From: Rich Felker <dalias@aerifal.cx>
Date: Tue, 25 Aug 2020 01:38:49 +0000 (-0400)
Subject: make h_errno thread-local
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=9d0b8b92a508c328e7eac774847f001f80dfb5ff;p=musl

make h_errno thread-local

the framework to do this always existed but it was deemed unnecessary
because the only [ex-]standard functions using h_errno were not
thread-safe anyway. however, some of the nonstandard res_* functions
are also supposed to set h_errno to indicate the cause of error, and
were unable to do so because it was not thread-safe. this change is a
prerequisite for fixing them.
---

diff --git a/src/internal/pthread_impl.h b/src/internal/pthread_impl.h
index 5742dfc5..5749a336 100644
--- a/src/internal/pthread_impl.h
+++ b/src/internal/pthread_impl.h
@@ -43,6 +43,7 @@ struct pthread {
 		long off;
 		volatile void *volatile pending;
 	} robust_list;
+	int h_errno_val;
 	volatile int timer_id;
 	locale_t locale;
 	volatile int killlock[1];
diff --git a/src/network/h_errno.c b/src/network/h_errno.c
index 4f700cea..8677a92b 100644
--- a/src/network/h_errno.c
+++ b/src/network/h_errno.c
@@ -1,9 +1,7 @@
 #include <netdb.h>
-
-#undef h_errno
-int h_errno;
+#include "pthread_impl.h"
 
 int *__h_errno_location(void)
 {
-	return &h_errno;
+	return &__pthread_self()->h_errno_val;
 }