1 files changed, 251 insertions, 0 deletions
diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c
new file mode 100644
index 000000000000..47e766e6ba10
--- /dev/null
+++ b/arch/um/kernel/trap_kern.c
@@ -0,0 +1,251 @@
+/* 
+ * Copyright (C) 2000, 2001 Jeff Dike (jdike@karaya.com)
+ * Licensed under the GPL
+ */
+
+#include "linux/kernel.h"
+#include "asm/errno.h"
+#include "linux/sched.h"
+#include "linux/mm.h"
+#include "linux/spinlock.h"
+#include "linux/config.h"
+#include "linux/init.h"
+#include "linux/ptrace.h"
+#include "asm/semaphore.h"
+#include "asm/pgtable.h"
+#include "asm/pgalloc.h"
+#include "asm/tlbflush.h"
+#include "asm/a.out.h"
+#include "asm/current.h"
+#include "asm/irq.h"
+#include "user_util.h"
+#include "kern_util.h"
+#include "kern.h"
+#include "chan_kern.h"
+#include "mconsole_kern.h"
+#include "2_5compat.h"
+#include "mem.h"
+#include "mem_kern.h"
+
+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;
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	unsigned long page;
+	int err = -EFAULT;
+
+	*code_out = SEGV_MAPERR;
+	down_read(&mm->mmap_sem);
+	vma = find_vma(mm, address);
+	if(!vma) 
+		goto out;
+	else if(vma->vm_start <= address) 
+		goto good_area;
+	else if(!(vma->vm_flags & VM_GROWSDOWN)) 
+		goto out;
+	else if(!ARCH_IS_STACKGROW(address))
+		goto out;
+	else if(expand_stack(vma, address)) 
+		goto out;
+
+ good_area:
+	*code_out = SEGV_ACCERR;
+	if(is_write && !(vma->vm_flags & VM_WRITE)) 
+		goto out;
+	page = address & PAGE_MASK;
+	pgd = pgd_offset(mm, page);
+	pud = pud_offset(pgd, page);
+	pmd = pmd_offset(pud, page);
+	do {
+ survive:
+		switch (handle_mm_fault(mm, vma, address, is_write)){
+		case VM_FAULT_MINOR:
+			current->min_flt++;
+			break;
+		case VM_FAULT_MAJOR:
+			current->maj_flt++;
+			break;
+		case VM_FAULT_SIGBUS:
+			err = -EACCES;
+			goto out;
+		case VM_FAULT_OOM:
+			err = -ENOMEM;
+			goto out_of_memory;
+		default:
+			BUG();
+		}
+		pgd = pgd_offset(mm, page);
+		pud = pud_offset(pgd, page);
+		pmd = pmd_offset(pud, page);
+		pte = pte_offset_kernel(pmd, page);
+	} while(!pte_present(*pte));
+	err = 0;
+	*pte = pte_mkyoung(*pte);
+	if(pte_write(*pte)) *pte = pte_mkdirty(*pte);
+	flush_tlb_page(vma, page);
+ out:
+	up_read(&mm->mmap_sem);
+	return(err);
+
+/*
+ * 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:
+	if (current->pid == 1) {
+		up_read(&mm->mmap_sem);
+		yield();
+		down_read(&mm->mmap_sem);
+		goto survive;
+	}
+	goto out;
+}
+
+LIST_HEAD(physmem_remappers);
+
+void register_remapper(struct remapper *info)
+{
+	list_add(&info->list, &physmem_remappers);
+}
+
+static int check_remapped_addr(unsigned long address, int is_write)
+{
+	struct remapper *remapper;
+	struct list_head *ele;
+	__u64 offset;
+	int fd;
+
+	fd = phys_mapping(__pa(address), &offset);
+	if(fd == -1)
+		return(0);
+
+	list_for_each(ele, &physmem_remappers){
+		remapper = list_entry(ele, struct remapper, list);
+		if((*remapper->proc)(fd, address, is_write, offset))
+			return(1);
+	}
+
+	return(0);
+}
+
+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);
+        }
+	else if(check_remapped_addr(address & PAGE_MASK, is_write))
+		return(0);
+	else if(current->mm == NULL)
+		panic("Segfault with no mm");
+	err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
+
+	catcher = current->thread.fault_catcher;
+	if(!err)
+		return(0);
+	else if(catcher != NULL){
+		current->thread.fault_addr = (void *) address;
+		do_longjmp(catcher, 1);
+	} 
+	else if(current->thread.fault_addr != NULL)
+		panic("fault_addr set but no fault catcher");
+	else if(arch_fixup(ip, sc))
+		return(0);
+
+ 	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);
+	}
+	return(0);
+}
+
+void bad_segv(unsigned long address, unsigned long ip, int is_write)
+{
+	struct siginfo si;
+
+	si.si_signo = SIGSEGV;
+	si.si_code = SEGV_ACCERR;
+	si.si_addr = (void *) address;
+	current->thread.cr2 = address;
+	current->thread.err = is_write;
+	force_sig_info(SIGSEGV, &si, current);
+}
+
+void relay_signal(int sig, union uml_pt_regs *regs)
+{
+	if(arch_handle_signal(sig, regs)) return;
+	if(!UPT_IS_USER(regs))
+		panic("Kernel mode signal %d", sig);
+	force_sig(sig, current);
+}
+
+void bus_handler(int sig, union uml_pt_regs *regs)
+{
+	if(current->thread.fault_catcher != NULL)
+		do_longjmp(current->thread.fault_catcher, 1);
+	else relay_signal(sig, regs);
+}
+
+void winch(int sig, union uml_pt_regs *regs)
+{
+	do_IRQ(WINCH_IRQ, regs);
+}
+
+void trap_init(void)
+{
+}
+
+DEFINE_SPINLOCK(trap_lock);
+
+static int trap_index = 0;
+
+int next_trap_index(int limit)
+{
+	int ret;
+
+	spin_lock(&trap_lock);
+	ret = trap_index;
+	if(++trap_index == limit)
+		trap_index = 0;
+	spin_unlock(&trap_lock);
+	return(ret);
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only.  This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */