diff --git a/arch/frv/kernel/futex.c b/arch/frv/kernel/futex.c index eae874a970c6..53dc5ed1ebda 100644 --- a/arch/frv/kernel/futex.c +++ b/arch/frv/kernel/futex.c @@ -200,7 +200,7 @@ int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -223,7 +223,7 @@ int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) break; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c index f9f647cdbc7b..178bbfe6cbac 100644 --- a/arch/i386/mm/highmem.c +++ b/arch/i386/mm/highmem.c @@ -32,7 +32,7 @@ void *kmap_atomic(struct page *page, enum km_type type) unsigned long vaddr; /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ - inc_preempt_count(); + pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -52,8 +52,7 @@ void kunmap_atomic(void *kvaddr, enum km_type type) #ifdef CONFIG_DEBUG_HIGHMEM if (vaddr >= PAGE_OFFSET && vaddr < (unsigned long)high_memory) { - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); return; } @@ -68,8 +67,7 @@ void kunmap_atomic(void *kvaddr, enum km_type type) */ kpte_clear_flush(kmap_pte-idx, vaddr); - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } /* This is the same as kmap_atomic() but can map memory that doesn't @@ -80,7 +78,7 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) enum fixed_addresses idx; unsigned long vaddr; - inc_preempt_count(); + pagefault_disable(); idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c index 99ebf3ccc222..675502ada5a2 100644 --- a/arch/mips/mm/highmem.c +++ b/arch/mips/mm/highmem.c @@ -39,7 +39,7 @@ void *__kmap_atomic(struct page *page, enum km_type type) unsigned long vaddr; /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ - inc_preempt_count(); + pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -62,8 +62,7 @@ void __kunmap_atomic(void *kvaddr, enum km_type type) enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); if (vaddr < FIXADDR_START) { // FIXME - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); return; } @@ -78,8 +77,7 @@ void __kunmap_atomic(void *kvaddr, enum km_type type) local_flush_tlb_one(vaddr); #endif - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } #ifndef CONFIG_LIMITED_DMA @@ -92,7 +90,7 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) enum fixed_addresses idx; unsigned long vaddr; - inc_preempt_count(); + pagefault_disable(); idx = type + KM_TYPE_NR*smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c index 2d549ed2e113..bbaca66fa293 100644 --- a/arch/s390/lib/uaccess_std.c +++ b/arch/s390/lib/uaccess_std.c @@ -11,7 +11,7 @@ #include #include -#include +#include #include #ifndef __s390x__ @@ -258,7 +258,7 @@ int futex_atomic_op(int op, int __user *uaddr, int oparg, int *old) { int oldval = 0, newval, ret; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -284,7 +284,7 @@ int futex_atomic_op(int op, int __user *uaddr, int oparg, int *old) default: ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); *old = oldval; return ret; } diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c index 4d8ed9c65182..01fc6c254292 100644 --- a/arch/sparc/mm/highmem.c +++ b/arch/sparc/mm/highmem.c @@ -35,7 +35,7 @@ void *kmap_atomic(struct page *page, enum km_type type) unsigned long vaddr; /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ - inc_preempt_count(); + pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -70,8 +70,7 @@ void kunmap_atomic(void *kvaddr, enum km_type type) unsigned long idx = type + KM_TYPE_NR*smp_processor_id(); if (vaddr < FIXADDR_START) { // FIXME - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); return; } @@ -97,8 +96,7 @@ void kunmap_atomic(void *kvaddr, enum km_type type) #endif #endif - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } /* We may be fed a pagetable here by ptep_to_xxx and others. */ diff --git a/include/asm-frv/highmem.h b/include/asm-frv/highmem.h index 0f390f41f816..ff4d6cdeb152 100644 --- a/include/asm-frv/highmem.h +++ b/include/asm-frv/highmem.h @@ -115,7 +115,7 @@ static inline void *kmap_atomic(struct page *page, enum km_type type) { unsigned long paddr; - inc_preempt_count(); + pagefault_disable(); paddr = page_to_phys(page); switch (type) { @@ -170,8 +170,7 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type type) default: BUG(); } - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } #endif /* !__ASSEMBLY__ */ diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h index df893c160318..f422df0956a2 100644 --- a/include/asm-generic/futex.h +++ b/include/asm-generic/futex.h @@ -21,7 +21,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -33,7 +33,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/asm-i386/futex.h b/include/asm-i386/futex.h index 946d97cfea23..438ef0ec7101 100644 --- a/include/asm-i386/futex.h +++ b/include/asm-i386/futex.h @@ -56,7 +56,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); if (op == FUTEX_OP_SET) __futex_atomic_op1("xchgl %0, %2", ret, oldval, uaddr, oparg); @@ -88,7 +88,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) } } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/asm-ia64/futex.h b/include/asm-ia64/futex.h index 07d77f3a8cbe..8a98a2654139 100644 --- a/include/asm-ia64/futex.h +++ b/include/asm-ia64/futex.h @@ -59,7 +59,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -83,7 +83,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/asm-mips/futex.h b/include/asm-mips/futex.h index 927a216bd530..47e5679c2353 100644 --- a/include/asm-mips/futex.h +++ b/include/asm-mips/futex.h @@ -88,7 +88,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -115,7 +115,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/asm-parisc/futex.h b/include/asm-parisc/futex.h index d84bbb283fd1..dbee6e60aa81 100644 --- a/include/asm-parisc/futex.h +++ b/include/asm-parisc/futex.h @@ -21,7 +21,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -33,7 +33,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h index 936422e54891..3f3673fd3ff3 100644 --- a/include/asm-powerpc/futex.h +++ b/include/asm-powerpc/futex.h @@ -43,7 +43,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -65,7 +65,7 @@ static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr) ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/asm-ppc/highmem.h b/include/asm-ppc/highmem.h index 1d2c4ef81c22..f7b21ee302b4 100644 --- a/include/asm-ppc/highmem.h +++ b/include/asm-ppc/highmem.h @@ -79,7 +79,7 @@ static inline void *kmap_atomic(struct page *page, enum km_type type) unsigned long vaddr; /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ - inc_preempt_count(); + pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -101,8 +101,7 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type type) unsigned int idx = type + KM_TYPE_NR*smp_processor_id(); if (vaddr < KMAP_FIX_BEGIN) { // FIXME - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); return; } @@ -115,8 +114,7 @@ static inline void kunmap_atomic(void *kvaddr, enum km_type type) pte_clear(&init_mm, vaddr, kmap_pte+idx); flush_tlb_page(NULL, vaddr); #endif - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } static inline struct page *kmap_atomic_to_page(void *ptr) diff --git a/include/asm-sparc64/futex.h b/include/asm-sparc64/futex.h index 7392fc4a954e..876312fe82cc 100644 --- a/include/asm-sparc64/futex.h +++ b/include/asm-sparc64/futex.h @@ -45,7 +45,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) oparg = 1 << oparg; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -67,7 +67,7 @@ static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr) ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/asm-x86_64/futex.h b/include/asm-x86_64/futex.h index 9804bf07b092..5cdfb08013c3 100644 --- a/include/asm-x86_64/futex.h +++ b/include/asm-x86_64/futex.h @@ -55,7 +55,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int))) return -EFAULT; - inc_preempt_count(); + pagefault_disable(); switch (op) { case FUTEX_OP_SET: @@ -78,7 +78,7 @@ futex_atomic_op_inuser (int encoded_op, int __user *uaddr) ret = -ENOSYS; } - dec_preempt_count(); + pagefault_enable(); if (!ret) { switch (cmp) { diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index a48d7f11c7be..67918c22339c 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -1,8 +1,43 @@ #ifndef __LINUX_UACCESS_H__ #define __LINUX_UACCESS_H__ +#include #include +/* + * These routines enable/disable the pagefault handler in that + * it will not take any locks and go straight to the fixup table. + * + * They have great resemblance to the preempt_disable/enable calls + * and in fact they are identical; this is because currently there is + * no other way to make the pagefault handlers do this. So we do + * disable preemption but we don't necessarily care about that. + */ +static inline void pagefault_disable(void) +{ + inc_preempt_count(); + /* + * make sure to have issued the store before a pagefault + * can hit. + */ + barrier(); +} + +static inline void pagefault_enable(void) +{ + /* + * make sure to issue those last loads/stores before enabling + * the pagefault handler again. + */ + barrier(); + dec_preempt_count(); + /* + * make sure we do.. + */ + barrier(); + preempt_check_resched(); +} + #ifndef ARCH_HAS_NOCACHE_UACCESS static inline unsigned long __copy_from_user_inatomic_nocache(void *to, @@ -35,9 +70,9 @@ static inline unsigned long __copy_from_user_nocache(void *to, ({ \ long ret; \ \ - inc_preempt_count(); \ + pagefault_disable(); \ ret = __get_user(retval, addr); \ - dec_preempt_count(); \ + pagefault_enable(); \ ret; \ }) diff --git a/kernel/futex.c b/kernel/futex.c index 93ef30ba209f..af7b81cbde30 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -282,9 +282,9 @@ static inline int get_futex_value_locked(u32 *dest, u32 __user *from) { int ret; - inc_preempt_count(); + pagefault_disable(); ret = __copy_from_user_inatomic(dest, from, sizeof(u32)); - dec_preempt_count(); + pagefault_enable(); return ret ? -EFAULT : 0; } @@ -585,9 +585,9 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) if (!(uval & FUTEX_OWNER_DIED)) { newval = FUTEX_WAITERS | new_owner->pid; - inc_preempt_count(); + pagefault_disable(); curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); - dec_preempt_count(); + pagefault_enable(); if (curval == -EFAULT) return -EFAULT; if (curval != uval) @@ -618,9 +618,9 @@ static int unlock_futex_pi(u32 __user *uaddr, u32 uval) * There is no waiter, so we unlock the futex. The owner died * bit has not to be preserved here. We are the owner: */ - inc_preempt_count(); + pagefault_disable(); oldval = futex_atomic_cmpxchg_inatomic(uaddr, uval, 0); - dec_preempt_count(); + pagefault_enable(); if (oldval == -EFAULT) return oldval; @@ -1158,9 +1158,9 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, unsigned long sec, */ newval = current->pid; - inc_preempt_count(); + pagefault_disable(); curval = futex_atomic_cmpxchg_inatomic(uaddr, 0, newval); - dec_preempt_count(); + pagefault_enable(); if (unlikely(curval == -EFAULT)) goto uaddr_faulted; @@ -1183,9 +1183,9 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, unsigned long sec, uval = curval; newval = uval | FUTEX_WAITERS; - inc_preempt_count(); + pagefault_disable(); curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); - dec_preempt_count(); + pagefault_enable(); if (unlikely(curval == -EFAULT)) goto uaddr_faulted; @@ -1215,10 +1215,10 @@ static int futex_lock_pi(u32 __user *uaddr, int detect, unsigned long sec, newval = current->pid | FUTEX_OWNER_DIED | FUTEX_WAITERS; - inc_preempt_count(); + pagefault_disable(); curval = futex_atomic_cmpxchg_inatomic(uaddr, uval, newval); - dec_preempt_count(); + pagefault_enable(); if (unlikely(curval == -EFAULT)) goto uaddr_faulted; @@ -1390,9 +1390,9 @@ static int futex_unlock_pi(u32 __user *uaddr) * anyone else up: */ if (!(uval & FUTEX_OWNER_DIED)) { - inc_preempt_count(); + pagefault_disable(); uval = futex_atomic_cmpxchg_inatomic(uaddr, current->pid, 0); - dec_preempt_count(); + pagefault_enable(); } if (unlikely(uval == -EFAULT))