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Diffstat (limited to 'arch/sparc/mm/fault_32.c')
-rw-r--r--arch/sparc/mm/fault_32.c468
1 files changed, 468 insertions, 0 deletions
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
new file mode 100644
index 000000000..70d817154
--- /dev/null
+++ b/arch/sparc/mm/fault_32.c
@@ -0,0 +1,468 @@
+/*
+ * fault.c: Page fault handlers for the Sparc.
+ *
+ * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
+ * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
+ */
+
+#include <asm/head.h>
+
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/threads.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/perf_event.h>
+#include <linux/interrupt.h>
+#include <linux/kdebug.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/openprom.h>
+#include <asm/oplib.h>
+#include <asm/setup.h>
+#include <asm/smp.h>
+#include <asm/traps.h>
+#include <asm/uaccess.h>
+
+#include "mm_32.h"
+
+int show_unhandled_signals = 1;
+
+static void __noreturn unhandled_fault(unsigned long address,
+ struct task_struct *tsk,
+ struct pt_regs *regs)
+{
+ if ((unsigned long) address < PAGE_SIZE) {
+ printk(KERN_ALERT
+ "Unable to handle kernel NULL pointer dereference\n");
+ } else {
+ printk(KERN_ALERT "Unable to handle kernel paging request at virtual address %08lx\n",
+ address);
+ }
+ printk(KERN_ALERT "tsk->{mm,active_mm}->context = %08lx\n",
+ (tsk->mm ? tsk->mm->context : tsk->active_mm->context));
+ printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %08lx\n",
+ (tsk->mm ? (unsigned long) tsk->mm->pgd :
+ (unsigned long) tsk->active_mm->pgd));
+ die_if_kernel("Oops", regs);
+}
+
+asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc,
+ unsigned long address)
+{
+ struct pt_regs regs;
+ unsigned long g2;
+ unsigned int insn;
+ int i;
+
+ i = search_extables_range(ret_pc, &g2);
+ switch (i) {
+ case 3:
+ /* load & store will be handled by fixup */
+ return 3;
+
+ case 1:
+ /* store will be handled by fixup, load will bump out */
+ /* for _to_ macros */
+ insn = *((unsigned int *) pc);
+ if ((insn >> 21) & 1)
+ return 1;
+ break;
+
+ case 2:
+ /* load will be handled by fixup, store will bump out */
+ /* for _from_ macros */
+ insn = *((unsigned int *) pc);
+ if (!((insn >> 21) & 1) || ((insn>>19)&0x3f) == 15)
+ return 2;
+ break;
+
+ default:
+ break;
+ }
+
+ memset(&regs, 0, sizeof(regs));
+ regs.pc = pc;
+ regs.npc = pc + 4;
+ __asm__ __volatile__(
+ "rd %%psr, %0\n\t"
+ "nop\n\t"
+ "nop\n\t"
+ "nop\n" : "=r" (regs.psr));
+ unhandled_fault(address, current, &regs);
+
+ /* Not reached */
+ return 0;
+}
+
+static inline void
+show_signal_msg(struct pt_regs *regs, int sig, int code,
+ unsigned long address, struct task_struct *tsk)
+{
+ if (!unhandled_signal(tsk, sig))
+ return;
+
+ if (!printk_ratelimit())
+ return;
+
+ printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
+ task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
+ tsk->comm, task_pid_nr(tsk), address,
+ (void *)regs->pc, (void *)regs->u_regs[UREG_I7],
+ (void *)regs->u_regs[UREG_FP], code);
+
+ print_vma_addr(KERN_CONT " in ", regs->pc);
+
+ printk(KERN_CONT "\n");
+}
+
+static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
+ unsigned long addr)
+{
+ siginfo_t info;
+
+ info.si_signo = sig;
+ info.si_code = code;
+ info.si_errno = 0;
+ info.si_addr = (void __user *) addr;
+ info.si_trapno = 0;
+
+ if (unlikely(show_unhandled_signals))
+ show_signal_msg(regs, sig, info.si_code,
+ addr, current);
+
+ force_sig_info (sig, &info, current);
+}
+
+static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
+{
+ unsigned int insn;
+
+ if (text_fault)
+ return regs->pc;
+
+ if (regs->psr & PSR_PS)
+ insn = *(unsigned int *) regs->pc;
+ else
+ __get_user(insn, (unsigned int *) regs->pc);
+
+ return safe_compute_effective_address(regs, insn);
+}
+
+static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
+ int text_fault)
+{
+ unsigned long addr = compute_si_addr(regs, text_fault);
+
+ __do_fault_siginfo(code, sig, regs, addr);
+}
+
+asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
+ unsigned long address)
+{
+ struct vm_area_struct *vma;
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+ unsigned int fixup;
+ unsigned long g2;
+ int from_user = !(regs->psr & PSR_PS);
+ int fault, code;
+ unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
+
+ if (text_fault)
+ address = regs->pc;
+
+ /*
+ * We fault-in kernel-space virtual memory on-demand. The
+ * 'reference' page table is init_mm.pgd.
+ *
+ * NOTE! We MUST NOT take any locks for this case. We may
+ * be in an interrupt or a critical region, and should
+ * only copy the information from the master page table,
+ * nothing more.
+ */
+ code = SEGV_MAPERR;
+ if (address >= TASK_SIZE)
+ goto vmalloc_fault;
+
+ /*
+ * If we're in an interrupt or have no user
+ * context, we must not take the fault..
+ */
+ if (in_atomic() || !mm)
+ goto no_context;
+
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
+
+retry:
+ down_read(&mm->mmap_sem);
+
+ if (!from_user && address >= PAGE_OFFSET)
+ goto bad_area;
+
+ vma = find_vma(mm, address);
+ if (!vma)
+ goto bad_area;
+ if (vma->vm_start <= address)
+ goto good_area;
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ goto bad_area;
+ if (expand_stack(vma, address))
+ goto bad_area;
+ /*
+ * Ok, we have a good vm_area for this memory access, so
+ * we can handle it..
+ */
+good_area:
+ code = SEGV_ACCERR;
+ if (write) {
+ if (!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ } else {
+ /* Allow reads even for write-only mappings */
+ if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+ goto bad_area;
+ }
+
+ if (from_user)
+ flags |= FAULT_FLAG_USER;
+ if (write)
+ flags |= FAULT_FLAG_WRITE;
+
+ /*
+ * If for any reason at all we couldn't handle the fault,
+ * make sure we exit gracefully rather than endlessly redo
+ * the fault.
+ */
+ fault = handle_mm_fault(mm, vma, address, flags);
+
+ if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
+ return;
+
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ if (fault & VM_FAULT_OOM)
+ goto out_of_memory;
+ else if (fault & VM_FAULT_SIGSEGV)
+ goto bad_area;
+ else if (fault & VM_FAULT_SIGBUS)
+ goto do_sigbus;
+ BUG();
+ }
+
+ if (flags & FAULT_FLAG_ALLOW_RETRY) {
+ if (fault & VM_FAULT_MAJOR) {
+ current->maj_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
+ 1, regs, address);
+ } else {
+ current->min_flt++;
+ perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
+ 1, regs, address);
+ }
+ if (fault & VM_FAULT_RETRY) {
+ flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ flags |= FAULT_FLAG_TRIED;
+
+ /* No need to up_read(&mm->mmap_sem) as we would
+ * have already released it in __lock_page_or_retry
+ * in mm/filemap.c.
+ */
+
+ goto retry;
+ }
+ }
+
+ up_read(&mm->mmap_sem);
+ return;
+
+ /*
+ * Something tried to access memory that isn't in our memory map..
+ * Fix it, but check if it's kernel or user first..
+ */
+bad_area:
+ up_read(&mm->mmap_sem);
+
+bad_area_nosemaphore:
+ /* User mode accesses just cause a SIGSEGV */
+ if (from_user) {
+ do_fault_siginfo(code, SIGSEGV, regs, text_fault);
+ return;
+ }
+
+ /* Is this in ex_table? */
+no_context:
+ g2 = regs->u_regs[UREG_G2];
+ if (!from_user) {
+ fixup = search_extables_range(regs->pc, &g2);
+ /* Values below 10 are reserved for other things */
+ if (fixup > 10) {
+ extern const unsigned __memset_start[];
+ extern const unsigned __memset_end[];
+ extern const unsigned __csum_partial_copy_start[];
+ extern const unsigned __csum_partial_copy_end[];
+
+#ifdef DEBUG_EXCEPTIONS
+ printk("Exception: PC<%08lx> faddr<%08lx>\n",
+ regs->pc, address);
+ printk("EX_TABLE: insn<%08lx> fixup<%08x> g2<%08lx>\n",
+ regs->pc, fixup, g2);
+#endif
+ if ((regs->pc >= (unsigned long)__memset_start &&
+ regs->pc < (unsigned long)__memset_end) ||
+ (regs->pc >= (unsigned long)__csum_partial_copy_start &&
+ regs->pc < (unsigned long)__csum_partial_copy_end)) {
+ regs->u_regs[UREG_I4] = address;
+ regs->u_regs[UREG_I5] = regs->pc;
+ }
+ regs->u_regs[UREG_G2] = g2;
+ regs->pc = fixup;
+ regs->npc = regs->pc + 4;
+ return;
+ }
+ }
+
+ unhandled_fault(address, tsk, regs);
+ do_exit(SIGKILL);
+
+/*
+ * 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 (from_user) {
+ pagefault_out_of_memory();
+ return;
+ }
+ goto no_context;
+
+do_sigbus:
+ up_read(&mm->mmap_sem);
+ do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault);
+ if (!from_user)
+ goto no_context;
+
+vmalloc_fault:
+ {
+ /*
+ * Synchronize this task's top level page-table
+ * with the 'reference' page table.
+ */
+ int offset = pgd_index(address);
+ pgd_t *pgd, *pgd_k;
+ pmd_t *pmd, *pmd_k;
+
+ pgd = tsk->active_mm->pgd + offset;
+ pgd_k = init_mm.pgd + offset;
+
+ if (!pgd_present(*pgd)) {
+ if (!pgd_present(*pgd_k))
+ goto bad_area_nosemaphore;
+ pgd_val(*pgd) = pgd_val(*pgd_k);
+ return;
+ }
+
+ pmd = pmd_offset(pgd, address);
+ pmd_k = pmd_offset(pgd_k, address);
+
+ if (pmd_present(*pmd) || !pmd_present(*pmd_k))
+ goto bad_area_nosemaphore;
+
+ *pmd = *pmd_k;
+ return;
+ }
+}
+
+/* This always deals with user addresses. */
+static void force_user_fault(unsigned long address, int write)
+{
+ struct vm_area_struct *vma;
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+ unsigned int flags = FAULT_FLAG_USER;
+ int code;
+
+ code = SEGV_MAPERR;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, address);
+ if (!vma)
+ goto bad_area;
+ if (vma->vm_start <= address)
+ goto good_area;
+ if (!(vma->vm_flags & VM_GROWSDOWN))
+ goto bad_area;
+ if (expand_stack(vma, address))
+ goto bad_area;
+good_area:
+ code = SEGV_ACCERR;
+ if (write) {
+ if (!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ flags |= FAULT_FLAG_WRITE;
+ } else {
+ if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+ goto bad_area;
+ }
+ switch (handle_mm_fault(mm, vma, address, flags)) {
+ case VM_FAULT_SIGBUS:
+ case VM_FAULT_OOM:
+ goto do_sigbus;
+ }
+ up_read(&mm->mmap_sem);
+ return;
+bad_area:
+ up_read(&mm->mmap_sem);
+ __do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
+ return;
+
+do_sigbus:
+ up_read(&mm->mmap_sem);
+ __do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
+}
+
+static void check_stack_aligned(unsigned long sp)
+{
+ if (sp & 0x7UL)
+ force_sig(SIGILL, current);
+}
+
+void window_overflow_fault(void)
+{
+ unsigned long sp;
+
+ sp = current_thread_info()->rwbuf_stkptrs[0];
+ if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
+ force_user_fault(sp + 0x38, 1);
+ force_user_fault(sp, 1);
+
+ check_stack_aligned(sp);
+}
+
+void window_underflow_fault(unsigned long sp)
+{
+ if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
+ force_user_fault(sp + 0x38, 0);
+ force_user_fault(sp, 0);
+
+ check_stack_aligned(sp);
+}
+
+void window_ret_fault(struct pt_regs *regs)
+{
+ unsigned long sp;
+
+ sp = regs->u_regs[UREG_FP];
+ if (((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
+ force_user_fault(sp + 0x38, 0);
+ force_user_fault(sp, 0);
+
+ check_stack_aligned(sp);
+}
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