Merge branch 'lab2' of gitlab.unexploitable.systems:fedorind/jos into lab2

kern/ansi.h

@@ -3,6 +3,22 @@
 
 #include <inc/types.h>
 
+#define ACOL_WRAP(s) "\33[" s "m"
+#define ACOL_BLACK  ACOL_WRAP("30")
+#define ACOL_RED ACOL_WRAP("31")
+#define ACOL_GREEN ACOL_WRAP("32")
+#define ACOL_YELLOW ACOL_WRAP("33")
+#define ACOL_BLUE ACOL_WRAP("34")
+#define ACOL_MAGENTA ACOL_WRAP("35")
+#define ACOL_CYAN ACOL_WRAP("36")
+#define ACOL_WHITE ACOL_WRAP("37")
+#define ACOL_CLEAR ACOL_WRAP("0")
+
+#define ACOL_TAG(c, s) "[" c s ACOL_CLEAR "] "
+#define ACOL_NOTE(s) ACOL_TAG(ACOL_WHITE, " Note  ") s
+#define ACOL_WARN(s) ACOL_TAG(ACOL_YELLOW, "Warning") s
+#define ACOL_ERR(s) ACOL_TAG(ACOL_RED, " Error ") s
+
 struct AttrState {
 	uint8_t cattrs;
 	uint8_t attrs;

kern/monitor.c

@@ -7,9 +7,13 @@
 #include <inc/assert.h>
 #include <inc/x86.h>
 
+#include <kern/ansi.h>
 #include <kern/console.h>
 #include <kern/monitor.h>
 #include <kern/kdebug.h>
+#include <kern/pmap.h>
+
+#include <inc/string.h>
 
 #define CMDBUF_SIZE	80	// enough for one VGA text line
 
@@ -25,7 +29,10 @@ struct Command {
 static struct Command commands[] = {
 	{ "help", "Display this list of commands", mon_help },
 	{ "kerninfo", "Display information about the kernel", mon_kerninfo },
-	{ "backtrace", "Display current backtrace", mon_backtrace }
+	{ "backtrace", "Display current backtrace", mon_backtrace },
+	{ "showmappings", "Display the physical mappings for range", mon_showmappings },
+	{ "mperms", "Change the permissions of a memory range", mon_mperms }
+	
 };
 
 /***** Implementations of basic kernel monitor commands *****/
@@ -46,7 +53,7 @@ mon_kerninfo(int argc, char **argv, struct Trapframe *tf)
 	extern char _start[], entry[], etext[], edata[], end[];
 
 	cprintf("Special kernel symbols:\n");
-	cprintf("  _start                  %08x (phys)\n", _start);
+	cprintf("  _start		  %08x (phys)\n", _start);
 	cprintf("  entry  %08x (virt)  %08x (phys)\n", entry, entry - KERNBASE);
 	cprintf("  etext  %08x (virt)  %08x (phys)\n", etext, etext - KERNBASE);
 	cprintf("  edata  %08x (virt)  %08x (phys)\n", edata, edata - KERNBASE);
@@ -75,7 +82,7 @@ mon_backtrace(int argc, char **argv, struct Trapframe *tf)
 		ebp = (uint32_t*) ebp[0];
 		
 		debuginfo_eip(eip, &info);
-		cprintf("           %s:%d: %.*s+%d\n",
+		cprintf("	   %s:%d: %.*s+%d\n",
 			info.eip_file, info.eip_line,
 			info.eip_fn_namelen, info.eip_fn_name,
 			eip - info.eip_fn_addr);
@@ -84,7 +91,102 @@ mon_backtrace(int argc, char **argv, struct Trapframe *tf)
 	return 0;
 }
 
+#define EXPECT_ARGS(n, ac) if(ac - 1 != n) { \
+	cprintf(ACOL_ERR("Expected %d arguments, " \
+		"got %d\n"), n, ac - 1); \
+	return 1; }
 
+#define VA_TXT ACOL_CYAN "VA" ACOL_CLEAR
+#define PA_TXT ACOL_GREEN "PA" ACOL_CLEAR
+
+char*
+decode_pte_perms(pte_t pte, char* buffer) {
+	buffer[0] = (pte & PTE_W) ? 'w' : 'r';
+	buffer[1] = (pte & PTE_U) ? 'u' : 'k';
+	return buffer;
+}
+
+void
+get_pagebounds(char* one, char* two, uintptr_t* pone, uintptr_t* ptwo) {
+	long from = strtol(one, NULL, 0);
+	long to = strtol(two, NULL, 0);
+	*pone = ROUNDDOWN(from, PGSIZE);
+	*ptwo = ROUNDUP(to, PGSIZE);
+	if(*pone != from) cprintf(ACOL_WARN("Aligning start address %p down to %p\n"),
+		from, *pone);
+	if(*ptwo != to) cprintf(ACOL_WARN("Aligning end address %p up to %p\n"),
+		to, *ptwo);
+}
+
+int
+mon_showmappings(int argc, char** argv, struct Trapframe* tf) {
+	EXPECT_ARGS(2, argc);
+	uintptr_t va_start, va_end;
+	char buffer[3] = {0};
+
+	get_pagebounds(argv[1], argv[2], &va_start, &va_end);
+
+	if(va_start == va_end) va_end += PGSIZE;
+	while(va_start < va_end) {
+		pte_t* pte = pgdir_walk(kern_pgdir, (const void*) va_start, 0);
+		cprintf(VA_TXT " 0x%08p -> ", va_start);
+
+		if(pte && (*pte & PTE_P)) {
+			cprintf(PA_TXT " 0x%08p (%s)\n", PTE_ADDR(*pte),
+				decode_pte_perms(*pte, buffer));
+		} else {
+			cprintf(PA_TXT " ------------\n");
+		}
+
+		va_start += PGSIZE;
+	}
+
+	return 0;
+}
+
+int mon_mperms(int argc, char** argv, struct Trapframe* tf) {
+	EXPECT_ARGS(3, argc);
+	pte_t perms = 0;
+	enum {
+		PERM_ADD,
+		PERM_REMOVE,
+		PERM_SET
+	} pmode;
+
+	const char* str = argv[1];
+	if(str[0] == '+') { pmode = PERM_ADD; str++; }
+	else if(str[0] == '-') { pmode = PERM_REMOVE; str++; }
+	else pmode = PERM_SET;
+
+	while(*str) {
+		if(*str == 'w') perms |= PTE_W;
+		else if(*str == 'u') perms |= PTE_U;
+		else {
+			cprintf(ACOL_ERR("Unknown permission character %c\n"), *str);
+			return 1;
+		}
+		str++;
+	}
+
+	uintptr_t va_start, va_end;
+	get_pagebounds(argv[2], argv[3], &va_start, &va_end);
+	if(va_start == va_end) va_end += PGSIZE;
+	while(va_start < va_end) {
+		pte_t* pte = pgdir_walk(kern_pgdir, (void*) va_start, 0);
+		if(!pte || !(*pte & PTE_P)) { va_start += PGSIZE; continue; }
+		
+		if(pmode == PERM_ADD) {
+			*pte |= perms;
+		} else if(pmode == PERM_REMOVE) {
+			*pte &= ~perms;
+		} else if(pmode == PERM_SET) {
+			*pte = PTE_ADDR(*pte) | perms | PTE_P;
+		}
+		va_start += PGSIZE;
+	}
+
+	return 0;
+}
 
 /***** Kernel monitor command interpreter *****/
 

kern/monitor.h

@@ -15,5 +15,7 @@ void monitor(struct Trapframe *tf);
 int mon_help(int argc, char **argv, struct Trapframe *tf);
 int mon_kerninfo(int argc, char **argv, struct Trapframe *tf);
 int mon_backtrace(int argc, char **argv, struct Trapframe *tf);
+int mon_showmappings(int argc, char **argv, struct Trapframe *tf);
+int mon_mperms(int argc, char** argv, struct Trapframe* tf);
 
 #endif	// !JOS_KERN_MONITOR_H