[PATCH] fs/proc/kcore.c: Clear ret value in read_kcore_iter after successful iov_iter_zero

[Jiri Olsa <jolsa@kernel.org>]

If iov_iter_zero succeeds after failed copy_from_kernel_nofault,
we need to reset the ret value to zero otherwise it will be returned
as final return value of read_kcore_iter.

This fixes objdump -d dump over /proc/kcore for me.

Cc: stable@vger.kernel.org
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Fixes: 3d5854d75e31 ("fs/proc/kcore.c: allow translation of physical memory addresses")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 fs/proc/kcore.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 51446c59388f..c82c408e573e 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -600,6 +600,7 @@ static ssize_t read_kcore_iter(struct kiocb *iocb, struct iov_iter *iter)
 					ret = -EFAULT;
 					goto out;
 				}
+				ret = 0;
 			/*
 			 * We know the bounce buffer is safe to copy from, so
 			 * use _copy_to_iter() directly.
-- 
2.47.0