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fix: rare conditional jump with double fallthrough doesn't set eip correctly

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This commit is contained in:
Fabian 2022-11-15 19:33:06 -06:00
parent 1588687e2a
commit 3bcd997904
1 changed files with 27 additions and 2 deletions
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29
src/rust/jit.rs
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@ -1674,6 +1674,13 @@ fn jit_generate_module(
let next_block_branch_taken_addr =
next_block_branch_taken_addr.unwrap();
dbg_log!(
"Conditional control flow: fallthrough in both cases, page_switch={} next_is_multi={}",
Page::page_of(next_block_branch_taken_addr)
!= Page::page_of(block.addr),
next_addr.as_ref().unwrap().len() > 1,
);
dbg_assert!(
Page::page_of(next_block_addr) == Page::page_of(block.addr)
); // currently not possible
@ -1681,6 +1688,9 @@ fn jit_generate_module(
if Page::page_of(next_block_branch_taken_addr)
!= Page::page_of(block.addr)
{
codegen::gen_condition_fn(ctx, condition);
ctx.builder.if_void();
if jump_offset_is_32 {
codegen::gen_set_eip_low_bits_and_jump_rel32(
ctx.builder,
@ -1713,9 +1723,24 @@ fn jit_generate_module(
block.addr,
next_block_branch_taken_addr,
);
}
if next_addr.unwrap().len() > 1 {
dbg_assert!(next_addr.unwrap().len() > 1);
let target_index_taken =
*index_for_addr.get(&next_block_branch_taken_addr).unwrap();
let target_index_not_taken =
*index_for_addr.get(&next_block_addr).unwrap();
ctx.builder.const_i32(target_index_taken);
ctx.builder.set_local(target_block);
ctx.builder.else_();
ctx.builder.const_i32(target_index_not_taken);
ctx.builder.set_local(target_block);
ctx.builder.block_end();
}
else if next_addr.unwrap().len() > 1 {
let target_index_taken =
*index_for_addr.get(&next_block_branch_taken_addr).unwrap();
let target_index_not_taken =