Re: [PATCH v6 2/5] efi/boot.c: add file.need_to_free

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Tue, Sep 29, 2020 at 01:00:06PM +0200, Jan Beulich wrote:
> On 29.09.2020 12:45, Roger Pau Monné wrote:
> > On Mon, Sep 21, 2020 at 07:51:10AM -0400, Trammell Hudson wrote:
> >> --- 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 )
> > 
> > If you drop the addr check here...
> > 
> >>          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;
> > 
> > ... I think you need to clear need_to_free if AllocatePages fails?
> 
> But this has been moved to the success path, or am I overlooking
> anything?

Oh yes, sorry, somehow I looked at the wrong context. Please ignore my
comment.

Roger.