![Nick Piggin](/assets/img/avatar_default.png)
As explained in commit 1c0fe6e3bd
("mm: invoke oom-killer from page
fault") , we want to call the architecture independent oom killer when
getting an unexplained OOM from handle_mm_fault, rather than simply
killing current.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
327 lines
8 KiB
C
327 lines
8 KiB
C
/*
|
|
* linux/arch/frv/mm/fault.c
|
|
*
|
|
* Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
|
|
* - Written by David Howells (dhowells@redhat.com)
|
|
* - Derived from arch/m68knommu/mm/fault.c
|
|
* - Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>,
|
|
* - Copyright (C) 2000 Lineo, Inc. (www.lineo.com)
|
|
*
|
|
* Based on:
|
|
*
|
|
* linux/arch/m68k/mm/fault.c
|
|
*
|
|
* Copyright (C) 1995 Hamish Macdonald
|
|
*/
|
|
|
|
#include <linux/mman.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/hardirq.h>
|
|
|
|
#include <asm/system.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/gdb-stub.h>
|
|
|
|
/*****************************************************************************/
|
|
/*
|
|
* This routine handles page faults. It determines the problem, and
|
|
* then passes it off to one of the appropriate routines.
|
|
*/
|
|
asmlinkage void do_page_fault(int datammu, unsigned long esr0, unsigned long ear0)
|
|
{
|
|
struct vm_area_struct *vma;
|
|
struct mm_struct *mm;
|
|
unsigned long _pme, lrai, lrad, fixup;
|
|
siginfo_t info;
|
|
pgd_t *pge;
|
|
pud_t *pue;
|
|
pte_t *pte;
|
|
int write;
|
|
int fault;
|
|
|
|
#if 0
|
|
const char *atxc[16] = {
|
|
[0x0] = "mmu-miss", [0x8] = "multi-dat", [0x9] = "multi-sat",
|
|
[0xa] = "tlb-miss", [0xc] = "privilege", [0xd] = "write-prot",
|
|
};
|
|
|
|
printk("do_page_fault(%d,%lx [%s],%lx)\n",
|
|
datammu, esr0, atxc[esr0 >> 20 & 0xf], ear0);
|
|
#endif
|
|
|
|
mm = current->mm;
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* This verifies that the fault happens in kernel space
|
|
* and that the fault was a page not present (invalid) error
|
|
*/
|
|
if (!user_mode(__frame) && (esr0 & ESR0_ATXC) == ESR0_ATXC_AMRTLB_MISS) {
|
|
if (ear0 >= VMALLOC_START && ear0 < VMALLOC_END)
|
|
goto kernel_pte_fault;
|
|
if (ear0 >= PKMAP_BASE && ear0 < PKMAP_END)
|
|
goto kernel_pte_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);
|
|
|
|
vma = find_vma(mm, ear0);
|
|
if (!vma)
|
|
goto bad_area;
|
|
if (vma->vm_start <= ear0)
|
|
goto good_area;
|
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
|
goto bad_area;
|
|
|
|
if (user_mode(__frame)) {
|
|
/*
|
|
* accessing the stack below %esp is always a bug.
|
|
* The "+ 32" is there due to some instructions (like
|
|
* pusha) doing post-decrement on the stack and that
|
|
* doesn't show up until later..
|
|
*/
|
|
if ((ear0 & PAGE_MASK) + 2 * PAGE_SIZE < __frame->sp) {
|
|
#if 0
|
|
printk("[%d] ### Access below stack @%lx (sp=%lx)\n",
|
|
current->pid, ear0, __frame->sp);
|
|
show_registers(__frame);
|
|
printk("[%d] ### Code: [%08lx] %02x %02x %02x %02x %02x %02x %02x %02x\n",
|
|
current->pid,
|
|
__frame->pc,
|
|
((u8*)__frame->pc)[0],
|
|
((u8*)__frame->pc)[1],
|
|
((u8*)__frame->pc)[2],
|
|
((u8*)__frame->pc)[3],
|
|
((u8*)__frame->pc)[4],
|
|
((u8*)__frame->pc)[5],
|
|
((u8*)__frame->pc)[6],
|
|
((u8*)__frame->pc)[7]
|
|
);
|
|
#endif
|
|
goto bad_area;
|
|
}
|
|
}
|
|
|
|
if (expand_stack(vma, ear0))
|
|
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;
|
|
write = 0;
|
|
switch (esr0 & ESR0_ATXC) {
|
|
default:
|
|
/* handle write to write protected page */
|
|
case ESR0_ATXC_WP_EXCEP:
|
|
#ifdef TEST_VERIFY_AREA
|
|
if (!(user_mode(__frame)))
|
|
printk("WP fault at %08lx\n", __frame->pc);
|
|
#endif
|
|
if (!(vma->vm_flags & VM_WRITE))
|
|
goto bad_area;
|
|
write = 1;
|
|
break;
|
|
|
|
/* handle read from protected page */
|
|
case ESR0_ATXC_PRIV_EXCEP:
|
|
goto bad_area;
|
|
|
|
/* handle read, write or exec on absent page
|
|
* - can't support write without permitting read
|
|
* - don't support execute without permitting read and vice-versa
|
|
*/
|
|
case ESR0_ATXC_AMRTLB_MISS:
|
|
if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)))
|
|
goto bad_area;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* 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, ear0, write ? FAULT_FLAG_WRITE : 0);
|
|
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);
|
|
|
|
/* User mode accesses just cause a SIGSEGV */
|
|
if (user_mode(__frame)) {
|
|
info.si_signo = SIGSEGV;
|
|
info.si_errno = 0;
|
|
/* info.si_code has been set above */
|
|
info.si_addr = (void *) ear0;
|
|
force_sig_info(SIGSEGV, &info, current);
|
|
return;
|
|
}
|
|
|
|
no_context:
|
|
/* are we prepared to handle this kernel fault? */
|
|
if ((fixup = search_exception_table(__frame->pc)) != 0) {
|
|
__frame->pc = fixup;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Oops. The kernel tried to access some bad page. We'll have to
|
|
* terminate things with extreme prejudice.
|
|
*/
|
|
|
|
bust_spinlocks(1);
|
|
|
|
if (ear0 < PAGE_SIZE)
|
|
printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
|
|
else
|
|
printk(KERN_ALERT "Unable to handle kernel paging request");
|
|
printk(" at virtual addr %08lx\n", ear0);
|
|
printk(" PC : %08lx\n", __frame->pc);
|
|
printk(" EXC : esr0=%08lx ear0=%08lx\n", esr0, ear0);
|
|
|
|
asm("lrai %1,%0,#1,#0,#0" : "=&r"(lrai) : "r"(ear0));
|
|
asm("lrad %1,%0,#1,#0,#0" : "=&r"(lrad) : "r"(ear0));
|
|
|
|
printk(KERN_ALERT " LRAI: %08lx\n", lrai);
|
|
printk(KERN_ALERT " LRAD: %08lx\n", lrad);
|
|
|
|
__break_hijack_kernel_event();
|
|
|
|
pge = pgd_offset(current->mm, ear0);
|
|
pue = pud_offset(pge, ear0);
|
|
_pme = pue->pue[0].ste[0];
|
|
|
|
printk(KERN_ALERT " PGE : %8p { PME %08lx }\n", pge, _pme);
|
|
|
|
if (_pme & xAMPRx_V) {
|
|
unsigned long dampr, damlr, val;
|
|
|
|
asm volatile("movsg dampr2,%0 ! movgs %2,dampr2 ! movsg damlr2,%1"
|
|
: "=&r"(dampr), "=r"(damlr)
|
|
: "r" (_pme | xAMPRx_L|xAMPRx_SS_16Kb|xAMPRx_S|xAMPRx_C|xAMPRx_V)
|
|
);
|
|
|
|
pte = (pte_t *) damlr + __pte_index(ear0);
|
|
val = pte_val(*pte);
|
|
|
|
asm volatile("movgs %0,dampr2" :: "r" (dampr));
|
|
|
|
printk(KERN_ALERT " PTE : %8p { %08lx }\n", pte, val);
|
|
}
|
|
|
|
die_if_kernel("Oops\n");
|
|
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 (!user_mode(__frame))
|
|
goto no_context;
|
|
pagefault_out_of_memory();
|
|
return;
|
|
|
|
do_sigbus:
|
|
up_read(&mm->mmap_sem);
|
|
|
|
/*
|
|
* Send a sigbus, regardless of whether we were in kernel
|
|
* or user mode.
|
|
*/
|
|
info.si_signo = SIGBUS;
|
|
info.si_errno = 0;
|
|
info.si_code = BUS_ADRERR;
|
|
info.si_addr = (void *) ear0;
|
|
force_sig_info(SIGBUS, &info, current);
|
|
|
|
/* Kernel mode? Handle exceptions or die */
|
|
if (!user_mode(__frame))
|
|
goto no_context;
|
|
return;
|
|
|
|
/*
|
|
* The fault was caused by a kernel PTE (such as installed by vmalloc or kmap)
|
|
*/
|
|
kernel_pte_fault:
|
|
{
|
|
/*
|
|
* Synchronize this task's top level page-table
|
|
* with the 'reference' page table.
|
|
*
|
|
* Do _not_ use "tsk" here. We might be inside
|
|
* an interrupt in the middle of a task switch..
|
|
*/
|
|
int index = pgd_index(ear0);
|
|
pgd_t *pgd, *pgd_k;
|
|
pud_t *pud, *pud_k;
|
|
pmd_t *pmd, *pmd_k;
|
|
pte_t *pte_k;
|
|
|
|
pgd = (pgd_t *) __get_TTBR();
|
|
pgd = (pgd_t *)__va(pgd) + index;
|
|
pgd_k = ((pgd_t *)(init_mm.pgd)) + index;
|
|
|
|
if (!pgd_present(*pgd_k))
|
|
goto no_context;
|
|
//set_pgd(pgd, *pgd_k); /////// gcc ICE's on this line
|
|
|
|
pud_k = pud_offset(pgd_k, ear0);
|
|
if (!pud_present(*pud_k))
|
|
goto no_context;
|
|
|
|
pmd_k = pmd_offset(pud_k, ear0);
|
|
if (!pmd_present(*pmd_k))
|
|
goto no_context;
|
|
|
|
pud = pud_offset(pgd, ear0);
|
|
pmd = pmd_offset(pud, ear0);
|
|
set_pmd(pmd, *pmd_k);
|
|
|
|
pte_k = pte_offset_kernel(pmd_k, ear0);
|
|
if (!pte_present(*pte_k))
|
|
goto no_context;
|
|
return;
|
|
}
|
|
} /* end do_page_fault() */
|