mirror of https://gitee.com/openkylin/linux.git
530 lines
13 KiB
C
530 lines
13 KiB
C
/*
|
|
* arch/sparc64/mm/fault.c: Page fault handlers for the 64-bit Sparc.
|
|
*
|
|
* Copyright (C) 1996, 2008 David S. Miller (davem@davemloft.net)
|
|
* Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.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/signal.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/perf_event.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/kprobes.h>
|
|
#include <linux/kdebug.h>
|
|
#include <linux/percpu.h>
|
|
|
|
#include <asm/page.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/openprom.h>
|
|
#include <asm/oplib.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/asi.h>
|
|
#include <asm/lsu.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/mmu_context.h>
|
|
|
|
int show_unhandled_signals = 1;
|
|
|
|
static inline __kprobes int notify_page_fault(struct pt_regs *regs)
|
|
{
|
|
int ret = 0;
|
|
|
|
/* kprobe_running() needs smp_processor_id() */
|
|
if (kprobes_built_in() && !user_mode(regs)) {
|
|
preempt_disable();
|
|
if (kprobe_running() && kprobe_fault_handler(regs, 0))
|
|
ret = 1;
|
|
preempt_enable();
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void __kprobes 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 %016lx\n", (unsigned long)address);
|
|
}
|
|
printk(KERN_ALERT "tsk->{mm,active_mm}->context = %016lx\n",
|
|
(tsk->mm ?
|
|
CTX_HWBITS(tsk->mm->context) :
|
|
CTX_HWBITS(tsk->active_mm->context)));
|
|
printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %016lx\n",
|
|
(tsk->mm ? (unsigned long) tsk->mm->pgd :
|
|
(unsigned long) tsk->active_mm->pgd));
|
|
die_if_kernel("Oops", regs);
|
|
}
|
|
|
|
static void __kprobes bad_kernel_pc(struct pt_regs *regs, unsigned long vaddr)
|
|
{
|
|
printk(KERN_CRIT "OOPS: Bogus kernel PC [%016lx] in fault handler\n",
|
|
regs->tpc);
|
|
printk(KERN_CRIT "OOPS: RPC [%016lx]\n", regs->u_regs[15]);
|
|
printk("OOPS: RPC <%pS>\n", (void *) regs->u_regs[15]);
|
|
printk(KERN_CRIT "OOPS: Fault was to vaddr[%lx]\n", vaddr);
|
|
dump_stack();
|
|
unhandled_fault(regs->tpc, current, regs);
|
|
}
|
|
|
|
/*
|
|
* We now make sure that mmap_sem is held in all paths that call
|
|
* this. Additionally, to prevent kswapd from ripping ptes from
|
|
* under us, raise interrupts around the time that we look at the
|
|
* pte, kswapd will have to wait to get his smp ipi response from
|
|
* us. vmtruncate likewise. This saves us having to get pte lock.
|
|
*/
|
|
static unsigned int get_user_insn(unsigned long tpc)
|
|
{
|
|
pgd_t *pgdp = pgd_offset(current->mm, tpc);
|
|
pud_t *pudp;
|
|
pmd_t *pmdp;
|
|
pte_t *ptep, pte;
|
|
unsigned long pa;
|
|
u32 insn = 0;
|
|
unsigned long pstate;
|
|
|
|
if (pgd_none(*pgdp))
|
|
goto outret;
|
|
pudp = pud_offset(pgdp, tpc);
|
|
if (pud_none(*pudp))
|
|
goto outret;
|
|
pmdp = pmd_offset(pudp, tpc);
|
|
if (pmd_none(*pmdp))
|
|
goto outret;
|
|
|
|
/* This disables preemption for us as well. */
|
|
__asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
|
|
__asm__ __volatile__("wrpr %0, %1, %%pstate"
|
|
: : "r" (pstate), "i" (PSTATE_IE));
|
|
ptep = pte_offset_map(pmdp, tpc);
|
|
pte = *ptep;
|
|
if (!pte_present(pte))
|
|
goto out;
|
|
|
|
pa = (pte_pfn(pte) << PAGE_SHIFT);
|
|
pa += (tpc & ~PAGE_MASK);
|
|
|
|
/* Use phys bypass so we don't pollute dtlb/dcache. */
|
|
__asm__ __volatile__("lduwa [%1] %2, %0"
|
|
: "=r" (insn)
|
|
: "r" (pa), "i" (ASI_PHYS_USE_EC));
|
|
|
|
out:
|
|
pte_unmap(ptep);
|
|
__asm__ __volatile__("wrpr %0, 0x0, %%pstate" : : "r" (pstate));
|
|
outret:
|
|
return insn;
|
|
}
|
|
|
|
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->tpc, (void *)regs->u_regs[UREG_I7],
|
|
(void *)regs->u_regs[UREG_FP], code);
|
|
|
|
print_vma_addr(KERN_CONT " in ", regs->tpc);
|
|
|
|
printk(KERN_CONT "\n");
|
|
}
|
|
|
|
static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
|
|
unsigned int insn, int fault_code)
|
|
{
|
|
unsigned long addr;
|
|
siginfo_t info;
|
|
|
|
info.si_code = code;
|
|
info.si_signo = sig;
|
|
info.si_errno = 0;
|
|
if (fault_code & FAULT_CODE_ITLB)
|
|
addr = regs->tpc;
|
|
else
|
|
addr = compute_effective_address(regs, insn, 0);
|
|
info.si_addr = (void __user *) addr;
|
|
info.si_trapno = 0;
|
|
|
|
if (unlikely(show_unhandled_signals))
|
|
show_signal_msg(regs, sig, code, addr, current);
|
|
|
|
force_sig_info(sig, &info, current);
|
|
}
|
|
|
|
extern int handle_ldf_stq(u32, struct pt_regs *);
|
|
extern int handle_ld_nf(u32, struct pt_regs *);
|
|
|
|
static unsigned int get_fault_insn(struct pt_regs *regs, unsigned int insn)
|
|
{
|
|
if (!insn) {
|
|
if (!regs->tpc || (regs->tpc & 0x3))
|
|
return 0;
|
|
if (regs->tstate & TSTATE_PRIV) {
|
|
insn = *(unsigned int *) regs->tpc;
|
|
} else {
|
|
insn = get_user_insn(regs->tpc);
|
|
}
|
|
}
|
|
return insn;
|
|
}
|
|
|
|
static void __kprobes do_kernel_fault(struct pt_regs *regs, int si_code,
|
|
int fault_code, unsigned int insn,
|
|
unsigned long address)
|
|
{
|
|
unsigned char asi = ASI_P;
|
|
|
|
if ((!insn) && (regs->tstate & TSTATE_PRIV))
|
|
goto cannot_handle;
|
|
|
|
/* If user insn could be read (thus insn is zero), that
|
|
* is fine. We will just gun down the process with a signal
|
|
* in that case.
|
|
*/
|
|
|
|
if (!(fault_code & (FAULT_CODE_WRITE|FAULT_CODE_ITLB)) &&
|
|
(insn & 0xc0800000) == 0xc0800000) {
|
|
if (insn & 0x2000)
|
|
asi = (regs->tstate >> 24);
|
|
else
|
|
asi = (insn >> 5);
|
|
if ((asi & 0xf2) == 0x82) {
|
|
if (insn & 0x1000000) {
|
|
handle_ldf_stq(insn, regs);
|
|
} else {
|
|
/* This was a non-faulting load. Just clear the
|
|
* destination register(s) and continue with the next
|
|
* instruction. -jj
|
|
*/
|
|
handle_ld_nf(insn, regs);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Is this in ex_table? */
|
|
if (regs->tstate & TSTATE_PRIV) {
|
|
const struct exception_table_entry *entry;
|
|
|
|
entry = search_exception_tables(regs->tpc);
|
|
if (entry) {
|
|
regs->tpc = entry->fixup;
|
|
regs->tnpc = regs->tpc + 4;
|
|
return;
|
|
}
|
|
} else {
|
|
/* The si_code was set to make clear whether
|
|
* this was a SEGV_MAPERR or SEGV_ACCERR fault.
|
|
*/
|
|
do_fault_siginfo(si_code, SIGSEGV, regs, insn, fault_code);
|
|
return;
|
|
}
|
|
|
|
cannot_handle:
|
|
unhandled_fault (address, current, regs);
|
|
}
|
|
|
|
static void noinline __kprobes bogus_32bit_fault_tpc(struct pt_regs *regs)
|
|
{
|
|
static int times;
|
|
|
|
if (times++ < 10)
|
|
printk(KERN_ERR "FAULT[%s:%d]: 32-bit process reports "
|
|
"64-bit TPC [%lx]\n",
|
|
current->comm, current->pid,
|
|
regs->tpc);
|
|
show_regs(regs);
|
|
}
|
|
|
|
static void noinline __kprobes bogus_32bit_fault_address(struct pt_regs *regs,
|
|
unsigned long addr)
|
|
{
|
|
static int times;
|
|
|
|
if (times++ < 10)
|
|
printk(KERN_ERR "FAULT[%s:%d]: 32-bit process "
|
|
"reports 64-bit fault address [%lx]\n",
|
|
current->comm, current->pid, addr);
|
|
show_regs(regs);
|
|
}
|
|
|
|
asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
|
|
{
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
unsigned int insn = 0;
|
|
int si_code, fault_code, fault;
|
|
unsigned long address, mm_rss;
|
|
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
|
|
|
|
fault_code = get_thread_fault_code();
|
|
|
|
if (notify_page_fault(regs))
|
|
return;
|
|
|
|
si_code = SEGV_MAPERR;
|
|
address = current_thread_info()->fault_address;
|
|
|
|
if ((fault_code & FAULT_CODE_ITLB) &&
|
|
(fault_code & FAULT_CODE_DTLB))
|
|
BUG();
|
|
|
|
if (test_thread_flag(TIF_32BIT)) {
|
|
if (!(regs->tstate & TSTATE_PRIV)) {
|
|
if (unlikely((regs->tpc >> 32) != 0)) {
|
|
bogus_32bit_fault_tpc(regs);
|
|
goto intr_or_no_mm;
|
|
}
|
|
}
|
|
if (unlikely((address >> 32) != 0)) {
|
|
bogus_32bit_fault_address(regs, address);
|
|
goto intr_or_no_mm;
|
|
}
|
|
}
|
|
|
|
if (regs->tstate & TSTATE_PRIV) {
|
|
unsigned long tpc = regs->tpc;
|
|
|
|
/* Sanity check the PC. */
|
|
if ((tpc >= KERNBASE && tpc < (unsigned long) __init_end) ||
|
|
(tpc >= MODULES_VADDR && tpc < MODULES_END)) {
|
|
/* Valid, no problems... */
|
|
} else {
|
|
bad_kernel_pc(regs, address);
|
|
return;
|
|
}
|
|
} else
|
|
flags |= FAULT_FLAG_USER;
|
|
|
|
/*
|
|
* If we're in an interrupt or have no user
|
|
* context, we must not take the fault..
|
|
*/
|
|
if (in_atomic() || !mm)
|
|
goto intr_or_no_mm;
|
|
|
|
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address);
|
|
|
|
if (!down_read_trylock(&mm->mmap_sem)) {
|
|
if ((regs->tstate & TSTATE_PRIV) &&
|
|
!search_exception_tables(regs->tpc)) {
|
|
insn = get_fault_insn(regs, insn);
|
|
goto handle_kernel_fault;
|
|
}
|
|
|
|
retry:
|
|
down_read(&mm->mmap_sem);
|
|
}
|
|
|
|
vma = find_vma(mm, address);
|
|
if (!vma)
|
|
goto bad_area;
|
|
|
|
/* Pure DTLB misses do not tell us whether the fault causing
|
|
* load/store/atomic was a write or not, it only says that there
|
|
* was no match. So in such a case we (carefully) read the
|
|
* instruction to try and figure this out. It's an optimization
|
|
* so it's ok if we can't do this.
|
|
*
|
|
* Special hack, window spill/fill knows the exact fault type.
|
|
*/
|
|
if (((fault_code &
|
|
(FAULT_CODE_DTLB | FAULT_CODE_WRITE | FAULT_CODE_WINFIXUP)) == FAULT_CODE_DTLB) &&
|
|
(vma->vm_flags & VM_WRITE) != 0) {
|
|
insn = get_fault_insn(regs, 0);
|
|
if (!insn)
|
|
goto continue_fault;
|
|
/* All loads, stores and atomics have bits 30 and 31 both set
|
|
* in the instruction. Bit 21 is set in all stores, but we
|
|
* have to avoid prefetches which also have bit 21 set.
|
|
*/
|
|
if ((insn & 0xc0200000) == 0xc0200000 &&
|
|
(insn & 0x01780000) != 0x01680000) {
|
|
/* Don't bother updating thread struct value,
|
|
* because update_mmu_cache only cares which tlb
|
|
* the access came from.
|
|
*/
|
|
fault_code |= FAULT_CODE_WRITE;
|
|
}
|
|
}
|
|
continue_fault:
|
|
|
|
if (vma->vm_start <= address)
|
|
goto good_area;
|
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
|
goto bad_area;
|
|
if (!(fault_code & FAULT_CODE_WRITE)) {
|
|
/* Non-faulting loads shouldn't expand stack. */
|
|
insn = get_fault_insn(regs, insn);
|
|
if ((insn & 0xc0800000) == 0xc0800000) {
|
|
unsigned char asi;
|
|
|
|
if (insn & 0x2000)
|
|
asi = (regs->tstate >> 24);
|
|
else
|
|
asi = (insn >> 5);
|
|
if ((asi & 0xf2) == 0x82)
|
|
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:
|
|
si_code = SEGV_ACCERR;
|
|
|
|
/* If we took a ITLB miss on a non-executable page, catch
|
|
* that here.
|
|
*/
|
|
if ((fault_code & FAULT_CODE_ITLB) && !(vma->vm_flags & VM_EXEC)) {
|
|
BUG_ON(address != regs->tpc);
|
|
BUG_ON(regs->tstate & TSTATE_PRIV);
|
|
goto bad_area;
|
|
}
|
|
|
|
if (fault_code & FAULT_CODE_WRITE) {
|
|
if (!(vma->vm_flags & VM_WRITE))
|
|
goto bad_area;
|
|
|
|
/* Spitfire has an icache which does not snoop
|
|
* processor stores. Later processors do...
|
|
*/
|
|
if (tlb_type == spitfire &&
|
|
(vma->vm_flags & VM_EXEC) != 0 &&
|
|
vma->vm_file != NULL)
|
|
set_thread_fault_code(fault_code |
|
|
FAULT_CODE_BLKCOMMIT);
|
|
|
|
flags |= FAULT_FLAG_WRITE;
|
|
} else {
|
|
/* Allow reads even for write-only mappings */
|
|
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
|
|
goto bad_area;
|
|
}
|
|
|
|
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_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);
|
|
|
|
mm_rss = get_mm_rss(mm);
|
|
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
|
|
mm_rss -= (mm->context.huge_pte_count * (HPAGE_SIZE / PAGE_SIZE));
|
|
#endif
|
|
if (unlikely(mm_rss >
|
|
mm->context.tsb_block[MM_TSB_BASE].tsb_rss_limit))
|
|
tsb_grow(mm, MM_TSB_BASE, mm_rss);
|
|
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
|
|
mm_rss = mm->context.huge_pte_count;
|
|
if (unlikely(mm_rss >
|
|
mm->context.tsb_block[MM_TSB_HUGE].tsb_rss_limit)) {
|
|
if (mm->context.tsb_block[MM_TSB_HUGE].tsb)
|
|
tsb_grow(mm, MM_TSB_HUGE, mm_rss);
|
|
else
|
|
hugetlb_setup(regs);
|
|
|
|
}
|
|
#endif
|
|
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:
|
|
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;
|
|
}
|