[Xen-changelog] [qemu-xen-unstable] qemu-xen: fix sequence of operations in pt_msix_init()

[patchbot@xxxxxxx]

commit 4181a6d8c38bb86b1d8c3ef1b41831bee03424dd
Author: Jan Beulich <jbeulich@xxxxxxxx>
Date:   Thu Jan 5 17:15:46 2012 +0000

    qemu-xen: fix sequence of operations in pt_msix_init()
    
    Checking the return value of mmap() must be done before adjusting the
    value, otherwise failure may not be detected.
    
    Closing the file handle, on the other hand, can be done before checking
    the return value.
    
    Finally, printing the errno value without knowing whether the previous
    function actually failed is bogus (and superfluous since a subsequent
    message prints the strerror() representaton anyway).
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
 hw/pt-msi.c |   10 +++-------
 1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/hw/pt-msi.c b/hw/pt-msi.c
index 4a444ad..cf123ba 100644
--- a/hw/pt-msi.c
+++ b/hw/pt-msi.c
@@ -537,7 +537,6 @@ int pt_msix_init(struct pt_dev *dev, int pos)
     int i, total_entries, table_off, bar_index;
     struct pci_dev *pd = dev->pci_dev;
     int fd;
-    int err;
 
     id = pci_read_byte(pd, pos + PCI_CAP_LIST_ID);
 
@@ -585,17 +584,14 @@ int pt_msix_init(struct pt_dev *dev, int pos)
     dev->msix->phys_iomem_base = mmap(0, total_entries * 16 + 
dev->msix->table_offset_adjust,
                           PROT_READ, MAP_SHARED | MAP_LOCKED,
                           fd, dev->msix->table_base + table_off - 
dev->msix->table_offset_adjust);
-    dev->msix->phys_iomem_base = (void *)((char *)dev->msix->phys_iomem_base + 
-                          dev->msix->table_offset_adjust);
-    err = errno;
-    PT_LOG("errno = %d\n",err);
+    close(fd);
     if ( dev->msix->phys_iomem_base == MAP_FAILED )
     {
         PT_LOG("Error: Can't map physical MSI-X table: %s\n", strerror(errno));
-        close(fd);
         goto error_out;
     }
-    close(fd);
+
+    dev->msix->phys_iomem_base += dev->msix->table_offset_adjust;
 
     PT_LOG("mapping physical MSI-X table to %lx\n",
            (unsigned long)dev->msix->phys_iomem_base);
--
generated by git-patchbot for /home/xen/git/qemu-xen-unstable.git

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