diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-18 09:43:09 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-18 09:43:09 -0700 |
commit | 515b696b282f856c3ad1679ccd658120faa387d0 (patch) | |
tree | d9d7c1185c396617f128ca23463062308d11393b /arch/sh/mm/fault_32.c | |
parent | fa877c71e2136bd682b45022c96d5e073ced9f58 (diff) | |
parent | 064a16dc41be879d12bd5de5d2f9d38d890e0ee7 (diff) | |
download | linux-515b696b282f856c3ad1679ccd658120faa387d0.tar.bz2 |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (262 commits)
sh: mach-ecovec24: Add user debug switch support
sh: Kill off unused se_skipped in alignment trap notification code.
sh: Wire up HAVE_SYSCALL_TRACEPOINTS.
video: sh_mobile_lcdcfb: use both register sets for display panning
video: sh_mobile_lcdcfb: implement display panning
sh: Fix up sh7705 flush_dcache_page() build.
sh: kfr2r09: document the PLL/FLL <-> RF relationship.
sh: mach-ecovec24: need asm/clock.h.
sh: mach-ecovec24: deassert usb irq on boot.
sh: Add KEYSC support for EcoVec24
sh: add kycr2_delay for sh_keysc
sh: cpufreq: Include CPU id in info messages.
sh: multi-evt support for SH-X3 proto CPU.
sh: clkfwk: remove bogus set_bus_parent() from SH7709.
sh: Fix the indication point of the liquid crystal of AP-325RXA(AP3300)
sh: Add EcoVec24 romImage defconfig
sh: USB disable process is needed if romImage boot for EcoVec24
sh: EcoVec24: add HIZA setting for LED
sh: EcoVec24: write MAC address in boot
sh: Add romImage support for EcoVec24
...
Diffstat (limited to 'arch/sh/mm/fault_32.c')
-rw-r--r-- | arch/sh/mm/fault_32.c | 196 |
1 files changed, 121 insertions, 75 deletions
diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c index 71925946f1e1..781b413ff82d 100644 --- a/arch/sh/mm/fault_32.c +++ b/arch/sh/mm/fault_32.c @@ -2,7 +2,7 @@ * Page fault handler for SH with an MMU. * * Copyright (C) 1999 Niibe Yutaka - * Copyright (C) 2003 - 2008 Paul Mundt + * Copyright (C) 2003 - 2009 Paul Mundt * * Based on linux/arch/i386/mm/fault.c: * Copyright (C) 1995 Linus Torvalds @@ -25,18 +25,91 @@ static inline int notify_page_fault(struct pt_regs *regs, int trap) { int ret = 0; -#ifdef CONFIG_KPROBES - if (!user_mode(regs)) { + if (kprobes_built_in() && !user_mode(regs)) { preempt_disable(); if (kprobe_running() && kprobe_fault_handler(regs, trap)) ret = 1; preempt_enable(); } -#endif return ret; } +static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) +{ + unsigned index = pgd_index(address); + pgd_t *pgd_k; + pud_t *pud, *pud_k; + pmd_t *pmd, *pmd_k; + + pgd += index; + pgd_k = init_mm.pgd + index; + + if (!pgd_present(*pgd_k)) + return NULL; + + pud = pud_offset(pgd, address); + pud_k = pud_offset(pgd_k, address); + if (!pud_present(*pud_k)) + return NULL; + + pmd = pmd_offset(pud, address); + pmd_k = pmd_offset(pud_k, address); + if (!pmd_present(*pmd_k)) + return NULL; + + if (!pmd_present(*pmd)) + set_pmd(pmd, *pmd_k); + else { + /* + * The page tables are fully synchronised so there must + * be another reason for the fault. Return NULL here to + * signal that we have not taken care of the fault. + */ + BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k)); + return NULL; + } + + return pmd_k; +} + +/* + * Handle a fault on the vmalloc or module mapping area + */ +static noinline int vmalloc_fault(unsigned long address) +{ + pgd_t *pgd_k; + pmd_t *pmd_k; + pte_t *pte_k; + + /* Make sure we are in vmalloc/module/P3 area: */ + if (!(address >= VMALLOC_START && address < P3_ADDR_MAX)) + return -1; + + /* + * Synchronize this task's top level page-table + * with the 'reference' page table. + * + * Do _not_ use "current" here. We might be inside + * an interrupt in the middle of a task switch.. + */ + pgd_k = get_TTB(); + pmd_k = vmalloc_sync_one(pgd_k, address); + if (!pmd_k) + return -1; + + pte_k = pte_offset_kernel(pmd_k, address); + if (!pte_present(*pte_k)) + return -1; + + return 0; +} + +static int fault_in_kernel_space(unsigned long address) +{ + return address >= TASK_SIZE; +} + /* * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate @@ -46,6 +119,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, unsigned long writeaccess, unsigned long address) { + unsigned long vec; struct task_struct *tsk; struct mm_struct *mm; struct vm_area_struct * vma; @@ -53,59 +127,30 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, int fault; siginfo_t info; - /* - * We don't bother with any notifier callbacks here, as they are - * all handled through the __do_page_fault() fast-path. - */ - tsk = current; + mm = tsk->mm; si_code = SEGV_MAPERR; + vec = lookup_exception_vector(); - if (unlikely(address >= TASK_SIZE)) { - /* - * 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 offset = pgd_index(address); - pgd_t *pgd, *pgd_k; - pud_t *pud, *pud_k; - pmd_t *pmd, *pmd_k; - - pgd = get_TTB() + offset; - pgd_k = swapper_pg_dir + offset; - - if (!pgd_present(*pgd)) { - if (!pgd_present(*pgd_k)) - goto bad_area_nosemaphore; - set_pgd(pgd, *pgd_k); + /* + * 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. + */ + if (unlikely(fault_in_kernel_space(address))) { + if (vmalloc_fault(address) >= 0) return; - } - - pud = pud_offset(pgd, address); - pud_k = pud_offset(pgd_k, address); - - if (!pud_present(*pud)) { - if (!pud_present(*pud_k)) - goto bad_area_nosemaphore; - set_pud(pud, *pud_k); + if (notify_page_fault(regs, vec)) return; - } - pmd = pmd_offset(pud, address); - pmd_k = pmd_offset(pud_k, address); - if (pmd_present(*pmd) || !pmd_present(*pmd_k)) - goto bad_area_nosemaphore; - set_pmd(pmd, *pmd_k); - - return; + goto bad_area_nosemaphore; } - mm = tsk->mm; - - if (unlikely(notify_page_fault(regs, lookup_exception_vector()))) + if (unlikely(notify_page_fault(regs, vec))) return; /* Only enable interrupts if they were on before the fault */ @@ -115,8 +160,8 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, perf_swcounter_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address); /* - * If we're in an interrupt or have no user - * context, we must not take the fault.. + * If we're in an interrupt, have no user context or are running + * in an atomic region then we must not take the fault: */ if (in_atomic() || !mm) goto no_context; @@ -132,10 +177,11 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, 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.. - */ + + /* + * Ok, we have a good vm_area for this memory access, so + * we can handle it.. + */ good_area: si_code = SEGV_ACCERR; if (writeaccess) { @@ -173,10 +219,10 @@ survive: 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.. - */ + /* + * 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); @@ -272,16 +318,15 @@ do_sigbus: /* * Called with interrupts disabled. */ -asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs, - unsigned long writeaccess, - unsigned long address) +asmlinkage int __kprobes +handle_tlbmiss(struct pt_regs *regs, unsigned long writeaccess, + unsigned long address) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; pte_t entry; - int ret = 1; /* * We don't take page faults for P1, P2, and parts of P4, these @@ -292,40 +337,41 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs, pgd = pgd_offset_k(address); } else { if (unlikely(address >= TASK_SIZE || !current->mm)) - goto out; + return 1; pgd = pgd_offset(current->mm, address); } pud = pud_offset(pgd, address); if (pud_none_or_clear_bad(pud)) - goto out; + return 1; pmd = pmd_offset(pud, address); if (pmd_none_or_clear_bad(pmd)) - goto out; + return 1; pte = pte_offset_kernel(pmd, address); entry = *pte; if (unlikely(pte_none(entry) || pte_not_present(entry))) - goto out; + return 1; if (unlikely(writeaccess && !pte_write(entry))) - goto out; + return 1; if (writeaccess) entry = pte_mkdirty(entry); entry = pte_mkyoung(entry); + set_pte(pte, entry); + #if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP) /* - * ITLB is not affected by "ldtlb" instruction. - * So, we need to flush the entry by ourselves. + * SH-4 does not set MMUCR.RC to the corresponding TLB entry in + * the case of an initial page write exception, so we need to + * flush it in order to avoid potential TLB entry duplication. */ - local_flush_tlb_one(get_asid(), address & PAGE_MASK); + if (writeaccess == 2) + local_flush_tlb_one(get_asid(), address & PAGE_MASK); #endif - set_pte(pte, entry); update_mmu_cache(NULL, address, entry); - ret = 0; -out: - return ret; + return 0; } |