Unable to Cross compile seccom-pledge for OpenWrt

[mrdorababu]

Hi,

We are unable to cross-compile the project for OpenWrt. Please let us know what are the architectures it can support. The OpenWrt router we have has MIPS architecture.

• CPU info for OpenWrt router

  
  root@OpenWrt:~# cat /proc/cpuinfo                                                               
  system type             : MediaTek MT7621 ver:1 eco:3                                           
  machine                 : Linksys E5600                                                         
  processor               : 0                                                                     
  cpu model               : MIPS 1004Kc V2.15                                                     
  BogoMIPS                : 586.13                                                                
  wait instruction        : yes                                                                   
  microsecond timers      : yes                                                                   
  tlb_entries             : 32                                                                    
  extra interrupt vector  : yes                                                                   
  hardware watchpoint     : yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]     
  isa                     : mips1 mips2 mips32r1 mips32r2                                         
  ASEs implemented        : mips16 dsp mt                                                         
  Options implemented     : tlb 4kex 4k_cache prefetch mcheck ejtag llsc pindexed_dcache userlocal
  vint perf_cntr_intr_bit cdmm perf                                                              
  shadow register sets    : 1                                                                     
  kscratch registers      : 0                                                                     
  package                 : 0                                                                     
  core                    : 0                                                                     
  VPE                     : 0                                                                     
  VCED exceptions         : not available                                                         
  VCEI exceptions         : not available                                                         

processor : 1
cpu model : MIPS 1004Kc V2.15
BogoMIPS : 586.13
wait instruction : yes
microsecond timers : yes
tlb_entries : 32
extra interrupt vector : yes
hardware watchpoint : yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa : mips1 mips2 mips32r1 mips32r2
ASEs implemented : mips16 dsp mt
Options implemented : tlb 4kex 4k_cache prefetch mcheck ejtag llsc pindexed_dcache userlocal vint perf_cntr_intr_bit cdmm perf
shadow register sets : 1
kscratch registers : 0
package : 0
core : 0
VPE : 1
VCED exceptions : not available
VCEI exceptions : not available

processor : 2
cpu model : MIPS 1004Kc V2.15
BogoMIPS : 586.13
wait instruction : yes
microsecond timers : yes
tlb_entries : 32
extra interrupt vector : yes
hardware watchpoint : yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa : mips1 mips2 mips32r1 mips32r2
ASEs implemented : mips16 dsp mt
Options implemented : tlb 4kex 4k_cache prefetch mcheck ejtag llsc pindexed_dcache userlocal vint perf_cntr_intr_bit cdmm perf
shadow register sets : 1
kscratch registers : 0
package : 0
core : 1
VPE : 0
VCED exceptions : not available
VCEI exceptions : not available

processor : 3
cpu model : MIPS 1004Kc V2.15
BogoMIPS : 586.13
wait instruction : yes
microsecond timers : yes
tlb_entries : 32
extra interrupt vector : yes
hardware watchpoint : yes, count: 4, address/irw mask: [0x0ffc, 0x0ffc, 0x0ffb, 0x0ffb]
isa : mips1 mips2 mips32r1 mips32r2
ASEs implemented : mips16 dsp mt
Options implemented : tlb 4kex 4k_cache prefetch mcheck ejtag llsc pindexed_dcache userlocal vint perf_cntr_intr_bit cdmm perf
shadow register sets : 1
kscratch registers : 0
package : 0
core : 1
VPE : 1
VCED exceptions : not available
VCEI exceptions : not available

- Following errors occurred while we build the project 

dora@openwrtbuildpc:~/coderepo/openwrt/seccomp-pledge$ cargo build --release --target mips-unknown-linux-musl Compiling serde v1.0.152 Compiling libc v0.2.139 Compiling serde_json v1.0.91 Compiling itoa v1.0.5 Compiling ryu v1.0.12 Compiling optional-fields-serde-macro v0.1.1 Compiling optional-field v0.1.3 Compiling seccompiler v0.3.0 Compiling seccomp-pledge v0.1.0 (/home/dora/coderepo/openwrt/seccomp-pledge) error[E0432]: unresolved import seccompiler::BpfMap --> src/main.rs:2:5 | 2 | use seccompiler::BpfMap; | ^^^^^^^^^^^^^^^^^^^ no BpfMap in the root

error[E0433]: failed to resolve: could not find TargetArch in seccompiler --> src/main.rs:411:22 | 411 | seccompiler::TargetArch::x86_64, | ^^^^^^^^^^ could not find TargetArch in seccompiler

error[E0425]: cannot find function compile_from_json in crate seccompiler --> src/main.rs:409:66 | 409 | ...compiler::compile_from_json( | ^^^^^^^^^^^^^^^^^ not found in seccompiler

error[E0425]: cannot find function apply_filter in crate seccompiler --> src/main.rs:428:21 | 428 | if seccompiler::apply_filter(filter).is_err() { | ^^^^^^^^^^^^ not found in seccompiler

Some errors have detailed explanations: E0425, E0432, E0433. For more information about an error, try rustc --explain E0425. error: could not compile seccomp-pledge due to 4 previous errors dora@openwrtbuildpc:~/coderepo/openwrt/seccomp-pledge$

You can find the further details here 
https://www.notion.so/subcom/Daily-Logs-ef770c7e27f7457f875a198c65a5f604 

Please let us know how to solve these errors.

[DeviousCilantro]

This project utilizes the seccompiler crate which unfortunately only supports little-endian x86_64 and little-endian aarch64 host architectures, as specified in https://github.com/rust-vmm/seccompiler. Moreover, Justine Tunney's standalone pledge binary itself is an x86_64 ELF executable, so I am not sure even that would work on MIPS either.

[sn99]

@DeviousCilantro ~It builds natively without cross compiling.~ Nvm, english ggs

I think the issue is in the linker during cross compiling, seccompiler doesn’t define a linker target for mips https://github.com/rust-vmm/seccompiler/blob/main/.cargo/config, I found this that can help though https://github.com/rust-lang/rust/issues/37507#issuecomment-476026815

[sn99]

This library is only supported for x86_64 and aarch64.