From 5b34666bd2e70046f9880db01119c7d908e0888d Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Fri, 17 Mar 2017 00:48:27 +0000 Subject: [PATCH] powerpc/iommu: Stop using @current in mm_iommu_xxx [ Upstream commit d7baee6901b34c4895eb78efdbf13a49079d7404 ] This changes mm_iommu_xxx helpers to take mm_struct as a parameter instead of getting it from @current which in some situations may not have a valid reference to mm. This changes helpers to receive @mm and moves all references to @current to the caller, including checks for !current and !current->mm; checks in mm_iommu_preregistered() are removed as there is no caller yet. This moves the mm_iommu_adjust_locked_vm() call to the caller as it receives mm_iommu_table_group_mem_t but it needs mm. This should cause no behavioral change. Signed-off-by: Alexey Kardashevskiy Reviewed-by: David Gibson Acked-by: Alex Williamson Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/mmu_context.h | 16 ++++++------ arch/powerpc/mm/mmu_context_iommu.c | 46 +++++++++++++--------------------- drivers/vfio/vfio_iommu_spapr_tce.c | 14 ++++++++--- 3 files changed, 36 insertions(+), 40 deletions(-) diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 424844b..b9e3f0a 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -19,16 +19,18 @@ extern void destroy_context(struct mm_struct *mm); struct mm_iommu_table_group_mem_t; extern int isolate_lru_page(struct page *page); /* from internal.h */ -extern bool mm_iommu_preregistered(void); -extern long mm_iommu_get(unsigned long ua, unsigned long entries, +extern bool mm_iommu_preregistered(struct mm_struct *mm); +extern long mm_iommu_get(struct mm_struct *mm, + unsigned long ua, unsigned long entries, struct mm_iommu_table_group_mem_t **pmem); -extern long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem); +extern long mm_iommu_put(struct mm_struct *mm, + struct mm_iommu_table_group_mem_t *mem); extern void mm_iommu_init(struct mm_struct *mm); extern void mm_iommu_cleanup(struct mm_struct *mm); -extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua, - unsigned long size); -extern struct mm_iommu_table_group_mem_t *mm_iommu_find(unsigned long ua, - unsigned long entries); +extern struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm, + unsigned long ua, unsigned long size); +extern struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm, + unsigned long ua, unsigned long entries); extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem, unsigned long ua, unsigned long *hpa); extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem); diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index ad2e575..4c6db09 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -56,7 +56,7 @@ static long mm_iommu_adjust_locked_vm(struct mm_struct *mm, } pr_debug("[%d] RLIMIT_MEMLOCK HASH64 %c%ld %ld/%ld\n", - current->pid, + current ? current->pid : 0, incr ? '+' : '-', npages << PAGE_SHIFT, mm->locked_vm << PAGE_SHIFT, @@ -66,12 +66,9 @@ static long mm_iommu_adjust_locked_vm(struct mm_struct *mm, return ret; } -bool mm_iommu_preregistered(void) +bool mm_iommu_preregistered(struct mm_struct *mm) { - if (!current || !current->mm) - return false; - - return !list_empty(¤t->mm->context.iommu_group_mem_list); + return !list_empty(&mm->context.iommu_group_mem_list); } EXPORT_SYMBOL_GPL(mm_iommu_preregistered); @@ -124,19 +121,16 @@ static int mm_iommu_move_page_from_cma(struct page *page) return 0; } -long mm_iommu_get(unsigned long ua, unsigned long entries, +long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries, struct mm_iommu_table_group_mem_t **pmem) { struct mm_iommu_table_group_mem_t *mem; long i, j, ret = 0, locked_entries = 0; struct page *page = NULL; - if (!current || !current->mm) - return -ESRCH; /* process exited */ - mutex_lock(&mem_list_mutex); - list_for_each_entry_rcu(mem, ¤t->mm->context.iommu_group_mem_list, + list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) { if ((mem->ua == ua) && (mem->entries == entries)) { ++mem->used; @@ -154,7 +148,7 @@ long mm_iommu_get(unsigned long ua, unsigned long entries, } - ret = mm_iommu_adjust_locked_vm(current->mm, entries, true); + ret = mm_iommu_adjust_locked_vm(mm, entries, true); if (ret) goto unlock_exit; @@ -215,11 +209,11 @@ populate: mem->entries = entries; *pmem = mem; - list_add_rcu(&mem->next, ¤t->mm->context.iommu_group_mem_list); + list_add_rcu(&mem->next, &mm->context.iommu_group_mem_list); unlock_exit: if (locked_entries && ret) - mm_iommu_adjust_locked_vm(current->mm, locked_entries, false); + mm_iommu_adjust_locked_vm(mm, locked_entries, false); mutex_unlock(&mem_list_mutex); @@ -264,17 +258,13 @@ static void mm_iommu_free(struct rcu_head *head) static void mm_iommu_release(struct mm_iommu_table_group_mem_t *mem) { list_del_rcu(&mem->next); - mm_iommu_adjust_locked_vm(current->mm, mem->entries, false); call_rcu(&mem->rcu, mm_iommu_free); } -long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem) +long mm_iommu_put(struct mm_struct *mm, struct mm_iommu_table_group_mem_t *mem) { long ret = 0; - if (!current || !current->mm) - return -ESRCH; /* process exited */ - mutex_lock(&mem_list_mutex); if (mem->used == 0) { @@ -297,6 +287,8 @@ long mm_iommu_put(struct mm_iommu_table_group_mem_t *mem) /* @mapped became 0 so now mappings are disabled, release the region */ mm_iommu_release(mem); + mm_iommu_adjust_locked_vm(mm, mem->entries, false); + unlock_exit: mutex_unlock(&mem_list_mutex); @@ -304,14 +296,12 @@ unlock_exit: } EXPORT_SYMBOL_GPL(mm_iommu_put); -struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua, - unsigned long size) +struct mm_iommu_table_group_mem_t *mm_iommu_lookup(struct mm_struct *mm, + unsigned long ua, unsigned long size) { struct mm_iommu_table_group_mem_t *mem, *ret = NULL; - list_for_each_entry_rcu(mem, - ¤t->mm->context.iommu_group_mem_list, - next) { + list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) { if ((mem->ua <= ua) && (ua + size <= mem->ua + (mem->entries << PAGE_SHIFT))) { @@ -324,14 +314,12 @@ struct mm_iommu_table_group_mem_t *mm_iommu_lookup(unsigned long ua, } EXPORT_SYMBOL_GPL(mm_iommu_lookup); -struct mm_iommu_table_group_mem_t *mm_iommu_find(unsigned long ua, - unsigned long entries) +struct mm_iommu_table_group_mem_t *mm_iommu_find(struct mm_struct *mm, + unsigned long ua, unsigned long entries) { struct mm_iommu_table_group_mem_t *mem, *ret = NULL; - list_for_each_entry_rcu(mem, - ¤t->mm->context.iommu_group_mem_list, - next) { + list_for_each_entry_rcu(mem, &mm->context.iommu_group_mem_list, next) { if ((mem->ua == ua) && (mem->entries == entries)) { ret = mem; break; diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c index 2a6e138..4efd2b2 100644 --- a/drivers/vfio/vfio_iommu_spapr_tce.c +++ b/drivers/vfio/vfio_iommu_spapr_tce.c @@ -107,14 +107,17 @@ static long tce_iommu_unregister_pages(struct tce_container *container, { struct mm_iommu_table_group_mem_t *mem; + if (!current || !current->mm) + return -ESRCH; /* process exited */ + if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK)) return -EINVAL; - mem = mm_iommu_find(vaddr, size >> PAGE_SHIFT); + mem = mm_iommu_find(current->mm, vaddr, size >> PAGE_SHIFT); if (!mem) return -ENOENT; - return mm_iommu_put(mem); + return mm_iommu_put(current->mm, mem); } static long tce_iommu_register_pages(struct tce_container *container, @@ -124,11 +127,14 @@ static long tce_iommu_register_pages(struct tce_container *container, struct mm_iommu_table_group_mem_t *mem = NULL; unsigned long entries = size >> PAGE_SHIFT; + if (!current || !current->mm) + return -ESRCH; /* process exited */ + if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) || ((vaddr + size) < vaddr)) return -EINVAL; - ret = mm_iommu_get(vaddr, entries, &mem); + ret = mm_iommu_get(current->mm, vaddr, entries, &mem); if (ret) return ret; @@ -375,7 +381,7 @@ static int tce_iommu_prereg_ua_to_hpa(unsigned long tce, unsigned long size, long ret = 0; struct mm_iommu_table_group_mem_t *mem; - mem = mm_iommu_lookup(tce, size); + mem = mm_iommu_lookup(current->mm, tce, size); if (!mem) return -EINVAL; -- 2.7.4