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chore: Remove unnecessary syscalls
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@clabby
clabby committed Oct 10, 2024
1 parent ed31690 commit 0f117ec
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Showing 6 changed files with 6 additions and 820 deletions.
129 changes: 0 additions & 129 deletions rvgo/fast/vm.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -204,39 +204,6 @@ func (inst *InstrumentedState) riscvStep() (outErr error) {
return out
}

storeMemUnaligned := func(addr U64, size U64, value U256, proofIndexL uint8, proofIndexR uint8, verifyL bool, verifyR bool) {
if size > 32 {
revertWithCode(riscv.ErrStoreExceeds32Bytes, fmt.Errorf("cannot store more than 32 bytes: %d", size))
}
var bytez [32]byte
binary.LittleEndian.PutUint64(bytez[:8], value[0])
binary.LittleEndian.PutUint64(bytez[8:16], value[1])
binary.LittleEndian.PutUint64(bytez[16:24], value[2])
binary.LittleEndian.PutUint64(bytez[24:], value[3])

leftAddr := addr &^ 31
if verifyL {
inst.trackMemAccess(leftAddr, proofIndexL)
}
inst.verifyMemChange(leftAddr, proofIndexL)
if (addr+size-1)&^31 == addr&^31 { // if aligned
s.Memory.SetUnaligned(addr, bytez[:size])
return
}
if proofIndexR == 0xff {
revertWithCode(riscv.ErrUnexpectedRProofStoreUnaligned, fmt.Errorf("unexpected need for right-side proof %d in storeMemUnaligned", proofIndexR))
}
// if not aligned
rightAddr := leftAddr + 32
leftSize := rightAddr - addr
s.Memory.SetUnaligned(addr, bytez[:leftSize])
if verifyR {
inst.trackMemAccess(rightAddr, proofIndexR)
}
inst.verifyMemChange(rightAddr, proofIndexR)
s.Memory.SetUnaligned(rightAddr, bytez[leftSize:size])
}

storeMem := func(addr U64, size U64, value U64, proofIndexL uint8, proofIndexR uint8, verifyL bool, verifyR bool) {
if size > 8 {
revertWithCode(riscv.ErrStoreExceeds8Bytes, fmt.Errorf("cannot store more than 8 bytes: %d", size))
Expand Down Expand Up @@ -368,22 +335,10 @@ func (inst *InstrumentedState) riscvStep() (outErr error) {
sysCall := func() {
a7 := getRegister(toU64(17))
switch a7 {
case riscv.SysExit: // exit the calling thread. No multi-thread support yet, so just exit.
a0 := getRegister(toU64(10))
setExitCode(uint8(a0))
setExited()
// program stops here, no need to change registers.
case riscv.SysExitGroup: // exit-group
a0 := getRegister(toU64(10))
setExitCode(uint8(a0))
setExited()
case riscv.SysBrk: // brk
// Go sys_linux_riscv64 runtime will only ever call brk(NULL), i.e. first argument (register a0) set to 0.

// brk(0) changes nothing about the memory, and returns the current page break
v := shl64(toU64(30), toU64(1)) // set program break at 1 GiB
setRegister(toU64(10), v)
setRegister(toU64(11), toU64(0)) // no error
case riscv.SysMmap: // mmap
// A0 = addr (hint)
addr := getRegister(toU64(10))
Expand Down Expand Up @@ -480,90 +435,6 @@ func (inst *InstrumentedState) riscvStep() (outErr error) {
}
setRegister(toU64(10), n)
setRegister(toU64(11), errCode)
case riscv.SysFcntl: // fcntl - file descriptor manipulation / info lookup
fd := getRegister(toU64(10)) // A0 = fd
cmd := getRegister(toU64(11)) // A1 = cmd
var out U64
var errCode U64
switch cmd {
case 0x1: // F_GETFD: get file descriptor flags
switch fd {
case 0: // stdin
out = toU64(0) // no flag set
case 1: // stdout
out = toU64(0) // no flag set
case 2: // stderr
out = toU64(0) // no flag set
case 3: // hint-read
out = toU64(0) // no flag set
case 4: // hint-write
out = toU64(0) // no flag set
case 5: // pre-image read
out = toU64(0) // no flag set
case 6: // pre-image write
out = toU64(0) // no flag set
default:
out = u64Mask()
errCode = toU64(0x4d) //EBADF
}
case 0x3: // F_GETFL: get file descriptor flags
switch fd {
case 0: // stdin
out = toU64(0) // O_RDONLY
case 1: // stdout
out = toU64(1) // O_WRONLY
case 2: // stderr
out = toU64(1) // O_WRONLY
case 3: // hint-read
out = toU64(0) // O_RDONLY
case 4: // hint-write
out = toU64(1) // O_WRONLY
case 5: // pre-image read
out = toU64(0) // O_RDONLY
case 6: // pre-image write
out = toU64(1) // O_WRONLY
default:
out = u64Mask()
errCode = toU64(0x4d) // EBADF
}
default: // no other commands: don't allow changing flags, duplicating FDs, etc.
out = u64Mask()
errCode = toU64(0x16) // EINVAL (cmd not recognized by this kernel)
}
setRegister(toU64(10), out)
setRegister(toU64(11), errCode) // EBADF
case riscv.SysOpenat: // openat - the Go linux runtime will try to open optional /sys/kernel files for performance hints
setRegister(toU64(10), u64Mask())
setRegister(toU64(11), toU64(0xd)) // EACCES - no access allowed
case riscv.SysClockGettime: // clock_gettime
addr := getRegister(toU64(11)) // addr of timespec struct
// write 1337s + 42ns as time
value := or(shortToU256(1337), shl(shortToU256(64), toU256(42)))
storeMemUnaligned(addr, toU64(16), value, 1, 2, true, true)
setRegister(toU64(10), toU64(0))
setRegister(toU64(11), toU64(0))
case riscv.SysClone: // clone - not supported
setRegister(toU64(10), toU64(1))
setRegister(toU64(11), toU64(0))
case riscv.SysGetrlimit: // getrlimit
res := getRegister(toU64(10))
addr := getRegister(toU64(11))
switch res {
case 0x7: // RLIMIT_NOFILE
// first 8 bytes: soft limit. 1024 file handles max open
// second 8 bytes: hard limit
storeMemUnaligned(addr, toU64(16), or(shortToU256(1024), shl(toU256(64), shortToU256(1024))), 1, 2, true, true)
setRegister(toU64(10), toU64(0))
setRegister(toU64(11), toU64(0))
default:
revertWithCode(riscv.ErrUnrecognizedResource, &UnrecognizedResourceErr{Resource: res})
}
case riscv.SysPrlimit64: // prlimit64 -- unsupported, we have getrlimit, is prlimit64 even called?
revertWithCode(riscv.ErrInvalidSyscall, &UnsupportedSyscallErr{SyscallNum: a7})
case riscv.SysFutex: // futex - not supported, for now
revertWithCode(riscv.ErrInvalidSyscall, &UnsupportedSyscallErr{SyscallNum: a7})
case riscv.SysNanosleep: // nanosleep - not supported, for now
revertWithCode(riscv.ErrInvalidSyscall, &UnsupportedSyscallErr{SyscallNum: a7})
default:
// Ignore(no-op) unsupported system calls
setRegister(toU64(10), toU64(0))
Expand Down
25 changes: 0 additions & 25 deletions rvgo/riscv/constants.go
View file
Original file line number Diff line number Diff line change
@@ -1,35 +1,10 @@
package riscv

const (
SysExit = 93
SysExitGroup = 94

Check failure on line 4 in rvgo/riscv/constants.go

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GitHub Actions / rvgo-lint 

File is not `goimports`-ed (goimports)
SysBrk = 214
SysMmap = 222
SysRead = 63
SysWrite = 64
SysFcntl = 25
SysOpenat = 56
SysSchedGetaffinity = 123
SysSchedYield = 124
SysClockGettime = 113
SysRtSigprocmask = 135
SysSigaltstack = 132
SysGettid = 178
SysRtSigaction = 134
SysClone = 220
SysGetrlimit = 163
SysMadvise = 233
SysEpollCreate1 = 20
SysEpollCtl = 21
SysPipe2 = 59
SysReadlinnkat = 78
SysNewfstatat = 79
SysNewuname = 160
SysMunmap = 215
SysGetRandom = 278
SysPrlimit64 = 261
SysFutex = 422
SysNanosleep = 101

FdStdin = 0
FdStdout = 1
Expand Down
96 changes: 0 additions & 96 deletions rvgo/slow/vm.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -568,22 +568,10 @@ func Step(calldata []byte, po PreimageOracle) (stateHash common.Hash, outErr err
sysCall := func() {
a7 := getRegister(toU64(17))
switch a7.val() {
case riscv.SysExit: // exit the calling thread. No multi-thread support yet, so just exit.
a0 := getRegister(toU64(10))
setExitCode(uint8(a0.val()))
setExited()
// program stops here, no need to change registers.
case riscv.SysExitGroup: // exit-group
a0 := getRegister(toU64(10))
setExitCode(uint8(a0.val()))
setExited()
case riscv.SysBrk: // brk
// Go sys_linux_riscv64 runtime will only ever call brk(NULL), i.e. first argument (register a0) set to 0.

// brk(0) changes nothing about the memory, and returns the current page break
v := shl64(toU64(30), toU64(1)) // set program break at 1 GiB
setRegister(toU64(10), v)
setRegister(toU64(11), toU64(0)) // no error
case riscv.SysMmap: // mmap
// A0 = addr (hint)
addr := getRegister(toU64(10))
Expand Down Expand Up @@ -660,90 +648,6 @@ func Step(calldata []byte, po PreimageOracle) (stateHash common.Hash, outErr err
}
setRegister(toU64(10), n)
setRegister(toU64(11), errCode)
case riscv.SysFcntl: // fcntl - file descriptor manipulation / info lookup
fd := getRegister(toU64(10)) // A0 = fd
cmd := getRegister(toU64(11)) // A1 = cmd
var out U64
var errCode U64
switch cmd.val() {
case 0x1: // F_GETFD: get file descriptor flags
switch fd.val() {
case 0: // stdin
out = toU64(0) // no flag set
case 1: // stdout
out = toU64(0) // no flag set
case 2: // stderr
out = toU64(0) // no flag set
case 3: // hint-read
out = toU64(0) // no flag set
case 4: // hint-write
out = toU64(0) // no flag set
case 5: // pre-image read
out = toU64(0) // no flag set
case 6: // pre-image write
out = toU64(0) // no flag set
default:
out = u64Mask()
errCode = toU64(0x4d) //EBADF
}
case 0x3: // F_GETFL: get file descriptor flags
switch fd.val() {
case 0: // stdin
out = toU64(0) // O_RDONLY
case 1: // stdout
out = toU64(1) // O_WRONLY
case 2: // stderr
out = toU64(1) // O_WRONLY
case 3: // hint-read
out = toU64(0) // O_RDONLY
case 4: // hint-write
out = toU64(1) // O_WRONLY
case 5: // pre-image read
out = toU64(0) // O_RDONLY
case 6: // pre-image write
out = toU64(1) // O_WRONLY
default:
out = u64Mask()
errCode = toU64(0x4d) // EBADF
}
default: // no other commands: don't allow changing flags, duplicating FDs, etc.
out = u64Mask()
errCode = toU64(0x16) // EINVAL (cmd not recognized by this kernel)
}
setRegister(toU64(10), out)
setRegister(toU64(11), errCode) // EBADF
case riscv.SysOpenat: // openat - the Go linux runtime will try to open optional /sys/kernel files for performance hints
setRegister(toU64(10), u64Mask())
setRegister(toU64(11), toU64(0xd)) // EACCES - no access allowed
case riscv.SysClockGettime: // clock_gettime
addr := getRegister(toU64(11)) // addr of timespec struct
// write 1337s + 42ns as time
value := or(shortToU256(1337), shl(shortToU256(64), toU256(42)))
storeMemUnaligned(addr, toU64(16), value, 1, 2)
setRegister(toU64(10), toU64(0))
setRegister(toU64(11), toU64(0))
case riscv.SysClone: // clone - not supported
setRegister(toU64(10), toU64(1))
setRegister(toU64(11), toU64(0))
case riscv.SysGetrlimit: // getrlimit
res := getRegister(toU64(10))
addr := getRegister(toU64(11))
switch res.val() {
case 0x7: // RLIMIT_NOFILE
// first 8 bytes: soft limit. 1024 file handles max open
// second 8 bytes: hard limit
storeMemUnaligned(addr, toU64(16), or(shortToU256(1024), shl(toU256(64), shortToU256(1024))), 1, 2)
setRegister(toU64(10), toU64(0))
setRegister(toU64(11), toU64(0))
default:
revertWithCode(riscv.ErrUnrecognizedResource, &UnrecognizedResourceErr{Resource: res})
}
case riscv.SysPrlimit64: // prlimit64 -- unsupported, we have getrlimit, is prlimit64 even called?
revertWithCode(riscv.ErrInvalidSyscall, &UnsupportedSyscallErr{SyscallNum: a7})
case riscv.SysFutex: // futex - not supported, for now
revertWithCode(riscv.ErrInvalidSyscall, &UnsupportedSyscallErr{SyscallNum: a7})
case riscv.SysNanosleep: // nanosleep - not supported, for now
revertWithCode(riscv.ErrInvalidSyscall, &UnsupportedSyscallErr{SyscallNum: a7})
default:
// Ignore(no-op) unsupported system calls
setRegister(toU64(10), toU64(0))
Expand Down
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