A number of small fixes for the uaccess merge.

arch/um/include/kern_util.h

@@ -33,9 +33,8 @@ extern int do_signal(int error);
 extern int is_stack_fault(unsigned long sp);
 extern unsigned long segv(unsigned long address, unsigned long ip, 
 			  int is_write, int is_user, void *sc);
-extern unsigned long handle_page_fault(unsigned long address, unsigned long ip,
-				       int is_write, int is_user, 
-				       int *code_out);
+extern int handle_page_fault(unsigned long address, unsigned long ip,
+			     int is_write, int is_user, int *code_out);
 extern void syscall_ready(void);
 extern void set_tracing(void *t, int tracing);
 extern int is_tracing(void *task);

arch/um/include/um_uaccess.h

@@ -54,7 +54,7 @@ static inline int clear_user(void *mem, int len)
 	return(CHOOSE_MODE_PROC(clear_user_tt, clear_user_skas, mem, len));
 }
 
-static inline int strnlen_user(void *str, int len)
+static inline int strnlen_user(const void *str, int len)
 {
 	return(CHOOSE_MODE_PROC(strnlen_user_tt, strnlen_user_skas, str, len));
 }

arch/um/kernel/Makefile

@@ -10,7 +10,7 @@ obj-y = config.o exec_kern.o exitcode.o frame_kern.o frame.o helper.o \
 	process_kern.o ptrace.o reboot.o resource.o sigio_user.o \
 	sigio_kern.o signal_kern.o signal_user.o smp.o syscall_kern.o \
 	syscall_user.o sysrq.o sys_call_table.o tempfile.o time.o \
-	time_kern.o tlb.o trap_kern.o trap_user.o uaccess_user.o um_arch.o \
+	time_kern.o tlb.o trap_kern.o trap_user.o um_arch.o \
 	umid.o user_util.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd_kern.o initrd_user.o

arch/um/kernel/process_kern.c

@@ -222,21 +222,25 @@ int page_mask(void)
 	return(PAGE_MASK);
 }
 
-unsigned long um_virt_to_phys(void *t, unsigned long addr)
+void *um_virt_to_phys(struct task_struct *task, unsigned long addr, 
+		      pte_t *pte_out)
 {
-	struct task_struct *task;
 	pgd_t *pgd;
 	pmd_t *pmd;
 	pte_t *pte;
 
-	task = t;
-	if(task->mm == NULL) return(0xffffffff);
+	if(task->mm == NULL) 
+		return(ERR_PTR(-EINVAL));
 	pgd = pgd_offset(task->mm, addr);
 	pmd = pmd_offset(pgd, addr);
-	if(!pmd_present(*pmd)) return(0xffffffff);
+	if(!pmd_present(*pmd)) 
+		return(ERR_PTR(-EINVAL));
 	pte = pte_offset_kernel(pmd, addr);
-	if(!pte_present(*pte)) return(0xffffffff);
-	return((pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
+	if(!pte_present(*pte)) 
+		return(ERR_PTR(-EINVAL));
+	if(pte_out != NULL)
+		*pte_out = *pte;
+	return((void *) (pte_val(*pte) & PAGE_MASK) + (addr & ~PAGE_MASK));
 }
 
 char *current_cmd(void)
@@ -244,8 +248,8 @@ char *current_cmd(void)
 #if defined(CONFIG_SMP) || defined(CONFIG_HIGHMEM)
 	return("(Unknown)");
 #else
-	unsigned long addr = um_virt_to_phys(current, current->mm->arg_start);
-	return addr == 0xffffffff? "(Unknown)": __va(addr);
+	void *addr = um_virt_to_phys(current, current->mm->arg_start, NULL);
+	return IS_ERR(addr) ? "(Unknown)": __va((unsigned long) addr);
 #endif
 }
 

arch/um/kernel/skas/include/uaccess.h

@@ -26,10 +26,6 @@ static inline int verify_area_skas(int type, const void * addr,
 	return(access_ok_skas(type, addr, size) ? 0 : -EFAULT);
 }
 
-extern unsigned long handle_page_fault(unsigned long address, 
-				       unsigned long ip, int is_write, 
-				       int is_user, int *code_out);
-
 extern void *um_virt_to_phys(struct task_struct *task, unsigned long virt,
 			     pte_t *pte_out);
 
@@ -212,7 +208,7 @@ static inline int strnlen_chunk(unsigned long str, int len, void *arg)
 	return(0);
 }
 
-static inline int strnlen_user_skas(void *str, int len)
+static inline int strnlen_user_skas(const void *str, int len)
 {
 	int count = 0, n;
 

arch/um/kernel/trap_kern.c

@@ -4,6 +4,7 @@
  */
 
 #include "linux/kernel.h"
+#include "asm/errno.h"
 #include "linux/sched.h"
 #include "linux/mm.h"
 #include "linux/spinlock.h"
@@ -19,41 +20,36 @@
 #include "kern_util.h"
 #include "kern.h"
 #include "chan_kern.h"
-#include "debug.h"
 #include "mconsole_kern.h"
 #include "2_5compat.h"
 
-extern int nsyscalls;
-
-unsigned long segv(unsigned long address, unsigned long ip, int is_write, 
-		   int is_user, void *sc)
+int handle_page_fault(unsigned long address, unsigned long ip, 
+		      int is_write, int is_user, int *code_out)
 {
 	struct mm_struct *mm = current->mm;
 	struct vm_area_struct *vma;
-	struct siginfo si;
-	void *catcher;
 	pgd_t *pgd;
 	pmd_t *pmd;
 	pte_t *pte;
 	unsigned long page;
+	int err = -EFAULT;
 
-	if((address >= start_vm) && (address < end_vm)){
-		flush_tlb_kernel_vm();
-		return(0);
-	}
-	if(mm == NULL) panic("Segfault with no mm");
-	catcher = current->thread.fault_catcher;
-	si.si_code = SEGV_MAPERR;
+	*code_out = SEGV_MAPERR;
 	down_read(&mm->mmap_sem);
 	vma = find_vma(mm, address);
-	if(!vma) goto bad;
-	else if(vma->vm_start <= address) goto good_area;
-	else if(!(vma->vm_flags & VM_GROWSDOWN)) goto bad;
-	else if(expand_stack(vma, address)) goto bad;
+	if(!vma) 
+		goto out;
+	else if(vma->vm_start <= address) 
+		goto good_area;
+	else if(!(vma->vm_flags & VM_GROWSDOWN)) 
+		goto out;
+	else if(expand_stack(vma, address)) 
+		goto out;
 
  good_area:
-	si.si_code = SEGV_ACCERR;
-	if(is_write && !(vma->vm_flags & VM_WRITE)) goto bad;
+	*code_out = SEGV_ACCERR;
+	if(is_write && !(vma->vm_flags & VM_WRITE)) 
+		goto out;
 	page = address & PAGE_MASK;
 	if(page == (unsigned long) current->thread_info + PAGE_SIZE)
 		panic("Kernel stack overflow");
@@ -69,8 +65,10 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
 			current->maj_flt++;
 			break;
 		case VM_FAULT_SIGBUS:
-			goto do_sigbus;
+			err = -EACCES;
+			goto out;
 		case VM_FAULT_OOM:
+			err = -ENOMEM;
 			goto out_of_memory;
 		default:
 			BUG();
@@ -80,43 +78,45 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
 	*pte = pte_mkyoung(*pte);
 	if(pte_write(*pte)) *pte = pte_mkdirty(*pte);
 	flush_tlb_page(vma, page);
+	err = 0;
+ out:
 	up_read(&mm->mmap_sem);
-	return(0);
-do_sigbus:
-	up_read(&mm->mmap_sem);
+	return(err);
 
-	/*
-	 * Send a sigbus, regardless of whether we were in kernel
-	 * or user mode.
-	 */
-	si.si_signo = SIGBUS;
-	si.si_errno = 0;
-	si.si_code = BUS_ADRERR;
-	si.si_addr = (void *)address;
-	force_sig_info(SIGBUS, &si, current);
-	if(!is_user) goto bad;
-	return(0);
 /*
  * We ran out of memory, or some other thing happened to us that made
  * us unable to handle the page fault gracefully.
  */
 out_of_memory:
-	up_read(&mm->mmap_sem);
 	if (current->pid == 1) {
+		up_read(&mm->mmap_sem);
 		yield();
 		down_read(&mm->mmap_sem);
 		goto survive;
 	}
-	printk("VM: killing process %s\n", current->comm);
-	if(is_user)
-		do_exit(SIGKILL);
+	err = -ENOMEM;
+	goto out;
+}
 
-	/* Fall through to bad */
+unsigned long segv(unsigned long address, unsigned long ip, int is_write, 
+		   int is_user, void *sc)
+{
+	struct siginfo si;
+	void *catcher;
+	int err;
+
+        if(!is_user && (address >= start_vm) && (address < end_vm)){
+                flush_tlb_kernel_vm();
+                return(0);
+        }
+        if(current->mm == NULL) panic("Segfault with no mm");
+	err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
 
- bad:
-	if(catcher != NULL){
+	catcher = current->thread.fault_catcher;
+	if(!err)
+		return(0);
+	else if(catcher != NULL){
 		current->thread.fault_addr = (void *) address;
-		up_read(&mm->mmap_sem);
 		do_longjmp(catcher, 1);
 	} 
 	else if(current->thread.fault_addr != NULL){
@@ -128,12 +128,25 @@ unsigned long segv(unsigned long address, unsigned long ip, int is_write,
  	if(!is_user) 
 		panic("Kernel mode fault at addr 0x%lx, ip 0x%lx", 
 		      address, ip);
+
+	if(err == -EACCES){
+		si.si_signo = SIGBUS;
+		si.si_errno = 0;
+		si.si_code = BUS_ADRERR;
+		si.si_addr = (void *)address;
+		force_sig_info(SIGBUS, &si, current);
+	}
+	else if(err == -ENOMEM){
+		printk("VM: killing process %s\n", current->comm);
+		do_exit(SIGKILL);
+	}
+	else {
 		si.si_signo = SIGSEGV;
 		si.si_addr = (void *) address;
 		current->thread.cr2 = address;
 		current->thread.err = is_write;
 		force_sig_info(SIGSEGV, &si, current);
-	up_read(&mm->mmap_sem);
+	}
 	return(0);
 }
 

arch/um/kernel/tt/include/uaccess.h

@@ -98,7 +98,7 @@ static inline int clear_user_tt(void *mem, int len)
 extern int __do_strnlen_user(const char *str, unsigned long n,
 			     void **fault_addr, void **fault_catcher);
 
-static inline int strnlen_user_tt(void *str, int len)
+static inline int strnlen_user_tt(const void *str, int len)
 {
 	return(__do_strnlen_user(str, len,
 				 &current->thread.fault_addr,