nptl: Add comment to __pthread_get_minstack about external users

Message ID 87sgt0jh8g.fsf@oldenburg2.str.redhat.com
State New
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  • nptl: Add comment to __pthread_get_minstack about external users
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Commit Message

Florian Weimer May 27, 2019, 10:59 a.m.
2019-05-27  Florian Weimer  <fweimer@redhat.com>

	* nptl/nptl-init.c: Add comment.

Comments

Carlos O'Donell May 27, 2019, 12:11 p.m. | #1
On 5/27/19 5:59 AM, Florian Weimer wrote:
> 2019-05-27  Florian Weimer  <fweimer@redhat.com>

> 

> 	* nptl/nptl-init.c: Add comment.

> 


OK for master. Given that I almost removed this once last year it's a good
thing to have a comment here.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>


> diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c

> index 2926558b91..73935f8be4 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)

>  {

> 



-- 
Cheers,
Carlos.

Patch

diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index 2926558b91..73935f8be4 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)
 {