On Tue, Jan 12, 2021 at 09:29:15PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <[email protected]> > > 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. > > Fixes: d0a3ac549f38 ("ubsan: enable for all*config builds") > Link: https://lore.kernel.org/lkml/[email protected]/ > Signed-off-by: Arnd Bergmann <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]> > --- > v2: only turn it off for i386 as discussed > --- > lib/Kconfig.ubsan | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan > index 8b635fd75fe4..3a0b1c930733 100644 > --- a/lib/Kconfig.ubsan > +++ b/lib/Kconfig.ubsan > @@ -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 > -- > 2.29.2 >
