FreeBSD 13-CURRENT: ZSTD, error: stack frame size of 16440 bytes in function

[PrivatePuffin]

System information

Type	Version/Name
Distribution Name	FreeBSD
Distribution Version	13
Linux Kernel	na
Architecture	na
ZFS Version	master 21-08-2020
SPL Version

Describe the problem you're observing

originaly reported by @freqlabs on #10278

Frame stack size warnings are ignored for the ZSTD library (because we don't use said code portions in the library and don't want to edit the library itself to remove those). Those are ignored using:
module/zstd/makefile.in

$(obj)/lib/zstd.o: c_flags += -Wframe-larger-than=20480

and
lib/libzstd/makefile.am:

lib/zstd.$(OBJEXT):  CFLAGS += -Wframe-larger-than=20480
lib/zstd.l$(OBJEXT): CFLAGS += -Wframe-larger-than=20480

Even though said warnings are ignrored, a non-debug build on FreeBSD 13-CURRENT still gives stack frame size warnings.
A non debug build of FreeBSD 12-STABLE works just fine.
So this might be compiler related.

Describe how to reproduce the problem

• Build without debug options on FreeBSD 13-CURRENT
• Notice the warnings and failed build due to too many warnings

Include any warning/errors/backtraces from the system logs

../../module/zstd/lib/zstd.c:3030:8: error: stack frame size of 16440 bytes in function 'FSE_decompress' [-Werror,-Wframe-larger-than=]                       [16/3363]
size_t FSE_decompress(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize)
       ^
../../module/zstd/lib/zstd.c:7651:8: error: stack frame size of 4136 bytes in function 'FSE_buildCTable' [-Werror,-Wframe-larger-than=]
size_t FSE_buildCTable(FSE_CTable* ct, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog)
       ^
../../module/zstd/lib/zstd.c:8163:8: error: stack frame size of 14424 bytes in function 'FSE_compress2' [-Werror,-Wframe-larger-than=]
size_t FSE_compress2 (void* dst, size_t dstCapacity, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog)
       ^
../../module/zstd/lib/zstd.c:8335:8: error: stack frame size of 4136 bytes in function 'HIST_countFast' [-Werror,-Wframe-larger-than=]
size_t HIST_countFast(unsigned* count, unsigned* maxSymbolValuePtr,
       ^
../../module/zstd/lib/zstd.c:8357:8: error: stack frame size of 4136 bytes in function 'HIST_count' [-Werror,-Wframe-larger-than=]
size_t HIST_count(unsigned* count, unsigned* maxSymbolValuePtr,
       ^
../../module/zstd/lib/zstd.c:8780:8: error: stack frame size of 4392 bytes in function 'HUF_buildCTable' [-Werror,-Wframe-larger-than=]
size_t HUF_buildCTable (HUF_CElt* tree, const unsigned* count, unsigned maxSymbolValue, unsigned maxNbBits)
       ^
../../module/zstd/lib/zstd.c:9114:8: error: stack frame size of 6472 bytes in function 'HUF_compress1X' [-Werror,-Wframe-larger-than=]
size_t HUF_compress1X (void* dst, size_t dstSize,
       ^
../../module/zstd/lib/zstd.c:9151:8: error: stack frame size of 6472 bytes in function 'HUF_compress2' [-Werror,-Wframe-larger-than=]
size_t HUF_compress2 (void* dst, size_t dstSize,
       ^
../../module/zstd/lib/zstd.c:17683:8: error: stack frame size of 6216 bytes in function 'ZSTD_compressBlock_doubleFast' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_doubleFast(
       ^
../../module/zstd/lib/zstd.c:21215:8: error: stack frame size of 6280 bytes in function 'ZSTD_compressBlock_btopt' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_btopt(
       ^
../../module/zstd/lib/zstd.c:21280:8: error: stack frame size of 6280 bytes in function 'ZSTD_compressBlock_btultra' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_btultra(
       ^
../../module/zstd/lib/zstd.c:21288:8: error: stack frame size of 6280 bytes in function 'ZSTD_compressBlock_btultra2' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_btultra2(
       ^
../../module/zstd/lib/zstd.c:21330:8: error: stack frame size of 6280 bytes in function 'ZSTD_compressBlock_btopt_extDict' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_btopt_extDict(
       ^
../../module/zstd/lib/zstd.c:21337:8: error: stack frame size of 6280 bytes in function 'ZSTD_compressBlock_btultra_extDict' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_btultra_extDict(
       ^
../../module/zstd/lib/zstd.c:18241:8: error: stack frame size of 4200 bytes in function 'ZSTD_compressBlock_fast_dictMatchState' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_fast_dictMatchState(
       ^
../../module/zstd/lib/zstd.c:17703:8: error: stack frame size of 6216 bytes in function 'ZSTD_compressBlock_doubleFast_dictMatchState' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_doubleFast_dictMatchState(
       ^
../../module/zstd/lib/zstd.c:21316:8: error: stack frame size of 6280 bytes in function 'ZSTD_compressBlock_btopt_dictMatchState' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_btopt_dictMatchState(
       ^
../../module/zstd/lib/zstd.c:21323:8: error: stack frame size of 6280 bytes in function 'ZSTD_compressBlock_btultra_dictMatchState' [-Werror,-Wframe-larger-than=]
size_t ZSTD_compressBlock_btultra_dictMatchState(
       ^
../../module/zstd/lib/zstd.c:21253:1: error: stack frame size of 6280 bytes in function 'ZSTD_initStats_ultra' [-Werror,-Wframe-larger-than=]
ZSTD_initStats_ultra(ZSTD_matchState_t* ms,
^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.

[ghost]

Figured it out, it was in my build script on this machine:

gmake -j20 CFLAGS="-march=native"

Apparently the CFLAGS passed on the command line are overriding what's in the Makefile, instead of being appended to.

[PrivatePuffin]

@freqlabs Thats... weird as... well... weird. Thanks for looking into it. So basically I can close this now it seems, but very good to know none-the-less 👍

[ghost]

Well I think lib/libzfs/Makefile.am could be made to accommodate this since this has been working up until now. I'm testing a patch and will open a PR if it works.

It worked