From 203e964b2c592c5f5b09916503da29f860e32193 Mon Sep 17 00:00:00 2001
From: shichunma <masc2008@gmail.com>
Date: Sun, 3 May 2026 08:51:59 +0800
Subject: [PATCH] include/errno.h: skip set_errno in interrupt context

set_errno() should not modify the interrupted task's errno.
Add a check using up_interrupt_context() and skip the assignment
when called from an interrupt handler.

Signed-off-by: Jerry Ma <shichunma@bestechnic.com>
---
 include/errno.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/include/errno.h b/include/errno.h
index 615ebc818a0a2..1be449988313d 100644
--- a/include/errno.h
+++ b/include/errno.h
@@ -29,6 +29,10 @@
 
 #include <nuttx/compiler.h>
 
+#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
+#  include <nuttx/irq.h>
+#endif
+
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
@@ -41,12 +45,24 @@
  */
 
 #define errno *__errno()
+#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
+#define set_errno(e) \
+  do \
+    { \
+      if (!up_interrupt_context()) \
+        { \
+          errno = (int)(e); \
+        } \
+    } \
+  while (0)
+#else
 #define set_errno(e) \
   do \
     { \
       errno = (int)(e); \
     } \
   while (0)
+#endif
 #define get_errno() errno
 
 /* Definitions of error numbers and the string that would be