diff options
| author | Marcelo Tosatti <marcelo@kvack.org> | 2008-03-13 12:32:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-03-13 13:11:43 -0700 |
| commit | fb39380b8d683b55630ba5ba381f4e43e417420e (patch) | |
| tree | 4fa4386d054b2af1b66651f8cc3d87eeb48ebf73 /fs/proc/task_mmu.c | |
| parent | b500ce8d24d1f14426643da5f6fada28c1f60533 (diff) | |
| download | lwn-fb39380b8d683b55630ba5ba381f4e43e417420e.tar.gz lwn-fb39380b8d683b55630ba5ba381f4e43e417420e.zip | |
pagemap: proper read error handling
Fix pagemap_read() error handling by releasing acquired resources and checking
for get_user_pages() partial failure.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/task_mmu.c')
| -rw-r--r-- | fs/proc/task_mmu.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 6dc0334815f7..4206454734e0 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -640,17 +640,17 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, ret = -EACCES; if (!ptrace_may_attach(task)) - goto out; + goto out_task; ret = -EINVAL; /* file position must be aligned */ if (*ppos % PM_ENTRY_BYTES) - goto out; + goto out_task; ret = 0; mm = get_task_mm(task); if (!mm) - goto out; + goto out_task; ret = -ENOMEM; uaddr = (unsigned long)buf & PAGE_MASK; @@ -658,7 +658,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, pagecount = (PAGE_ALIGN(uend) - uaddr) / PAGE_SIZE; pages = kmalloc(pagecount * sizeof(struct page *), GFP_KERNEL); if (!pages) - goto out_task; + goto out_mm; down_read(¤t->mm->mmap_sem); ret = get_user_pages(current, current->mm, uaddr, pagecount, @@ -668,6 +668,12 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, if (ret < 0) goto out_free; + if (ret != pagecount) { + pagecount = ret; + ret = -EFAULT; + goto out_pages; + } + pm.out = buf; pm.end = buf + count; @@ -699,15 +705,17 @@ static ssize_t pagemap_read(struct file *file, char __user *buf, ret = pm.out - buf; } +out_pages: for (; pagecount; pagecount--) { page = pages[pagecount-1]; if (!PageReserved(page)) SetPageDirty(page); page_cache_release(page); } - mmput(mm); out_free: kfree(pages); +out_mm: + mmput(mm); out_task: put_task_struct(task); out: |