[Qemu-devel] [PATCH 52/56] Bugfix for loading multiboot kernels

[Michael Roth]

From: Martijn van den Broek <address@hidden>

This patch fixes a bug in rom_copy introduced by
commit d60fa42e8bae39440f997ebfe8fe328269a57d16.

rom_copy failed to load roms with a "datasize" of 0.
As a result, multiboot kernels were not loaded correctly
when they contain a segment with a "file size" of 0.

https://bugs.launchpad.net/qemu/+bug/1208944

Signed-off-by: Martijn van den Broek <address@hidden>
Reviewed-by: Paolo Bonzini <address@hidden>
Message-id: address@hidden
Signed-off-by: Anthony Liguori <address@hidden>
(cherry picked from commit 0dd5ce38fbeb2fb97b01cc8c1c97292211e48ee6)

Signed-off-by: Michael Roth <address@hidden>
---
 hw/core/loader.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index 7507914..8514eaf 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -779,9 +779,6 @@ int rom_copy(uint8_t *dest, hwaddr addr, size_t size)
         if (rom->addr > end) {
             break;
         }
-        if (!rom->data) {
-            continue;
-        }
 
         d = dest + (rom->addr - addr);
         s = rom->data;
@@ -791,7 +788,9 @@ int rom_copy(uint8_t *dest, hwaddr addr, size_t size)
             l = dest - d;
         }
 
-        memcpy(d, s, l);
+        if (l > 0) {
+            memcpy(d, s, l);
+        }
 
         if (rom->romsize > rom->datasize) {
             /* If datasize is less than romsize, it means that we didn't
-- 
1.7.9.5