From: Stefan Eissing <stefan@eissing.org>
Date: Fri, 10 Oct 2025 08:15:38 +0000 (+0200)
Subject: thread: errno on thread creation
X-Git-Tag: rc-8_17_0-1~7
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=03448f477a0cfa3868dfd15a7b9278dcecf944a2;p=thirdparty%2Fcurl.git

thread: errno on thread creation

When thread creation fails, the code uses `errno` to remember the cause.
But pthread_create() never sets errno and gives the error as return value.
Fix that by setting the return value into errno on failure.

Windows: I think the ifdef was the wrong way around. Also set a generic
Windows Error code on CE systems.

Reported-by: Joshua Rogers
Closes #18998
---

diff --git a/lib/curl_threads.c b/lib/curl_threads.c
index a585d26d3f..352e002a3d 100644
--- a/lib/curl_threads.c
+++ b/lib/curl_threads.c
@@ -60,14 +60,18 @@ curl_thread_t Curl_thread_create(CURL_THREAD_RETURN_T
 {
   curl_thread_t t = malloc(sizeof(pthread_t));
   struct Curl_actual_call *ac = malloc(sizeof(struct Curl_actual_call));
+  int rc;
   if(!(ac && t))
     goto err;
 
   ac->func = func;
   ac->arg = arg;
 
-  if(pthread_create(t, NULL, curl_thread_create_thunk, ac) != 0)
+  rc = pthread_create(t, NULL, curl_thread_create_thunk, ac);
+  if(rc) {
+    CURL_SETERRNO(rc);
     goto err;
+  }
 
   return t;
 
@@ -103,13 +107,15 @@ curl_thread_t Curl_thread_create(CURL_THREAD_RETURN_T
 {
   curl_thread_t t = CreateThread(NULL, 0, func, arg, 0, NULL);
   if(!t) {
-#ifdef UNDER_CE
+#ifndef UNDER_CE
     DWORD gle = GetLastError();
     /* !checksrc! disable ERRNOVAR 1 */
     int err = (gle == ERROR_ACCESS_DENIED ||
                gle == ERROR_NOT_ENOUGH_MEMORY) ?
                EACCES : EINVAL;
     CURL_SETERRNO(err);
+#else
+    CURL_SETERRNO(31); /* Windows ERROR_GEN_FAILURE */
 #endif
     return curl_thread_t_null;
   }