From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: AndrĂ© Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/sparc/mm/fault_32.c | 468 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 468 insertions(+) create mode 100644 arch/sparc/mm/fault_32.c (limited to 'arch/sparc/mm/fault_32.c') 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 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +#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(®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; +} + +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); +} -- cgit v1.2.3-54-g00ecf