diff options
| author | Jiri Slaby (SUSE) <jirislaby@kernel.org> | 2024-01-22 12:03:20 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-28 03:08:52 +0100 |
| commit | d321cd13f6dca3c1b0e9e9735901fb5eee7a501c (patch) | |
| tree | 23b990ec9ba2afa076b724747dc07c40b27a9442 | |
| parent | tty: vt: pass proper pointers from tioclinux() (diff) | |
| download | linux-d321cd13f6dca3c1b0e9e9735901fb5eee7a501c.tar.xz linux-d321cd13f6dca3c1b0e9e9735901fb5eee7a501c.zip | |
tty: vt: push console lock from tioclinux() down to 2 functions
Avoid costly user copies under the console lock. So push the lock down
from tioclinux() to sel_loadlut() and set_vesa_blanking().
It is now obvious what is actually protected.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-7-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/vt/selection.c | 11 | ||||
| -rw-r--r-- | drivers/tty/vt/vt.c | 13 |
2 files changed, 14 insertions, 10 deletions
diff --git a/drivers/tty/vt/selection.c b/drivers/tty/vt/selection.c index e172ede235a0..91d789c025c6 100644 --- a/drivers/tty/vt/selection.c +++ b/drivers/tty/vt/selection.c @@ -113,15 +113,22 @@ static inline int inword(const u32 c) * sel_loadlut() - load the LUT table * @lut: user table * - * Load the LUT table from user space. The caller must hold the console - * lock. Make a temporary copy so a partial update doesn't make a mess. + * Load the LUT table from user space. Make a temporary copy so a partial + * update doesn't make a mess. + * + * Locking: The console lock is acquired. */ int sel_loadlut(u32 __user *lut) { u32 tmplut[ARRAY_SIZE(inwordLut)]; + if (copy_from_user(tmplut, lut, sizeof(inwordLut))) return -EFAULT; + + console_lock(); memcpy(inwordLut, tmplut, sizeof(inwordLut)); + console_unlock(); + return 0; } diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 079dbff562fd..3a6f60ad2224 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -3162,10 +3162,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg) case TIOCL_SELLOADLUT: if (!capable(CAP_SYS_ADMIN)) return -EPERM; - console_lock(); - ret = sel_loadlut(param_aligned32); - console_unlock(); - break; + return sel_loadlut(param_aligned32); case TIOCL_GETSHIFTSTATE: /* * Make it possible to react to Shift+Mousebutton. Note that @@ -3181,10 +3178,7 @@ int tioclinux(struct tty_struct *tty, unsigned long arg) console_unlock(); return put_user(data, p); case TIOCL_SETVESABLANK: - console_lock(); - ret = set_vesa_blanking(param); - console_unlock(); - break; + return set_vesa_blanking(param); case TIOCL_GETKMSGREDIRECT: data = vt_get_kmsg_redirect(); return put_user(data, p); @@ -4270,7 +4264,10 @@ static int set_vesa_blanking(u8 __user *mode_user) if (get_user(mode, mode_user)) return -EFAULT; + console_lock(); vesa_blank_mode = (mode < 4) ? mode : 0; + console_unlock(); + return 0; } |