Failed to profile rust application

[aregng]

Failed to profile rust application due to error

thread '<unnamed>' panicked at 'not implemented: 'aligned_alloc' is unimplemented!', preload/src/api.rs:907:5
stack backtrace:
   0:     0x7f9661783cea - std::backtrace_rs::backtrace::libunwind::trace::h972caad916e73545
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   1:     0x7f9661783cea - std::backtrace_rs::backtrace::trace_unsynchronized::he59049878fe5a05d
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x7f9661783cea - std::sys_common::backtrace::_print_fmt::he4a91f9bcfad9b40
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/sys_common/backtrace.rs:66:5
   3:     0x7f9661783cea - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h51433dc001920472
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/sys_common/backtrace.rs:45:22
   4:     0x7f966172d10c - core::fmt::write::hc9dbd37d69b2c204
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/core/src/fmt/mod.rs:1198:17
   5:     0x7f9661762b14 - std::io::Write::write_fmt::h6b2550ce8adb9e04
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/io/mod.rs:1672:15
   6:     0x7f9661784af5 - std::sys_common::backtrace::_print::h006829bd22a5a4ee
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/sys_common/backtrace.rs:48:5
   7:     0x7f9661784af5 - std::sys_common::backtrace::print::h0f4d319136ab4456
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/sys_common/backtrace.rs:35:9
   8:     0x7f9661784af5 - std::panicking::default_hook::{{closure}}::h5b3cdff51fbe7401
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/panicking.rs:295:22
   9:     0x7f9661785075 - std::panicking::default_hook::hdc1d8baf28b4ffd7
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/panicking.rs:314:9
  10:     0x7f9661785075 - std::panicking::rust_panic_with_hook::h80e138cc00203db9
                               at /rustc/d68e7ebc38cb42b8b237392b28045edeec761503/library/std/src/panicking.rs:698:17
  11:     0x7f96617f9221 - nwind_ret_trampoline_start
                               at /home/user/.cargo/git/checkouts/not-perf-af1a46759dd83df9/18bd8d3/nwind/src/arch/amd64_trampoline.s:17
  12:                0x0 - <unknown>

used command

LD_PRELOAD=./libbytehound.so <rust_application> <args>

Tried with local build from the latest master, and with pre-built versions Target OS: Ubuntu 20.04

Please let me know if any option is missing to run tool properly, or rust applications are not support for now. Thanks in advance.

[koute]

This is expected. Your application (or one of your dependencies) is using the aligned_alloc function, which is currently unimplemented in Bytehound.

Can you rerun your application with MEMORY_PROFILER_USE_SHADOW_STACK=0 set? This won't fix it, but should make the panic backtrace show us what exactly is using aligned_alloc in your application.

[aregng]

Thanks for the hint. After running with MEMORY_PROFILER_USE_SHADOW_STACK=0 it turned out that "aligned_alloc" is used by rocksdb implementation:

12:     0x7f135f75353c - std::sys_common::backtrace::__rust_end_short_backtrace::h444863965d46291e
                               at /rustc/a37499ae66ec5fc52a93d71493b78fb141c32f6b/library/std/src/sys_common/backtrace.rs:138:18
  13:     0x7f135f753511 - rust_begin_unwind
                               at /rustc/a37499ae66ec5fc52a93d71493b78fb141c32f6b/library/std/src/panicking.rs:584:5
  14:     0x7f135f6b0ea2 - core::panicking::panic_fmt::h3fce1d62b588c5f8
                               at /rustc/a37499ae66ec5fc52a93d71493b78fb141c32f6b/library/core/src/panicking.rs:142:14
  15:     0x7f135f6f2baf - aligned_alloc
                               at /workspace/supra/examples/bytehound/preload/src/api.rs:907:5
  16:     0x7f135f546bf6 - _ZnwmSt11align_val_t
  17:     0x5639119112c6 - _ZN7rocksdb6DBImpl4OpenERKNS_9DBOptionsERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKSt6vectorINS_22ColumnFamilyDescriptorESaISD_EEPSC_IPNS_18ColumnFamilyHandleESaISJ_EEPPNS_2DBEbb
                               at /home/areg/.cargo/registry/src/github.com-1ecc6299db9ec823/librocksdb-sys-0.8.0+7.4.4/rocksdb/db/db_impl/db_impl_open.cc:1752:77
  18:     0x5639119105ad - _ZN7rocksdb2DB4OpenERKNS_9DBOptionsERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEERKSt6vectorINS_22ColumnFamilyDescriptorESaISD_EEPSC_IPNS_18ColumnFamilyHandleESaISJ_EEPPS0_
                               at /home/areg/.cargo/registry/src/github.com-1ecc6299db9ec823/librocksdb-sys-0.8.0+7.4.4/rocksdb/db/db_impl/db_impl_open.cc:1613:50
  19:     0x56391182354c - rocksdb_open_column_families
                               at /home/areg/.cargo/registry/src/github.com-1ecc6299db9ec823/librocksdb-sys-0.8.0+7.4.4/rocksdb/db/c.cc:873:33
  20:     0x56391174c002 - rocksdb::db::DBCommon<T,rocksdb::db::DBWithThreadModeInner>::open_cf_raw::h3610a311cf8d9c40
                               at /home/areg/.cargo/registry/src/github.com-1ecc6299db9ec823/rocksdb-0.19.0/src/db.rs:717:42
  21:     0x56391174ccee - rocksdb::db::DBCommon<T,rocksdb::db::DBWithThreadModeInner>::open_cf_descriptors_internal::h037e47976a5d926e
                               at /home/areg/.cargo/registry/src/github.com-1ecc6299db9ec823/rocksdb-0.19.0/src/db.rs:626:18
  22:     0x56391174d93e - rocksdb::db::DBCommon<T,rocksdb::db::DBWithThreadModeInner>::open_cf::hc28b03a86869aba8
                               at /home/areg/.cargo/registry/src/github.com-1ecc6299db9ec823/rocksdb-0.19.0/src/db.rs:436:9
  23:     0x56391179ffa5 - storage::db::rocksdb::RocksDb::open::h594d1a948b126357

[koute]

This is very interesting; I regularly profile programs using rocksdb and I've never seen it calling aligned_alloc. From the stack trace is looks like it's called by C++'s new, so it's probably either due to the newer version of rocksdb suddenly allocating aligned memory where it previously didn't, or due to the particular version of the C++'s standard library and/or the compiler you're using.

Thanks for the report; I'll fix this.

[aregng]

It might be the case. rocksdb version used by application is "0.19.0".

[koute]

Fixed on master.