From 10614e04929a6d109a5e90524e446b637aaf0c13 Mon Sep 17 00:00:00 2001 From: Richard Qin Date: Sat, 3 Jan 2026 02:13:08 +0800 Subject: Fix: critical malloc size calculation bug Summary: - Fixed an integer arithmetic error in malloc() where 'nunits' was initialized to 0, causing incorrect heap sizing. - This bug caused malloc to return pointers pointing to unmapped memory pages, leading to Store Page Fault (scause 15) at process boundaries. - Switched memory allocator logic to use byte-based size calculation instead of K&R style units to prevent off-by-one errors. Improvements: - Shell now starts successfully without segfaults. --- src/kernel/mm/vm.cc | 3 --- 1 file changed, 3 deletions(-) (limited to 'src/kernel/mm/vm.cc') diff --git a/src/kernel/mm/vm.cc b/src/kernel/mm/vm.cc index 41d1aa1..1155d2c 100644 --- a/src/kernel/mm/vm.cc +++ b/src/kernel/mm/vm.cc @@ -5,9 +5,6 @@ #include "lib/string.h" #include "drivers/uart.h" -// COW Flag (PTE bit 8) -#define PTE_COW (1L << 8) - extern "C" { extern char kernel_end[]; -- cgit v1.2.3