EFI: further "need_to_free" adjustments

When processing "chain" directives, the previously loaded config file
gets freed. This needs to be recorded accordingly such that no error
path would try to free the same block of memory a 2nd time.

Furthermore, neither .addr nor .size being zero has any meaning towards
the need to free an allocated chunk anymore. Drop (from read_file()) and
replace (in Arm's efi_arch_use_config_file(), to sensibly retain the
comment) respective assignments.

Fixes: 04be2c3a0678 ("efi/boot.c: add file.need_to_free")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
index f64a6604af5b21477ce7c7836005c8229d8d6068..cf9c37153feafc2d1c65215a03579e0d689b11b3 100644 (file)
--- a/xen/arch/arm/efi/efi-boot.h
+++ b/xen/arch/arm/efi/efi-boot.h
@@ -591,7 +591,7 @@ static bool __init efi_arch_use_config_file(EFI_SYSTEM_TABLE *SystemTable)
 
     fdt = lookup_fdt_config_table(SystemTable);
     dtbfile.ptr = fdt;
-    dtbfile.size = 0;  /* Config table memory can't be freed, so set size to 0 */
+    dtbfile.need_to_free = false; /* Config table memory can't be freed. */
     if ( !fdt || fdt_node_offset_by_compatible(fdt, 0, "multiboot,module") < 0 )
     {
         /*

diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index eb1ef91ba418debf59033b10a6b809d832bda57e..63e289ab850617ce882fef6b95d927fd386576e5 100644 (file)
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -601,10 +601,7 @@ static bool __init read_file(EFI_FILE_HANDLE dir_handle, CHAR16 *name,
                                     PFN_UP(size), &file->addr);
     }
     if ( EFI_ERROR(ret) )
-    {
-        file->addr = 0;
         what = what ?: L"Allocation";
-    }
     else
     {
         file->need_to_free = true;
@@ -1271,8 +1268,11 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable)
             name.s = get_value(&cfg, "global", "chain");
             if ( !name.s )
                 break;
-            efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
-            cfg.addr = 0;
+            if ( cfg.need_to_free )
+            {
+                efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
+                cfg.need_to_free = false;
+            }
             if ( !read_file(dir_handle, s2w(&name), &cfg, NULL) )
             {
                 PrintStr(L"Chained configuration file '");