Re: [PATCH v2 1/5] fs: rework getname_kernel to handle up to PATH_MAX sized filenames

In preparation for expanded use in the kernel, make getname_kernel() more useful by allowing it to handle any legal filename length. Thanks to Guenter Roeck for his suggestion to substitute memcpy() for strlcpy(). CC: linux(a)roeck-us.net CC: viro(a)zeniv.linux.org.uk CC: linux-fsdevel(a)vger.kernel.org Signed-off-by: Paul Moore <pmoore(a)redhat.com&gt;

--- fs/namei.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 9eb787e..63eaaf6 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -211,32 +211,38 @@ getname(const char __user * filename) return getname_flags(filename, 0, NULL); } -/* - * The "getname_kernel()" interface doesn't do pathnames longer - * than EMBEDDED_NAME_MAX. Deal with it - you're a kernel user. - */ struct filename * getname_kernel(const char * filename) { struct filename *result; - char *kname; - int len; - - len = strlen(filename); - if (len >= EMBEDDED_NAME_MAX) - return ERR_PTR(-ENAMETOOLONG); + int len = strlen(filename) + 1; result = __getname(); if (unlikely(!result)) return ERR_PTR(-ENOMEM); - kname = (char *)result + sizeof(*result); - result->name = kname; + if (len <= EMBEDDED_NAME_MAX) { + result->name = (char *)(result) + sizeof(*result); + result->separate = false; + } else if (len <= PATH_MAX) { + struct filename *tmp; + + tmp = kmalloc(sizeof(*tmp), GFP_KERNEL); + if (unlikely(!tmp)) { + __putname(result); + return ERR_PTR(-ENOMEM); + } + tmp->name = (char *)result; + tmp->separate = true; + result = tmp; + } else { + __putname(result); + return ERR_PTR(-ENAMETOOLONG); + } + memcpy((char *)result->name, filename, len); result->uptr = NULL; result->aname = NULL; - result->separate = false; - strlcpy(kname, filename, EMBEDDED_NAME_MAX); return result; }