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]>
---
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
