Re: [PATCH v2 2/2] x86/e820: fix the function type for e820__mapped_all

Randy Dunlap
2020-11-14T01:19:46Z

On 11/13/20 4:23 PM, 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 int 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.dilek@gmail.com>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Acked-by: Randy Dunlap <rdunlap@infradead.org>

Thanks.

> ---
> 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..a122ca2784b2 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 int type);
>
> extern void e820__range_add (u64 start, u64 size, enum e820_type type);
> extern u64 e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type);
> diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
> index 22aad412f965..24b82ff53513 100644
> --- a/arch/x86/kernel/e820.c
> +++ b/arch/x86/kernel/e820.c
> @@ -145,7 +145,7 @@ static struct e820_entry *__e820__mapped_all(u64 start, u64 end,
> /*
> * This function checks if the entire range <start,end> is mapped with type.
> */
> -bool __init e820__mapped_all(u64 start, u64 end, enum e820_type type)
> +bool __init e820__mapped_all(u64 start, u64 end, unsigned int type)
> {
> return __e820__mapped_all(start, end, type);
> }
>

--
~Randy