[PATCH] kernel/module: Use BUG_ON instead of if condition followed by BUG.

From: zhouchuangao
Date: Sat Apr 17 2021 - 06:27:33 EST


First:
This patch comes from cocinelle warning.

Second:
BUG_ON uses unlikely in if(). Through disassembly, we can see that
brk #0x800 is compiled to the end of the function.
As you can see below:
......
ffffff8008660bec: d65f03c0 ret
ffffff8008660bf0: d4210000 brk #0x800

Usually, the condition in if () is not satisfied. For the
multi-stage pipeline, we do not need to perform fetch decode
and excute operation on brk instruction.

In my opinion, this can improve the efficiency of the
multi-stage pipeline.

Signed-off-by: zhouchuangao <zhouchuangao@xxxxxxxx>
---
kernel/module.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 3047935..f46fc4f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1014,8 +1014,8 @@ void __symbol_put(const char *symbol)
};

preempt_disable();
- if (!find_symbol(&fsa))
- BUG();
+ BUG_ON(!find_symbol(&fsa));
+
module_put(fsa.owner);
preempt_enable();
}
--
2.7.4