[v8,1/5] efi/boot.c: add file.need_to_free

Commit Message

Trammell Hudson Sept. 30, 2020, noon UTC

The config file, kernel, initrd, etc should only be freed if they
are allocated with the UEFI allocator.  On x86 the ucode, and on
ARM the dtb, are also marked as need_to_free when allocated or
expanded.

This also fixes a memory leak in ARM fdt_increase_size() if there
is an error in building the new device tree.

Signed-off-by: Trammell Hudson <[e-mail]>
---
 xen/arch/arm/efi/efi-boot.h | 11 +++++++++--
 xen/arch/x86/efi/efi-boot.h |  2 +-
 xen/common/efi/boot.c       | 10 ++++++----
 3 files changed, 16 insertions(+), 7 deletions(-)

Comments

Jan Beulich Oct. 2, 2020, 8:15 a.m. UTC | #1

On 30.09.2020 14:00, Trammell Hudson wrote:
> The config file, kernel, initrd, etc should only be freed if they
> are allocated with the UEFI allocator.  On x86 the ucode, and on
> ARM the dtb, are also marked as need_to_free when allocated or
> expanded.
> 
> This also fixes a memory leak in ARM fdt_increase_size() if there
> is an error in building the new device tree.
> 
> Signed-off-by: Trammell Hudson <[e-mail]>

Reviewed-by: Jan Beulich <[e-mail]>

Patch

diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
index 27dd0b1a94..c6200fda0e 100644
--- a/xen/arch/arm/efi/efi-boot.h
+++ b/xen/arch/arm/efi/efi-boot.h
@@ -314,7 +314,10 @@  static void __init *fdt_increase_size(struct file *fdtfile, int add_size)
     if ( fdt_size )
     {
         if ( fdt_open_into(dtbfile.ptr, new_fdt, pages * EFI_PAGE_SIZE) )
+        {
+            efi_bs->FreePages(fdt_addr, pages);
             return NULL;
+        }
     }
     else
     {
@@ -326,7 +329,10 @@  static void __init *fdt_increase_size(struct file *fdtfile, int add_size)
          * system table that is passed in the FDT.
          */
         if ( fdt_create_empty_tree(new_fdt, pages * EFI_PAGE_SIZE) )
+        {
+            efi_bs->FreePages(fdt_addr, pages);
             return NULL;
+        }
     }
 
     /*
@@ -335,12 +341,13 @@  static void __init *fdt_increase_size(struct file *fdtfile, int add_size)
      * code will free it.  If the original FDT came from a configuration
      * table, we don't own that memory and can't free it.
      */
-    if ( dtbfile.size )
+    if ( dtbfile.need_to_free )
         efi_bs->FreePages(dtbfile.addr, PFN_UP(dtbfile.size));
 
     /* Update 'file' info for new memory so we clean it up on error exits */
     dtbfile.addr = fdt_addr;
     dtbfile.size = pages * EFI_PAGE_SIZE;
+    dtbfile.need_to_free = true;
     return new_fdt;
 }
 
@@ -546,7 +553,7 @@  static void __init efi_arch_cpu(void)
 
 static void __init efi_arch_blexit(void)
 {
-    if ( dtbfile.addr && dtbfile.size )
+    if ( dtbfile.need_to_free )
         efi_bs->FreePages(dtbfile.addr, PFN_UP(dtbfile.size));
     if ( memmap )
         efi_bs->FreePool(memmap);
diff --git a/xen/arch/x86/efi/efi-boot.h b/xen/arch/x86/efi/efi-boot.h
index eef3f52789..1025000afd 100644
--- a/xen/arch/x86/efi/efi-boot.h
+++ b/xen/arch/x86/efi/efi-boot.h
@@ -689,7 +689,7 @@  static void __init efi_arch_cpu(void)
 
 static void __init efi_arch_blexit(void)
 {
-    if ( ucode.addr )
+    if ( ucode.need_to_free )
         efi_bs->FreePages(ucode.addr, PFN_UP(ucode.size));
 }
 
diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c
index 157fe0e8c5..c2ce0c7294 100644
--- a/xen/common/efi/boot.c
+++ b/xen/common/efi/boot.c
@@ -102,6 +102,7 @@  union string {
 
 struct file {
     UINTN size;
+    bool need_to_free;
     union {
         EFI_PHYSICAL_ADDRESS addr;
         char *str;
@@ -280,13 +281,13 @@  void __init noreturn blexit(const CHAR16 *str)
     if ( !efi_bs )
         efi_arch_halt();
 
-    if ( cfg.addr )
+    if ( cfg.need_to_free )
         efi_bs->FreePages(cfg.addr, PFN_UP(cfg.size));
-    if ( kernel.addr )
+    if ( kernel.need_to_free )
         efi_bs->FreePages(kernel.addr, PFN_UP(kernel.size));
-    if ( ramdisk.addr )
+    if ( ramdisk.need_to_free )
         efi_bs->FreePages(ramdisk.addr, PFN_UP(ramdisk.size));
-    if ( xsm.addr )
+    if ( xsm.need_to_free )
         efi_bs->FreePages(xsm.addr, PFN_UP(xsm.size));
 
     efi_arch_blexit();
@@ -581,6 +582,7 @@  static bool __init read_file(EFI_FILE_HANDLE dir_handle, CHAR16 *name,
     }
     else
     {
+        file->need_to_free = true;
         file->size = size;
         if ( file != &cfg )
         {