[Xen-changelog] [xen-unstable] tools/libxc: free thread specific hypercall buffer on xc_interface_close

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Ian Campbell <ian.campbell@xxxxxxxxxx>
# Date 1282147765 -3600
# Node ID aa078b53ff624a7f49fb9b92e9925000afbb3c1c
# Parent  af6799abc6e93a1a877cc56913584b7ea0b43c91
tools/libxc: free thread specific hypercall buffer on xc_interface_close

The per-thread hypercall buffer is usually cleaned up on pthread_exit
by the destructor passed to pthread_key_create. However if the calling
application is not threaded then the destructor is never called.

This frees the data for the current thread only but that is OK since
any other threads will be cleaned up by the destructor.

Changed since v1:
 * Ensure hcall_buf_pkey is initialised before use. Thanks to
   Christoph Egger for his help diagnosing this issue on NetBSD.
 * Remove redundant if (hcall_buf) from xc_clean_hcall_buf since
   _xc_clean_hcall_buf includes the same check.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
---
 tools/libxc/xc_private.c |   14 ++++++++++++++
 1 files changed, 14 insertions(+)

diff -r af6799abc6e9 -r aa078b53ff62 tools/libxc/xc_private.c
--- a/tools/libxc/xc_private.c  Wed Aug 18 16:48:25 2010 +0100
+++ b/tools/libxc/xc_private.c  Wed Aug 18 17:09:25 2010 +0100
@@ -57,6 +57,8 @@ xc_interface *xc_interface_open(xentooll
     return 0;
 }
 
+static void xc_clean_hcall_buf(void);
+
 int xc_interface_close(xc_interface *xch)
 {
     int rc = 0;
@@ -68,6 +70,9 @@ int xc_interface_close(xc_interface *xch
         rc = xc_interface_close_core(xch, xch->fd);
         if (rc) PERROR("Could not close hypervisor interface");
     }
+
+    xc_clean_hcall_buf();
+
     free(xch);
     return rc;
 }
@@ -180,6 +185,8 @@ int hcall_buf_prep(void **addr, size_t l
 int hcall_buf_prep(void **addr, size_t len) { return 0; }
 void hcall_buf_release(void **addr, size_t len) { }
 
+static void xc_clean_hcall_buf(void) { }
+
 #else /* !__sun__ */
 
 int lock_pages(void *addr, size_t len)
@@ -228,6 +235,13 @@ static void _xc_init_hcall_buf(void)
 static void _xc_init_hcall_buf(void)
 {
     pthread_key_create(&hcall_buf_pkey, _xc_clean_hcall_buf);
+}
+
+static void xc_clean_hcall_buf(void)
+{
+    pthread_once(&hcall_buf_pkey_once, _xc_init_hcall_buf);
+
+    _xc_clean_hcall_buf(pthread_getspecific(hcall_buf_pkey));
 }
 
 int hcall_buf_prep(void **addr, size_t len)

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