[Qemu-devel] [PATCH for-1.3] hw/ide/macio: Fix segfault caused by NULL DMAContext*

[Peter Maydell]

Pass qemu_sglist_init the global dma_context_memory rather than a NULL
pointer; this fixes a segfault in dma_memory_map() when the guest
starts using DMA.

Reported-by: Amadeusz Sławiński <address@hidden>
Signed-off-by: Peter Maydell <address@hidden>
---
Test case: download the squeeze standard image from
http://people.debian.org/~aurel32/qemu/powerpc/
and run with
  qemu-system-ppc -hda debian_squeeze_powerpc_standard.qcow2
Without this patch it will crash as soon as Linux tries to
talk to the disk (the boot loader is OK as it doesn't DMA).

Obvious for-1.3 bugfix.

 hw/ide/macio.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hw/ide/macio.c b/hw/ide/macio.c
index 720af6e..d2edcc0 100644
--- a/hw/ide/macio.c
+++ b/hw/ide/macio.c
@@ -76,7 +76,8 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
 
     s->io_buffer_size = io->len;
 
-    qemu_sglist_init(&s->sg, io->len / MACIO_PAGE_SIZE + 1, NULL);
+    qemu_sglist_init(&s->sg, io->len / MACIO_PAGE_SIZE + 1,
+                     &dma_context_memory);
     qemu_sglist_add(&s->sg, io->addr, io->len);
     io->addr += io->len;
     io->len = 0;
@@ -132,7 +133,8 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
     s->io_buffer_index = 0;
     s->io_buffer_size = io->len;
 
-    qemu_sglist_init(&s->sg, io->len / MACIO_PAGE_SIZE + 1, NULL);
+    qemu_sglist_init(&s->sg, io->len / MACIO_PAGE_SIZE + 1,
+                     &dma_context_memory);
     qemu_sglist_add(&s->sg, io->addr, io->len);
     io->addr += io->len;
     io->len = 0;
-- 
1.7.9.5