处理SIGSEGV与恢复?

The signal package states:

Synchronous signals are signals triggered by errors in program execution: SIGBUS, SIGFPE, and SIGSEGV. These are only considered synchronous when caused by program execution, not when sent using os.Process.Kill or the kill program or some similar mechanism. In general, except as discussed below, Go programs will convert a synchronous signal into a run-time panic.

However, it seems recover() is not catching this.

Program:

package main

import (
    "fmt"
    "unsafe"

    "log"
)

func seeAnotherDay() {
    defer func() {
        if p := recover(); p != nil {
            err := fmt.Errorf("recover panic: panic call")
            log.Println(err)
            return
        }
    }()
    panic("oops")
}

func notSoMuch() {
    defer func() {
        if p := recover(); p != nil {
            err := fmt.Errorf("recover panic: sigseg")
            log.Println(err)
            return
        }
    }()
    b := make([]byte, 1)
    log.Println("access some memory")
    foo := (*int)(unsafe.Pointer(uintptr(unsafe.Pointer(&b[0])) + uintptr(9999999999999999)))
    fmt.Print(*foo + 1)
}

func main() {
    seeAnotherDay()
    notSoMuch()
}

Output:

2017/04/04 12:13:16 recover panic: panic call
2017/04/04 12:13:16 access some memory
unexpected fault address 0xb01dfacedebac1e
fatal error: fault
[signal SIGSEGV: segmentation violation code=0x1 addr=0xb01dfacedebac1e pc=0x108aa8a]

goroutine 1 [running]:
runtime.throw(0x10b5807, 0x5)
        /usr/local/go/src/runtime/panic.go:596 +0x95 fp=0xc420043ea8 sp=0xc420043e88
runtime.sigpanic()
        /usr/local/go/src/runtime/signal_unix.go:297 +0x28c fp=0xc420043ef8 sp=0xc420043ea8
main.notSoMuch()
        /Users/kbrandt/src/sigseg/main.go:32 +0xca fp=0xc420043f78 sp=0xc420043ef8
main.main()
        /Users/kbrandt/src/sigseg/main.go:37 +0x25 fp=0xc420043f88 sp=0xc420043f78
runtime.main()
        /usr/local/go/src/runtime/proc.go:185 +0x20a fp=0xc420043fe0 sp=0xc420043f88
runtime.goexit()
        /usr/local/go/src/runtime/asm_amd64.s:2197 +0x1 fp=0xc420043fe8 sp=0xc420043fe0
exit status 2

Is there any way I could handle SIGSEGV in a way localized to certain parts of the code?

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dt614037527
dt614037527
2017/04/04 16:17
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