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f88620b9c5
Missing error types, attributes, and report fields. Pad out to 64-bytes. Make string reporting cleaner and easier to extend in the future using "const char *" arrays that index by either bit position, or absolute field value. Report the raw 64-byte error report as a sequence of u64s before the annotated version. Only report fields which are valid, given the context and the attribute bits which are set. For shutdown requests, use the local copy of the error report not the one we just freed up back to the queue. Also, use orderly_poweroff() just like the Domain Services shutdown request code does. If the real-address reported is "-1" (unknown) try to disassemble the instruction to report the effective address of the access. Only do this in privileged mode. Signed-off-by: David S. Miller <davem@davemloft.net>
523 lines
13 KiB
C
523 lines
13 KiB
C
/*
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* arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc.
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*
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* Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
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* Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
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*/
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#include <asm/head.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <linux/ptrace.h>
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#include <linux/mman.h>
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#include <linux/signal.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/perf_event.h>
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#include <linux/interrupt.h>
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#include <linux/kprobes.h>
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#include <linux/kdebug.h>
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#include <linux/percpu.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/openprom.h>
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#include <asm/oplib.h>
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#include <asm/uaccess.h>
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#include <asm/asi.h>
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#include <asm/lsu.h>
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#include <asm/sections.h>
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#include <asm/mmu_context.h>
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int show_unhandled_signals = 1;
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static inline __kprobes int notify_page_fault(struct pt_regs *regs)
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{
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int ret = 0;
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/* kprobe_running() needs smp_processor_id() */
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if (kprobes_built_in() && !user_mode(regs)) {
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preempt_disable();
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if (kprobe_running() && kprobe_fault_handler(regs, 0))
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ret = 1;
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preempt_enable();
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}
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return ret;
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}
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static void __kprobes unhandled_fault(unsigned long address,
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struct task_struct *tsk,
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struct pt_regs *regs)
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{
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if ((unsigned long) address < PAGE_SIZE) {
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printk(KERN_ALERT "Unable to handle kernel NULL "
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"pointer dereference\n");
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} else {
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printk(KERN_ALERT "Unable to handle kernel paging request "
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"at virtual address %016lx\n", (unsigned long)address);
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}
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printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
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(tsk->mm ?
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CTX_HWBITS(tsk->mm->context) :
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CTX_HWBITS(tsk->active_mm->context)));
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printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
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(tsk->mm ? (unsigned long) tsk->mm->pgd :
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(unsigned long) tsk->active_mm->pgd));
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die_if_kernel("Oops", regs);
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}
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static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
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{
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printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
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regs->tpc);
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printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
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printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
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printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
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dump_stack();
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unhandled_fault(regs->tpc, current, regs);
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}
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/*
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* We now make sure that mmap_sem is held in all paths that call
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* this. Additionally, to prevent kswapd from ripping ptes from
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* under us, raise interrupts around the time that we look at the
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* pte, kswapd will have to wait to get his smp ipi response from
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* us. vmtruncate likewise. This saves us having to get pte lock.
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*/
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static unsigned int get_user_insn(unsigned long tpc)
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{
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pgd_t *pgdp = pgd_offset(current->mm, tpc);
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pud_t *pudp;
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pmd_t *pmdp;
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pte_t *ptep, pte;
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unsigned long pa;
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u32 insn = 0;
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unsigned long pstate;
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if (pgd_none(*pgdp))
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goto outret;
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pudp = pud_offset(pgdp, tpc);
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if (pud_none(*pudp))
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goto outret;
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pmdp = pmd_offset(pudp, tpc);
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if (pmd_none(*pmdp))
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goto outret;
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/* This disables preemption for us as well. */
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__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
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__asm__ __volatile__("wrpr %0, %1, %%pstate"
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: : "r" (pstate), "i" (PSTATE_IE));
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ptep = pte_offset_map(pmdp, tpc);
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pte = *ptep;
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if (!pte_present(pte))
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goto out;
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pa = (pte_pfn(pte) << PAGE_SHIFT);
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pa += (tpc & ~PAGE_MASK);
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/* Use phys bypass so we don't pollute dtlb/dcache. */
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__asm__ __volatile__("lduwa [%1] %2, %0"
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: "=r" (insn)
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: "r" (pa), "i" (ASI_PHYS_USE_EC));
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out:
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pte_unmap(ptep);
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__asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate));
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outret:
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return insn;
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}
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static inline void
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show_signal_msg(struct pt_regs *regs, int sig, int code,
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unsigned long address, struct task_struct *tsk)
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{
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if (!unhandled_signal(tsk, sig))
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return;
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if (!printk_ratelimit())
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return;
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printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
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task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
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tsk->comm, task_pid_nr(tsk), address,
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(void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
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(void *)regs->u_regs[UREG_FP], code);
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print_vma_addr(KERN_CONT " in ", regs->tpc);
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printk(KERN_CONT "\n");
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}
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static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
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unsigned int insn, int fault_code)
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{
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unsigned long addr;
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siginfo_t info;
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info.si_code = code;
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info.si_signo = sig;
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info.si_errno = 0;
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if (fault_code & FAULT_CODE_ITLB)
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addr = regs->tpc;
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else
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addr = compute_effective_address(regs, insn, 0);
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info.si_addr = (void __user *) addr;
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info.si_trapno = 0;
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if (unlikely(show_unhandled_signals))
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show_signal_msg(regs, sig, code, addr, current);
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force_sig_info(sig, &info, current);
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}
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extern int handle_ldf_stq(u32, struct pt_regs *);
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extern int handle_ld_nf(u32, struct pt_regs *);
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static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
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{
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if (!insn) {
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if (!regs->tpc || (regs->tpc & 0x3))
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return 0;
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if (regs->tstate & TSTATE_PRIV) {
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insn = *(unsigned int *) regs->tpc;
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} else {
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insn = get_user_insn(regs->tpc);
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}
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}
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return insn;
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}
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static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
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int fault_code, unsigned int insn,
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unsigned long address)
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{
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unsigned char asi = ASI_P;
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if ((!insn) && (regs->tstate & TSTATE_PRIV))
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goto cannot_handle;
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/* If user insn could be read (thus insn is zero), that
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* is fine. We will just gun down the process with a signal
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* in that case.
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*/
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if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) &&
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(insn & 0xc0800000) == 0xc0800000) {
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if (insn & 0x2000)
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asi = (regs->tstate >> 24);
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else
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asi = (insn >> 5);
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if ((asi & 0xf2) == 0x82) {
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if (insn & 0x1000000) {
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handle_ldf_stq(insn, regs);
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} else {
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/* This was a non-faulting load. Just clear the
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* destination register(s) and continue with the next
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* instruction. -jj
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*/
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handle_ld_nf(insn, regs);
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}
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return;
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}
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}
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/* Is this in ex_table? */
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if (regs->tstate & TSTATE_PRIV) {
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const struct exception_table_entry *entry;
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entry = search_exception_tables(regs->tpc);
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if (entry) {
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regs->tpc = entry->fixup;
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regs->tnpc = regs->tpc + 4;
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return;
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}
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} else {
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/* The si_code was set to make clear whether
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* this was a SEGV_MAPERR or SEGV_ACCERR fault.
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*/
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do_fault_siginfo(si_code, SIGSEGV, regs, insn, fault_code);
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return;
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}
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cannot_handle:
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unhandled_fault (address, current, regs);
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}
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static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
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{
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static int times;
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if (times++ < 10)
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printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
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"64-bit TPC [%lx]\n",
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current->comm, current->pid,
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regs->tpc);
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show_regs(regs);
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}
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static void noinline __kprobes bogus_32bit_fault_address(struct pt_regs *regs,
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unsigned long addr)
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{
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static int times;
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if (times++ < 10)
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printk(KERN_ERR "FAULT[%s:%d]: 32-bit process "
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"reports 64-bit fault address [%lx]\n",
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current->comm, current->pid, addr);
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show_regs(regs);
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}
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asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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unsigned int insn = 0;
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int si_code, fault_code, fault;
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unsigned long address, mm_rss;
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unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
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fault_code = get_thread_fault_code();
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if (notify_page_fault(regs))
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return;
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si_code = SEGV_MAPERR;
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address = current_thread_info()->fault_address;
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if ((fault_code & FAULT_CODE_ITLB) &&
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(fault_code & FAULT_CODE_DTLB))
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BUG();
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if (test_thread_flag(TIF_32BIT)) {
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if (!(regs->tstate & TSTATE_PRIV)) {
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if (unlikely((regs->tpc >> 32) != 0)) {
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bogus_32bit_fault_tpc(regs);
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goto intr_or_no_mm;
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}
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}
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if (unlikely((address >> 32) != 0)) {
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bogus_32bit_fault_address(regs, address);
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goto intr_or_no_mm;
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}
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}
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if (regs->tstate & TSTATE_PRIV) {
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unsigned long tpc = regs->tpc;
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/* Sanity check the PC. */
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if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) ||
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(tpc >= MODULES_VADDR && tpc < MODULES_END)) {
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/* Valid, no problems... */
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} else {
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bad_kernel_pc(regs, address);
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return;
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}
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}
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/*
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* If we're in an interrupt or have no user
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* context, we must not take the fault..
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*/
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if (in_atomic() || !mm)
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goto intr_or_no_mm;
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perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
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if (!down_read_trylock(&mm->mmap_sem)) {
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if ((regs->tstate & TSTATE_PRIV) &&
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!search_exception_tables(regs->tpc)) {
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insn = get_fault_insn(regs, insn);
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goto handle_kernel_fault;
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}
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retry:
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down_read(&mm->mmap_sem);
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}
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vma = find_vma(mm, address);
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if (!vma)
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goto bad_area;
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/* Pure DTLB misses do not tell us whether the fault causing
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* load/store/atomic was a write or not, it only says that there
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* was no match. So in such a case we (carefully) read the
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* instruction to try and figure this out. It's an optimization
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* so it's ok if we can't do this.
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*
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* Special hack, window spill/fill knows the exact fault type.
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*/
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if (((fault_code &
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(FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
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(vma->vm_flags & VM_WRITE) != 0) {
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insn = get_fault_insn(regs, 0);
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if (!insn)
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goto continue_fault;
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/* All loads, stores and atomics have bits 30 and 31 both set
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* in the instruction. Bit 21 is set in all stores, but we
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* have to avoid prefetches which also have bit 21 set.
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*/
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if ((insn & 0xc0200000) == 0xc0200000 &&
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(insn & 0x01780000) != 0x01680000) {
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/* Don't bother updating thread struct value,
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* because update_mmu_cache only cares which tlb
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* the access came from.
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*/
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fault_code |= FAULT_CODE_WRITE;
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}
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}
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continue_fault:
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if (vma->vm_start <= address)
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goto good_area;
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if (!(vma->vm_flags & VM_GROWSDOWN))
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goto bad_area;
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if (!(fault_code & FAULT_CODE_WRITE)) {
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/* Non-faulting loads shouldn't expand stack. */
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insn = get_fault_insn(regs, insn);
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if ((insn & 0xc0800000) == 0xc0800000) {
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unsigned char asi;
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if (insn & 0x2000)
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asi = (regs->tstate >> 24);
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else
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asi = (insn >> 5);
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if ((asi & 0xf2) == 0x82)
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goto bad_area;
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}
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}
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if (expand_stack(vma, address))
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goto bad_area;
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/*
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* Ok, we have a good vm_area for this memory access, so
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* we can handle it..
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*/
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good_area:
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si_code = SEGV_ACCERR;
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/* If we took a ITLB miss on a non-executable page, catch
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* that here.
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*/
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if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
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BUG_ON(address != regs->tpc);
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BUG_ON(regs->tstate & TSTATE_PRIV);
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goto bad_area;
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}
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if (fault_code & FAULT_CODE_WRITE) {
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if (!(vma->vm_flags & VM_WRITE))
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goto bad_area;
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/* Spitfire has an icache which does not snoop
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* processor stores. Later processors do...
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*/
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if (tlb_type == spitfire &&
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(vma->vm_flags & VM_EXEC) != 0 &&
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vma->vm_file != NULL)
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set_thread_fault_code(fault_code |
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FAULT_CODE_BLKCOMMIT);
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} else {
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/* Allow reads even for write-only mappings */
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if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
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goto bad_area;
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}
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flags |= ((fault_code & FAULT_CODE_WRITE) ? FAULT_FLAG_WRITE : 0);
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fault = handle_mm_fault(mm, vma, address, flags);
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if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(current))
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return;
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if (unlikely(fault & VM_FAULT_ERROR)) {
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if (fault & VM_FAULT_OOM)
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goto out_of_memory;
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else if (fault & VM_FAULT_SIGBUS)
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goto do_sigbus;
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BUG();
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}
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if (flags & FAULT_FLAG_ALLOW_RETRY) {
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if (fault & VM_FAULT_MAJOR) {
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current->maj_flt++;
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perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
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1, regs, address);
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} else {
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current->min_flt++;
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perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
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1, regs, address);
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}
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if (fault & VM_FAULT_RETRY) {
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flags &= ~FAULT_FLAG_ALLOW_RETRY;
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flags |= FAULT_FLAG_TRIED;
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/* No need to up_read(&mm->mmap_sem) as we would
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* have already released it in __lock_page_or_retry
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* in mm/filemap.c.
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*/
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goto retry;
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}
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}
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up_read(&mm->mmap_sem);
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mm_rss = get_mm_rss(mm);
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#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
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mm_rss -= (mm->context.huge_pte_count * (HPAGE_SIZE / PAGE_SIZE));
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#endif
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if (unlikely(mm_rss >
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mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
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tsb_grow(mm, MM_TSB_BASE, mm_rss);
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#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
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mm_rss = mm->context.huge_pte_count;
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if (unlikely(mm_rss >
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mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit))
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tsb_grow(mm, MM_TSB_HUGE, mm_rss);
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#endif
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return;
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/*
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|
* 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:
|
|
insn = get_fault_insn(regs, insn);
|
|
up_read(&mm->mmap_sem);
|
|
|
|
handle_kernel_fault:
|
|
do_kernel_fault(regs, si_code, fault_code, insn, address);
|
|
return;
|
|
|
|
/*
|
|
* 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:
|
|
insn = get_fault_insn(regs, insn);
|
|
up_read(&mm->mmap_sem);
|
|
if (!(regs->tstate & TSTATE_PRIV)) {
|
|
pagefault_out_of_memory();
|
|
return;
|
|
}
|
|
goto handle_kernel_fault;
|
|
|
|
intr_or_no_mm:
|
|
insn = get_fault_insn(regs, 0);
|
|
goto handle_kernel_fault;
|
|
|
|
do_sigbus:
|
|
insn = get_fault_insn(regs, insn);
|
|
up_read(&mm->mmap_sem);
|
|
|
|
/*
|
|
* Send a sigbus, regardless of whether we were in kernel
|
|
* or user mode.
|
|
*/
|
|
do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, insn, fault_code);
|
|
|
|
/* Kernel mode? Handle exceptions or die */
|
|
if (regs->tstate & TSTATE_PRIV)
|
|
goto handle_kernel_fault;
|
|
}
|