On Sat, Feb 04, 2012 at 10:02:19PM +0400, Cyrill Gorcunov wrote:
> 
> Strictly speaking, kvm__init need more serious rewrite together with
> kvm__arch_init/kvm_ipc__start/kvm_ipc__register_handler ret. vals tests,
> i'll do this a bit late.
> 

Sorry for delay, was busy. Anyway, here is a quickfix for sigsev and close()s.

        Cyrill
---
Subject: kvm tool: Don't close not yet opened files and SIGSEV fix

In case if there error happened in kvm__init and we have
no files opened -- we should not try to close them.

Also once kvm failed to init the caller should not try
to dereference a pointer obtained, otherwise we might get
SIGSEV

 | [cyrill@moon kvm]$ ./lkvm run ...
 | Error: '/dev/kvm' not found. Please make sure your kernel has CONFIG_KVM
 | enabled and that the KVM modules are loaded.
 | Segmentation fault (core dumped)
 | [cyrill@moon kvm]$

Signed-off-by: Cyrill Gorcunov <gorcu...@gmail.com>
---
 tools/kvm/builtin-run.c |    4 ++++
 tools/kvm/kvm.c         |   41 +++++++++++++++++++++--------------------
 2 files changed, 25 insertions(+), 20 deletions(-)

Index: linux-2.6.git/tools/kvm/builtin-run.c
===================================================================
--- linux-2.6.git.orig/tools/kvm/builtin-run.c
+++ linux-2.6.git/tools/kvm/builtin-run.c
@@ -997,6 +997,10 @@ static int kvm_cmd_run_init(int argc, co
        }
 
        kvm = kvm__init(dev, hugetlbfs_path, ram_size, guest_name);
+       if (IS_ERR(kvm)) {
+               r = PTR_ERR(kvm);
+               goto fail;
+       }
 
        kvm->single_step = single_step;
 
Index: linux-2.6.git/tools/kvm/kvm.c
===================================================================
--- linux-2.6.git.orig/tools/kvm/kvm.c
+++ linux-2.6.git/tools/kvm/kvm.c
@@ -123,10 +123,12 @@ static int kvm__check_extensions(struct
 static struct kvm *kvm__new(void)
 {
        struct kvm *kvm = calloc(1, sizeof(*kvm));
-
        if (!kvm)
                return ERR_PTR(-ENOMEM);
 
+       kvm->sys_fd = -1;
+       kvm->vm_fd = -1;
+
        return kvm;
 }
 
@@ -341,47 +343,42 @@ struct kvm *kvm__init(const char *kvm_de
        }
 
        kvm = kvm__new();
-       if (IS_ERR_OR_NULL(kvm))
+       if (IS_ERR(kvm))
                return kvm;
 
        kvm->sys_fd = open(kvm_dev, O_RDWR);
        if (kvm->sys_fd < 0) {
-               if (errno == ENOENT) {
+               if (errno == ENOENT)
                        pr_err("'%s' not found. Please make sure your kernel 
has CONFIG_KVM "
-                               "enabled and that the KVM modules are loaded.", 
kvm_dev);
-                       ret = -errno;
-                       goto cleanup;
-               }
-               if (errno == ENODEV) {
-                       die("'%s' KVM driver not available.\n  # (If the KVM "
-                               "module is loaded then 'dmesg' may offer 
further clues "
-                               "about the failure.)", kvm_dev);
-                       ret = -errno;
-                       goto cleanup;
-               }
+                              "enabled and that the KVM modules are loaded.", 
kvm_dev);
+               else if (errno == ENODEV)
+                       pr_err("'%s' KVM driver not available.\n  # (If the KVM 
"
+                              "module is loaded then 'dmesg' may offer further 
clues "
+                              "about the failure.)", kvm_dev);
+               else
+                       pr_err("Could not open %s: ", kvm_dev);
 
-               pr_err("Could not open %s: ", kvm_dev);
                ret = -errno;
-               goto cleanup;
+               goto err_free;
        }
 
        ret = ioctl(kvm->sys_fd, KVM_GET_API_VERSION, 0);
        if (ret != KVM_API_VERSION) {
                pr_err("KVM_API_VERSION ioctl");
                ret = -errno;
-               goto cleanup;
+               goto err_sys_fd;
        }
 
        kvm->vm_fd = ioctl(kvm->sys_fd, KVM_CREATE_VM, 0);
        if (kvm->vm_fd < 0) {
                ret = kvm->vm_fd;
-               goto cleanup;
+               goto err_sys_fd;
        }
 
        kvm->name = strdup(name);
        if (!kvm->name) {
                ret = -ENOMEM;
-               goto cleanup;
+               goto err;
        }
 
        if (kvm__check_extensions(kvm)) {
@@ -393,10 +390,14 @@ struct kvm *kvm__init(const char *kvm_de
 
        kvm_ipc__start(kvm__create_socket(kvm));
        kvm_ipc__register_handler(KVM_IPC_PID, kvm__pid);
+
        return kvm;
-cleanup:
+
+err:
        close(kvm->vm_fd);
+err_sys_fd:
        close(kvm->sys_fd);
+err_free:
        free(kvm);
 
        return ERR_PTR(ret);
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to