Commit 2865baf54077a changed get_sigset_argpack() to use
masked_user_access_begin() and avoid a slow synchronisation instruction.
Replace the rather unwieldy code pattern with
masked_user_read_access_begin().
Make the same change to get_compat_sigset_argpack().
Use masked_user_write_access_begin() in do_sys_poll() to avoid
the size calculation and conditional branch for access_ok().
Code generated for get_sigset_argpack() is identical.
Signed-off-by: David Laight <david.laight.linux@xxxxxxxxx>
---
fs/select.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/fs/select.c b/fs/select.c
index 7da531b1cf6b..abe2c1a57274 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -776,9 +776,7 @@ static inline int get_sigset_argpack(struct sigset_argpack *to,
{
// the path is hot enough for overhead of copy_from_user() to matter
if (from) {
- if (can_do_masked_user_access())
- from = masked_user_access_begin(from);
- else if (!user_read_access_begin(from, sizeof(*from)))
+ if (!masked_user_read_access_begin(&from, sizeof(*from)))
return -EFAULT;
unsafe_get_user(to->p, &from->p, Efault);
unsafe_get_user(to->size, &from->size, Efault);
@@ -1009,7 +1007,7 @@ static int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
fdcount = do_poll(head, &table, end_time);
poll_freewait(&table);
- if (!user_write_access_begin(ufds, nfds * sizeof(*ufds)))
+ if (!masked_user_write_access_begin(&ufds, nfds * sizeof(*ufds)))
goto out_fds;
for (walk = head; walk; walk = walk->next) {
@@ -1347,7 +1345,7 @@ static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to,
struct compat_sigset_argpack __user *from)
{
if (from) {
- if (!user_read_access_begin(from, sizeof(*from)))
+ if (!masked_user_read_access_begin(&from, sizeof(*from)))
return -EFAULT;
unsafe_get_user(to->p, &from->p, Efault);
unsafe_get_user(to->size, &from->size, Efault);
--
2.39.5
