(nuttx) branch master updated: sched/irq: Fix potential deadlock in irqchain_detach

[acassis]

This is an automated email from the ASF dual-hosted git repository.

acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new d7bb8da6954 sched/irq: Fix potential deadlock in irqchain_detach
d7bb8da6954 is described below

commit d7bb8da6954d6034b56f656e472ad5eacb1494d8
Author: pangzhen1 <pangzh...@xiaomi.com>
AuthorDate: Wed Sep 3 15:11:20 2025 +0800

    sched/irq: Fix potential deadlock in irqchain_detach
    
    Release g_irqchainlock before calling irq_detach to avoid holding two locks
    simultaneously, which can cause thread deadlock.
    
    The irqchain_detach function was calling irq_detach while holding 
g_irqchainlock,
    and irq_detach attempts to acquire g_irqlock. This lock ordering violation 
could
    lead to deadlock in multithreaded scenarios.
    
    Fix:
    - Move spin_unlock_irqrestore(&g_irqchainlock, flags) before irq_detach call
    - Ensure locks are released in proper order to prevent circular wait
    
    This is part of the irq_chain_lock feature for safer IRQ chain handling.
    
    Signed-off-by: pangzhen1 <pangzh...@xiaomi.com>
---
 sched/irq/irq_chain.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/sched/irq/irq_chain.c b/sched/irq/irq_chain.c
index bd9b43ff5e0..757ca963d8e 100644
--- a/sched/irq/irq_chain.c
+++ b/sched/irq/irq_chain.c
@@ -257,13 +257,14 @@ int irqchain_detach(int irq, xcpt_t isr, FAR void *arg)
                   break;
                 }
             }
+
+          spin_unlock_irqrestore(&g_irqchainlock, flags);
         }
       else
         {
+          spin_unlock_irqrestore(&g_irqchainlock, flags);
           ret = irq_detach(irq);
         }
-
-      spin_unlock_irqrestore(&g_irqchainlock, flags);
     }
 
   return ret;