[PATCH v2 1/3] n_tty: Uninline tty_copy_to_user()

From: Peter Hurley
Date: Fri Nov 27 2015 - 14:12:27 EST


Merge the multiple tty_copy_to_user() calls into a single copy
sequence within tty_copy_to_user().

Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/n_tty.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index b4bc8ea..9a96f26 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -163,12 +163,23 @@ static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
return put_user(x, ptr);
}

-static inline int tty_copy_to_user(struct tty_struct *tty,
- void __user *to,
- const void *from,
- unsigned long n)
+static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
+ size_t tail, size_t n)
{
struct n_tty_data *ldata = tty->disc_data;
+ size_t size = N_TTY_BUF_SIZE - tail;
+ const void *from = read_buf_addr(ldata, tail);
+ int uncopied;
+
+ if (n > size) {
+ tty_audit_add_data(tty, from, size, ldata->icanon);
+ uncopied = copy_to_user(to, from, size);
+ if (uncopied)
+ return uncopied;
+ to += size;
+ n -= size;
+ from = ldata->read_buf;
+ }

tty_audit_add_data(tty, from, n, ldata->icanon);
return copy_to_user(to, from, n);
@@ -2073,7 +2084,6 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
} else if (eol != size)
found = 1;

- size = N_TTY_BUF_SIZE - tail;
n = eol - tail;
if (n > N_TTY_BUF_SIZE)
n += N_TTY_BUF_SIZE;
@@ -2084,17 +2094,10 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
n = c;
}

- n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu size:%zu more:%zu\n",
- __func__, eol, found, n, c, size, more);
-
- if (n > size) {
- ret = tty_copy_to_user(tty, *b, read_buf_addr(ldata, tail), size);
- if (ret)
- return -EFAULT;
- ret = tty_copy_to_user(tty, *b + size, ldata->read_buf, n - size);
- } else
- ret = tty_copy_to_user(tty, *b, read_buf_addr(ldata, tail), n);
+ n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n",
+ __func__, eol, found, n, c, tail, more);

+ ret = tty_copy_to_user(tty, *b, tail, n);
if (ret)
return -EFAULT;
*b += n;
--
2.6.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/