Commit-ID: 86e5e4af0c518ec3e9f59f4621fd662813acb9f2
Gitweb: http://git.kernel.org/tip/86e5e4af0c518ec3e9f59f4621fd662813acb9f2
Author: Pekka Enberg <penberg@xxxxxxxxxx>
AuthorDate: Wed, 18 May 2011 22:19:40 +0300
Committer: Pekka Enberg <penberg@xxxxxxxxxx>
CommitDate: Wed, 18 May 2011 22:23:12 +0300
kvm tools: Fail if passed initrd is not really an initrd
We recently changed the meaning of "-i" from disk image to initrd. This has
confused many users because kvm just reports:
Fatal: mmap() failed.
if a disk image is passed as initrd. This patch fixes that by checking for the
first two ID bytes in initrd:
$ ./kvm run -i ~/images/linux-0.2.qcow
# kvm run -k ../../arch/x86/boot/bzImage -m 256 -c 1
Fatal: /home/penberg/images/linux-0.2.qcow is not an initrd
Reported-by: Thomas Heil <heil@xxxxxxxxxxxxxxxxxxxxxx>
Suggested-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxx>
---
tools/kvm/kvm.c | 25 +++++++++++++++++++++++--
1 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
index 815cacf..4393a41 100644
--- a/tools/kvm/kvm.c
+++ b/tools/kvm/kvm.c
@@ -1,10 +1,11 @@
#include "kvm/kvm.h"
+#include "kvm/boot-protocol.h"
#include "kvm/cpufeature.h"
+#include "kvm/read-write.h"
#include "kvm/interrupt.h"
-#include "kvm/boot-protocol.h"
-#include "kvm/util.h"
#include "kvm/mptable.h"
+#include "kvm/util.h"
#include <linux/kvm.h>
@@ -422,6 +423,23 @@ static bool load_bzimage(struct kvm *kvm, int fd_kernel,
return true;
}
+/* RFC 1952 */
+#define GZIP_ID1 0x1f
+#define GZIP_ID2 0x8b
+
+static bool initrd_check(int fd)
+{
+ unsigned char id[2];
+
+ if (read_in_full(fd, id, ARRAY_SIZE(id)) < 0)
+ return false;
+
+ if (lseek(fd, 0, SEEK_SET) < 0)
+ die_perror("lseek");
+
+ return id[0] == GZIP_ID1 && id[1] == GZIP_ID2;
+}
+
bool kvm__load_kernel(struct kvm *kvm, const char *kernel_filename,
const char *initrd_filename, const char *kernel_cmdline)
{
@@ -436,6 +454,9 @@ bool kvm__load_kernel(struct kvm *kvm, const char *kernel_filename,
fd_initrd = open(initrd_filename, O_RDONLY);
if (fd_initrd < 0)
die("Unable to open initrd %s", initrd_filename);
+
+ if (!initrd_check(fd_initrd))
+ die("%s is not an initrd", initrd_filename);
}
ret = load_bzimage(kvm, fd_kernel, fd_initrd, kernel_cmdline);
--
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