Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
new file mode 100644
index 0000000..eaa7014
--- /dev/null
+++ b/arch/parisc/mm/fault.c
@@ -0,0 +1,271 @@
+/* $Id: fault.c,v 1.5 2000/01/26 16:20:29 jsm Exp $
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ *
+ * Copyright (C) 1995, 1996, 1997, 1998 by Ralf Baechle
+ * Copyright 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org)
+ * Copyright 1999 Hewlett Packard Co.
+ *
+ */
+
+#include <linux/mm.h>
+#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+
+#include <asm/uaccess.h>
+#include <asm/traps.h>
+
+#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */
+ /* dumped to the console via printk) */
+
+
+/* Defines for parisc_acctyp() */
+#define READ 0
+#define WRITE 1
+
+/* Various important other fields */
+#define bit22set(x) (x & 0x00000200)
+#define bits23_25set(x) (x & 0x000001c0)
+#define isGraphicsFlushRead(x) ((x & 0xfc003fdf) == 0x04001a80)
+ /* extended opcode is 0x6a */
+
+#define BITSSET 0x1c0 /* for identifying LDCW */
+
+
+DEFINE_PER_CPU(struct exception_data, exception_data);
+
+/*
+ * parisc_acctyp(unsigned int inst) --
+ * Given a PA-RISC memory access instruction, determine if the
+ * the instruction would perform a memory read or memory write
+ * operation.
+ *
+ * This function assumes that the given instruction is a memory access
+ * instruction (i.e. you should really only call it if you know that
+ * the instruction has generated some sort of a memory access fault).
+ *
+ * Returns:
+ * VM_READ if read operation
+ * VM_WRITE if write operation
+ * VM_EXEC if execute operation
+ */
+static unsigned long
+parisc_acctyp(unsigned long code, unsigned int inst)
+{
+ if (code == 6 || code == 16)
+ return VM_EXEC;
+
+ switch (inst & 0xf0000000) {
+ case 0x40000000: /* load */
+ case 0x50000000: /* new load */
+ return VM_READ;
+
+ case 0x60000000: /* store */
+ case 0x70000000: /* new store */
+ return VM_WRITE;
+
+ case 0x20000000: /* coproc */
+ case 0x30000000: /* coproc2 */
+ if (bit22set(inst))
+ return VM_WRITE;
+
+ case 0x0: /* indexed/memory management */
+ if (bit22set(inst)) {
+ /*
+ * Check for the 'Graphics Flush Read' instruction.
+ * It resembles an FDC instruction, except for bits
+ * 20 and 21. Any combination other than zero will
+ * utilize the block mover functionality on some
+ * older PA-RISC platforms. The case where a block
+ * move is performed from VM to graphics IO space
+ * should be treated as a READ.
+ *
+ * The significance of bits 20,21 in the FDC
+ * instruction is:
+ *
+ * 00 Flush data cache (normal instruction behavior)
+ * 01 Graphics flush write (IO space -> VM)
+ * 10 Graphics flush read (VM -> IO space)
+ * 11 Graphics flush read/write (VM <-> IO space)
+ */
+ if (isGraphicsFlushRead(inst))
+ return VM_READ;
+ return VM_WRITE;
+ } else {
+ /*
+ * Check for LDCWX and LDCWS (semaphore instructions).
+ * If bits 23 through 25 are all 1's it is one of
+ * the above two instructions and is a write.
+ *
+ * Note: With the limited bits we are looking at,
+ * this will also catch PROBEW and PROBEWI. However,
+ * these should never get in here because they don't
+ * generate exceptions of the type:
+ * Data TLB miss fault/data page fault
+ * Data memory protection trap
+ */
+ if (bits23_25set(inst) == BITSSET)
+ return VM_WRITE;
+ }
+ return VM_READ; /* Default */
+ }
+ return VM_READ; /* Default */
+}
+
+#undef bit22set
+#undef bits23_25set
+#undef isGraphicsFlushRead
+#undef BITSSET
+
+
+#if 0
+/* This is the treewalk to find a vma which is the highest that has
+ * a start < addr. We're using find_vma_prev instead right now, but
+ * we might want to use this at some point in the future. Probably
+ * not, but I want it committed to CVS so I don't lose it :-)
+ */
+ while (tree != vm_avl_empty) {
+ if (tree->vm_start > addr) {
+ tree = tree->vm_avl_left;
+ } else {
+ prev = tree;
+ if (prev->vm_next == NULL)
+ break;
+ if (prev->vm_next->vm_start > addr)
+ break;
+ tree = tree->vm_avl_right;
+ }
+ }
+#endif
+
+void do_page_fault(struct pt_regs *regs, unsigned long code,
+ unsigned long address)
+{
+ struct vm_area_struct *vma, *prev_vma;
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+ const struct exception_table_entry *fix;
+ unsigned long acc_type;
+
+ if (in_interrupt() || !mm)
+ goto no_context;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma_prev(mm, address, &prev_vma);
+ if (!vma || address < vma->vm_start)
+ goto check_expansion;
+/*
+ * Ok, we have a good vm_area for this memory access. We still need to
+ * check the access permissions.
+ */
+
+good_area:
+
+ acc_type = parisc_acctyp(code,regs->iir);
+
+ if ((vma->vm_flags & acc_type) != acc_type)
+ goto bad_area;
+
+ /*
+ * If for any reason at all we couldn't handle the fault, make
+ * sure we exit gracefully rather than endlessly redo the
+ * fault.
+ */
+
+ switch (handle_mm_fault(mm, vma, address, (acc_type & VM_WRITE) != 0)) {
+ case 1:
+ ++current->min_flt;
+ break;
+ case 2:
+ ++current->maj_flt;
+ break;
+ case 0:
+ /*
+ * We ran out of memory, or some other thing happened
+ * to us that made us unable to handle the page fault
+ * gracefully.
+ */
+ goto bad_area;
+ default:
+ goto out_of_memory;
+ }
+ up_read(&mm->mmap_sem);
+ return;
+
+check_expansion:
+ vma = prev_vma;
+ if (vma && (expand_stack(vma, address) == 0))
+ goto good_area;
+
+/*
+ * Something tried to access memory that isn't in our memory map..
+ */
+bad_area:
+ up_read(&mm->mmap_sem);
+
+ if (user_mode(regs)) {
+ struct siginfo si;
+
+#ifdef PRINT_USER_FAULTS
+ printk(KERN_DEBUG "\n");
+ printk(KERN_DEBUG "do_page_fault() pid=%d command='%s' type=%lu address=0x%08lx\n",
+ tsk->pid, tsk->comm, code, address);
+ if (vma) {
+ printk(KERN_DEBUG "vm_start = 0x%08lx, vm_end = 0x%08lx\n",
+ vma->vm_start, vma->vm_end);
+ }
+ show_regs(regs);
+#endif
+ /* FIXME: actually we need to get the signo and code correct */
+ si.si_signo = SIGSEGV;
+ si.si_errno = 0;
+ si.si_code = SEGV_MAPERR;
+ si.si_addr = (void __user *) address;
+ force_sig_info(SIGSEGV, &si, current);
+ return;
+ }
+
+no_context:
+
+ if (!user_mode(regs)) {
+ fix = search_exception_tables(regs->iaoq[0]);
+
+ if (fix) {
+ struct exception_data *d;
+
+ d = &__get_cpu_var(exception_data);
+ d->fault_ip = regs->iaoq[0];
+ d->fault_space = regs->isr;
+ d->fault_addr = regs->ior;
+
+ regs->iaoq[0] = ((fix->fixup) & ~3);
+
+ /*
+ * NOTE: In some cases the faulting instruction
+ * may be in the delay slot of a branch. We
+ * don't want to take the branch, so we don't
+ * increment iaoq[1], instead we set it to be
+ * iaoq[0]+4, and clear the B bit in the PSW
+ */
+
+ regs->iaoq[1] = regs->iaoq[0] + 4;
+ regs->gr[0] &= ~PSW_B; /* IPSW in gr[0] */
+
+ return;
+ }
+ }
+
+ parisc_terminate("Bad Address (null pointer deref?)", regs, code, address);
+
+ out_of_memory:
+ up_read(&mm->mmap_sem);
+ printk(KERN_CRIT "VM: killing process %s\n", current->comm);
+ if (user_mode(regs))
+ do_exit(SIGKILL);
+ goto no_context;
+}