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Merge pull request #2486 from cfallin/fix-probestack

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Two Lucet-related fixes to stack overflow handling.
This commit is contained in:
Chris Fallin
2020-12-07 16:47:37 -08:00
committed by GitHub
parent 2c765c18c2 3a01d14712
commit 2cec20aa57
8 changed files with 169 additions and 19 deletions
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96
cranelift/codegen/src/isa/x64/inst/emit.rs
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@@ -182,6 +182,7 @@ impl LegacyPrefixes {
fn emit_std_enc_mem(
sink: &mut MachBuffer<Inst>,
state: &EmitState,
info: &EmitInfo,
prefixes: LegacyPrefixes,
opcodes: u32,
mut num_opcodes: usize,
@@ -194,7 +195,8 @@ fn emit_std_enc_mem(
// expression. But `enc_g` can be derived from a register of any class.
let srcloc = state.cur_srcloc();
if srcloc != SourceLoc::default() && mem_e.can_trap() {
let can_trap = mem_e.can_trap();
if srcloc != SourceLoc::default() && can_trap {
sink.add_trap(srcloc, TrapCode::HeapOutOfBounds);
}
@@ -202,6 +204,12 @@ fn emit_std_enc_mem(
match mem_e {
Amode::ImmReg { simm32, base, .. } => {
// If this is an access based off of RSP, it may trap with a stack overflow if it's the
// first touch of a new stack page.
if *base == regs::rsp() && !can_trap && info.flags().enable_probestack() {
sink.add_trap(srcloc, TrapCode::StackOverflow);
}
// First, the REX byte.
let enc_e = int_reg_enc(*base);
rex.emit_two_op(sink, enc_g, enc_e);
@@ -262,6 +270,12 @@ fn emit_std_enc_mem(
shift,
..
} => {
// If this is an access based off of RSP, it may trap with a stack overflow if it's the
// first touch of a new stack page.
if *reg_base == regs::rsp() && !can_trap && info.flags().enable_probestack() {
sink.add_trap(srcloc, TrapCode::StackOverflow);
}
let enc_base = int_reg_enc(*reg_base);
let enc_index = int_reg_enc(*reg_index);
@@ -350,6 +364,7 @@ fn emit_std_enc_enc(
fn emit_std_reg_mem(
sink: &mut MachBuffer<Inst>,
state: &EmitState,
info: &EmitInfo,
prefixes: LegacyPrefixes,
opcodes: u32,
num_opcodes: usize,
@@ -361,6 +376,7 @@ fn emit_std_reg_mem(
emit_std_enc_mem(
sink,
state,
info,
prefixes,
opcodes,
num_opcodes,
@@ -538,6 +554,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
0x0FAF,
2,
@@ -597,6 +614,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
opcode_m,
1,
@@ -654,6 +672,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode,
num_opcodes,
@@ -717,7 +736,9 @@ pub(crate) fn emit(
}
RegMem::Mem { addr: src } => {
let amode = src.finalize(state, sink);
emit_std_enc_mem(sink, state, prefix, opcode, 1, subopcode, &amode, rex_flags);
emit_std_enc_mem(
sink, state, info, prefix, opcode, 1, subopcode, &amode, rex_flags,
);
}
}
}
@@ -738,7 +759,9 @@ pub(crate) fn emit(
}
RegMem::Mem { addr: src } => {
let amode = src.finalize(state, sink);
emit_std_enc_mem(sink, state, prefix, 0xF7, 1, subopcode, &amode, rex_flags);
emit_std_enc_mem(
sink, state, info, prefix, 0xF7, 1, subopcode, &amode, rex_flags,
);
}
}
}
@@ -987,6 +1010,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
opcodes,
num_opcodes,
@@ -1004,6 +1028,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
0x8B,
1,
@@ -1019,6 +1044,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
0x8D,
1,
@@ -1081,6 +1107,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
opcodes,
num_opcodes,
@@ -1108,7 +1135,17 @@ pub(crate) fn emit(
};
// MOV r8, r/m8 is (REX.W==0) 88 /r
emit_std_reg_mem(sink, state, LegacyPrefixes::None, 0x88, 1, *src, dst, rex)
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
0x88,
1,
*src,
dst,
rex,
)
}
2 => {
@@ -1116,6 +1153,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::_66,
0x89,
1,
@@ -1130,6 +1168,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
0x89,
1,
@@ -1144,6 +1183,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
LegacyPrefixes::None,
0x89,
1,
@@ -1253,6 +1293,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode_bytes,
2,
@@ -1311,7 +1352,7 @@ pub(crate) fn emit(
let addr = &addr.finalize(state, sink);
// Whereas here we revert to the "normal" G-E ordering.
let opcode = if *size == 1 { 0x3A } else { 0x3B };
emit_std_reg_mem(sink, state, prefix, opcode, 1, *reg_g, addr, rex);
emit_std_reg_mem(sink, state, info, prefix, opcode, 1, *reg_g, addr, rex);
}
RegMemImm::Imm { simm32 } => {
@@ -1372,6 +1413,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode,
2,
@@ -1408,6 +1450,10 @@ pub(crate) fn emit(
}
Inst::Push64 { src } => {
if info.flags().enable_probestack() {
sink.add_trap(state.cur_srcloc(), TrapCode::StackOverflow);
}
match src {
RegMemImm::Reg { reg } => {
let enc_reg = int_reg_enc(*reg);
@@ -1423,6 +1469,7 @@ pub(crate) fn emit(
emit_std_enc_mem(
sink,
state,
info,
LegacyPrefixes::None,
0xFF,
1,
@@ -1454,6 +1501,9 @@ pub(crate) fn emit(
}
Inst::CallKnown { dest, opcode, .. } => {
if info.flags().enable_probestack() {
sink.add_trap(state.cur_srcloc(), TrapCode::StackOverflow);
}
if let Some(s) = state.take_stack_map() {
sink.add_stack_map(StackMapExtent::UpcomingBytes(5), s);
}
@@ -1469,6 +1519,9 @@ pub(crate) fn emit(
}
Inst::CallUnknown { dest, opcode, .. } => {
if info.flags().enable_probestack() {
sink.add_trap(state.cur_srcloc(), TrapCode::StackOverflow);
}
let start_offset = sink.cur_offset();
match dest {
RegMem::Reg { reg } => {
@@ -1489,6 +1542,7 @@ pub(crate) fn emit(
emit_std_enc_mem(
sink,
state,
info,
LegacyPrefixes::None,
0xFF,
1,
@@ -1587,6 +1641,7 @@ pub(crate) fn emit(
emit_std_enc_mem(
sink,
state,
info,
LegacyPrefixes::None,
0xFF,
1,
@@ -1733,6 +1788,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode,
num_opcodes,
@@ -1863,6 +1919,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode,
length,
@@ -2012,7 +2069,17 @@ pub(crate) fn emit(
!regs_swapped,
"No existing way to encode a mem argument in the ModRM r/m field."
);
emit_std_reg_mem(sink, state, prefix, opcode, len, dst.to_reg(), addr, rex);
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode,
len,
dst.to_reg(),
addr,
rex,
);
}
}
sink.put1(*imm);
@@ -2045,6 +2112,7 @@ pub(crate) fn emit(
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode,
2,
@@ -2109,7 +2177,17 @@ pub(crate) fn emit(
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_reg_mem(sink, state, prefix, opcode, 2, reg_g.to_reg(), addr, rex);
emit_std_reg_mem(
sink,
state,
info,
prefix,
opcode,
2,
reg_g.to_reg(),
addr,
rex,
);
}
}
}
@@ -2129,7 +2207,7 @@ pub(crate) fn emit(
}
RegMem::Mem { addr } => {
let addr = &addr.finalize(state, sink);
emit_std_reg_mem(sink, state, prefix, opcode, len, *dst, addr, rex);
emit_std_reg_mem(sink, state, info, prefix, opcode, len, *dst, addr, rex);
}
}
}
@@ -2643,7 +2721,7 @@ pub(crate) fn emit(
_ => unreachable!(),
};
let amode = dst.finalize(state, sink);
emit_std_reg_mem(sink, state, prefix, opcodes, 2, *src, &amode, rex);
emit_std_reg_mem(sink, state, info, prefix, opcodes, 2, *src, &amode, rex);
}
Inst::AtomicRmwSeq { ty, op } => {