diff options
Diffstat (limited to 'arch/sparc/mm/fault.c')
| -rw-r--r-- | arch/sparc/mm/fault.c | 543 |
1 files changed, 0 insertions, 543 deletions
diff --git a/arch/sparc/mm/fault.c b/arch/sparc/mm/fault.c deleted file mode 100644 index a507e117466..00000000000 --- a/arch/sparc/mm/fault.c +++ /dev/null @@ -1,543 +0,0 @@ -/* - * 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(®s, 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, ®s); - - /* 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); -} |