[Xen-changelog] [xen stable-4.4] efi: avoid calling boot services after ExitBootServices()

[patchbot@xxxxxxx]

commit e50f0478955a800aa31a643dcfbeb13d33194dc9
Author:     Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
AuthorDate: Thu Jun 18 09:36:25 2015 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Jun 18 09:36:25 2015 +0200

    efi: avoid calling boot services after ExitBootServices()
    
    After the first call to ExitBootServices(), avoid calling any boot
    services (except GetMemoryMap() and ExitBootServices()) by setting
    setting efi_bs to NULL and halting in blexit(). Only GetMemoryMap() and
    ExitBootServices() are explicitly allowed to be called after the first
    call to ExitBootServices() and so are are called via
    SystemTable->BootServices.
    
    Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
    Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
    master commit: d4300db3a03a0cd999745135d7879fc4b6b5aa61
    master date: 2015-06-10 12:00:10 +0200
---
 xen/arch/x86/efi/boot.c |   17 ++++++++++++++---
 1 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/xen/arch/x86/efi/boot.c b/xen/arch/x86/efi/boot.c
index 598cf76..98dd60f 100644
--- a/xen/arch/x86/efi/boot.c
+++ b/xen/arch/x86/efi/boot.c
@@ -189,6 +189,13 @@ static void __init __attribute__((__noreturn__)) 
blexit(const CHAR16 *str)
         PrintStr((CHAR16 *)str);
     PrintStr(newline);
 
+    if ( !efi_bs )
+    {
+        local_irq_disable();
+        for ( ; ; )
+            halt();
+    }
+
     if ( cfg.addr )
         efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
     if ( kernel.addr )
@@ -1393,8 +1400,10 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
*SystemTable)
         struct e820entry *e;
 
         efi_memmap_size = info_size;
-        status = efi_bs->GetMemoryMap(&efi_memmap_size, efi_memmap, &map_key,
-                                      &efi_mdesc_size, &mdesc_ver);
+        status = SystemTable->BootServices->GetMemoryMap(&efi_memmap_size,
+                                                         efi_memmap, &map_key,
+                                                         &efi_mdesc_size,
+                                                         &mdesc_ver);
         if ( EFI_ERROR(status) )
             PrintErrMesg(L"Cannot obtain memory map", status);
 
@@ -1457,7 +1466,9 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE 
*SystemTable)
             relocate_trampoline(cfg.addr);
         }
 
-        status = efi_bs->ExitBootServices(ImageHandle, map_key);
+        status = SystemTable->BootServices->ExitBootServices(ImageHandle,
+                                                             map_key);
+        efi_bs = NULL;
         if ( status != EFI_INVALID_PARAMETER || retry )
             break;
     }
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.4

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