@@ -303,7 +303,6 @@ static int call_break_hook(struct pt_regs *regs, unsigned long esr)
{
struct break_hook *hook;
struct list_head *list;
- int (*fn)(struct pt_regs *regs, unsigned long esr) = NULL;
list = user_mode(regs) ? &user_break_hook : &kernel_break_hook;
@@ -313,10 +312,10 @@ static int call_break_hook(struct pt_regs *regs, unsigned long esr)
*/
list_for_each_entry_rcu(hook, list, node) {
if ((esr_brk_comment(esr) & ~hook->mask) == hook->imm)
- fn = hook->fn;
+ return hook->fn(regs, esr);
}
- return fn ? fn(regs, esr) : DBG_HOOK_ERROR;
+ return DBG_HOOK_ERROR;
}
NOKPROBE_SYMBOL(call_break_hook);
The search for breakpoint handlers iterate through the entire linked list. Given that all registered hook has a valid fn field, and no registered hooks share the same mask and imm. This commit optimize the efficiency slightly by returning early as a matching handler is found. v2->v1: Remove all WARN_ON(!hook->fn) in v1 as Will suggested. Signed-off-by: Liao Chang <liaochang1@huawei.com> --- arch/arm64/kernel/debug-monitors.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)