我为erlang构建了一个rocksdb的副本(gitlab.com/Vagabond1/erlang-rocksdb@8708fe8)针对基于armv7的目标。这是一个iMX6 SoloX处理器，下面是cpuinfo:
processor : 0
model name : ARMv7 Processor rev 10 (v7l)
BogoMIPS : 7.54
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpd32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x2
CPU part : 0xc09
CPU revision : 10
Hardware : Freescale i.MX6 SoloX (Device Tree)
Revision : 0500
我有一个程序可以加载编译后的liberocksdb.so，但它会因SIGILL而崩溃，下面是回溯：
#0 0xb1b2a7b0 in std::__detail::_Mod_range_hashing::operator()(unsigned int, unsigned int) const () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#1 0xb1b79b48 in std::__detail::_Hash_code_base<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, std::__detail::_Select1st, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, true>::_M_bucket_index(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned int, unsigned int) const () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#2 0xb1b751d4 in std::_Hashtable<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> >, std::__detail::_Select1st, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_M_bucket_index(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, unsigned int) const ()
from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#3 0xb1b6e01c in std::pair<std::__detail::_Node_iterator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, false, true>, bool> std::_Hashtable<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> >, std::__detail::_Select1st, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_M_insert<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> const&, std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, true> > > >(std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> const&, std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, true> > > const&, std::integral_constant<bool, true>) () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#4 0xb1b63edc in std::__detail::_Insert_base<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> >, std::__detail::_Select1st, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::insert(std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> const&) ()
from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#5 0xb1b568b8 in std::_Hashtable<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> >, std::__detail::_Select1st, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> const*>(std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> const*, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> const*, unsigned int, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, std::__detail::_Mod_range_hashing const&, std::__detail::_Default_ranged_hash const&, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, std::__detail::_Select1st const&, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> > const&) () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#6 0xb1b489fc in std::_Hashtable<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> >, std::__detail::_Select1st, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_Hashtable(std::initializer_list<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> >, unsigned int, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> > const&) () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#7 0xb1b3c10c in std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, rocksdb::OptionsSanityCheckLevel, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> > >::unordered_map(std::initializer_list<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> >, unsigned int, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > const&, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, rocksdb::OptionsSanityCheckLevel> > const&) () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#8 0xb1b28b04 in __static_initialization_and_destruction_0 () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#9 0xb1b29d30 in _GLOBAL__sub_I_db_impl.cc () from /opt/miner/lib/rocksdb-1.5.0/priv/liberocksdb.so
#10 0xb6fddff8 in ?? () from /lib/ld-linux-armhf.so.3
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
以下是拆卸：
(gdb) disas /m
Dump of assembler code for function _ZNKSt8__detail18_Mod_range_hashingclEjj:
0xb1b2a790 <+0>: push {r11} ; (str r11, [sp, #-4]!)
0xb1b2a794 <+4>: add r11, sp, #0
0xb1b2a798 <+8>: sub sp, sp, #20
0xb1b2a79c <+12>: str r0, [r11, #-8]
0xb1b2a7a0 <+16>: str r1, [r11, #-12]
0xb1b2a7a4 <+20>: str r2, [r11, #-16]
0xb1b2a7a8 <+24>: ldr r3, [r11, #-12]
0xb1b2a7ac <+28>: ldr r2, [r11, #-16]
=> 0xb1b2a7b0 <+32>: udiv r2, r3, r2
0xb1b2a7b4 <+36>: ldr r1, [r11, #-16]
0xb1b2a7b8 <+40>: mul r2, r1, r2
0xb1b2a7bc <+44>: sub r3, r3, r2
0xb1b2a7c0 <+48>: mov r0, r3
0xb1b2a7c4 <+52>: add sp, r11, #0
0xb1b2a7c8 <+56>: pop {r11} ; (ldr r11, [sp], #4)
0xb1b2a7cc <+60>: bx lr
End of assembler dump.
我不是这个领域的专家，但据我所知，程序崩溃是因为指令udiv对我的CPU来说是非法的。我查看了ARM开发者网站，这是一条Cortex M3指令，我相信我的CPU是Cortex M4，所以我想它应该有这个指令？
也许我的分析是错误的，这是另一回事？
我的交叉编译是使用该CPU和rootfs的交叉工具链进行的，并且包含诸如-march=armv7-a -marm -mfpu=neon -mfloat-abi=hard之类的参数，这些参数应该提供兼容的二进制文件。
感谢
cmake脚本强制使用与我的CPU不兼容的-march=armv8-a+crc。
https://gitlab.com/Vagabond1/erlang-rocksdb/-/commit/6bf4a440b8132ef643682ba87dee6de87dc47d58