aboutsummaryrefslogtreecommitdiff
path: root/arch/sparc/mm/fault_32.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sparc/mm/fault_32.c')
-rw-r--r--arch/sparc/mm/fault_32.c543
1 files changed, 543 insertions, 0 deletions
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
new file mode 100644
index 00000000000..a507e117466
--- /dev/null
+++ b/arch/sparc/mm/fault_32.c
@@ -0,0 +1,543 @@
+/*
+ * 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/interrupt.h>
+#include <linux/module.h>
+#include <linux/kdebug.h>
+
+#include <asm/system.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/memreg.h>
+#include <asm/openprom.h>
+#include <asm/oplib.h>
+#include <asm/smp.h>
+#include <asm/traps.h>
+#include <asm/uaccess.h>
+
+extern int prom_node_root;
+
+/* At boot time we determine these two values necessary for setting
+ * up the segment maps and page table entries (pte's).
+ */
+
+int num_segmaps, num_contexts;
+int invalid_segment;
+
+/* various Virtual Address Cache parameters we find at boot time... */
+
+int vac_size, vac_linesize, vac_do_hw_vac_flushes;
+int vac_entries_per_context, vac_entries_per_segment;
+int vac_entries_per_page;
+
+/* Return how much physical memory we have. */
+unsigned long probe_memory(void)
+{
+ unsigned long total = 0;
+ int i;
+
+ for (i = 0; sp_banks[i].num_bytes; i++)
+ total += sp_banks[i].num_bytes;
+
+ return total;
+}
+
+extern void sun4c_complete_all_stores(void);
+
+/* Whee, a level 15 NMI interrupt memory error. Let's have fun... */
+asmlinkage void sparc_lvl15_nmi(struct pt_regs *regs, unsigned long serr,
+ unsigned long svaddr, unsigned long aerr,
+ unsigned long avaddr)
+{
+ sun4c_complete_all_stores();
+ printk("FAULT: NMI received\n");
+ printk("SREGS: Synchronous Error %08lx\n", serr);
+ printk(" Synchronous Vaddr %08lx\n", svaddr);
+ printk(" Asynchronous Error %08lx\n", aerr);
+ printk(" Asynchronous Vaddr %08lx\n", avaddr);
+ if (sun4c_memerr_reg)
+ printk(" Memory Parity Error %08lx\n", *sun4c_memerr_reg);
+ printk("REGISTER DUMP:\n");
+ show_regs(regs);
+ prom_halt();
+}
+
+static void unhandled_fault(unsigned long, struct task_struct *,
+ struct pt_regs *) __attribute__ ((noreturn));
+
+static void 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;
+}
+
+extern unsigned long safe_compute_effective_address(struct pt_regs *,
+ unsigned int);
+
+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);
+}
+
+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;
+ siginfo_t info;
+ int from_user = !(regs->psr & PSR_PS);
+ int fault;
+
+ 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.
+ */
+ if (!ARCH_SUN4C && address >= TASK_SIZE)
+ goto vmalloc_fault;
+
+ info.si_code = SEGV_MAPERR;
+
+ /*
+ * If we're in an interrupt or have no user
+ * context, we must not take the fault..
+ */
+ if (in_atomic() || !mm)
+ goto no_context;
+
+ down_read(&mm->mmap_sem);
+
+ /*
+ * The kernel referencing a bad kernel pointer can lock up
+ * a sun4c machine completely, so we must attempt recovery.
+ */
+ 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:
+ info.si_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 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, write);
+ if (unlikely(fault & VM_FAULT_ERROR)) {
+ if (fault & VM_FAULT_OOM)
+ goto out_of_memory;
+ else if (fault & VM_FAULT_SIGBUS)
+ goto do_sigbus;
+ BUG();
+ }
+ if (fault & VM_FAULT_MAJOR)
+ current->maj_flt++;
+ else
+ current->min_flt++;
+ 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) {
+#if 0
+ printk("Fault whee %s [%d]: segfaults at %08lx pc=%08lx\n",
+ tsk->comm, tsk->pid, address, regs->pc);
+#endif
+ info.si_signo = SIGSEGV;
+ info.si_errno = 0;
+ /* info.si_code set above to make clear whether
+ this was a SEGV_MAPERR or SEGV_ACCERR fault. */
+ info.si_addr = (void __user *)compute_si_addr(regs, text_fault);
+ info.si_trapno = 0;
+ force_sig_info (SIGSEGV, &info, tsk);
+ return;
+ }
+
+ /* Is this in ex_table? */
+no_context:
+ g2 = regs->u_regs[UREG_G2];
+ if (!from_user && (fixup = search_extables_range(regs->pc, &g2))) {
+ if (fixup > 10) { /* Values below are reserved for other things */
+ 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);
+ printk("VM: killing process %s\n", tsk->comm);
+ if (from_user)
+ do_group_exit(SIGKILL);
+ goto no_context;
+
+do_sigbus:
+ up_read(&mm->mmap_sem);
+ info.si_signo = SIGBUS;
+ info.si_errno = 0;
+ info.si_code = BUS_ADRERR;
+ info.si_addr = (void __user *) compute_si_addr(regs, text_fault);
+ info.si_trapno = 0;
+ force_sig_info (SIGBUS, &info, tsk);
+ 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;
+ }
+}
+
+asmlinkage void do_sun4c_fault(struct pt_regs *regs, int text_fault, int write,
+ unsigned long address)
+{
+ extern void sun4c_update_mmu_cache(struct vm_area_struct *,
+ unsigned long,pte_t);
+ extern pte_t *sun4c_pte_offset_kernel(pmd_t *,unsigned long);
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+ pgd_t *pgdp;
+ pte_t *ptep;
+
+ if (text_fault) {
+ address = regs->pc;
+ } else if (!write &&
+ !(regs->psr & PSR_PS)) {
+ unsigned int insn, __user *ip;
+
+ ip = (unsigned int __user *)regs->pc;
+ if (!get_user(insn, ip)) {
+ if ((insn & 0xc1680000) == 0xc0680000)
+ write = 1;
+ }
+ }
+
+ if (!mm) {
+ /* We are oopsing. */
+ do_sparc_fault(regs, text_fault, write, address);
+ BUG(); /* P3 Oops already, you bitch */
+ }
+
+ pgdp = pgd_offset(mm, address);
+ ptep = sun4c_pte_offset_kernel((pmd_t *) pgdp, address);
+
+ if (pgd_val(*pgdp)) {
+ if (write) {
+ if ((pte_val(*ptep) & (_SUN4C_PAGE_WRITE|_SUN4C_PAGE_PRESENT))
+ == (_SUN4C_PAGE_WRITE|_SUN4C_PAGE_PRESENT)) {
+ unsigned long flags;
+
+ *ptep = __pte(pte_val(*ptep) | _SUN4C_PAGE_ACCESSED |
+ _SUN4C_PAGE_MODIFIED |
+ _SUN4C_PAGE_VALID |
+ _SUN4C_PAGE_DIRTY);
+
+ local_irq_save(flags);
+ if (sun4c_get_segmap(address) != invalid_segment) {
+ sun4c_put_pte(address, pte_val(*ptep));
+ local_irq_restore(flags);
+ return;
+ }
+ local_irq_restore(flags);
+ }
+ } else {
+ if ((pte_val(*ptep) & (_SUN4C_PAGE_READ|_SUN4C_PAGE_PRESENT))
+ == (_SUN4C_PAGE_READ|_SUN4C_PAGE_PRESENT)) {
+ unsigned long flags;
+
+ *ptep = __pte(pte_val(*ptep) | _SUN4C_PAGE_ACCESSED |
+ _SUN4C_PAGE_VALID);
+
+ local_irq_save(flags);
+ if (sun4c_get_segmap(address) != invalid_segment) {
+ sun4c_put_pte(address, pte_val(*ptep));
+ local_irq_restore(flags);
+ return;
+ }
+ local_irq_restore(flags);
+ }
+ }
+ }
+
+ /* This conditional is 'interesting'. */
+ if (pgd_val(*pgdp) && !(write && !(pte_val(*ptep) & _SUN4C_PAGE_WRITE))
+ && (pte_val(*ptep) & _SUN4C_PAGE_VALID))
+ /* Note: It is safe to not grab the MMAP semaphore here because
+ * we know that update_mmu_cache() will not sleep for
+ * any reason (at least not in the current implementation)
+ * and therefore there is no danger of another thread getting
+ * on the CPU and doing a shrink_mmap() on this vma.
+ */
+ sun4c_update_mmu_cache (find_vma(current->mm, address), address,
+ *ptep);
+ else
+ do_sparc_fault(regs, text_fault, write, address);
+}
+
+/* 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;
+ siginfo_t info;
+
+ info.si_code = SEGV_MAPERR;
+
+#if 0
+ printk("wf<pid=%d,wr=%d,addr=%08lx>\n",
+ tsk->pid, write, address);
+#endif
+ 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:
+ info.si_code = SEGV_ACCERR;
+ if(write) {
+ if(!(vma->vm_flags & VM_WRITE))
+ goto bad_area;
+ } else {
+ if(!(vma->vm_flags & (VM_READ | VM_EXEC)))
+ goto bad_area;
+ }
+ switch (handle_mm_fault(mm, vma, address, write)) {
+ case VM_FAULT_SIGBUS:
+ case VM_FAULT_OOM:
+ goto do_sigbus;
+ }
+ up_read(&mm->mmap_sem);
+ return;
+bad_area:
+ up_read(&mm->mmap_sem);
+#if 0
+ printk("Window whee %s [%d]: segfaults at %08lx\n",
+ tsk->comm, tsk->pid, address);
+#endif
+ info.si_signo = SIGSEGV;
+ info.si_errno = 0;
+ /* info.si_code set above to make clear whether
+ this was a SEGV_MAPERR or SEGV_ACCERR fault. */
+ info.si_addr = (void __user *) address;
+ info.si_trapno = 0;
+ force_sig_info (SIGSEGV, &info, tsk);
+ return;
+
+do_sigbus:
+ up_read(&mm->mmap_sem);
+ info.si_signo = SIGBUS;
+ info.si_errno = 0;
+ info.si_code = BUS_ADRERR;
+ info.si_addr = (void __user *) address;
+ info.si_trapno = 0;
+ force_sig_info (SIGBUS, &info, tsk);
+}
+
+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);
+}
+
+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);
+}
+
+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);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 10:59:05 +0000