From: Matthias Kruk <m@m10k.eu>
Date: Wed, 18 Dec 2019 08:44:15 +0000 (+0900)
Subject: Add pg_dir_mmap() and pg_dir_munmap() functions to implement the low-level half of... 
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=96eed2e4c9a8fb8159c5d0aeddaf628fb9d080f3;p=corax

Add pg_dir_mmap() and pg_dir_munmap() functions to implement the low-level half of the mmap() and munmap() syscalls
---

diff --git a/kernel/arch/paging.c b/kernel/arch/paging.c
index 23a36e6..e31b0d2 100644
--- a/kernel/arch/paging.c
+++ b/kernel/arch/paging.c
@@ -23,6 +23,7 @@
 #include <debug.h>
 #include <arch.h>
 #include <string.h>
+#include <sys/mman.h>
 #include "cpu.h"
 #include "paging.h"
 #include "heap.h"
@@ -788,6 +789,7 @@ static void* _pg_dir_heap_start(pg_dir_t *pd)
 
 			break;
 
+		case REGION_MMAP:
 		case REGION_TEXT:
 		case REGION_BSS:
 		case REGION_DATA:
@@ -859,6 +861,7 @@ static int _pg_dir_heap_map(pg_dir_t *pd, u32_t heap_size)
 			 */
 			break;
 
+		case REGION_MMAP:
 		case REGION_TEXT:
 		case REGION_BSS:
 		case REGION_DATA:
@@ -1593,7 +1596,7 @@ void pg_fault_debug(pg_dir_t *pdir, void *addr)
 		dbg_printf("pdir[%03u]      = 0x%08x\n", pdi, (u32_t)pde);
 
 		if(!(pde & PAGE_ATTR_SIZE)) {
-			pte = ((page_table_t*)(pde & 0xfffff000))->pt_entries[pti];
+			pte = ((page_table_t*)((size_t)pde & 0xfffff000))->pt_entries[pti];
 			dbg_printf("pdir[%03u][%03u] = 0x%08x\n", pdi, pti, (u32_t)pte);
 		}
 
@@ -1609,3 +1612,64 @@ void pg_fault_debug(pg_dir_t *pdir, void *addr)
 
 	return;
 }
+
+int pg_dir_mmap(pg_dir_t *pgdir, void *addr, u32_t size, int prot, int flags, void **dst)
+{
+	int ret_val;
+
+	ret_val = -EINVAL;
+
+	if(pgdir && dst) {
+		ret_val = -EFAULT;
+
+		/* FIXME: Lock the page directory */
+
+		if(flags & MAP_PHYS) {
+			u32_t attrs;
+
+			/* map the physical memory addr:size into the page directory */
+			/* FIXME: Add another flag for identity mappings and otherwise map non-identically */
+
+			attrs = PAGE_ATTR_PRESENT;
+
+			if(!(prot & PROT_EXEC)) {
+				attrs |= PAGE_ATTR_NO_EXEC;
+			}
+
+			if(prot & PROT_WRITE) {
+				attrs |= PAGE_ATTR_WRITABLE;
+			}
+
+			if(prot & PROT_READ) {
+				attrs |= PAGE_ATTR_USER;
+			}
+
+			ret_val = pg_dir_map(pgdir, addr, addr, size, attrs);
+
+			if(!ret_val) {
+				/* also account for the new region */
+				ret_val = _pg_dir_add_region(pgdir, addr, size,
+											 REGION_MMAP, 0, REGION_SHARED);
+
+				/* or unmap if it can't be accounted for */
+				if(ret_val < 0) {
+					pg_dir_unmap(pgdir, addr, size);
+				}
+			}
+		}
+
+		/* FIXME: Unlock the page directory */
+
+		if(!ret_val) {
+			/* success - write the result to *dst */
+			*dst = addr;
+		}
+	}
+
+	return(ret_val);
+}
+
+int pg_dir_munmap(pg_dir_t *pgdir, void *addr, u32_t size)
+{
+	return(-ENOSYS);
+}
diff --git a/kernel/include/arch.h b/kernel/include/arch.h
index f275d4f..cc88308 100644
--- a/kernel/include/arch.h
+++ b/kernel/include/arch.h
@@ -79,6 +79,7 @@ struct task {
 #define REGION_KSTACK 4
 #define REGION_STACK  5
 #define REGION_HEAP   6
+#define REGION_MMAP   7
 
 #define REGION_SHARED (1 << 0)
 #define REGION_KERNEL (1 << 1)
@@ -185,6 +186,8 @@ void*   pg_dir_get_ustack(pg_dir_t*);
 void*   pg_dir_sbrk(pg_dir_t*, i32_t);
 int     pg_dir_foreach_region(pg_dir_t*, int(*)(pg_dir_t*, struct region*, void*), void*);
 int     pg_dir_memcpy(pg_dir_t*, void*, pg_dir_t*, void*, u32_t);
+int     pg_dir_mmap(pg_dir_t*, void*, u32_t, int, int, void**);
+int     pg_dir_munmap(pg_dir_t*, void*, u32_t);
 
 #endif /* !__ASSEMBLY_SOURCE */