From 5d658937ce874422c66ac4c7d9723df8bb69ecd7 Mon Sep 17 00:00:00 2001

From: Nathan Hjelm <hjelmn@me.com>

Date: Fri, 5 Oct 2018 16:30:06 -0600

Subject: [PATCH 40/52] btl/vader: fix race condition in writing header

Signed-off-by: Nathan Hjelm <hjelmn@me.com>

(cherry picked from commit 8291f6722d890efd15333bf7b26f0d07952fa41e)

Signed-off-by: Nathan Hjelm <hjelmn@me.com>

---

 opal/mca/btl/vader/btl_vader_fbox.h | 19 ++++++++++++-------

 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/opal/mca/btl/vader/btl_vader_fbox.h b/opal/mca/btl/vader/btl_vader_fbox.h

index 6df9a2d..4ebfde8 100644

--- a/opal/mca/btl/vader/btl_vader_fbox.h

+++ b/opal/mca/btl/vader/btl_vader_fbox.h

@@ -29,6 +29,10 @@ typedef union mca_btl_vader_fbox_hdr_t {

         /** sequence number */

         uint16_t  seq;

     } data;

+    struct {

+        uint32_t value0;

+        uint32_t value1;

+    } data_i32;

     uint64_t ival;

 } mca_btl_vader_fbox_hdr_t;

@@ -50,19 +54,20 @@ void mca_btl_vader_poll_handle_frag (mca_btl_vader_hdr_t *hdr, mca_btl_base_endp

 static inline void mca_btl_vader_fbox_set_header (mca_btl_vader_fbox_hdr_t *hdr, uint16_t tag,

                                                   uint16_t seq, uint32_t size)

 {

-    mca_btl_vader_fbox_hdr_t tmp = {.data = {.tag = 0, .seq = seq, .size = size}};

-    hdr->ival = tmp.ival;

+    mca_btl_vader_fbox_hdr_t tmp = {.data = {.tag = tag, .seq = seq, .size = size}};

+    /* clear out existing tag/seq */

+    hdr->data_i32.value1 = 0;

+    opal_atomic_wmb ();

+    hdr->data_i32.value0 = size;

     opal_atomic_wmb ();

-    hdr->data.tag = tag;

+    hdr->data_i32.value1 = tmp.data_i32.value1;

 }

 static inline mca_btl_vader_fbox_hdr_t mca_btl_vader_fbox_read_header (mca_btl_vader_fbox_hdr_t *hdr)

 {

-    mca_btl_vader_fbox_hdr_t tmp;

-    uint16_t tag = hdr->data.tag;

+    mca_btl_vader_fbox_hdr_t tmp = {.data_i32 = {.value1 = hdr->data_i32.value1}};;

     opal_atomic_rmb ();

-    tmp.ival = hdr->ival;

-    tmp.data.tag = tag;

+    tmp.data_i32.value0 = hdr->data_i32.value0;

     return tmp;

 }

-- 

1.8.3.1