[hurd,commited,3/6] htl: Move cleanup stack to variable shared between libc and pthread

Message ID 20200614165757.4156687-4-samuel.thibault@ens-lyon.org
State New
Headers show
Series
  • Make write and pwrite64 cancellation points
Related show

Commit Message

Samuel Thibault June 14, 2020, 4:57 p.m.
If libpthread gets loaded dynamically, the stack needs to already contain the
cleanup handlers of the main thread.

* htl/libc_pthread_init.c (__pthread_cleanup_stack): New per-thread variable.
* htl/Versions (libc): Add __pthread_cleanup_stack as private symbol.
* htl/pt-internal.h (struct __pthread): Remove cancelation_handlers
field.
(__pthread_cleanup_stack): Add variable declaration.
* htl/pt-alloc.c (initialize_pthread): Remove initialization of
cancelation_handlers field.
* htl/pt-cleanup.c (__pthread_get_cleanup_stack): Return the address of
__pthread_cleanup_stack instead of that of the cancelation_handlers
field.
* htl/forward.c: Include <pt-internal.h>.
(dummy_list): Remove variable.
(__pthread_get_cleanup_stack): Return the address of __pthread_cleanup_stack
instead of that of dummy_list.
---
 htl/Versions            | 1 +
 htl/forward.c           | 4 ++--
 htl/libc_pthread_init.c | 2 ++
 htl/pt-alloc.c          | 2 --
 htl/pt-cleanup.c        | 2 +-
 htl/pt-internal.h       | 4 +++-
 6 files changed, 9 insertions(+), 6 deletions(-)

-- 
2.27.0

Patch

diff --git a/htl/Versions b/htl/Versions
index fd9eefbaee..832cc5d814 100644
--- a/htl/Versions
+++ b/htl/Versions
@@ -29,6 +29,7 @@  libc {
   GLIBC_PRIVATE {
     __libc_alloca_cutoff;
     __libc_pthread_init;
+    __pthread_cleanup_stack;
   }
 }
 
diff --git a/htl/forward.c b/htl/forward.c
index dfb7b79327..544e7da058 100644
--- a/htl/forward.c
+++ b/htl/forward.c
@@ -23,6 +23,7 @@ 
 #include <pthread-functions.h>
 #include <libc-lock.h>
 #include <fork.h>
+#include <pt-internal.h>
 
 /* Pointers to the libc functions.  */
 struct pthread_functions __libc_pthread_functions attribute_hidden;
@@ -140,6 +141,5 @@  strong_alias (__pthread_setcancelstate, pthread_setcancelstate);
 
 FORWARD (pthread_setcanceltype, (int type, int *oldtype), (type, oldtype), 0)
 
-struct __pthread_cancelation_handler *dummy_list;
 FORWARD2 (__pthread_get_cleanup_stack, struct __pthread_cancelation_handler **,
-	  (void), (), return &dummy_list);
+	  (void), (), return &__pthread_cleanup_stack);
diff --git a/htl/libc_pthread_init.c b/htl/libc_pthread_init.c
index cee92f76ee..f617c4e0be 100644
--- a/htl/libc_pthread_init.c
+++ b/htl/libc_pthread_init.c
@@ -19,6 +19,8 @@ 
 #include <string.h>
 #include <pthread-functions.h>
 
+__thread struct __pthread_cancelation_handler *__pthread_cleanup_stack;
+
 void
 __libc_pthread_init (const struct pthread_functions *functions)
 {
diff --git a/htl/pt-alloc.c b/htl/pt-alloc.c
index d4426bb2e3..bf37aca729 100644
--- a/htl/pt-alloc.c
+++ b/htl/pt-alloc.c
@@ -65,8 +65,6 @@  initialize_pthread (struct __pthread *new)
   new->state_lock = (pthread_mutex_t) PTHREAD_MUTEX_INITIALIZER;
   new->state_cond = (pthread_cond_t) PTHREAD_COND_INITIALIZER;
 
-  new->cancelation_handlers = 0;
-
   memset (&new->res_state, '\0', sizeof (new->res_state));
 
   new->tcb = NULL;
diff --git a/htl/pt-cleanup.c b/htl/pt-cleanup.c
index a9a7c95847..7e6149bda9 100644
--- a/htl/pt-cleanup.c
+++ b/htl/pt-cleanup.c
@@ -23,6 +23,6 @@ 
 struct __pthread_cancelation_handler **
 __pthread_get_cleanup_stack (void)
 {
-  return &_pthread_self ()->cancelation_handlers;
+  return &__pthread_cleanup_stack;
 }
 hidden_def(__pthread_get_cleanup_stack)
diff --git a/htl/pt-internal.h b/htl/pt-internal.h
index 918c207c3e..e0baa6bcda 100644
--- a/htl/pt-internal.h
+++ b/htl/pt-internal.h
@@ -81,7 +81,6 @@  struct __pthread
   int cancel_state;
   int cancel_type;
   int cancel_pending;
-  struct __pthread_cancelation_handler *cancelation_handlers;
 
   /* Thread stack.  */
   void *stackaddr;
@@ -197,6 +196,9 @@  extern pthread_rwlock_t __pthread_threads_lock;
 #ifndef _pthread_self
 extern struct __pthread *_pthread_self (void);
 #endif
+
+/* Stores the stack of cleanup handlers for the thread.  */
+extern __thread struct __pthread_cancelation_handler *__pthread_cleanup_stack;
 
 
 /* Initialize the pthreads library.  */