Re: [PATCH v6] Avoid crash calling PrintErrMesg from efi_multiboot2

[Frediano Ziglio <frediano.ziglio@xxxxxxxxx>]

On Mon, Feb 17, 2025 at 4:41 PM Andrew Cooper <andrew.cooper3@xxxxxxxxxx> wrote:
>
> On 17/02/2025 4:31 pm, Jan Beulich wrote:
> > On 17.02.2025 17:26, Frediano Ziglio wrote:
> >> --- a/xen/common/efi/efi-common.mk
> >> +++ b/xen/common/efi/efi-common.mk
> >> @@ -2,6 +2,7 @@ EFIOBJ-y := boot.init.o pe.init.o ebmalloc.o runtime.o
> >>  EFIOBJ-$(CONFIG_COMPAT) += compat.o
> >>
> >>  CFLAGS-y += -fshort-wchar
> >> +CFLAGS-y += -fno-jump-tables
> >>  CFLAGS-y += -iquote $(srctree)/common/efi
> >>  CFLAGS-y += -iquote $(srcdir)
> > Do source files other than boot.c really need this? Do any other files 
> > outside
> > of efi/ maybe also need this (iirc this point was made along with the v5 
> > comment
> > you got)?
>
> Every TU reachable from efi_multiboot2() needs this, because all of
> those have logic executed at an incorrect virtual address.
>
> ~Andrew

I assume all the files in efi directory will deal with EFI boot so
it's good to have the option enabled for the files inside the
directory. The only exception seems runtime.c file.
About external dependencies not sure how to detect them (beside
looking at all symbols).

Frediano