On Fri, Nov 13, 2020 at 10:26:54AM -0800, Sami Tolvanen wrote:
> e820__mapped_all is passed as a callback to is_mmconf_reserved, which
> expects a function of type:
>
> typedef bool (*check_reserved_t)(u64 start, u64 end, unsigned type);
>
> This trips indirect call checking with Clang's Control-Flow Integrity
> (CFI). Change the last argument from enum e820_type to unsigned to fix
> the type mismatch.
>
> Reported-by: Sedat Dilek <sedat.di...@gmail.com>
> Signed-off-by: Sami Tolvanen <samitolva...@google.com>
> ---
> arch/x86/include/asm/e820/api.h | 2 +-
> arch/x86/kernel/e820.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h
> index e8f58ddd06d9..e872a796619d 100644
> --- a/arch/x86/include/asm/e820/api.h
> +++ b/arch/x86/include/asm/e820/api.h
> @@ -12,7 +12,7 @@ extern unsigned long pci_mem_start;
>
> extern bool e820__mapped_raw_any(u64 start, u64 end, enum e820_type type);
> extern bool e820__mapped_any(u64 start, u64 end, enum e820_type type);
> -extern bool e820__mapped_all(u64 start, u64 end, enum e820_type type);
> +extern bool e820__mapped_all(u64 start, u64 end, unsigned type);
I think the proper fix is to fix the typedef to:
typedef bool (*check_reserved_t)(u64 start, u64 end, enum e820_type
type);
because
* is_mmconf_reserved() is passing in E820_TYPE_RESERVED which is enum e820_type
* is_acpi_reserved() is the other check_reserved_t function ptr and the last arg
type there is unused so it can just as well be enum e820_type.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
