Hi Jens,
After merging the block tree, today's linux-next build (powerpc
allnoconfig) failed like this:
fs/fcntl.o: In function `do_fcntl':
fcntl.c:(.text+0x6d4): undefined reference to `__get_user_bad'
fcntl.c:(.text+0x730): undefined reference to `__get_user_bad'
Probably caused by commit
c75b1d9421f8 ("fs: add fcntl() interface for setting/getting write life time hints")
On powerpc (at least) you cannot use get_user() to fetch anything larger
than "unsigned long" i.e. 32 bits on 32 bit powerpc.
This has been discussed before (and, I think, a fix attempted).
For now I have applied the following patch:
From: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Date: Wed, 28 Jun 2017 17:50:31 +1000
Subject: [PATCH] fs: don't read an enum directly from a u64 __user *
Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
---
fs/fcntl.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index 24e233c75a33..19825eb7c40d 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -277,6 +277,7 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
{
struct inode *inode = file_inode(file);
u64 *argp = (u64 __user *)arg;
+ u64 h;
enum rw_hint hint;
switch (cmd) {
@@ -285,8 +286,9 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
return -EFAULT;
return 0;
case F_SET_FILE_RW_HINT:
- if (get_user(hint, argp))
+ if (copy_from_user(&h, argp, sizeof(h)))
return -EFAULT;
+ hint = (enum rw_hint)h;
if (!rw_hint_valid(hint))
return -EINVAL;
@@ -299,8 +301,9 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd,
return -EFAULT;
return 0;
case F_SET_RW_HINT:
- if (get_user(hint, argp))
+ if (copy_from_user(&h, argp, sizeof(h)))
return -EFAULT;
+ hint = (enum rw_hint)h;
if (!rw_hint_valid(hint))
return -EINVAL;
--
2.11.0
--
Cheers,
Stephen Rothwell
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