changed the vma table from static to dynamically allocated array and …

…removed the option VMA_REGIONS

fs/procfs/data.c

@@ -544,19 +544,23 @@ int data_proc_pid_exe(char *buffer, __pid_t pid)
 	if((p = get_proc_by_pid(pid))) {
 
 		/* kernel and zombie processes are programless */
-		if(!p->vma || !p->vma->inode) {
+
+		/*
+		 * This assumes that the first entry in the vma_table
+		 * contains the program's inode.
+		 */
+		if(!p->vma_table || !p->vma_table->inode) {
 			return -ENOENT;
 		}
 
-		i = p->vma->inode;
+		i = p->vma_table->inode;
 		size = sprintk(buffer, "[%02d%02d]:%d", MAJOR(i->rdev), MINOR(i->rdev), i->inode);
 	}
 	return size;
 }
 
 int data_proc_pid_maps(char *buffer, __pid_t pid)
 {
-	unsigned int n;
 	int size, len;
 	__ino_t inode;
 	int major, minor;
@@ -567,11 +571,8 @@ int data_proc_pid_maps(char *buffer, __pid_t pid)
 
 	size = 0;
 	if((p = get_proc_by_pid(pid))) {
-		if(!p->vma) {
-			return 0;
-		}
-		vma = p->vma;
-		for(n = 0; n < VMA_REGIONS && vma->start; n++, vma++) {
+		vma = p->vma_table;
+		while(vma) {
 			r = vma->prot & PROT_READ ? 'r' : '-';
 			w = vma->prot & PROT_WRITE ? 'w' : '-';
 			x = vma->prot & PROT_EXEC ? 'x' : '-';
@@ -609,8 +610,10 @@ int data_proc_pid_maps(char *buffer, __pid_t pid)
 			}
 			len = sprintk(buffer + size, "%08x-%08x %c%c%c%c %08x %02d:%02d %- 10u [%s]\n", vma->start, vma->end, r, w, x, f, vma->offset, major, minor, inode, section);
 			size += len;
+			vma = vma->next;
 		}
 	}
+
 	return size;
 }
 
@@ -660,7 +663,7 @@ int data_proc_pid_root(char *buffer, __pid_t pid)
 
 int data_proc_pid_stat(char *buffer, __pid_t pid)
 {
-	int n, size, vma_start, vma_end;
+	int size, vma_start, vma_end;
 	unsigned int esp, eip;
 	int signum, mask;
 	__sigset_t sigignored, sigcaught;
@@ -671,14 +674,19 @@ int data_proc_pid_stat(char *buffer, __pid_t pid)
 
 	size = text = data = stack = mmap = 0;
 	if((p = get_proc_by_pid(pid))) {
-		if(!p->vma) {
+		vma = p->vma_table;
+		if(!vma) {
 			return 0;
 		}
-		vma_start = p->vma[0].start;
-		vma_end = p->vma[0].end;
 
-		vma = p->vma;
-		for(n = 0; n < VMA_REGIONS && vma->start; n++, vma++) {
+		/*
+		 * This assumes that the first entry in the vma_table
+		 * contains the program's inode.
+		 */
+		vma_start = vma->start;
+		vma_end = vma->end;
+
+		while(vma) {
 			switch(vma->s_type) {
 				case P_TEXT:
 					text += vma->end - vma->start;
@@ -694,6 +702,7 @@ int data_proc_pid_stat(char *buffer, __pid_t pid)
 					mmap += vma->end - vma->start;
 					break;
 			}
+			vma = vma->next;
 		}
 
 		sigignored = sigcaught = 0;
@@ -713,55 +722,55 @@ int data_proc_pid_stat(char *buffer, __pid_t pid)
 			eip = sc->eip;
 		}
 		size = sprintk(buffer, "%d (%s) %c %d %d %d %d %d %d %d %d %d %d %u %u %u %u %d %d %d %d %d %d %u %u %u %u %u %u %u %d %d %u %u %u\n",
-		p->pid,
-		p->argv0,
-		pstate[p->state][0],
-		p->ppid, p->pgid, p->sid,
-		p->ctty ? p->ctty->dev : 0,
-		p->ctty ? p->ctty->pgid : - 1,
-		0,			/* flags */
-		0, 0, 0, 0,		/* minflt, cminflt, majflt, cmajflt */
-		tv2ticks(&p->usage.ru_utime),
-		tv2ticks(&p->usage.ru_stime),
-		tv2ticks(&p->cusage.ru_utime),
-		tv2ticks(&p->cusage.ru_stime),
-		0,			/* counter */
-		0,			/* priority */
-		0,			/* timeout */
-		0,			/* itrealvalue */
-		p->start_time,
-		text + data + stack + mmap,
-		p->rss,
-		0x7FFFFFFF,		/* rlim */
-		vma_start,		/* startcode */
-		vma_end,		/* endcode */
-		PAGE_OFFSET - 1,	/* startstack */
-		esp,			/* kstkesp */
-		eip,			/* kstkeip */
-		p->sigpending,
-		p->sigblocked,
-		sigignored,
-		sigcaught,
-		p->sleep_address
+			p->pid,
+			p->argv0,
+			pstate[p->state][0],
+			p->ppid, p->pgid, p->sid,
+			p->ctty ? p->ctty->dev : 0,
+			p->ctty ? p->ctty->pgid : - 1,
+			0,			/* flags */
+			0, 0, 0, 0,		/* minflt, cminflt, majflt, cmajflt */
+			tv2ticks(&p->usage.ru_utime),
+			tv2ticks(&p->usage.ru_stime),
+			tv2ticks(&p->cusage.ru_utime),
+			tv2ticks(&p->cusage.ru_stime),
+			0,			/* counter */
+			0,			/* priority */
+			0,			/* timeout */
+			0,			/* itrealvalue */
+			p->start_time,
+			text + data + stack + mmap,
+			p->rss,
+			0x7FFFFFFF,		/* rlim */
+			vma_start,		/* startcode */
+			vma_end,		/* endcode */
+			PAGE_OFFSET - 1,	/* startstack */
+			esp,			/* kstkesp */
+			eip,			/* kstkeip */
+			p->sigpending,
+			p->sigblocked,
+			sigignored,
+			sigcaught,
+			p->sleep_address
 		);
 	}
 	return size;
 }
 
 int data_proc_pid_statm(char *buffer, __pid_t pid)
 {
-	int n, size;
+	int size;
 	struct proc *p;
 	struct vma *vma;
 	int text, data, stack, mmap;
 
 	size = text = data = stack = mmap = 0;
 	if((p = get_proc_by_pid(pid))) {
-		if(!p->vma) {
+		vma = p->vma_table;
+		if(!vma) {
 			return 0;
 		}
-		vma = p->vma;
-		for(n = 0; n < VMA_REGIONS && vma->start; n++, vma++) {
+		while(vma) {
 			switch(vma->s_type) {
 				case P_TEXT:
 					text += vma->end - vma->start;
@@ -777,6 +786,7 @@ int data_proc_pid_statm(char *buffer, __pid_t pid)
 					mmap += vma->end - vma->start;
 					break;
 			}
+			vma = vma->next;
 		}
 
 		size = sprintk(buffer, "%d", (text + data + stack + mmap) / PAGE_SIZE);
@@ -792,7 +802,7 @@ int data_proc_pid_statm(char *buffer, __pid_t pid)
 
 int data_proc_pid_status(char *buffer, __pid_t pid)
 {
-	int n, size;
+	int size;
 	int signum, mask;
 	__sigset_t sigignored, sigcaught;
 	struct proc *p;
@@ -801,11 +811,11 @@ int data_proc_pid_status(char *buffer, __pid_t pid)
 
 	size = text = data = stack = mmap = 0;
 	if((p = get_proc_by_pid(pid))) {
-		if(!p->vma) {
+		vma = p->vma_table;
+		if(!vma) {
 			return 0;
 		}
-		vma = p->vma;
-		for(n = 0; n < VMA_REGIONS && vma->start; n++, vma++) {
+		while(vma) {
 			switch(vma->s_type) {
 				case P_TEXT:
 					text += vma->end - vma->start;
@@ -821,6 +831,7 @@ int data_proc_pid_status(char *buffer, __pid_t pid)
 					mmap += vma->end - vma->start;
 					break;
 			}
+			vma = vma->next;
 		}
 
 		size = sprintk(buffer, "Name:\t%s\n", p->argv0);

fs/procfs/symlink.c

@@ -1,7 +1,7 @@
 /*
  * fiwix/fs/procfs/symlink.c
  *
- * Copyright 2018-2021, Jordi Sanfeliu. All rights reserved.
+ * Copyright 2018-2022, Jordi Sanfeliu. All rights reserved.
  * Distributed under the terms of the Fiwix License.
  */
 
@@ -123,11 +123,15 @@ int procfs_followlink(struct inode *dir, struct inode *i, struct inode **i_res)
 			iput(i);
 			break;
 		case PROC_PID_EXE:
-			if(!p->vma || !p->vma->inode) {
+			/*
+			 * This assumes that the first entry in the vma_table
+			 * contains the program's inode.
+			 */
+			if(!p->vma_table || !p->vma_table->inode) {
 				return -ENOENT;
 			}
-			*i_res = p->vma->inode;
-			p->vma->inode->count++;
+			*i_res = p->vma_table->inode;
+			p->vma_table->inode->count++;
 			iput(i);
 			break;
 		case PROC_PID_ROOT:

include/fiwix/config.h

@@ -32,7 +32,6 @@
 					   scroll back */
 #define MAX_SPU_NOTICES		10	/* max. number of messages on spurious
 					   interrupts */
-#define VMA_REGIONS		150	/* max. number of virtual memory maps */
 
 
 /* toggle configuration options */

include/fiwix/process.h

@@ -14,10 +14,12 @@ struct vma {
 	char prot;		/* PROT_READ, PROT_WRITE, ... */
 	unsigned int flags;	/* MAP_SHARED, MAP_PRIVATE, ... */
 	unsigned int offset;
-	char s_type;		/* section type (P_TEXT, P_DATA, ...) */
+	char s_type;		/* segment type (P_TEXT, P_DATA, ...) */
 	struct inode *inode;	/* file inode */
 	char o_mode;		/* open mode (O_RDONLY, O_RDWR, ...) */
 	void *object;		/* generic pointer (currently only for shm) */
+	struct vma *prev;
+	struct vma *next;
 };
 
 #include <fiwix/config.h>
@@ -132,7 +134,7 @@ struct proc {
 	int envc;
 	char **envp;
 	char pidstr[5];			/* PID number converted to string */
-	struct vma vma[VMA_REGIONS];	/* virtual memory-map addresses */
+	struct vma *vma_table;		/* virtual memory-map addresses */
 	unsigned int brk_lower;		/* lower limit of the heap section */
 	unsigned int brk;		/* current limit of the heap */
 	__sigset_t sigpending;

kernel/init.c

@@ -63,7 +63,6 @@ void init_init(void)
 	memcpy_b(pgdir, kpage_dir, PAGE_SIZE);
 	init->tss.cr3 = V2P((unsigned int)pgdir);
 
-	memset_b(init->vma, 0, sizeof(init->vma));
 	init->ppid = 0;
 	init->pgid = 0;
 	init->sid = 0;

kernel/syscalls.c

@@ -27,33 +27,35 @@ static int verify_address(int type, const void *addr, unsigned int size)
 	unsigned int start;
 
 	/*
-	 * Verifies if the 'vma' array of that process is not empty. It can
-	 * only be empty during the initialization of INIT, when it calls to
-	 * sys_execve and sys_open without having yet a proper setup.
+	 * The vma_table of the INIT process is not setup yet when it
+	 * calls sys_open() and sys_execve() from init_trampoline(),
+	 * but these calls are trusted.
 	 */
-	if(current->vma[0].s_type != 0) {
-		start = (unsigned int)addr;
-		if(!(vma = find_vma_region(start))) {
-			return -EFAULT;
-		}
+	if(!current->vma_table) {
+		return 0;
+	}
 
-		for(;;) {
-			if(type == VERIFY_WRITE) {
-				if(!(vma->prot & PROT_WRITE)) {
-					return -EFAULT;
-				}
-			} else {
-				if(!(vma->prot & PROT_READ)) {
-					return -EFAULT;
-				}
-			}
-			if(start + size < vma->end) {
-				break;
+	start = (unsigned int)addr;
+	if(!(vma = find_vma_region(start))) {
+		return -EFAULT;
+	}
+
+	for(;;) {
+		if(type == VERIFY_WRITE) {
+			if(!(vma->prot & PROT_WRITE)) {
+				return -EFAULT;
 			}
-			if(!(vma = find_vma_region(vma->end))) {
+		} else {
+			if(!(vma->prot & PROT_READ)) {
 				return -EFAULT;
 			}
 		}
+		if(start + size < vma->end) {
+			break;
+		}
+		if(!(vma = find_vma_region(vma->end))) {
+			return -EFAULT;
+		}
 	}
 #endif /* CONFIG_LAZY_USER_ADDR_CHECK */