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* [PATCH] kvm tool: Make kvm structure to carry name copy
@ 2012-02-03 19:57 Cyrill Gorcunov
  2012-02-04 12:15 ` Pekka Enberg
  0 siblings, 1 reply; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-03 19:57 UTC (permalink / raw)
  To: Pekka Enberg, Sasha Levin, Asias He, Ingo Molnar, KVM-ML

If guest name is used (which is default case) the kvm might end
up carrying the pointer to name which is allocated on stack.

kvm_cmd_run_init
  (on stack) default_name
  kvm__init(..., default_name)
    kvm->name = default_name

So I think better to allow kvm to carry own copy
of guest name. 64 symbols should be more than enough.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

I hope I didn't miss anything?

 tools/kvm/kvm.c                          |    2 +-
 tools/kvm/powerpc/include/kvm/kvm-arch.h |    2 +-
 tools/kvm/x86/include/kvm/kvm-arch.h     |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

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
@@ -384,7 +384,7 @@ struct kvm *kvm__init(const char *kvm_de
 
 	kvm__arch_init(kvm, hugetlbfs_path, ram_size);
 
-	kvm->name = name;
+	strncpy(kvm->name, name, sizeof(kvm->name));
 
 	kvm_ipc__start(kvm__create_socket(kvm));
 	kvm_ipc__register_handler(KVM_IPC_PID, kvm__pid);
Index: linux-2.6.git/tools/kvm/powerpc/include/kvm/kvm-arch.h
===================================================================
--- linux-2.6.git.orig/tools/kvm/powerpc/include/kvm/kvm-arch.h
+++ linux-2.6.git/tools/kvm/powerpc/include/kvm/kvm-arch.h
@@ -64,7 +64,7 @@ struct kvm {
 	unsigned long		fdt_gra;
 	unsigned long		initrd_gra;
 	unsigned long		initrd_size;
-	const char		*name;
+	char			name[64];
 	int			vm_state;
 };
 
Index: linux-2.6.git/tools/kvm/x86/include/kvm/kvm-arch.h
===================================================================
--- linux-2.6.git.orig/tools/kvm/x86/include/kvm/kvm-arch.h
+++ linux-2.6.git/tools/kvm/x86/include/kvm/kvm-arch.h
@@ -48,7 +48,7 @@ struct kvm {
 	struct disk_image       **disks;
 	int                     nr_disks;
 
-	const char		*name;
+	char			name[64];
 
 	int			vm_state;
 };

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] kvm tool: Make kvm structure to carry name copy
  2012-02-03 19:57 [PATCH] kvm tool: Make kvm structure to carry name copy Cyrill Gorcunov
@ 2012-02-04 12:15 ` Pekka Enberg
  2012-02-04 12:20   ` Cyrill Gorcunov
  0 siblings, 1 reply; 6+ messages in thread
From: Pekka Enberg @ 2012-02-04 12:15 UTC (permalink / raw)
  To: Cyrill Gorcunov; +Cc: Sasha Levin, Asias He, Ingo Molnar, KVM-ML

On Fri, 3 Feb 2012, Cyrill Gorcunov wrote:
> If guest name is used (which is default case) the kvm might end
> up carrying the pointer to name which is allocated on stack.
>
> kvm_cmd_run_init
>  (on stack) default_name
>  kvm__init(..., default_name)
>    kvm->name = default_name
>
> So I think better to allow kvm to carry own copy
> of guest name. 64 symbols should be more than enough.
>
> Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> ---
>
> I hope I didn't miss anything?

Can't we just use strdup()?

 			Pekka

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] kvm tool: Make kvm structure to carry name copy
  2012-02-04 12:15 ` Pekka Enberg
@ 2012-02-04 12:20   ` Cyrill Gorcunov
  2012-02-04 12:26     ` Cyrill Gorcunov
  0 siblings, 1 reply; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-04 12:20 UTC (permalink / raw)
  To: Pekka Enberg; +Cc: Sasha Levin, Asias He, Ingo Molnar, KVM-ML

On Sat, Feb 04, 2012 at 02:15:36PM +0200, Pekka Enberg wrote:
> On Fri, 3 Feb 2012, Cyrill Gorcunov wrote:
> >If guest name is used (which is default case) the kvm might end
> >up carrying the pointer to name which is allocated on stack.
> >
> >kvm_cmd_run_init
> > (on stack) default_name
> > kvm__init(..., default_name)
> >   kvm->name = default_name
> >
> >So I think better to allow kvm to carry own copy
> >of guest name. 64 symbols should be more than enough.
> >
> >Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> >---
> >
> >I hope I didn't miss anything?
> 
> Can't we just use strdup()?
> 

Yeah, I think this will be even better, I'll update.

	Cyrill

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] kvm tool: Make kvm structure to carry name copy
  2012-02-04 12:20   ` Cyrill Gorcunov
@ 2012-02-04 12:26     ` Cyrill Gorcunov
  2012-02-04 12:57       ` Pekka Enberg
  0 siblings, 1 reply; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-04 12:26 UTC (permalink / raw)
  To: Pekka Enberg, Sasha Levin, Asias He, Ingo Molnar, KVM-ML

On Sat, Feb 04, 2012 at 04:20:05PM +0400, Cyrill Gorcunov wrote:
> On Sat, Feb 04, 2012 at 02:15:36PM +0200, Pekka Enberg wrote:
> > On Fri, 3 Feb 2012, Cyrill Gorcunov wrote:
> > >If guest name is used (which is default case) the kvm might end
> > >up carrying the pointer to name which is allocated on stack.
> > >
> > >kvm_cmd_run_init
> > > (on stack) default_name
> > > kvm__init(..., default_name)
> > >   kvm->name = default_name
> > >
> > >So I think better to allow kvm to carry own copy
> > >of guest name. 64 symbols should be more than enough.
> > >
> > >Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
> > >---
> > >
> > >I hope I didn't miss anything?
> > 
> > Can't we just use strdup()?
> > 
> 
> Yeah, I think this will be even better, I'll update.
> 

Something like below I think.

	Cyrill
---
Subject: [PATCH] kvm tool: Make kvm structure to carry name copy

If default guest name is used (which is the default
case) the kvm might end up carrying the pointer to
a name which is allocated on stack.

kvm_cmd_run_init
  (on stack) default_name
  kvm__init(..., default_name)
    kvm->name = default_name

So make it to carry a copy of name.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

 tools/kvm/kvm.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

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
@@ -254,6 +254,7 @@ int kvm__exit(struct kvm *kvm)
 	kvm__arch_delete_ram(kvm);
 	kvm_ipc__stop();
 	kvm__remove_socket(kvm->name);
+	free((void *)kvm->name);
 	free(kvm);
 
 	return 0;
@@ -377,6 +378,12 @@ struct kvm *kvm__init(const char *kvm_de
 		goto cleanup;
 	}
 
+	kvm->name = strdup(name);
+	if (!kvm->name) {
+		ret = -ENOMEM;
+		goto cleanup;
+	}
+
 	if (kvm__check_extensions(kvm)) {
 		pr_err("A required KVM extention is not supported by OS");
 		ret = -ENOSYS;
@@ -384,8 +391,6 @@ struct kvm *kvm__init(const char *kvm_de
 
 	kvm__arch_init(kvm, hugetlbfs_path, ram_size);
 
-	kvm->name = name;
-
 	kvm_ipc__start(kvm__create_socket(kvm));
 	kvm_ipc__register_handler(KVM_IPC_PID, kvm__pid);
 	return kvm;

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] kvm tool: Make kvm structure to carry name copy
  2012-02-04 12:26     ` Cyrill Gorcunov
@ 2012-02-04 12:57       ` Pekka Enberg
  2012-02-04 13:08         ` Cyrill Gorcunov
  0 siblings, 1 reply; 6+ messages in thread
From: Pekka Enberg @ 2012-02-04 12:57 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
> @@ -254,6 +254,7 @@ int kvm__exit(struct kvm *kvm)
> 	kvm__arch_delete_ram(kvm);
> 	kvm_ipc__stop();
> 	kvm__remove_socket(kvm->name);
> +	free((void *)kvm->name);

Please fix the struct definition and drop the cast.

> 	free(kvm);
>
> 	return 0;
> @@ -377,6 +378,12 @@ struct kvm *kvm__init(const char *kvm_de

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] kvm tool: Make kvm structure to carry name copy
  2012-02-04 12:57       ` Pekka Enberg
@ 2012-02-04 13:08         ` Cyrill Gorcunov
  0 siblings, 0 replies; 6+ messages in thread
From: Cyrill Gorcunov @ 2012-02-04 13:08 UTC (permalink / raw)
  To: Pekka Enberg; +Cc: Sasha Levin, Asias He, Ingo Molnar, KVM-ML

On Sat, Feb 04, 2012 at 02:57:23PM +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
> >@@ -254,6 +254,7 @@ int kvm__exit(struct kvm *kvm)
> >	kvm__arch_delete_ram(kvm);
> >	kvm_ipc__stop();
> >	kvm__remove_socket(kvm->name);
> >+	free((void *)kvm->name);
> 
> Please fix the struct definition and drop the cast.
> 

I believe having it as const char * might save us some
potential troubles, but sure, here we go ;)

	Cyrill
---
kvm tool: Make kvm structure to carry name copy

If default guest name is used (which is the default
case) the kvm might end up carrying the pointer to
a name which is allocated on stack.

kvm_cmd_run_init
  (on stack) default_name
  kvm__init(..., default_name)
    kvm->name = default_name

So make it to carry a copy of name.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---

 tools/kvm/kvm.c                          |    9 +++++++--
 tools/kvm/powerpc/include/kvm/kvm-arch.h |    2 +-
 tools/kvm/x86/include/kvm/kvm-arch.h     |    2 +-
 3 files changed, 9 insertions(+), 4 deletions(-)

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
@@ -254,6 +254,7 @@ int kvm__exit(struct kvm *kvm)
 	kvm__arch_delete_ram(kvm);
 	kvm_ipc__stop();
 	kvm__remove_socket(kvm->name);
+	free(kvm->name);
 	free(kvm);
 
 	return 0;
@@ -377,6 +378,12 @@ struct kvm *kvm__init(const char *kvm_de
 		goto cleanup;
 	}
 
+	kvm->name = strdup(name);
+	if (!kvm->name) {
+		ret = -ENOMEM;
+		goto cleanup;
+	}
+
 	if (kvm__check_extensions(kvm)) {
 		pr_err("A required KVM extention is not supported by OS");
 		ret = -ENOSYS;
@@ -384,8 +391,6 @@ struct kvm *kvm__init(const char *kvm_de
 
 	kvm__arch_init(kvm, hugetlbfs_path, ram_size);
 
-	kvm->name = name;
-
 	kvm_ipc__start(kvm__create_socket(kvm));
 	kvm_ipc__register_handler(KVM_IPC_PID, kvm__pid);
 	return kvm;
Index: linux-2.6.git/tools/kvm/powerpc/include/kvm/kvm-arch.h
===================================================================
--- linux-2.6.git.orig/tools/kvm/powerpc/include/kvm/kvm-arch.h
+++ linux-2.6.git/tools/kvm/powerpc/include/kvm/kvm-arch.h
@@ -64,7 +64,7 @@ struct kvm {
 	unsigned long		fdt_gra;
 	unsigned long		initrd_gra;
 	unsigned long		initrd_size;
-	const char		*name;
+	char			*name;
 	int			vm_state;
 };
 
Index: linux-2.6.git/tools/kvm/x86/include/kvm/kvm-arch.h
===================================================================
--- linux-2.6.git.orig/tools/kvm/x86/include/kvm/kvm-arch.h
+++ linux-2.6.git/tools/kvm/x86/include/kvm/kvm-arch.h
@@ -48,7 +48,7 @@ struct kvm {
 	struct disk_image       **disks;
 	int                     nr_disks;
 
-	const char		*name;
+	char			*name;
 
 	int			vm_state;
 };

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2012-02-04 13:08 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-02-03 19:57 [PATCH] kvm tool: Make kvm structure to carry name copy Cyrill Gorcunov
2012-02-04 12:15 ` Pekka Enberg
2012-02-04 12:20   ` Cyrill Gorcunov
2012-02-04 12:26     ` Cyrill Gorcunov
2012-02-04 12:57       ` Pekka Enberg
2012-02-04 13:08         ` Cyrill Gorcunov

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