diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/uprobes.c | 213 | ||||
| -rw-r--r-- | kernel/sched/core.c | 2 |
2 files changed, 98 insertions, 117 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f93532748bca..c08a22d02f72 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -32,6 +32,7 @@ #include <linux/swap.h> /* try_to_free_swap */ #include <linux/ptrace.h> /* user_enable_single_step */ #include <linux/kdebug.h> /* notifier mechanism */ +#include "../../mm/internal.h" /* munlock_vma_page */ #include <linux/uprobes.h> @@ -112,14 +113,14 @@ static bool valid_vma(struct vm_area_struct *vma, bool is_register) return false; } -static loff_t vma_address(struct vm_area_struct *vma, loff_t offset) +static unsigned long offset_to_vaddr(struct vm_area_struct *vma, loff_t offset) { - loff_t vaddr; - - vaddr = vma->vm_start + offset; - vaddr -= vma->vm_pgoff << PAGE_SHIFT; + return vma->vm_start + offset - ((loff_t)vma->vm_pgoff << PAGE_SHIFT); +} - return vaddr; +static loff_t vaddr_to_offset(struct vm_area_struct *vma, unsigned long vaddr) +{ + return ((loff_t)vma->vm_pgoff << PAGE_SHIFT) + (vaddr - vma->vm_start); } /** @@ -127,25 +128,27 @@ static loff_t vma_address(struct vm_area_struct *vma, loff_t offset) * based on replace_page in mm/ksm.c * * @vma: vma that holds the pte pointing to page + * @addr: address the old @page is mapped at * @page: the cowed page we are replacing by kpage * @kpage: the modified page we replace page by * * Returns 0 on success, -EFAULT on failure. */ -static int __replace_page(struct vm_area_struct *vma, struct page *page, struct page *kpage) +static int __replace_page(struct vm_area_struct *vma, unsigned long addr, + struct page *page, struct page *kpage) { struct mm_struct *mm = vma->vm_mm; - unsigned long addr; spinlock_t *ptl; pte_t *ptep; + int err; - addr = page_address_in_vma(page, vma); - if (addr == -EFAULT) - return -EFAULT; + /* For try_to_free_swap() and munlock_vma_page() below */ + lock_page(page); + err = -EAGAIN; ptep = page_check_address(page, mm, addr, &ptl, 0); if (!ptep) - return -EAGAIN; + goto unlock; get_page(kpage); page_add_new_anon_rmap(kpage, vma, addr); @@ -162,10 +165,16 @@ static int __replace_page(struct vm_area_struct *vma, struct page *page, struct page_remove_rmap(page); if (!page_mapped(page)) try_to_free_swap(page); - put_page(page); pte_unmap_unlock(ptep, ptl); - return 0; + if (vma->vm_flags & VM_LOCKED) + munlock_vma_page(page); + put_page(page); + + err = 0; + unlock: + unlock_page(page); + return err; } /** @@ -206,45 +215,23 @@ static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr, uprobe_opcode_t opcode) { struct page *old_page, *new_page; - struct address_space *mapping; void *vaddr_old, *vaddr_new; struct vm_area_struct *vma; - struct uprobe *uprobe; int ret; + retry: /* Read the page with vaddr into memory */ ret = get_user_pages(NULL, mm, vaddr, 1, 0, 0, &old_page, &vma); if (ret <= 0) return ret; - ret = -EINVAL; - - /* - * We are interested in text pages only. Our pages of interest - * should be mapped for read and execute only. We desist from - * adding probes in write mapped pages since the breakpoints - * might end up in the file copy. - */ - if (!valid_vma(vma, is_swbp_insn(&opcode))) - goto put_out; - - uprobe = container_of(auprobe, struct uprobe, arch); - mapping = uprobe->inode->i_mapping; - if (mapping != vma->vm_file->f_mapping) - goto put_out; - ret = -ENOMEM; new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr); if (!new_page) - goto put_out; + goto put_old; __SetPageUptodate(new_page); - /* - * lock page will serialize against do_wp_page()'s - * PageAnon() handling - */ - lock_page(old_page); /* copy the page now that we've got it stable */ vaddr_old = kmap_atomic(old_page); vaddr_new = kmap_atomic(new_page); @@ -257,17 +244,13 @@ retry: ret = anon_vma_prepare(vma); if (ret) - goto unlock_out; + goto put_new; - lock_page(new_page); - ret = __replace_page(vma, old_page, new_page); - unlock_page(new_page); + ret = __replace_page(vma, vaddr, old_page, new_page); -unlock_out: - unlock_page(old_page); +put_new: page_cache_release(new_page); - -put_out: +put_old: put_page(old_page); if (unlikely(ret == -EAGAIN)) @@ -791,7 +774,7 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register) curr = info; info->mm = vma->vm_mm; - info->vaddr = vma_address(vma, offset); + info->vaddr = offset_to_vaddr(vma, offset); } mutex_unlock(&mapping->i_mmap_mutex); @@ -839,12 +822,13 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) goto free; down_write(&mm->mmap_sem); - vma = find_vma(mm, (unsigned long)info->vaddr); - if (!vma || !valid_vma(vma, is_register)) + vma = find_vma(mm, info->vaddr); + if (!vma || !valid_vma(vma, is_register) || + vma->vm_file->f_mapping->host != uprobe->inode) goto unlock; - if (vma->vm_file->f_mapping->host != uprobe->inode || - vma_address(vma, uprobe->offset) != info->vaddr) + if (vma->vm_start > info->vaddr || + vaddr_to_offset(vma, info->vaddr) != uprobe->offset) goto unlock; if (is_register) { @@ -960,59 +944,66 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume put_uprobe(uprobe); } -/* - * Of all the nodes that correspond to the given inode, return the node - * with the least offset. - */ -static struct rb_node *find_least_offset_node(struct inode *inode) +static struct rb_node * +find_node_in_range(struct inode *inode, loff_t min, loff_t max) { - struct uprobe u = { .inode = inode, .offset = 0}; struct rb_node *n = uprobes_tree.rb_node; - struct rb_node *close_node = NULL; - struct uprobe *uprobe; - int match; while (n) { - uprobe = rb_entry(n, struct uprobe, rb_node); - match = match_uprobe(&u, uprobe); - - if (uprobe->inode == inode) - close_node = n; - - if (!match) - return close_node; + struct uprobe *u = rb_entry(n, struct uprobe, rb_node); - if (match < 0) + if (inode < u->inode) { n = n->rb_left; - else + } else if (inode > u->inode) { n = n->rb_right; + } else { + if (max < u->offset) + n = n->rb_left; + else if (min > u->offset) + n = n->rb_right; + else + break; + } } - return close_node; + return n; } /* - * For a given inode, build a list of probes that need to be inserted. + * For a given range in vma, build a list of probes that need to be inserted. */ -static void build_probe_list(struct inode *inode, struct list_head *head) +static void build_probe_list(struct inode *inode, + struct vm_area_struct *vma, + unsigned long start, unsigned long end, + struct list_head *head) { - struct uprobe *uprobe; + loff_t min, max; unsigned long flags; - struct rb_node *n; - - spin_lock_irqsave(&uprobes_treelock, flags); - - n = find_least_offset_node(inode); + struct rb_node *n, *t; + struct uprobe *u; - for (; n; n = rb_next(n)) { - uprobe = rb_entry(n, struct uprobe, rb_node); - if (uprobe->inode != inode) - break; + INIT_LIST_HEAD(head); + min = vaddr_to_offset(vma, start); + max = min + (end - start) - 1; - list_add(&uprobe->pending_list, head); - atomic_inc(&uprobe->ref); + spin_lock_irqsave(&uprobes_treelock, flags); + n = find_node_in_range(inode, min, max); + if (n) { + for (t = n; t; t = rb_prev(t)) { + u = rb_entry(t, struct uprobe, rb_node); + if (u->inode != inode || u->offset < min) + break; + list_add(&u->pending_list, head); + atomic_inc(&u->ref); + } + for (t = n; (t = rb_next(t)); ) { + u = rb_entry(t, struct uprobe, rb_node); + if (u->inode != inode || u->offset > max) + break; + list_add(&u->pending_list, head); + atomic_inc(&u->ref); + } } - spin_unlock_irqrestore(&uprobes_treelock, flags); } @@ -1031,7 +1022,7 @@ static void build_probe_list(struct inode *inode, struct list_head *head) int uprobe_mmap(struct vm_area_struct *vma) { struct list_head tmp_list; - struct uprobe *uprobe; + struct uprobe *uprobe, *u; struct inode *inode; int ret, count; @@ -1042,21 +1033,15 @@ int uprobe_mmap(struct vm_area_struct *vma) if (!inode) return 0; - INIT_LIST_HEAD(&tmp_list); mutex_lock(uprobes_mmap_hash(inode)); - build_probe_list(inode, &tmp_list); + build_probe_list(inode, vma, vma->vm_start, vma->vm_end, &tmp_list); ret = 0; count = 0; - list_for_each_entry(uprobe, &tmp_list, pending_list) { + list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) { if (!ret) { - loff_t vaddr = vma_address(vma, uprobe->offset); - - if (vaddr < vma->vm_start || vaddr >= vma->vm_end) { - put_uprobe(uprobe); - continue; - } + unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset); ret = install_breakpoint(uprobe, vma->vm_mm, vma, vaddr); /* @@ -1097,12 +1082,15 @@ int uprobe_mmap(struct vm_area_struct *vma) void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned long end) { struct list_head tmp_list; - struct uprobe *uprobe; + struct uprobe *uprobe, *u; struct inode *inode; if (!atomic_read(&uprobe_events) || !valid_vma(vma, false)) return; + if (!atomic_read(&vma->vm_mm->mm_users)) /* called by mmput() ? */ + return; + if (!atomic_read(&vma->vm_mm->uprobes_state.count)) return; @@ -1110,21 +1098,17 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon if (!inode) return; - INIT_LIST_HEAD(&tmp_list); mutex_lock(uprobes_mmap_hash(inode)); - build_probe_list(inode, &tmp_list); - - list_for_each_entry(uprobe, &tmp_list, pending_list) { - loff_t vaddr = vma_address(vma, uprobe->offset); - - if (vaddr >= start && vaddr < end) { - /* - * An unregister could have removed the probe before - * unmap. So check before we decrement the count. - */ - if (is_swbp_at_addr(vma->vm_mm, vaddr) == 1) - atomic_dec(&vma->vm_mm->uprobes_state.count); - } + build_probe_list(inode, vma, start, end, &tmp_list); + + list_for_each_entry_safe(uprobe, u, &tmp_list, pending_list) { + unsigned long vaddr = offset_to_vaddr(vma, uprobe->offset); + /* + * An unregister could have removed the probe before + * unmap. So check before we decrement the count. + */ + if (is_swbp_at_addr(vma->vm_mm, vaddr) == 1) + atomic_dec(&vma->vm_mm->uprobes_state.count); put_uprobe(uprobe); } mutex_unlock(uprobes_mmap_hash(inode)); @@ -1463,12 +1447,9 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp) vma = find_vma(mm, bp_vaddr); if (vma && vma->vm_start <= bp_vaddr) { if (valid_vma(vma, false)) { - struct inode *inode; - loff_t offset; + struct inode *inode = vma->vm_file->f_mapping->host; + loff_t offset = vaddr_to_offset(vma, bp_vaddr); - inode = vma->vm_file->f_mapping->host; - offset = bp_vaddr - vma->vm_start; - offset += (vma->vm_pgoff << PAGE_SHIFT); uprobe = find_uprobe(inode, offset); } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5d011ef4c0df..d325c4b2dcbb 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1910,12 +1910,12 @@ static inline void prepare_task_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) { + trace_sched_switch(prev, next); sched_info_switch(prev, next); perf_event_task_sched_out(prev, next); fire_sched_out_preempt_notifiers(prev, next); prepare_lock_switch(rq, next); prepare_arch_switch(next); - trace_sched_switch(prev, next); } /** |