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| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-06-16 11:36:47 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-06-16 11:37:50 -0400 |
| commit | 3438995bc43939ed1502bb2639ff7007169574ea (patch) | |
| tree | 079a2732cc9eacb98200914c1278aee264b89ba9 /lib/strnlen_user.c | |
| parent | 5ba12443a132420be45d089e4c4ac8a1e26b7da8 (diff) | |
| parent | 40c6ed0c8a7f2c5d67f5d6774bbce230a42176db (diff) | |
Merge tag 'nfs-rdma-for-4.2' of git://git.linux-nfs.org/projects/anna/nfs-rdma
NFS: NFSoRDMA Client Changes
These patches continue to build up for improving the rsize and wsize that the
NFS client uses when talking over RDMA. In addition, these patches also add
in scalability enhancements and other bugfixes.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
* tag 'nfs-rdma-for-4.2' of git://git.linux-nfs.org/projects/anna/nfs-rdma: (142 commits)
xprtrdma: Reduce per-transport MR allocation
xprtrdma: Stack relief in fmr_op_map()
xprtrdma: Split rb_lock
xprtrdma: Remove rpcrdma_ia::ri_memreg_strategy
xprtrdma: Remove ->ro_reset
xprtrdma: Remove unused LOCAL_INV recovery logic
xprtrdma: Acquire MRs in rpcrdma_register_external()
xprtrdma: Introduce an FRMR recovery workqueue
xprtrdma: Acquire FMRs in rpcrdma_fmr_register_external()
xprtrdma: Introduce helpers for allocating MWs
xprtrdma: Use ib_device pointer safely
xprtrdma: Remove rr_func
xprtrdma: Replace rpcrdma_rep::rr_buffer with rr_rxprt
xprtrdma: Warn when there are orphaned IB objects
...
Diffstat (limited to 'lib/strnlen_user.c')
| -rw-r--r-- | lib/strnlen_user.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index a28df5206d95..fe9a32591c24 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -57,7 +57,8 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, return res + find_zero(data) + 1 - align; } res += sizeof(unsigned long); - if (unlikely(max < sizeof(unsigned long))) + /* We already handled 'unsigned long' bytes. Did we do it all ? */ + if (unlikely(max <= sizeof(unsigned long))) break; max -= sizeof(unsigned long); if (unlikely(__get_user(c,(unsigned long __user *)(src+res)))) @@ -89,8 +90,15 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count, * Get the size of a NUL-terminated string in user space. * * Returns the size of the string INCLUDING the terminating NUL. - * If the string is too long, returns 'count+1'. + * If the string is too long, returns a number larger than @count. User + * has to check the return value against "> count". * On exception (or invalid count), returns 0. + * + * NOTE! You should basically never use this function. There is + * almost never any valid case for using the length of a user space + * string, since the string can be changed at any time by other + * threads. Use "strncpy_from_user()" instead to get a stable copy + * of the string. */ long strnlen_user(const char __user *str, long count) { |