fix FDE binary search for case where PC is not exactly on first instruction

This commit is contained in:
Nikita Smith
2025-11-07 14:39:45 -08:00
committed by Ryan Fleury
parent d44efc15c8
commit 821af9b104
+19 -21
View File
@@ -331,8 +331,8 @@ eh_find_nearest_fde(EH_FrameHdr header, EH_PtrCtx *ptr_ctx, U64 pc)
goto exit;
}
U64 last_off = header.table.size - header.entry_byte_size;
U64 last = 0;
U64 last_off = header.table.size - header.entry_byte_size;
U64 last = 0;
U64 last_size = eh_parse_ptr(header.table, last_off, ptr_ctx->pc_vaddr + last_off, ptr_ctx, header.table_enc, &last);
AssertAlways(last_size);
if (last <= pc) {
@@ -340,27 +340,25 @@ eh_find_nearest_fde(EH_FrameHdr header, EH_PtrCtx *ptr_ctx, U64 pc)
goto exit;
}
if (first <= pc && pc < last) {
U64 l = 0;
U64 r = header.fde_count - 1;
while (l <= r) {
U64 m = l + (r - l) / 2;
U64 m_pc_off = m * header.entry_byte_size;
U64 m_pc = 0;
U64 m_pc_size = eh_parse_ptr(header.table, m_pc_off, ptr_ctx->pc_vaddr + m_pc_off, ptr_ctx, header.table_enc, &m_pc);
Assert(m_pc_size);
if (m_pc == pc) {
fde_idx = m;
goto exit;
} else if (m_pc < pc) {
l = m + 1;
} else {
r = m - 1;
}
U64 l = 0;
U64 r = header.fde_count - 1;
while (l <= r) {
U64 m = l + (r - l) / 2;
U64 m_pc_off = m * header.entry_byte_size;
U64 m_pc = 0;
U64 m_pc_size = eh_parse_ptr(header.table, m_pc_off, ptr_ctx->pc_vaddr + m_pc_off, ptr_ctx, header.table_enc, &m_pc);
Assert(m_pc_size);
if (m_pc > pc) {
r = m - 1;
} else if (m_pc < pc) {
l = m + 1;
} else {
fde_idx = m;
goto exit;
}
fde_idx = l;
}
fde_idx = l > 0 ? l-1 : 0;
}
}