Messages in this thread Patch in this message | | | From | Richard Genoud <> | Subject | [PATCH] proc: return on proc_readdir error | Date | Mon, 19 Aug 2013 18:30:31 +0200 |
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commit f0c3b5093addc8bfe9fe3a5b01acb7ec7969eafa "[readdir] convert procfs" introduced a bug on the listing of the proc file-system. The return value of proc_readdir() isn't tested anymore in the proc_root_readdir function.
This lead to an "interesting" behaviour when we are using the getdents() system call with a buffer too small: Instead of failing, it returns the first entries of /proc (enough to fill the given buffer), plus the PID directories.
This is not triggered on glibc (as getdents is called with a 32KB buffer), but on uclibc, the buffer size is only 1KB, thus some proc entries are missing. (described more in details here: https://lkml.org/lkml/2013/8/12/288 )
Signed-off-by: Richard Genoud <richard.genoud@gmail.com> --- [added Linus Torvalds and Andrew Morton in CC since Al Viro seems to be on holidays and it's starting to getting late in the -rc cycles]
fs/proc/root.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/proc/root.c b/fs/proc/root.c index 229e366..e0a790d 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -205,7 +205,9 @@ static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentr static int proc_root_readdir(struct file *file, struct dir_context *ctx) { if (ctx->pos < FIRST_PROCESS_ENTRY) { - proc_readdir(file, ctx); + int error = proc_readdir(file, ctx); + if (unlikely(error <= 0)) + return error; ctx->pos = FIRST_PROCESS_ENTRY; } -- 1.7.10.4
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