From 74d1edbf9f60f9631883feba68b87e1cca2f752d Mon Sep 17 00:00:00 2001 From: Tom-on64 Date: Sun, 22 Mar 2026 14:27:30 +0100 Subject: [PATCH] Fixed #GP from pmm_free() --- kernel/src/pmm.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/kernel/src/pmm.c b/kernel/src/pmm.c index 8aafb60..dfddd8f 100644 --- a/kernel/src/pmm.c +++ b/kernel/src/pmm.c @@ -9,35 +9,48 @@ uint64_t* pmm_head = NULL; int pmm_init(void) { + size_t total_mem = 0; + debugf("[pmm] Physical memory map:\n"); // We're gonna use the loop to also print the memmap for (size_t i = 0; i < bootloader.mm_entry_count; i++) { struct limine_memmap_entry* entry = bootloader.mm_entries[i]; debugf( - "\t0x%x - 0x%x (%d bytes), type %d\n", + "\t%p - %p (%d bytes), type %d\n", entry->base, entry->base + entry->length, entry->length, entry->type ); if (entry->type != LIMINE_MEMMAP_USABLE) continue; + // Limine spec says that it'll be aligned, but just as a sanity check + if (entry->base % PAGE_SIZE != 0) { + size_t diff = PAGE_SIZE - (entry->base % PAGE_SIZE); + debugf("\t Not 4 kiB aligned, shifting %p -> %p (%d bytes).\n", entry->base, entry->base + diff, diff); + entry->base += diff; + entry->length -= diff; + } + for (offset_t offset = 0; offset < entry->length; offset += PAGE_SIZE) { - uint64_t* addr = (uint64_t*)(entry->base + offset + bootloader.hhdm_offset); + uint64_t* addr = TO_VIRT(entry->base) + offset; *addr = (uint64_t)pmm_head; pmm_head = addr; + total_mem += PAGE_SIZE; } } + debugf("[pmm] %d bytes of available memory.\n", total_mem); + return 0; } void* pmm_alloc() { uint64_t* addr = pmm_head; pmm_head = (uint64_t*)(*addr); - return addr - bootloader.hhdm_offset; + return TO_PHYS(addr); } void pmm_free(void* page) { - uint64_t* addr = (uint64_t*)(page - bootloader.hhdm_offset); + uint64_t* addr = TO_VIRT(page); *addr = (uint64_t)pmm_head; pmm_head = addr; }