ubsan: disable unsigned-overflow check for i386

Building ubsan kernels even for compile-testing introduced these
warnings in my randconfig environment:

  crypto/blake2b_generic.c:98:13: error: stack frame size of 9636 bytes in function 'blake2b_compress' [-Werror,-Wframe-larger-than=]
  static void blake2b_compress(struct blake2b_state *S,

  crypto/sha512_generic.c:151:13: error: stack frame size of 1292 bytes in function 'sha512_generic_block_fn' [-Werror,-Wframe-larger-than=]
  static void sha512_generic_block_fn(struct sha512_state *sst, u8 const *src,

  lib/crypto/curve25519-fiat32.c:312:22: error: stack frame size of 2180 bytes in function 'fe_mul_impl' [-Werror,-Wframe-larger-than=]
  static noinline void fe_mul_impl(u32 out[10], const u32 in1[10], const u32 in2[10])

  lib/crypto/curve25519-fiat32.c:444:22: error: stack frame size of 1588 bytes in function 'fe_sqr_impl' [-Werror,-Wframe-larger-than=]
  static noinline void fe_sqr_impl(u32 out[10], const u32 in1[10])

Further testing showed that this is caused by
-fsanitize=unsigned-integer-overflow, but is isolated to the 32-bit x86
architecture.

The one in blake2b immediately overflows the 8KB stack area
architectures, so better ensure this never happens by disabling the
option for 32-bit x86.

Link: https://lkml.kernel.org/r/20210112202922.2454435-1-arnd@kernel.org
Link: https://lore.kernel.org/lkml/20201230154749.746641-1-arnd@kernel.org/
Fixes: d0a3ac549f ("ubsan: enable for all*config builds")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Marco Elver <elver@google.com>
Cc: George Popescu <georgepope@android.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Arnd Bergmann 2021-01-23 21:01:48 -08:00 committed by Linus Torvalds
parent acb35b177c
commit 251b5497c5
1 changed files with 1 additions and 0 deletions

View File

@ -123,6 +123,7 @@ config UBSAN_SIGNED_OVERFLOW
config UBSAN_UNSIGNED_OVERFLOW
bool "Perform checking for unsigned arithmetic overflow"
depends on $(cc-option,-fsanitize=unsigned-integer-overflow)
depends on !X86_32 # avoid excessive stack usage on x86-32/clang
help
This option enables -fsanitize=unsigned-integer-overflow which checks
for overflow of any arithmetic operations with unsigned integers. This