[glibc] nptl: Add comment to __pthread_get_minstack about external users

[glibc] nptl: Add comment to __pthread_get_minstack about external users

[Florian Weimer]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=85188d8211698d1a255f0aec6529546db5c56de3

commit 85188d8211698d1a255f0aec6529546db5c56de3
Author: Florian Weimer <fweimer@redhat.com>
Date:   Mon May 27 12:57:45 2019 +0200

    nptl: Add comment to __pthread_get_minstack about external users

Diff:
---
 ChangeLog        | 4 ++++
 nptl/nptl-init.c | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index b46b581..53a3ae4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2019-05-27  Florian Weimer  <fweimer@redhat.com>
+
+	* nptl/nptl-init.c: Add comment.
+
 2019-05-24  Florian Weimer  <fweimer@redhat.com>
 
 	* resolv/nss_dns/dns-host.c (getanswer_r): Be more explicit about
diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index 2926558..73935f8 100644
--- a/nptl/nptl-init.c
+++ b/nptl/nptl-init.c
@@ -407,6 +407,14 @@ strong_alias (__pthread_initialize_minimal_internal,
 	      __pthread_initialize_minimal)
 
 
+/* This function is internal (it has a GLIBC_PRIVATE) version, but it
+   is widely used (either via weak symbol, or dlsym) to obtain the
+   __static_tls_size value.  This value is then used to adjust the
+   value of the stack size attribute, so that applications receive the
+   full requested stack size, not diminished by the TCB and static TLS
+   allocation on the stack.  Once the TCB is separately allocated,
+   this function should be removed or renamed (if it is still
+   necessary at that point).  */
 size_t
 __pthread_get_minstack (const pthread_attr_t *attr)
 {