coredump: Add gosym sub command

[felixge]

gosym symbolizes go test cases using gopclntab and prints them. This is useful for
debugging the correctness of go stack unwinding results.

Example:

$ go run ./tools/coredump gosym -case ./tools/coredump/testdata/arm64/hello.3345.hello3.body.stp-after-bl.json

{
  "coredump-ref": "c5cafafe70f6a5aa9513c11e6606ad1a5ff2396a636766e6fc05b3c0c132a9d3",
  "threads": [
    {
      "lwp": 3662,
      "frames": [
        "main.hello3 in /media/psf/devel/prodfiler/utils/coredump/testsources/go/hello.go:30 (hello.3345+0x90c94)",
        "main.hello2 in /media/psf/devel/prodfiler/utils/coredump/testsources/go/hello.go:24 (hello.3345+0x90c43)",
        "main.hello1 in /media/psf/devel/prodfiler/utils/coredump/testsources/go/hello.go:16 (hello.3345+0x90b3b)",
        "main.hello in /media/psf/devel/prodfiler/utils/coredump/testsources/go/hello.go:11 (hello.3345+0x90afb)",
        "main.main in /media/psf/devel/prodfiler/utils/coredump/testsources/go/hello.go:46 (hello.3345+0x90e4b)",
        "runtime.main in /usr/local/go/src/runtime/proc.go:250 (hello.3345+0x43533)",
        "runtime.goexit in /usr/local/go/src/runtime/asm_arm64.s:1165 (hello.3345+0x6c513)"
      ]
    },
    {
      "lwp": 3664,
      "frames": [
        "runtime.usleep in /usr/local/go/src/runtime/sys_linux_arm64.s:142 (hello.3345+0x6d324)",
        "runtime.sysmon in /usr/local/go/src/runtime/proc.go:5145 (hello.3345+0x4eec7)",
        "runtime.mstart1 in /usr/local/go/src/runtime/proc.go:1425 (hello.3345+0x46237)",
        "runtime.mstart0 in /usr/local/go/src/runtime/proc.go:1382 (hello.3345+0x46187)",
        "runtime.mstart in /usr/local/go/src/runtime/asm_arm64.s:128 (hello.3345+0x69f5f)"
      ]
    },
    {
      "lwp": 3665,
      "frames": [
        "runtime.futex in /usr/local/go/src/runtime/sys_linux_arm64.s:666 (hello.3345+0x6d9bc)",
        "runtime.futexsleep in /usr/local/go/src/runtime/os_linux.go:69 (hello.3345+0x3d6fb)",
        "runtime.notesleep in /usr/local/go/src/runtime/lock_futex.go:160 (hello.3345+0x1993f)",
        "runtime.stopm in /usr/local/go/src/runtime/proc.go:1457 (hello.3345+0x47b13)",
        "runtime.findRunnable in /usr/local/go/src/runtime/proc.go:2866 (hello.3345+0x4938b)",
        "runtime.schedule in /usr/local/go/src/runtime/proc.go:3206 (hello.3345+0x4a3a7)",
        "runtime.park_m in /usr/local/go/src/runtime/proc.go:3355 (hello.3345+0x4a8ff)",
        "runtime.mcall in /usr/local/go/src/runtime/asm_arm64.s:192 (hello.3345+0x69fd3)"
      ]
    },
    {
      "lwp": 3666,
      "frames": [
        "runtime.futex in /usr/local/go/src/runtime/sys_linux_arm64.s:666 (hello.3345+0x6d9bc)",
        "runtime.futexsleep in /usr/local/go/src/runtime/os_linux.go:69 (hello.3345+0x3d6fb)",
        "runtime.notesleep in /usr/local/go/src/runtime/lock_futex.go:160 (hello.3345+0x1993f)",
        "runtime.stopm in /usr/local/go/src/runtime/proc.go:1457 (hello.3345+0x47b13)",
        "runtime.startlockedm in /usr/local/go/src/runtime/proc.go:2470 (hello.3345+0x485db)",
        "runtime.schedule in /usr/local/go/src/runtime/proc.go:3240 (hello.3345+0x4a363)",
        "runtime.park_m in /usr/local/go/src/runtime/proc.go:3355 (hello.3345+0x4a8ff)",
        "runtime.mcall in /usr/local/go/src/runtime/asm_arm64.s:192 (hello.3345+0x69fd3)"
      ]
    },
    {
      "lwp": 3667,
      "frames": [
        "runtime.futex in /usr/local/go/src/runtime/sys_linux_arm64.s:666 (hello.3345+0x6d9bc)",
        "runtime.futexsleep in /usr/local/go/src/runtime/os_linux.go:69 (hello.3345+0x3d6fb)",
        "runtime.notesleep in /usr/local/go/src/runtime/lock_futex.go:160 (hello.3345+0x1993f)",
        "runtime.stopm in /usr/local/go/src/runtime/proc.go:1457 (hello.3345+0x47b13)",
        "runtime.findRunnable in /usr/local/go/src/runtime/proc.go:2866 (hello.3345+0x4938b)",
        "runtime.schedule in /usr/local/go/src/runtime/proc.go:3206 (hello.3345+0x4a3a7)",
        "runtime.park_m in /usr/local/go/src/runtime/proc.go:3355 (hello.3345+0x4a8ff)",
        "runtime.mcall in /usr/local/go/src/runtime/asm_arm64.s:192 (hello.3345+0x69fd3)"
      ]
    }
  ],
  "modules": [
    {
      "ref": "bb87b9bba238372aad8a65bacbf088583cf7a580daa23abfed2467a19307c707",
      "local-path": "/media/psf/devel/prodfiler/utils/coredump/testsources/go/hello.3345"
    }
  ]
}

[felixge]

Thanks for the review, I incorporated your suggestions 🙇

[fabled]

Could this instead be a flag for analyze command instead of a new command? Especially I'd expect this to not be Go specific. I would also love to see/follow up with the ELF dynamic symbol decoration based on same flag.

[felixge]

Could this instead be a flag for analyze command instead of a new command?

I could try that. What would you like to name this flag? -nativesym ?

Especially I'd expect this to not be Go specific. I would also love to see/follow up with the ELF dynamic symbol decoration based on same flag.

I probably won't have time to take care of non-Go binaries for now. This is already a bit of yak shave since what I'm really trying to do is debug and improve some go unwinding issues I'm seeing 😅. But yeah, making this more generic sounds good to me.