T0b1/wasmtime
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge pull request #2463 from cfallin/fix-heap-bounds-check-x64

Browse Source 
x64 backend: fix condition-code used for part of explicit heap check.
This commit is contained in:
Chris Fallin
2020-12-02 11:24:54 -08:00
committed by GitHub
parent 1511cedaee c9a81f008d
commit dcbc4768c9
2 changed files with 29 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
cranelift/codegen/src/isa/x64/mod.rs
View File

@@ -92,15 +92,15 @@ impl MachBackend for X64Backend {
} }
fn unsigned_add_overflow_condition(&self) -> IntCC { fn unsigned_add_overflow_condition(&self) -> IntCC {
// Unsigned `>=`; this corresponds to the carry flag set on x86, which happens on // Unsigned `<`; this corresponds to the carry flag set on x86, which
// overflow of an add. // indicates an add has overflowed.
IntCC::UnsignedGreaterThanOrEqual IntCC::UnsignedLessThan
} }
fn unsigned_sub_overflow_condition(&self) -> IntCC { fn unsigned_sub_overflow_condition(&self) -> IntCC {
// unsigned `>=`; this corresponds to the carry flag set on x86, which happens on // unsigned `<`; this corresponds to the carry flag set on x86, which
// underflow of a subtract (carry is borrow for subtract). // indicates a sub has underflowed (carry is borrow for subtract).
IntCC::UnsignedGreaterThanOrEqual IntCC::UnsignedLessThan
} }
#[cfg(feature = "unwind")] #[cfg(feature = "unwind")]

23
cranelift/filetests/filetests/isa/x64/heap.clif Normal file
View File

@@ -0,0 +1,23 @@
test compile
target x86_64
feature "experimental_x64"
function %f(i32, i64 vmctx) -> i64 {
gv0 = vmctx
gv1 = load.i64 notrap aligned gv0+0
gv2 = load.i32 notrap aligned gv0+8
heap0 = dynamic gv1, bound gv2, offset_guard 0x1000, index_type i32
block0(v0: i32, v1: i64):
v2 = heap_addr.i64 heap0, v0, 0x8000
; check: movl 8(%rsi), %r12d
; nextln: movq %rdi, %r13
; nextln: addl $$32768, %r13d
; nextln: jnb ; ud2 heap_oob ;
; nextln: cmpl %r12d, %r13d
; nextln: jbe label1; j label2
; check: Block 1:
return v2
}