The patch titled
check ADVICE of fadvise64_64 even if get_xip_page is given
has been removed from the -mm tree. Its filename was
check-advice-of-fadvice64_64-even-if-get_xip_page-is-given.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: check ADVICE of fadvise64_64 even if get_xip_page is given
From: Masatake YAMATO <yamato@xxxxxxxxxx>
I've written some test programs in ltp project. During writing I met an
problem which I cannot solve in user land. So I wrote a patch for linux
kernel. Please, include this patch if acceptable.
The test program tests the 4th parameter of fadvise64_64:
long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice);
My test case calls fadvise64_64 with invalid advice value and checks errno is
set to EINVAL. About the advice parameter man page says:
...
Permissible values for advice include:
POSIX_FADV_NORMAL
...
POSIX_FADV_SEQUENTIAL
...
POSIX_FADV_RANDOM
...
POSIX_FADV_NOREUSE
...
POSIX_FADV_WILLNEED
...
POSIX_FADV_DONTNEED
...
ERRORS
...
EINVAL An invalid value was specified for advice.
However, I got a bug report that the system call invocations
in my test case returned 0 unexpectedly.
I've inspected the kernel code:
asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice)
{
struct file *file = fget(fd);
struct address_space *mapping;
struct backing_dev_info *bdi;
loff_t endbyte; /* inclusive */
pgoff_t start_index;
pgoff_t end_index;
unsigned long nrpages;
int ret = 0;
if (!file)
return -EBADF;
if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
ret = -ESPIPE;
goto out;
}
mapping = file->f_mapping;
if (!mapping || len < 0) {
ret = -EINVAL;
goto out;
}
if (mapping->a_ops->get_xip_page)
/* no bad return value, but ignore advice */
goto out;
...
out:
fput(file);
return ret;
}
I found the advice parameter is just ignored in the case
mapping->a_ops->get_xip_page is given. This behavior is different from
what is written on the man page. Is this o.k.?
get_xip_page is given if CONFIG_EXT2_FS_XIP is true.
Anyway I cannot find the easy way to detect get_xip_page
field is given or CONFIG_EXT2_FS_XIP is true from the
user space.
I propose the following patch which checks the advice parameter
even if get_xip_page is given.
Signed-off-by: Masatake YAMATO <yamato@xxxxxxxxxx>
Acked-by: Carsten Otte <cotte@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/fadvise.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff -puN mm/fadvise.c~check-advice-of-fadvice64_64-even-if-get_xip_page-is-given mm/fadvise.c
--- a/mm/fadvise.c~check-advice-of-fadvice64_64-even-if-get_xip_page-is-given
+++ a/mm/fadvise.c
@@ -49,9 +49,21 @@ asmlinkage long sys_fadvise64_64(int fd,
goto out;
}
- if (mapping->a_ops->get_xip_page)
- /* no bad return value, but ignore advice */
+ if (mapping->a_ops->get_xip_page) {
+ switch (advice) {
+ case POSIX_FADV_NORMAL:
+ case POSIX_FADV_RANDOM:
+ case POSIX_FADV_SEQUENTIAL:
+ case POSIX_FADV_WILLNEED:
+ case POSIX_FADV_NOREUSE:
+ case POSIX_FADV_DONTNEED:
+ /* no bad return value, but ignore advice */
+ break;
+ default:
+ ret = -EINVAL;
+ }
goto out;
+ }
/* Careful about overflows. Len == 0 means "as much as possible" */
endbyte = offset + len;
_
Patches currently in -mm which might be from yamato@xxxxxxxxxx are
origin.patch
-
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