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Diffstat (limited to 'ANDROID_3.4.5/arch/powerpc/mm/fault.c')
-rw-r--r--ANDROID_3.4.5/arch/powerpc/mm/fault.c521
1 files changed, 0 insertions, 521 deletions
diff --git a/ANDROID_3.4.5/arch/powerpc/mm/fault.c b/ANDROID_3.4.5/arch/powerpc/mm/fault.c
deleted file mode 100644
index 08ffcf52..00000000
--- a/ANDROID_3.4.5/arch/powerpc/mm/fault.c
+++ /dev/null
@@ -1,521 +0,0 @@
-/*
- * PowerPC version
- * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
- *
- * Derived from "arch/i386/mm/fault.c"
- * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
- *
- * Modified by Cort Dougan and Paul Mackerras.
- *
- * Modified for PPC64 by Dave Engebretsen (engebret@ibm.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/signal.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/ptrace.h>
-#include <linux/mman.h>
-#include <linux/mm.h>
-#include <linux/interrupt.h>
-#include <linux/highmem.h>
-#include <linux/module.h>
-#include <linux/kprobes.h>
-#include <linux/kdebug.h>
-#include <linux/perf_event.h>
-#include <linux/magic.h>
-#include <linux/ratelimit.h>
-
-#include <asm/firmware.h>
-#include <asm/page.h>
-#include <asm/pgtable.h>
-#include <asm/mmu.h>
-#include <asm/mmu_context.h>
-#include <asm/uaccess.h>
-#include <asm/tlbflush.h>
-#include <asm/siginfo.h>
-#include <asm/debug.h>
-#include <mm/mmu_decl.h>
-
-#include "icswx.h"
-
-#ifdef CONFIG_KPROBES
-static inline int notify_page_fault(struct pt_regs *regs)
-{
- int ret = 0;
-
- /* kprobe_running() needs smp_processor_id() */
- if (!user_mode(regs)) {
- preempt_disable();
- if (kprobe_running() && kprobe_fault_handler(regs, 11))
- ret = 1;
- preempt_enable();
- }
-
- return ret;
-}
-#else
-static inline int notify_page_fault(struct pt_regs *regs)
-{
- return 0;
-}
-#endif
-
-/*
- * Check whether the instruction at regs->nip is a store using
- * an update addressing form which will update r1.
- */
-static int store_updates_sp(struct pt_regs *regs)
-{
- unsigned int inst;
-
- if (get_user(inst, (unsigned int __user *)regs->nip))
- return 0;
- /* check for 1 in the rA field */
- if (((inst >> 16) & 0x1f) != 1)
- return 0;
- /* check major opcode */
- switch (inst >> 26) {
- case 37: /* stwu */
- case 39: /* stbu */
- case 45: /* sthu */
- case 53: /* stfsu */
- case 55: /* stfdu */
- return 1;
- case 62: /* std or stdu */
- return (inst & 3) == 1;
- case 31:
- /* check minor opcode */
- switch ((inst >> 1) & 0x3ff) {
- case 181: /* stdux */
- case 183: /* stwux */
- case 247: /* stbux */
- case 439: /* sthux */
- case 695: /* stfsux */
- case 759: /* stfdux */
- return 1;
- }
- }
- return 0;
-}
-/*
- * do_page_fault error handling helpers
- */
-
-#define MM_FAULT_RETURN 0
-#define MM_FAULT_CONTINUE -1
-#define MM_FAULT_ERR(sig) (sig)
-
-static int out_of_memory(struct pt_regs *regs)
-{
- /*
- * We ran out of memory, or some other thing happened to us that made
- * us unable to handle the page fault gracefully.
- */
- up_read(&current->mm->mmap_sem);
- if (!user_mode(regs))
- return MM_FAULT_ERR(SIGKILL);
- pagefault_out_of_memory();
- return MM_FAULT_RETURN;
-}
-
-static int do_sigbus(struct pt_regs *regs, unsigned long address)
-{
- siginfo_t info;
-
- up_read(&current->mm->mmap_sem);
-
- if (user_mode(regs)) {
- info.si_signo = SIGBUS;
- info.si_errno = 0;
- info.si_code = BUS_ADRERR;
- info.si_addr = (void __user *)address;
- force_sig_info(SIGBUS, &info, current);
- return MM_FAULT_RETURN;
- }
- return MM_FAULT_ERR(SIGBUS);
-}
-
-static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
-{
- /*
- * Pagefault was interrupted by SIGKILL. We have no reason to
- * continue the pagefault.
- */
- if (fatal_signal_pending(current)) {
- /*
- * If we have retry set, the mmap semaphore will have
- * alrady been released in __lock_page_or_retry(). Else
- * we release it now.
- */
- if (!(fault & VM_FAULT_RETRY))
- up_read(&current->mm->mmap_sem);
- /* Coming from kernel, we need to deal with uaccess fixups */
- if (user_mode(regs))
- return MM_FAULT_RETURN;
- return MM_FAULT_ERR(SIGKILL);
- }
-
- /* No fault: be happy */
- if (!(fault & VM_FAULT_ERROR))
- return MM_FAULT_CONTINUE;
-
- /* Out of memory */
- if (fault & VM_FAULT_OOM)
- return out_of_memory(regs);
-
- /* Bus error. x86 handles HWPOISON here, we'll add this if/when
- * we support the feature in HW
- */
- if (fault & VM_FAULT_SIGBUS)
- return do_sigbus(regs, addr);
-
- /* We don't understand the fault code, this is fatal */
- BUG();
- return MM_FAULT_CONTINUE;
-}
-
-/*
- * For 600- and 800-family processors, the error_code parameter is DSISR
- * for a data fault, SRR1 for an instruction fault. For 400-family processors
- * the error_code parameter is ESR for a data fault, 0 for an instruction
- * fault.
- * For 64-bit processors, the error_code parameter is
- * - DSISR for a non-SLB data access fault,
- * - SRR1 & 0x08000000 for a non-SLB instruction access fault
- * - 0 any SLB fault.
- *
- * The return value is 0 if the fault was handled, or the signal
- * number if this is a kernel fault that can't be handled here.
- */
-int __kprobes do_page_fault(struct pt_regs *regs, unsigned long address,
- unsigned long error_code)
-{
- struct vm_area_struct * vma;
- struct mm_struct *mm = current->mm;
- unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
- int code = SEGV_MAPERR;
- int is_write = 0;
- int trap = TRAP(regs);
- int is_exec = trap == 0x400;
- int fault;
-
-#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
- /*
- * Fortunately the bit assignments in SRR1 for an instruction
- * fault and DSISR for a data fault are mostly the same for the
- * bits we are interested in. But there are some bits which
- * indicate errors in DSISR but can validly be set in SRR1.
- */
- if (trap == 0x400)
- error_code &= 0x48200000;
- else
- is_write = error_code & DSISR_ISSTORE;
-#else
- is_write = error_code & ESR_DST;
-#endif /* CONFIG_4xx || CONFIG_BOOKE */
-
- if (is_write)
- flags |= FAULT_FLAG_WRITE;
-
-#ifdef CONFIG_PPC_ICSWX
- /*
- * we need to do this early because this "data storage
- * interrupt" does not update the DAR/DEAR so we don't want to
- * look at it
- */
- if (error_code & ICSWX_DSI_UCT) {
- int rc = acop_handle_fault(regs, address, error_code);
- if (rc)
- return rc;
- }
-#endif /* CONFIG_PPC_ICSWX */
-
- if (notify_page_fault(regs))
- return 0;
-
- if (unlikely(debugger_fault_handler(regs)))
- return 0;
-
- /* On a kernel SLB miss we can only check for a valid exception entry */
- if (!user_mode(regs) && (address >= TASK_SIZE))
- return SIGSEGV;
-
-#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE) || \
- defined(CONFIG_PPC_BOOK3S_64))
- if (error_code & DSISR_DABRMATCH) {
- /* DABR match */
- do_dabr(regs, address, error_code);
- return 0;
- }
-#endif
-
- /* We restore the interrupt state now */
- if (!arch_irq_disabled_regs(regs))
- local_irq_enable();
-
- if (in_atomic() || mm == NULL) {
- if (!user_mode(regs))
- return SIGSEGV;
- /* in_atomic() in user mode is really bad,
- as is current->mm == NULL. */
- printk(KERN_EMERG "Page fault in user mode with "
- "in_atomic() = %d mm = %p\n", in_atomic(), mm);
- printk(KERN_EMERG "NIP = %lx MSR = %lx\n",
- regs->nip, regs->msr);
- die("Weird page fault", regs, SIGSEGV);
- }
-
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
-
- /* When running in the kernel we expect faults to occur only to
- * addresses in user space. All other faults represent errors in the
- * kernel and should generate an OOPS. Unfortunately, in the case of an
- * erroneous fault occurring in a code path which already holds mmap_sem
- * we will deadlock attempting to validate the fault against the
- * address space. Luckily the kernel only validly references user
- * space from well defined areas of code, which are listed in the
- * exceptions table.
- *
- * As the vast majority of faults will be valid we will only perform
- * the source reference check when there is a possibility of a deadlock.
- * Attempt to lock the address space, if we cannot we then validate the
- * source. If this is invalid we can skip the address space check,
- * thus avoiding the deadlock.
- */
- if (!down_read_trylock(&mm->mmap_sem)) {
- if (!user_mode(regs) && !search_exception_tables(regs->nip))
- goto bad_area_nosemaphore;
-
-retry:
- down_read(&mm->mmap_sem);
- } else {
- /*
- * The above down_read_trylock() might have succeeded in
- * which case we'll have missed the might_sleep() from
- * down_read():
- */
- might_sleep();
- }
-
- 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;
-
- /*
- * N.B. The POWER/Open ABI allows programs to access up to
- * 288 bytes below the stack pointer.
- * The kernel signal delivery code writes up to about 1.5kB
- * below the stack pointer (r1) before decrementing it.
- * The exec code can write slightly over 640kB to the stack
- * before setting the user r1. Thus we allow the stack to
- * expand to 1MB without further checks.
- */
- if (address + 0x100000 < vma->vm_end) {
- /* get user regs even if this fault is in kernel mode */
- struct pt_regs *uregs = current->thread.regs;
- if (uregs == NULL)
- goto bad_area;
-
- /*
- * A user-mode access to an address a long way below
- * the stack pointer is only valid if the instruction
- * is one which would update the stack pointer to the
- * address accessed if the instruction completed,
- * i.e. either stwu rs,n(r1) or stwux rs,r1,rb
- * (or the byte, halfword, float or double forms).
- *
- * If we don't check this then any write to the area
- * between the last mapped region and the stack will
- * expand the stack rather than segfaulting.
- */
- if (address + 2048 < uregs->gpr[1]
- && (!user_mode(regs) || !store_updates_sp(regs)))
- goto bad_area;
- }
- if (expand_stack(vma, address))
- goto bad_area;
-
-good_area:
- code = SEGV_ACCERR;
-#if defined(CONFIG_6xx)
- if (error_code & 0x95700000)
- /* an error such as lwarx to I/O controller space,
- address matching DABR, eciwx, etc. */
- goto bad_area;
-#endif /* CONFIG_6xx */
-#if defined(CONFIG_8xx)
- /* 8xx sometimes need to load a invalid/non-present TLBs.
- * These must be invalidated separately as linux mm don't.
- */
- if (error_code & 0x40000000) /* no translation? */
- _tlbil_va(address, 0, 0, 0);
-
- /* The MPC8xx seems to always set 0x80000000, which is
- * "undefined". Of those that can be set, this is the only
- * one which seems bad.
- */
- if (error_code & 0x10000000)
- /* Guarded storage error. */
- goto bad_area;
-#endif /* CONFIG_8xx */
-
- if (is_exec) {
-#ifdef CONFIG_PPC_STD_MMU
- /* Protection fault on exec go straight to failure on
- * Hash based MMUs as they either don't support per-page
- * execute permission, or if they do, it's handled already
- * at the hash level. This test would probably have to
- * be removed if we change the way this works to make hash
- * processors use the same I/D cache coherency mechanism
- * as embedded.
- */
- if (error_code & DSISR_PROTFAULT)
- goto bad_area;
-#endif /* CONFIG_PPC_STD_MMU */
-
- /*
- * Allow execution from readable areas if the MMU does not
- * provide separate controls over reading and executing.
- *
- * Note: That code used to not be enabled for 4xx/BookE.
- * It is now as I/D cache coherency for these is done at
- * set_pte_at() time and I see no reason why the test
- * below wouldn't be valid on those processors. This -may-
- * break programs compiled with a really old ABI though.
- */
- if (!(vma->vm_flags & VM_EXEC) &&
- (cpu_has_feature(CPU_FTR_NOEXECUTE) ||
- !(vma->vm_flags & (VM_READ | VM_WRITE))))
- goto bad_area;
- /* a write */
- } else if (is_write) {
- if (!(vma->vm_flags & VM_WRITE))
- goto bad_area;
- /* a read */
- } else {
- /* protection fault */
- if (error_code & 0x08000000)
- goto bad_area;
- if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
- 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, flags);
- if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) {
- int rc = mm_fault_error(regs, address, fault);
- if (rc >= MM_FAULT_RETURN)
- return rc;
- }
-
- /*
- * Major/minor page fault accounting is only done on the
- * initial attempt. If we go through a retry, it is extremely
- * likely that the page will be found in page cache at that point.
- */
- 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);
-#ifdef CONFIG_PPC_SMLPAR
- if (firmware_has_feature(FW_FEATURE_CMO)) {
- preempt_disable();
- get_lppaca()->page_ins += (1 << PAGE_FACTOR);
- preempt_enable();
- }
-#endif /* CONFIG_PPC_SMLPAR */
- } else {
- current->min_flt++;
- perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1,
- regs, address);
- }
- if (fault & VM_FAULT_RETRY) {
- /* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
- * of starvation. */
- flags &= ~FAULT_FLAG_ALLOW_RETRY;
- goto retry;
- }
- }
-
- up_read(&mm->mmap_sem);
- return 0;
-
-bad_area:
- up_read(&mm->mmap_sem);
-
-bad_area_nosemaphore:
- /* User mode accesses cause a SIGSEGV */
- if (user_mode(regs)) {
- _exception(SIGSEGV, regs, code, address);
- return 0;
- }
-
- if (is_exec && (error_code & DSISR_PROTFAULT))
- printk_ratelimited(KERN_CRIT "kernel tried to execute NX-protected"
- " page (%lx) - exploit attempt? (uid: %d)\n",
- address, current_uid());
-
- return SIGSEGV;
-
-}
-
-/*
- * bad_page_fault is called when we have a bad access from the kernel.
- * It is called from the DSI and ISI handlers in head.S and from some
- * of the procedures in traps.c.
- */
-void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
-{
- const struct exception_table_entry *entry;
- unsigned long *stackend;
-
- /* Are we prepared to handle this fault? */
- if ((entry = search_exception_tables(regs->nip)) != NULL) {
- regs->nip = entry->fixup;
- return;
- }
-
- /* kernel has accessed a bad area */
-
- switch (regs->trap) {
- case 0x300:
- case 0x380:
- printk(KERN_ALERT "Unable to handle kernel paging request for "
- "data at address 0x%08lx\n", regs->dar);
- break;
- case 0x400:
- case 0x480:
- printk(KERN_ALERT "Unable to handle kernel paging request for "
- "instruction fetch\n");
- break;
- default:
- printk(KERN_ALERT "Unable to handle kernel paging request for "
- "unknown fault\n");
- break;
- }
- printk(KERN_ALERT "Faulting instruction address: 0x%08lx\n",
- regs->nip);
-
- stackend = end_of_stack(current);
- if (current != &init_task && *stackend != STACK_END_MAGIC)
- printk(KERN_ALERT "Thread overran stack, or stack corrupted\n");
-
- die("Kernel access of bad area", regs, sig);
-}