diff mbox

[v3,01/10] xen: make xen loader callable multiple times

Message ID 1455729577-23702-2-git-send-email-jgross@suse.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jürgen Groß Feb. 17, 2016, 5:19 p.m. UTC
The loader for xen paravirtualized environment isn't callable multiple
times as it won't free any memory in case of failure.

Call grub_relocator_unload() as other modules do it before allocating
a new relocator or when unloading the module.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 grub-core/loader/i386/xen.c        | 28 +++++++++++++++++++---------
 grub-core/loader/i386/xen_fileXX.c | 17 +++++++++++------
 2 files changed, 30 insertions(+), 15 deletions(-)

Comments

Daniel Kiper Feb. 18, 2016, 10:12 a.m. UTC | #1
On Wed, Feb 17, 2016 at 06:19:28PM +0100, Juergen Gross wrote:
> The loader for xen paravirtualized environment isn't callable multiple
> times as it won't free any memory in case of failure.
>
> Call grub_relocator_unload() as other modules do it before allocating

Do you mean grub_xen_reset?

> a new relocator or when unloading the module.
>
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
>  grub-core/loader/i386/xen.c        | 28 +++++++++++++++++++---------
>  grub-core/loader/i386/xen_fileXX.c | 17 +++++++++++------
>  2 files changed, 30 insertions(+), 15 deletions(-)
>
> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
> index c4d9689..ff7c553 100644
> --- a/grub-core/loader/i386/xen.c
> +++ b/grub-core/loader/i386/xen.c
> @@ -316,11 +316,23 @@ grub_xen_boot (void)
>  				  xen_inf.virt_base);
>  }
>
> +static void
> +grub_xen_reset (void)
> +{
> +  grub_memset (&next_start, 0, sizeof (next_start));
> +  xen_module_info_page = NULL;
> +  n_modules = 0;
> +
> +  grub_relocator_unload (relocator);
> +  relocator = NULL;
> +  loaded = 0;
> +}
> +
>  static grub_err_t
>  grub_xen_unload (void)
>  {
> +  grub_xen_reset ();
>    grub_dl_unref (my_mod);
> -  loaded = 0;
>    return GRUB_ERR_NONE;
>  }
>
> @@ -403,10 +415,7 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
>
>    grub_loader_unset ();
>
> -  grub_memset (&next_start, 0, sizeof (next_start));
> -
> -  xen_module_info_page = NULL;
> -  n_modules = 0;
> +  grub_xen_reset ();
>
>    grub_create_loader_cmdline (argc - 1, argv + 1,
>  			      (char *) next_start.cmd_line,
> @@ -503,16 +512,17 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
>    goto fail;
>
>  fail:
> +  err = grub_errno;

I do not think this is needed.

>    if (elf)
>      grub_elf_close (elf);
>    else if (file)
>      grub_file_close (file);
>
> -  if (grub_errno != GRUB_ERR_NONE)
> -    loaded = 0;
> +  if (err != GRUB_ERR_NONE)
> +    grub_xen_reset ();
>
> -  return grub_errno;
> +  return err;
>  }
>
>  static grub_err_t
> @@ -552,7 +562,7 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
>      {
>        err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, size);
>        if (err)
> -	return err;
> +	goto fail;

It looks that this change should not be part of this patch.

>        if (grub_initrd_load (&initrd_ctx, argv,
>  			    get_virtual_current_address (ch)))
> diff --git a/grub-core/loader/i386/xen_fileXX.c b/grub-core/loader/i386/xen_fileXX.c
> index 1ba5649..5475819 100644
> --- a/grub-core/loader/i386/xen_fileXX.c
> +++ b/grub-core/loader/i386/xen_fileXX.c
> @@ -35,7 +35,8 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>    if (grub_file_read (elf->file, buf, sz) != (grub_ssize_t) sz)
>      {
>        if (grub_errno)
> -	return grub_errno;
> +	goto out;
> +      grub_free (buf);

Ditto.

>        return grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
>  			 elf->file->name);
>      }
> @@ -123,14 +124,14 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>  	{
>  	  xi->virt_base = grub_strtoull (ptr + sizeof ("VIRT_BASE=") - 1, &ptr, 16);
>  	  if (grub_errno)
> -	    return grub_errno;
> +	    goto out;

Ditto.

>  	  continue;
>  	}
>        if (grub_strncmp (ptr, "VIRT_ENTRY=", sizeof ("VIRT_ENTRY=") - 1) == 0)
>  	{
>  	  xi->entry_point = grub_strtoull (ptr + sizeof ("VIRT_ENTRY=") - 1, &ptr, 16);
>  	  if (grub_errno)
> -	    return grub_errno;
> +	    goto out;

Ditto.

>  	  continue;
>  	}
>        if (grub_strncmp (ptr, "HYPERCALL_PAGE=", sizeof ("HYPERCALL_PAGE=") - 1) == 0)
> @@ -138,7 +139,7 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>  	  xi->hypercall_page = grub_strtoull (ptr + sizeof ("HYPERCALL_PAGE=") - 1, &ptr, 16);
>  	  xi->has_hypercall_page = 1;
>  	  if (grub_errno)
> -	    return grub_errno;
> +	    goto out;

Ditto.

>  	  continue;
>  	}
>        if (grub_strncmp (ptr, "ELF_PADDR_OFFSET=", sizeof ("ELF_PADDR_OFFSET=") - 1) == 0)
> @@ -146,7 +147,7 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>  	  xi->paddr_offset = grub_strtoull (ptr + sizeof ("ELF_PADDR_OFFSET=") - 1, &ptr, 16);
>  	  has_paddr = 1;
>  	  if (grub_errno)
> -	    return grub_errno;
> +	    goto out;

Ditto.

>  	  continue;
>  	}
>      }
> @@ -154,7 +155,11 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>      xi->hypercall_page = (xi->hypercall_page << 12) + xi->virt_base;
>    if (!has_paddr)
>      xi->paddr_offset = xi->virt_base;
> -  return GRUB_ERR_NONE;
> +
> +out:
> +  grub_free (buf);
> +
> +  return grub_errno;

Make sense but this should be separate patch.

Daniel
Jürgen Groß Feb. 18, 2016, 10:32 a.m. UTC | #2
On 18/02/16 11:12, Daniel Kiper wrote:
> On Wed, Feb 17, 2016 at 06:19:28PM +0100, Juergen Gross wrote:
>> The loader for xen paravirtualized environment isn't callable multiple
>> times as it won't free any memory in case of failure.
>>
>> Call grub_relocator_unload() as other modules do it before allocating
> 
> Do you mean grub_xen_reset?

No. I do want to call grub_relocator_unload() and I'm doing it in
grub_xen_reset(). Other modules don't call grub_xen_reset(). :-)

> 
>> a new relocator or when unloading the module.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>>  grub-core/loader/i386/xen.c        | 28 +++++++++++++++++++---------
>>  grub-core/loader/i386/xen_fileXX.c | 17 +++++++++++------
>>  2 files changed, 30 insertions(+), 15 deletions(-)
>>
>> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
>> index c4d9689..ff7c553 100644
>> --- a/grub-core/loader/i386/xen.c
>> +++ b/grub-core/loader/i386/xen.c
>> @@ -316,11 +316,23 @@ grub_xen_boot (void)
>>  				  xen_inf.virt_base);
>>  }
>>
>> +static void
>> +grub_xen_reset (void)
>> +{
>> +  grub_memset (&next_start, 0, sizeof (next_start));
>> +  xen_module_info_page = NULL;
>> +  n_modules = 0;
>> +
>> +  grub_relocator_unload (relocator);
>> +  relocator = NULL;
>> +  loaded = 0;
>> +}
>> +
>>  static grub_err_t
>>  grub_xen_unload (void)
>>  {
>> +  grub_xen_reset ();
>>    grub_dl_unref (my_mod);
>> -  loaded = 0;
>>    return GRUB_ERR_NONE;
>>  }
>>
>> @@ -403,10 +415,7 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
>>
>>    grub_loader_unset ();
>>
>> -  grub_memset (&next_start, 0, sizeof (next_start));
>> -
>> -  xen_module_info_page = NULL;
>> -  n_modules = 0;
>> +  grub_xen_reset ();
>>
>>    grub_create_loader_cmdline (argc - 1, argv + 1,
>>  			      (char *) next_start.cmd_line,
>> @@ -503,16 +512,17 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
>>    goto fail;
>>
>>  fail:
>> +  err = grub_errno;
> 
> I do not think this is needed.

grub_elf_close() and others might clobber grub_errno.

>>    if (elf)
>>      grub_elf_close (elf);
>>    else if (file)
>>      grub_file_close (file);
>>
>> -  if (grub_errno != GRUB_ERR_NONE)
>> -    loaded = 0;
>> +  if (err != GRUB_ERR_NONE)
>> +    grub_xen_reset ();
>>
>> -  return grub_errno;
>> +  return err;
>>  }
>>
>>  static grub_err_t
>> @@ -552,7 +562,7 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
>>      {
>>        err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, size);
>>        if (err)
>> -	return err;
>> +	goto fail;
> 
> It looks that this change should not be part of this patch.

Why not? It's correcting a memory leak in case of failure. Like the
other cases below, too. That's the purpose of this patch, after all.


Juergen

> 
>>        if (grub_initrd_load (&initrd_ctx, argv,
>>  			    get_virtual_current_address (ch)))
>> diff --git a/grub-core/loader/i386/xen_fileXX.c b/grub-core/loader/i386/xen_fileXX.c
>> index 1ba5649..5475819 100644
>> --- a/grub-core/loader/i386/xen_fileXX.c
>> +++ b/grub-core/loader/i386/xen_fileXX.c
>> @@ -35,7 +35,8 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>>    if (grub_file_read (elf->file, buf, sz) != (grub_ssize_t) sz)
>>      {
>>        if (grub_errno)
>> -	return grub_errno;
>> +	goto out;
>> +      grub_free (buf);
> 
> Ditto.
> 
>>        return grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
>>  			 elf->file->name);
>>      }
>> @@ -123,14 +124,14 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>>  	{
>>  	  xi->virt_base = grub_strtoull (ptr + sizeof ("VIRT_BASE=") - 1, &ptr, 16);
>>  	  if (grub_errno)
>> -	    return grub_errno;
>> +	    goto out;
> 
> Ditto.
> 
>>  	  continue;
>>  	}
>>        if (grub_strncmp (ptr, "VIRT_ENTRY=", sizeof ("VIRT_ENTRY=") - 1) == 0)
>>  	{
>>  	  xi->entry_point = grub_strtoull (ptr + sizeof ("VIRT_ENTRY=") - 1, &ptr, 16);
>>  	  if (grub_errno)
>> -	    return grub_errno;
>> +	    goto out;
> 
> Ditto.
> 
>>  	  continue;
>>  	}
>>        if (grub_strncmp (ptr, "HYPERCALL_PAGE=", sizeof ("HYPERCALL_PAGE=") - 1) == 0)
>> @@ -138,7 +139,7 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>>  	  xi->hypercall_page = grub_strtoull (ptr + sizeof ("HYPERCALL_PAGE=") - 1, &ptr, 16);
>>  	  xi->has_hypercall_page = 1;
>>  	  if (grub_errno)
>> -	    return grub_errno;
>> +	    goto out;
> 
> Ditto.
> 
>>  	  continue;
>>  	}
>>        if (grub_strncmp (ptr, "ELF_PADDR_OFFSET=", sizeof ("ELF_PADDR_OFFSET=") - 1) == 0)
>> @@ -146,7 +147,7 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>>  	  xi->paddr_offset = grub_strtoull (ptr + sizeof ("ELF_PADDR_OFFSET=") - 1, &ptr, 16);
>>  	  has_paddr = 1;
>>  	  if (grub_errno)
>> -	    return grub_errno;
>> +	    goto out;
> 
> Ditto.
> 
>>  	  continue;
>>  	}
>>      }
>> @@ -154,7 +155,11 @@ parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
>>      xi->hypercall_page = (xi->hypercall_page << 12) + xi->virt_base;
>>    if (!has_paddr)
>>      xi->paddr_offset = xi->virt_base;
>> -  return GRUB_ERR_NONE;
>> +
>> +out:
>> +  grub_free (buf);
>> +
>> +  return grub_errno;
> 
> Make sense but this should be separate patch.
> 
> Daniel
>
Daniel Kiper Feb. 18, 2016, 4:58 p.m. UTC | #3
On Thu, Feb 18, 2016 at 11:32:16AM +0100, Juergen Gross wrote:
> On 18/02/16 11:12, Daniel Kiper wrote:
> > On Wed, Feb 17, 2016 at 06:19:28PM +0100, Juergen Gross wrote:
> >> The loader for xen paravirtualized environment isn't callable multiple
> >> times as it won't free any memory in case of failure.
> >>
> >> Call grub_relocator_unload() as other modules do it before allocating
> >
> > Do you mean grub_xen_reset?
>
> No. I do want to call grub_relocator_unload() and I'm doing it in
> grub_xen_reset(). Other modules don't call grub_xen_reset(). :-)
>
> >
> >> a new relocator or when unloading the module.
> >>
> >> Signed-off-by: Juergen Gross <jgross@suse.com>
> >> ---
> >>  grub-core/loader/i386/xen.c        | 28 +++++++++++++++++++---------
> >>  grub-core/loader/i386/xen_fileXX.c | 17 +++++++++++------
> >>  2 files changed, 30 insertions(+), 15 deletions(-)
> >>
> >> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
> >> index c4d9689..ff7c553 100644
> >> --- a/grub-core/loader/i386/xen.c
> >> +++ b/grub-core/loader/i386/xen.c
> >> @@ -316,11 +316,23 @@ grub_xen_boot (void)
> >>  				  xen_inf.virt_base);
> >>  }
> >>
> >> +static void
> >> +grub_xen_reset (void)
> >> +{
> >> +  grub_memset (&next_start, 0, sizeof (next_start));
> >> +  xen_module_info_page = NULL;
> >> +  n_modules = 0;
> >> +
> >> +  grub_relocator_unload (relocator);
> >> +  relocator = NULL;
> >> +  loaded = 0;
> >> +}
> >> +
> >>  static grub_err_t
> >>  grub_xen_unload (void)
> >>  {
> >> +  grub_xen_reset ();
> >>    grub_dl_unref (my_mod);
> >> -  loaded = 0;
> >>    return GRUB_ERR_NONE;
> >>  }
> >>
> >> @@ -403,10 +415,7 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
> >>
> >>    grub_loader_unset ();
> >>
> >> -  grub_memset (&next_start, 0, sizeof (next_start));
> >> -
> >> -  xen_module_info_page = NULL;
> >> -  n_modules = 0;
> >> +  grub_xen_reset ();
> >>
> >>    grub_create_loader_cmdline (argc - 1, argv + 1,
> >>  			      (char *) next_start.cmd_line,
> >> @@ -503,16 +512,17 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
> >>    goto fail;
> >>
> >>  fail:
> >> +  err = grub_errno;
> >
> > I do not think this is needed.
>
> grub_elf_close() and others might clobber grub_errno.

OK, so, please say it in comment. It is not obvious.

> >>    if (elf)
> >>      grub_elf_close (elf);
> >>    else if (file)
> >>      grub_file_close (file);
> >>
> >> -  if (grub_errno != GRUB_ERR_NONE)
> >> -    loaded = 0;
> >> +  if (err != GRUB_ERR_NONE)
> >> +    grub_xen_reset ();
> >>
> >> -  return grub_errno;
> >> +  return err;
> >>  }
> >>
> >>  static grub_err_t
> >> @@ -552,7 +562,7 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
> >>      {
> >>        err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, size);
> >>        if (err)
> >> -	return err;
> >> +	goto fail;
> >
> > It looks that this change should not be part of this patch.
>
> Why not? It's correcting a memory leak in case of failure. Like the
> other cases below, too. That's the purpose of this patch, after all.

OK but you are referring to grub_relocator_unload() in commit message
and below you are trying to fix different memory leak in the same patch.
So, I think everything below should be separate patch.

Daniel
Jürgen Groß Feb. 19, 2016, 5:21 a.m. UTC | #4
On 18/02/16 17:58, Daniel Kiper wrote:
> On Thu, Feb 18, 2016 at 11:32:16AM +0100, Juergen Gross wrote:
>> On 18/02/16 11:12, Daniel Kiper wrote:
>>> On Wed, Feb 17, 2016 at 06:19:28PM +0100, Juergen Gross wrote:
>>>> The loader for xen paravirtualized environment isn't callable multiple
>>>> times as it won't free any memory in case of failure.
>>>>
>>>> Call grub_relocator_unload() as other modules do it before allocating
>>>
>>> Do you mean grub_xen_reset?
>>
>> No. I do want to call grub_relocator_unload() and I'm doing it in
>> grub_xen_reset(). Other modules don't call grub_xen_reset(). :-)
>>
>>>
>>>> a new relocator or when unloading the module.
>>>>
>>>> Signed-off-by: Juergen Gross <jgross@suse.com>
>>>> ---
>>>>  grub-core/loader/i386/xen.c        | 28 +++++++++++++++++++---------
>>>>  grub-core/loader/i386/xen_fileXX.c | 17 +++++++++++------
>>>>  2 files changed, 30 insertions(+), 15 deletions(-)
>>>>
>>>> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
>>>> index c4d9689..ff7c553 100644
>>>> --- a/grub-core/loader/i386/xen.c
>>>> +++ b/grub-core/loader/i386/xen.c
>>>> @@ -316,11 +316,23 @@ grub_xen_boot (void)
>>>>  				  xen_inf.virt_base);
>>>>  }
>>>>
>>>> +static void
>>>> +grub_xen_reset (void)
>>>> +{
>>>> +  grub_memset (&next_start, 0, sizeof (next_start));
>>>> +  xen_module_info_page = NULL;
>>>> +  n_modules = 0;
>>>> +
>>>> +  grub_relocator_unload (relocator);
>>>> +  relocator = NULL;
>>>> +  loaded = 0;
>>>> +}
>>>> +
>>>>  static grub_err_t
>>>>  grub_xen_unload (void)
>>>>  {
>>>> +  grub_xen_reset ();
>>>>    grub_dl_unref (my_mod);
>>>> -  loaded = 0;
>>>>    return GRUB_ERR_NONE;
>>>>  }
>>>>
>>>> @@ -403,10 +415,7 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
>>>>
>>>>    grub_loader_unset ();
>>>>
>>>> -  grub_memset (&next_start, 0, sizeof (next_start));
>>>> -
>>>> -  xen_module_info_page = NULL;
>>>> -  n_modules = 0;
>>>> +  grub_xen_reset ();
>>>>
>>>>    grub_create_loader_cmdline (argc - 1, argv + 1,
>>>>  			      (char *) next_start.cmd_line,
>>>> @@ -503,16 +512,17 @@ grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
>>>>    goto fail;
>>>>
>>>>  fail:
>>>> +  err = grub_errno;
>>>
>>> I do not think this is needed.
>>
>> grub_elf_close() and others might clobber grub_errno.
> 
> OK, so, please say it in comment. It is not obvious.

Okay.

>>>>    if (elf)
>>>>      grub_elf_close (elf);
>>>>    else if (file)
>>>>      grub_file_close (file);
>>>>
>>>> -  if (grub_errno != GRUB_ERR_NONE)
>>>> -    loaded = 0;
>>>> +  if (err != GRUB_ERR_NONE)
>>>> +    grub_xen_reset ();
>>>>
>>>> -  return grub_errno;
>>>> +  return err;
>>>>  }
>>>>
>>>>  static grub_err_t
>>>> @@ -552,7 +562,7 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
>>>>      {
>>>>        err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, size);
>>>>        if (err)
>>>> -	return err;
>>>> +	goto fail;
>>>
>>> It looks that this change should not be part of this patch.
>>
>> Why not? It's correcting a memory leak in case of failure. Like the
>> other cases below, too. That's the purpose of this patch, after all.
> 
> OK but you are referring to grub_relocator_unload() in commit message
> and below you are trying to fix different memory leak in the same patch.
> So, I think everything below should be separate patch.

Okay.


Juergen
diff mbox

Patch

diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
index c4d9689..ff7c553 100644
--- a/grub-core/loader/i386/xen.c
+++ b/grub-core/loader/i386/xen.c
@@ -316,11 +316,23 @@  grub_xen_boot (void)
 				  xen_inf.virt_base);
 }
 
+static void
+grub_xen_reset (void)
+{
+  grub_memset (&next_start, 0, sizeof (next_start));
+  xen_module_info_page = NULL;
+  n_modules = 0;
+
+  grub_relocator_unload (relocator);
+  relocator = NULL;
+  loaded = 0;
+}
+
 static grub_err_t
 grub_xen_unload (void)
 {
+  grub_xen_reset ();
   grub_dl_unref (my_mod);
-  loaded = 0;
   return GRUB_ERR_NONE;
 }
 
@@ -403,10 +415,7 @@  grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
 
   grub_loader_unset ();
 
-  grub_memset (&next_start, 0, sizeof (next_start));
-
-  xen_module_info_page = NULL;
-  n_modules = 0;
+  grub_xen_reset ();
 
   grub_create_loader_cmdline (argc - 1, argv + 1,
 			      (char *) next_start.cmd_line,
@@ -503,16 +512,17 @@  grub_cmd_xen (grub_command_t cmd __attribute__ ((unused)),
   goto fail;
 
 fail:
+  err = grub_errno;
 
   if (elf)
     grub_elf_close (elf);
   else if (file)
     grub_file_close (file);
 
-  if (grub_errno != GRUB_ERR_NONE)
-    loaded = 0;
+  if (err != GRUB_ERR_NONE)
+    grub_xen_reset ();
 
-  return grub_errno;
+  return err;
 }
 
 static grub_err_t
@@ -552,7 +562,7 @@  grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
     {
       err = grub_relocator_alloc_chunk_addr (relocator, &ch, max_addr, size);
       if (err)
-	return err;
+	goto fail;
 
       if (grub_initrd_load (&initrd_ctx, argv,
 			    get_virtual_current_address (ch)))
diff --git a/grub-core/loader/i386/xen_fileXX.c b/grub-core/loader/i386/xen_fileXX.c
index 1ba5649..5475819 100644
--- a/grub-core/loader/i386/xen_fileXX.c
+++ b/grub-core/loader/i386/xen_fileXX.c
@@ -35,7 +35,8 @@  parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
   if (grub_file_read (elf->file, buf, sz) != (grub_ssize_t) sz)
     {
       if (grub_errno)
-	return grub_errno;
+	goto out;
+      grub_free (buf);
       return grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),
 			 elf->file->name);
     }
@@ -123,14 +124,14 @@  parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
 	{
 	  xi->virt_base = grub_strtoull (ptr + sizeof ("VIRT_BASE=") - 1, &ptr, 16);
 	  if (grub_errno)
-	    return grub_errno;
+	    goto out;
 	  continue;
 	}
       if (grub_strncmp (ptr, "VIRT_ENTRY=", sizeof ("VIRT_ENTRY=") - 1) == 0)
 	{
 	  xi->entry_point = grub_strtoull (ptr + sizeof ("VIRT_ENTRY=") - 1, &ptr, 16);
 	  if (grub_errno)
-	    return grub_errno;
+	    goto out;
 	  continue;
 	}
       if (grub_strncmp (ptr, "HYPERCALL_PAGE=", sizeof ("HYPERCALL_PAGE=") - 1) == 0)
@@ -138,7 +139,7 @@  parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
 	  xi->hypercall_page = grub_strtoull (ptr + sizeof ("HYPERCALL_PAGE=") - 1, &ptr, 16);
 	  xi->has_hypercall_page = 1;
 	  if (grub_errno)
-	    return grub_errno;
+	    goto out;
 	  continue;
 	}
       if (grub_strncmp (ptr, "ELF_PADDR_OFFSET=", sizeof ("ELF_PADDR_OFFSET=") - 1) == 0)
@@ -146,7 +147,7 @@  parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
 	  xi->paddr_offset = grub_strtoull (ptr + sizeof ("ELF_PADDR_OFFSET=") - 1, &ptr, 16);
 	  has_paddr = 1;
 	  if (grub_errno)
-	    return grub_errno;
+	    goto out;
 	  continue;
 	}
     }
@@ -154,7 +155,11 @@  parse_xen_guest (grub_elf_t elf, struct grub_xen_file_info *xi,
     xi->hypercall_page = (xi->hypercall_page << 12) + xi->virt_base;
   if (!has_paddr)
     xi->paddr_offset = xi->virt_base;
-  return GRUB_ERR_NONE;
+
+out:
+  grub_free (buf);
+
+  return grub_errno;
 }
 
 #pragma GCC diagnostic ignored "-Wcast-align"