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Diffstat (limited to 'kernel/events/uprobes.c')
-rw-r--r--kernel/events/uprobes.c48
1 files changed, 25 insertions, 23 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index ece7e13f6e4a..bb0862873dba 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -162,14 +162,12 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
};
int err;
struct mmu_notifier_range range;
- struct mem_cgroup *memcg;
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, addr,
addr + PAGE_SIZE);
if (new_page) {
- err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL,
- &memcg, false);
+ err = mem_cgroup_charge(new_page, vma->vm_mm, GFP_KERNEL);
if (err)
return err;
}
@@ -179,17 +177,13 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
mmu_notifier_invalidate_range_start(&range);
err = -EAGAIN;
- if (!page_vma_mapped_walk(&pvmw)) {
- if (new_page)
- mem_cgroup_cancel_charge(new_page, memcg, false);
+ if (!page_vma_mapped_walk(&pvmw))
goto unlock;
- }
VM_BUG_ON_PAGE(addr != pvmw.address, old_page);
if (new_page) {
get_page(new_page);
page_add_new_anon_rmap(new_page, vma, addr, false);
- mem_cgroup_commit_charge(new_page, memcg, false, false);
lru_cache_add_active_or_unevictable(new_page, vma);
} else
/* no new page, just dec_mm_counter for old_page */
@@ -463,7 +457,7 @@ static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm,
* @vaddr: the virtual address to store the opcode.
* @opcode: opcode to be written at @vaddr.
*
- * Called with mm->mmap_sem held for write.
+ * Called with mm->mmap_lock held for write.
* Return 0 (success) or a negative errno.
*/
int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
@@ -867,10 +861,6 @@ static int prepare_uprobe(struct uprobe *uprobe, struct file *file,
if (ret)
goto out;
- /* uprobe_write_opcode() assumes we don't cross page boundary */
- BUG_ON((uprobe->offset & ~PAGE_MASK) +
- UPROBE_SWBP_INSN_SIZE > PAGE_SIZE);
-
smp_wmb(); /* pairs with the smp_rmb() in handle_swbp() */
set_bit(UPROBE_COPY_INSN, &uprobe->flags);
@@ -1064,7 +1054,7 @@ register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new)
if (err && is_register)
goto free;
- down_write(&mm->mmap_sem);
+ mmap_write_lock(mm);
vma = find_vma(mm, info->vaddr);
if (!vma || !valid_vma(vma, is_register) ||
file_inode(vma->vm_file) != uprobe->inode)
@@ -1086,7 +1076,7 @@ register_for_each_vma(struct uprobe *uprobe, struct uprobe_consumer *new)
}
unlock:
- up_write(&mm->mmap_sem);
+ mmap_write_unlock(mm);
free:
mmput(mm);
info = free_map_info(info);
@@ -1166,6 +1156,15 @@ static int __uprobe_register(struct inode *inode, loff_t offset,
if (offset > i_size_read(inode))
return -EINVAL;
+ /*
+ * This ensures that copy_from_page(), copy_to_page() and
+ * __update_ref_ctr() can't cross page boundary.
+ */
+ if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE))
+ return -EINVAL;
+ if (!IS_ALIGNED(ref_ctr_offset, sizeof(short)))
+ return -EINVAL;
+
retry:
uprobe = alloc_uprobe(inode, offset, ref_ctr_offset);
if (!uprobe)
@@ -1241,7 +1240,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
struct vm_area_struct *vma;
int err = 0;
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
unsigned long vaddr;
loff_t offset;
@@ -1258,7 +1257,7 @@ static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
vaddr = offset_to_vaddr(vma, uprobe->offset);
err |= remove_breakpoint(uprobe, mm, vaddr);
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
return err;
}
@@ -1355,7 +1354,7 @@ static int delayed_ref_ctr_inc(struct vm_area_struct *vma)
}
/*
- * Called from mmap_region/vma_adjust with mm->mmap_sem acquired.
+ * Called from mmap_region/vma_adjust with mm->mmap_lock acquired.
*
* Currently we ignore all errors and always return 0, the callers
* can't handle the failure anyway.
@@ -1445,7 +1444,7 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area)
struct vm_area_struct *vma;
int ret;
- if (down_write_killable(&mm->mmap_sem))
+ if (mmap_write_lock_killable(mm))
return -EINTR;
if (mm->uprobes_state.xol_area) {
@@ -1475,7 +1474,7 @@ static int xol_add_vma(struct mm_struct *mm, struct xol_area *area)
/* pairs with get_xol_area() */
smp_store_release(&mm->uprobes_state.xol_area, area); /* ^^^ */
fail:
- up_write(&mm->mmap_sem);
+ mmap_write_unlock(mm);
return ret;
}
@@ -1674,7 +1673,7 @@ void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
copy_to_page(page, vaddr, src, len);
/*
- * We probably need flush_icache_user_range() but it needs vma.
+ * We probably need flush_icache_user_page() but it needs vma.
* This should work on most of architectures by default. If
* architecture needs to do something different it can define
* its own version of the function.
@@ -2014,6 +2013,9 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
uprobe_opcode_t opcode;
int result;
+ if (WARN_ON_ONCE(!IS_ALIGNED(vaddr, UPROBE_SWBP_INSN_SIZE)))
+ return -EINVAL;
+
pagefault_disable();
result = __get_user(opcode, (uprobe_opcode_t __user *)vaddr);
pagefault_enable();
@@ -2045,7 +2047,7 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
struct uprobe *uprobe = NULL;
struct vm_area_struct *vma;
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
vma = find_vma(mm, bp_vaddr);
if (vma && vma->vm_start <= bp_vaddr) {
if (valid_vma(vma, false)) {
@@ -2063,7 +2065,7 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
if (!uprobe && test_and_clear_bit(MMF_RECALC_UPROBES, &mm->flags))
mmf_recalc_uprobes(mm);
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
return uprobe;
}