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Re: [PATCH v3 01/10] xen: make xen loader callable multiple times
From: |
Juergen Gross |
Subject: |
Re: [PATCH v3 01/10] xen: make xen loader callable multiple times |
Date: |
Thu, 18 Feb 2016 11:32:16 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 |
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 <address@hidden>
>> ---
>> 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
>
- Re: [PATCH v3 03/10] xen: add elfnote.h to avoid using numbers instead of constants, (continued)
[PATCH v3 08/10] xen: add capability to load initrd outside of initial mapping, Juergen Gross, 2016/02/17
[PATCH v3 04/10] xen: synchronize xen header, Juergen Gross, 2016/02/17