Messages in this thread | | | From | Arnd Bergmann <> | Date | Wed, 6 Jan 2021 23:06:39 +0100 | Subject | Re: [PATCH] ubsan: disable unsigned-integer-overflow sanitizer with clang |
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On Wed, Jan 6, 2021 at 10:38 PM Nathan Chancellor <natechancellor@gmail.com> wrote: > On Wed, Jan 06, 2021 at 10:12:51AM +0100, Arnd Bergmann wrote: > > On Tue, Jan 5, 2021 at 10:25 AM Arnd Bergmann <arnd@kernel.org> wrote: > > > > > > On Mon, Jan 4, 2021 at 11:33 PM Nathan Chancellor > > > <natechancellor@gmail.com> wrote: > > > > On Wed, Dec 30, 2020 at 05:13:03PM +0100, Marco Elver wrote: > > > > > On Wed, 30 Dec 2020 at 16:47, Arnd Bergmann <arnd@kernel.org> wrote: > > > > > > > > > > > > From: Arnd Bergmann <arnd@arndb.de> > > > > > > > > > > > > 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. > > > > > > > > > > > > The one in blake2b immediately overflows the 8KB stack area on 32-bit > > > > > > architectures, so better ensure this never happens by making this > > > > > > option gcc-only. > > > > > > > > This patch also fixes the failed BUILD_BUG issue in mm/mremap.c that you > > > > sent a patch for [1], along with a couple of other issues I see such as: > > > > > > I'm fairly sure I still saw that BUILD_BUG() even after I had applied this > > > patch, I would guess that one just depends on inlining decisions that > > > are influenced by all kinds of compiler options including > > > -fsanitize=unsigned-integer-overflow, so it becomes less likely. > > > > > > I'll revert my other patch in the randconfig tree to see if it comes back. > > > > The qcom/gpi.c failure still happens with this patch applied: > > > > In file included from /git/arm-soc/drivers/dma/qcom/gpi.c:8: > > In function 'field_multiplier', > > inlined from 'gpi_update_reg' at > > /git/arm-soc/include/linux/bitfield.h:124:17: > > /git/arm-soc/include/linux/bitfield.h:119:3: error: call to > > '__bad_mask' declared with attribute error: bad bitfield mask > > 119 | __bad_mask(); > > | ^~~~~~~~~~~~ > > In function 'field_multiplier', > > inlined from 'gpi_update_reg' at > > /git/arm-soc/include/linux/bitfield.h:154:1: > > /git/arm-soc/include/linux/bitfield.h:119:3: error: call to > > '__bad_mask' declared with attribute error: bad bitfield mask > > 119 | __bad_mask(); > > | ^~~~~~~~~~~~ > > > > See https://pastebin.com/8UH6x4A2 for the .config > > > > Arnd > > That config does not build for me, am I holding it wrong? > > $ curl -LSso .config https://pastebin.com/raw/8UH6x4A2
Sorry about that, you ran into a bug that I have applied a local fix for. You could enable CONFIG_EPOLL, or apply this patch:
https://lore.kernel.org/linux-arm-kernel/20200429132349.1294904-1-arnd@arndb.de/
Arnd
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