[Xen-devel] [PATCH v3 01/10] xen: make xen loader callable multiple times

[Juergen Gross <jgross@xxxxxxxx>]

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@xxxxxxxx>
---
 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;
 
   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"
-- 
2.6.2


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