On Tue, Mar 29, 2022 at 02:40:07PM +0200, Alexander Potapenko wrote:
> KMSAN inserts API function calls in a lot of places (function entries
> and exits, local variables, memory accesses), so they may get called
> from the uaccess regions as well.
That's insufficient. Explain how you did the right thing and made these
functions actually safe to be called in this context.
> Signed-off-by: Alexander Potapenko <glider@google.com>
> ---
> Link: https://linux-review.googlesource.com/id/I242bc9816273fecad4ea3d977393784396bb3c35
> ---
> tools/objtool/check.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/tools/objtool/check.c b/tools/objtool/check.c
> index 7c33ec67c4a95..8518eaf05bff0 100644
> --- a/tools/objtool/check.c
> +++ b/tools/objtool/check.c
> @@ -943,6 +943,25 @@ static const char *uaccess_safe_builtin[] = {
> "__sanitizer_cov_trace_cmp4",
> "__sanitizer_cov_trace_cmp8",
> "__sanitizer_cov_trace_switch",
> + /* KMSAN */
> + "kmsan_copy_to_user",
> + "kmsan_report",
> + "kmsan_unpoison_memory",
> + "__msan_chain_origin",
> + "__msan_get_context_state",
> + "__msan_instrument_asm_store",
> + "__msan_metadata_ptr_for_load_1",
> + "__msan_metadata_ptr_for_load_2",
> + "__msan_metadata_ptr_for_load_4",
> + "__msan_metadata_ptr_for_load_8",
> + "__msan_metadata_ptr_for_load_n",
> + "__msan_metadata_ptr_for_store_1",
> + "__msan_metadata_ptr_for_store_2",
> + "__msan_metadata_ptr_for_store_4",
> + "__msan_metadata_ptr_for_store_8",
> + "__msan_metadata_ptr_for_store_n",
> + "__msan_poison_alloca",
> + "__msan_warning",
> /* UBSAN */
> "ubsan_type_mismatch_common",
> "__ubsan_handle_type_mismatch",
> --
> 2.35.1.1021.g381101b075-goog
>