1 files changed, 174 insertions, 49 deletions

diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index 2b772776fcda..69bb1652eccd 100644
--- a/arch/sh/kernel/traps_32.c
+++ b/arch/sh/kernel/traps_32.c
@@ -24,6 +24,7 @@
 #include <linux/kdebug.h>
 #include <linux/kexec.h>
 #include <linux/limits.h>
+#include <linux/proc_fs.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <asm/fpu.h>
@@ -44,6 +45,85 @@
 #define TRAP_ILLEGAL_SLOT_INST	13
 #endif
 
+static unsigned long se_user;
+static unsigned long se_sys;
+static unsigned long se_half;
+static unsigned long se_word;
+static unsigned long se_dword;
+static unsigned long se_multi;
+/* bitfield: 1: warn 2: fixup 4: signal -> combinations 2|4 && 1|2|4 are not
+   valid! */
+static int se_usermode = 3;
+/* 0: no warning 1: print a warning message */
+static int se_kernmode_warn = 1;
+
+#ifdef CONFIG_PROC_FS
+static const char *se_usermode_action[] = {
+	"ignored",
+	"warn",
+	"fixup",
+	"fixup+warn",
+	"signal",
+	"signal+warn"
+};
+
+static int
+proc_alignment_read(char *page, char **start, off_t off, int count, int *eof,
+		    void *data)
+{
+	char *p = page;
+	int len;
+
+	p += sprintf(p, "User:\t\t%lu\n", se_user);
+	p += sprintf(p, "System:\t\t%lu\n", se_sys);
+	p += sprintf(p, "Half:\t\t%lu\n", se_half);
+	p += sprintf(p, "Word:\t\t%lu\n", se_word);
+	p += sprintf(p, "DWord:\t\t%lu\n", se_dword);
+	p += sprintf(p, "Multi:\t\t%lu\n", se_multi);
+	p += sprintf(p, "User faults:\t%i (%s)\n", se_usermode,
+			se_usermode_action[se_usermode]);
+	p += sprintf(p, "Kernel faults:\t%i (fixup%s)\n", se_kernmode_warn,
+			se_kernmode_warn ? "+warn" : "");
+
+	len = (p - page) - off;
+	if (len < 0)
+		len = 0;
+
+	*eof = (len <= count) ? 1 : 0;
+	*start = page + off;
+
+	return len;
+}
+
+static int proc_alignment_write(struct file *file, const char __user *buffer,
+				unsigned long count, void *data)
+{
+	char mode;
+
+	if (count > 0) {
+		if (get_user(mode, buffer))
+			return -EFAULT;
+		if (mode >= '0' && mode <= '5')
+			se_usermode = mode - '0';
+	}
+	return count;
+}
+
+static int proc_alignment_kern_write(struct file *file, const char __user *buffer,
+				     unsigned long count, void *data)
+{
+	char mode;
+
+	if (count > 0) {
+		if (get_user(mode, buffer))
+			return -EFAULT;
+		if (mode >= '0' && mode <= '1')
+			se_kernmode_warn = mode - '0';
+	}
+	return count;
+}
+#endif
+
 static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
 {
 	unsigned long p;
@@ -136,6 +216,7 @@ static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
 			regs->pc = fixup->fixup;
 			return;
 		}
+
 		die(str, regs, err);
 	}
 }
@@ -193,6 +274,13 @@ static int handle_unaligned_ins(insn_size_t instruction, struct pt_regs *regs,
 
 	count = 1<<(instruction&3);
 
+	switch (count) {
+	case 1: se_half  += 1; break;
+	case 2: se_word  += 1; break;
+	case 4: se_dword += 1; break;
+	case 8: se_multi += 1; break; /* ??? */
+	}
+
 	ret = -EFAULT;
 	switch (instruction>>12) {
 	case 0: /* mov.[bwl] to/from memory via r0+rn */
@@ -358,31 +446,28 @@ static inline int handle_delayslot(struct pt_regs *regs,
 #define SH_PC_8BIT_OFFSET(instr) ((((signed char)(instr))*2) + 4)
 #define SH_PC_12BIT_OFFSET(instr) ((((signed short)(instr<<4))>>3) + 4)
 
-/*
- * XXX: SH-2A needs this too, but it needs an overhaul thanks to mixed 32-bit
- * opcodes..
- */
-
-static int handle_unaligned_notify_count = 10;
-
 int handle_unaligned_access(insn_size_t instruction, struct pt_regs *regs,
-			    struct mem_access *ma)
+			    struct mem_access *ma, int expected)
 {
 	u_int rm;
 	int ret, index;
 
+	/*
+	 * XXX: We can't handle mixed 16/32-bit instructions yet
+	 */
+	if (instruction_size(instruction) != 2)
+		return -EINVAL;
+
 	index = (instruction>>8)&15;	/* 0x0F00 */
 	rm = regs->regs[index];
 
-	/* shout about the first ten userspace fixups */
-	if (user_mode(regs) && handle_unaligned_notify_count>0) {
-		handle_unaligned_notify_count--;
-
-		printk(KERN_NOTICE "Fixing up unaligned userspace access "
+	/* shout about fixups */
+	if (!expected && printk_ratelimit())
+		printk(KERN_NOTICE "Fixing up unaligned %s access "
 		       "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
+		       user_mode(regs) ? "userspace" : "kernel",
 		       current->comm, task_pid_nr(current),
 		       (void *)regs->pc, instruction);
-	}
 
 	ret = -EFAULT;
 	switch (instruction&0xF000) {
@@ -538,24 +623,44 @@ asmlinkage void do_address_error(struct pt_regs *regs,
 
 		local_irq_enable();
 
-		/* bad PC is not something we can fix */
-		if (regs->pc & 1) {
-			si_code = BUS_ADRALN;
-			goto uspace_segv;
-		}
+		se_user += 1;
 
 		set_fs(USER_DS);
-		if (copy_from_user(&instruction, (void __user *)(regs->pc),
+		if (copy_from_user(&instruction, (insn_size_t *)(regs->pc & ~1),
 				   sizeof(instruction))) {
-			/* Argh. Fault on the instruction itself.
-			   This should never happen non-SMP
-			*/
 			set_fs(oldfs);
 			goto uspace_segv;
 		}
+		set_fs(oldfs);
+
+		/* shout about userspace fixups */
+		if (se_usermode & 1)
+			printk(KERN_NOTICE "Unaligned userspace access "
+			       "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
+			       current->comm, current->pid, (void *)regs->pc,
+			       instruction);
+
+		if (se_usermode & 2)
+			goto fixup;
 
+		if (se_usermode & 4)
+			goto uspace_segv;
+		else {
+			/* ignore */
+			regs->pc += instruction_size(instruction);
+			return;
+		}
+
+fixup:
+		/* bad PC is not something we can fix */
+		if (regs->pc & 1) {
+			si_code = BUS_ADRALN;
+			goto uspace_segv;
+		}
+
+		set_fs(USER_DS);
 		tmp = handle_unaligned_access(instruction, regs,
-					      &user_mem_access);
+					      &user_mem_access, 0);
 		set_fs(oldfs);
 
 		if (tmp==0)
@@ -571,6 +676,8 @@ uspace_segv:
 		info.si_addr = (void __user *)address;
 		force_sig_info(SIGBUS, &info, current);
 	} else {
+		se_sys += 1;
+
 		if (regs->pc & 1)
 			die("unaligned program counter", regs, error_code);
 
@@ -584,7 +691,14 @@ uspace_segv:
 			die("insn faulting in do_address_error", regs, 0);
 		}
 
-		handle_unaligned_access(instruction, regs, &user_mem_access);
+		if (se_kernmode_warn)
+			printk(KERN_NOTICE "Unaligned kernel access "
+			       "on behalf of \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
+			       current->comm, current->pid, (void *)regs->pc,
+			       instruction);
+
+		handle_unaligned_access(instruction, regs,
+					&user_mem_access, 0);
 		set_fs(oldfs);
 	}
 }
@@ -858,30 +972,6 @@ void __init trap_init(void)
 	per_cpu_trap_init();
 }
 
-void show_trace(struct task_struct *tsk, unsigned long *sp,
-		struct pt_regs *regs)
-{
-	unsigned long addr;
-
-	if (regs && user_mode(regs))
-		return;
-
-	printk("\nCall trace:\n");
-
-	while (!kstack_end(sp)) {
-		addr = *sp++;
-		if (kernel_text_address(addr))
-			print_ip_sym(addr);
-	}
-
-	printk("\n");
-
-	if (!tsk)
-		tsk = current;
-
-	debug_show_held_locks(tsk);
-}
-
 void show_stack(struct task_struct *tsk, unsigned long *sp)
 {
 	unsigned long stack;
@@ -904,3 +994,38 @@ void dump_stack(void)
 	show_stack(NULL, NULL);
 }
 EXPORT_SYMBOL(dump_stack);
+
+#ifdef CONFIG_PROC_FS
+/*
+ * This needs to be done after sysctl_init, otherwise sys/ will be
+ * overwritten.  Actually, this shouldn't be in sys/ at all since
+ * it isn't a sysctl, and it doesn't contain sysctl information.
+ * We now locate it in /proc/cpu/alignment instead.
+ */
+static int __init alignment_init(void)
+{
+	struct proc_dir_entry *dir, *res;
+
+	dir = proc_mkdir("cpu", NULL);
+	if (!dir)
+		return -ENOMEM;
+
+	res = create_proc_entry("alignment", S_IWUSR | S_IRUGO, dir);
+	if (!res)
+		return -ENOMEM;
+
+	res->read_proc = proc_alignment_read;
+	res->write_proc = proc_alignment_write;
+
+        res = create_proc_entry("kernel_alignment", S_IWUSR | S_IRUGO, dir);
+        if (!res)
+                return -ENOMEM;
+
+        res->read_proc = proc_alignment_read;
+        res->write_proc = proc_alignment_kern_write;
+
+	return 0;
+}
+
+fs_initcall(alignment_init);
+#endif