了解 SIGILL 并排除故障

Understand and troubleshoot SIGILL

我已经为 erlang (gitlab.com/Vagabond1/erlang-rocksdb@8708fe8) 构建了一个 rocksdb 的副本,用于基于 armv7 的目标。这是一个 iMX6 SoloX 处理器,这里是 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

我有一个加载编译后的程序 liberocksdb.so 但它因 SIGILL 而崩溃,这是回溯:

#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?)

这是反汇编:

(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,但据我了解,程序崩溃是因为指令 udiv 对我的 CPU 是非法的。 我查看了 ARM 开发者网站,这是一个 Cortex M3 instruction and I believe that my CPU is Cortex M4,所以我猜它应该有这个指令?

也许我的分析有误,这是别的原因?

我的交叉编译是使用 CPU 和 rootfs 的交叉工具链进行的,并包含 -march=armv7-a -marm -mfpu=neon -mfloat-abi=hard 等应该提供兼容二进制文件的参数。

谢谢

cmake 脚本强制使用 -march=armv8-a+crc,这与我的 CPU.

不兼容

https://gitlab.com/Vagabond1/erlang-rocksdb/-/commit/6bf4a440b8132ef643682ba87dee6de87dc47d58