* [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix
@ 2012-02-04 16:32 Cyrill Gorcunov
2012-02-04 17:38 ` Pekka Enberg
2012-02-04 17:54 ` Pekka Enberg
0 siblings, 2 replies; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-04 16:32 UTC (permalink / raw)
To: Pekka Enberg, Sasha Levin, Asias He, Ingo Molnar, KVM-ML
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 <gorcunov@gmail.com>
---
tools/kvm/builtin-run.c | 4 ++++
tools/kvm/kvm.c | 11 ++++++++---
2 files changed, 12 insertions(+), 3 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_OR_NULL(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;
}
@@ -394,9 +396,12 @@ 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:
- close(kvm->vm_fd);
- close(kvm->sys_fd);
+ if (kvm->vm_fd >= 0)
+ close(kvm->vm_fd);
+ if (kvm->sys_fd >= 0)
+ close(kvm->sys_fd);
free(kvm);
return ERR_PTR(ret);
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix
2012-02-04 16:32 [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix Cyrill Gorcunov
@ 2012-02-04 17:38 ` Pekka Enberg
2012-02-04 17:48 ` Cyrill Gorcunov
2012-02-04 17:54 ` Pekka Enberg
1 sibling, 1 reply; 6+ messages in thread
From: Pekka Enberg @ 2012-02-04 17:38 UTC (permalink / raw)
To: Cyrill Gorcunov; +Cc: Sasha Levin, Asias He, Ingo Molnar, KVM-ML
On Sat, 4 Feb 2012, Cyrill Gorcunov wrote:
> 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 <gorcunov@gmail.com>
> ---
> tools/kvm/builtin-run.c | 4 ++++
> tools/kvm/kvm.c | 11 ++++++++---
> 2 files changed, 12 insertions(+), 3 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_OR_NULL(kvm)) {
PTR_ERR is still not going to work if kvm is NULL.
> + r = PTR_ERR(kvm);
> + goto fail;
> + }
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix
2012-02-04 17:38 ` Pekka Enberg
@ 2012-02-04 17:48 ` Cyrill Gorcunov
0 siblings, 0 replies; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-04 17:48 UTC (permalink / raw)
To: Pekka Enberg; +Cc: Sasha Levin, Asias He, Ingo Molnar, KVM-ML
On Sat, Feb 04, 2012 at 07:38:41PM +0200, Pekka Enberg wrote:
> On Sat, 4 Feb 2012, Cyrill Gorcunov wrote:
> >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 <gorcunov@gmail.com>
> >---
> >tools/kvm/builtin-run.c | 4 ++++
> >tools/kvm/kvm.c | 11 ++++++++---
> >2 files changed, 12 insertions(+), 3 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_OR_NULL(kvm)) {
>
> PTR_ERR is still not going to work if kvm is NULL.
>
It should be IS_ERR rather (kvm__init never returns with NULL),
but it's a candidate for another patch where both kvm__init
and kvm__new should test for IS_ERR only.
Pekka, could you please s/IS_ERR_OR_NULL/IS_ERR/ in this patch,
and that's all. Hm?
Cyrill
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix
2012-02-04 16:32 [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix Cyrill Gorcunov
2012-02-04 17:38 ` Pekka Enberg
@ 2012-02-04 17:54 ` Pekka Enberg
2012-02-04 18:02 ` Cyrill Gorcunov
1 sibling, 1 reply; 6+ messages in thread
From: Pekka Enberg @ 2012-02-04 17:54 UTC (permalink / raw)
To: Cyrill Gorcunov; +Cc: Sasha Levin, Asias He, Ingo Molnar, KVM-ML
On Sat, 4 Feb 2012, Cyrill Gorcunov wrote:
> 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;
> }
>
> @@ -394,9 +396,12 @@ 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:
> - close(kvm->vm_fd);
> - close(kvm->sys_fd);
> + if (kvm->vm_fd >= 0)
> + close(kvm->vm_fd);
> + if (kvm->sys_fd >= 0)
> + close(kvm->sys_fd);
No, please don't do this! Use specific error handling labels instead.
> free(kvm);
>
> return ERR_PTR(ret);
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix
2012-02-04 17:54 ` Pekka Enberg
@ 2012-02-04 18:02 ` Cyrill Gorcunov
2012-02-05 20:19 ` Cyrill Gorcunov
0 siblings, 1 reply; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-04 18:02 UTC (permalink / raw)
To: Pekka Enberg; +Cc: Sasha Levin, Asias He, Ingo Molnar, KVM-ML
On Sat, Feb 04, 2012 at 07:54:38PM +0200, Pekka Enberg wrote:
> On Sat, 4 Feb 2012, Cyrill Gorcunov wrote:
> >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;
> >}
> >
> >@@ -394,9 +396,12 @@ 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:
> >- close(kvm->vm_fd);
> >- close(kvm->sys_fd);
> >+ if (kvm->vm_fd >= 0)
> >+ close(kvm->vm_fd);
> >+ if (kvm->sys_fd >= 0)
> >+ close(kvm->sys_fd);
>
> No, please don't do this! Use specific error handling labels instead.
>
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.
Cyrill
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix
2012-02-04 18:02 ` Cyrill Gorcunov
@ 2012-02-05 20:19 ` Cyrill Gorcunov
0 siblings, 0 replies; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-05 20:19 UTC (permalink / raw)
To: Pekka Enberg, Sasha Levin, Asias He, Ingo Molnar, KVM-ML
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 <gorcunov@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);
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-02-05 20:19 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2012-02-04 16:32 [PATCH] kvm tool: Don't close not yet opened files and SIGSEV fix Cyrill Gorcunov
2012-02-04 17:38 ` Pekka Enberg
2012-02-04 17:48 ` Cyrill Gorcunov
2012-02-04 17:54 ` Pekka Enberg
2012-02-04 18:02 ` Cyrill Gorcunov
2012-02-05 20:19 ` Cyrill Gorcunov
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