
after calling bt_address().

Just remove unnecessary checks, no functional changes intended.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Stable-dep-of: 055c7e75190e ("LoongArch: Handle percpu handler address for ORC unwinder")
Signed-off-by: Sasha Levin <sashal@kernel.org>

1 files changed, 5 insertions, 11 deletions

diff --git a/arch/loongarch/kernel/unwind_orc.c b/arch/loongarch/kernel/unwind_orc.c
index 59809c3406c0..4924d1ecc457 100644
--- a/arch/loongarch/kernel/unwind_orc.c
+++ b/arch/loongarch/kernel/unwind_orc.c
@@ -359,12 +359,6 @@ static inline unsigned long bt_address(unsigned long ra)
 {
 	extern unsigned long eentry;
 
-	if (__kernel_text_address(ra))
-		return ra;
-
-	if (__module_text_address(ra))
-		return ra;
-
 	if (ra >= eentry && ra < eentry +  EXCCODE_INT_END * VECSIZE) {
 		unsigned long func;
 		unsigned long type = (ra - eentry) / VECSIZE;
@@ -382,10 +376,13 @@ static inline unsigned long bt_address(unsigned long ra)
 			break;
 		}
 
-		return func + offset;
+		ra = func + offset;
 	}
 
-	return ra;
+	if (__kernel_text_address(ra))
+		return ra;
+
+	return 0;
 }
 
 bool unwind_next_frame(struct unwind_state *state)
@@ -511,9 +508,6 @@ bool unwind_next_frame(struct unwind_state *state)
 		goto err;
 	}
 
-	if (!__kernel_text_address(state->pc))
-		goto err;
-
 	return true;
 
 err: