GCC 17 (upcoming release) is updating the type of
__stack_chk_guard from a void * to a uintptr_t.
This is only a type change, not a size change. However,
it does cause the GCC 17 build to fail because of the
type mismatch.
uintptr_t is defined as unsigned long, which is not
a type edk2 defines. It has the same size as UINTN
on a given system, but on 64 bit systems we have the
same type issue because UINTN is defined as unsigned long long,
not unsigned long.
To work around this and avoid defining a new type in edk2,
use the compiler built in __UINTPTR_TYPE__ which is the
underlying definition in GCC.
This is a backwards compatible change with previous versions
of GCC and CLANGDWARF but also fixes the upcoming definition
change for GCC 17.
Signed-off-by: Oliver Smith-Denny <osde@microsoft.com>
StackCheckLib defines the interface between a compiler
and the stack checking code. It is being converted from
a NULL library class to an actual library class to make
it easier to use for a platform and be easier to define
the expected interface with a compiler, so if there is
a compiler change it can be tracked and caught.
Signed-off-by: Oliver Smith-Denny <osde@microsoft.com>
StackCheckLib contains the required functionality for initializing
the stack cookie value, checking the value, and triggering an interrupt
when a mismatch occurs. The stack cookie is a random value placed on the
stack between the stack variables and the return address so that
continuously writing past the stack variables will cause the stack cookie
to be overwritten. Before the function returns, the stack cookie value
will be checked and if there is a mismatch then StackCheckLib handles the
failure.
Because UEFI doesn't use the C runtime libraries provided by MSVC, the
stack check code is written in assembly within this library. GCC and
Clang compilers have built-in support for stack cookie checking, so this
library only handles failures.
Signed-off-by: Oliver Smith-Denny <osde@linux.microsoft.com>
