[PATCH v3 05/26] compat_ioctl: move PPPIOCSPASS32/PPPIOCSACTIVE32 to ppp_generic.c

From: Arnd Bergmann
Date: Tue Apr 16 2019 - 16:21:27 EST


PPPIOCSPASS and PPPIOCSACTIVE are implemented in ppp_generic and isdn_ppp,
but the latter one doesn't work for compat mode in general, so we can
move these two into the generic code.

Again, the best implementation I could come up with was to merge
the compat handling into the regular ppp_ioctl() function and
treating all ioctl commands as compatible.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/ppp/ppp_generic.c | 39 ++++++++++++++++++++++++++++++-----
fs/compat_ioctl.c | 37 ---------------------------------
2 files changed, 34 insertions(+), 42 deletions(-)

diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 8d211c9c2e4e..b8a867fdd5ad 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -22,6 +22,7 @@
* ==FILEVERSION 20041108==
*/

+#include <linux/compat.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
@@ -567,14 +568,36 @@ struct ppp_option_data32 {
#endif

#ifdef CONFIG_PPP_FILTER
-static int get_filter(void __user *arg, struct sock_filter **p)
+#ifdef CONFIG_COMPAT
+struct sock_fprog32 {
+ unsigned short len;
+ compat_caddr_t filter;
+};
+#define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32)
+#define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32)
+#endif
+
+static int get_filter(void __user *arg, struct sock_filter **p, bool compat)
{
struct sock_fprog uprog;
struct sock_filter *code = NULL;
int len;

- if (copy_from_user(&uprog, arg, sizeof(uprog)))
- return -EFAULT;
+#ifdef CONFIG_COMPAT
+ if (compat) {
+ struct sock_fprog32 uprog32;
+
+ if (copy_from_user(&uprog32, arg, sizeof(uprog32)))
+ return -EFAULT;
+
+ uprog.len = uprog32.len;
+ uprog.filter = compat_ptr(uprog32.filter);
+ } else
+#endif
+ {
+ if (copy_from_user(&uprog, arg, sizeof(uprog)))
+ return -EFAULT;
+ }

if (!uprog.len) {
*p = NULL;
@@ -772,10 +795,13 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

#ifdef CONFIG_PPP_FILTER
case PPPIOCSPASS:
+#ifdef CONFIG_COMPAT
+ case PPPIOCSPASS32:
+#endif
{
struct sock_filter *code;

- err = get_filter(argp, &code);
+ err = get_filter(argp, &code, cmd != PPPIOCSPASS);
if (err >= 0) {
struct bpf_prog *pass_filter = NULL;
struct sock_fprog_kern fprog = {
@@ -798,10 +824,13 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
break;
}
case PPPIOCSACTIVE:
+#ifdef CONFIG_COMPAT
+ case PPPIOCSACTIVE32:
+#endif
{
struct sock_filter *code;

- err = get_filter(argp, &code);
+ err = get_filter(argp, &code, cmd != PPPIOCSACTIVE);
if (err >= 0) {
struct bpf_prog *active_filter = NULL;
struct sock_fprog_kern fprog = {
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index a7cea8f9c771..d507b7189958 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -271,40 +271,6 @@ static int sg_grt_trans(struct file *file,
}
#endif /* CONFIG_BLOCK */

-struct sock_fprog32 {
- unsigned short len;
- compat_caddr_t filter;
-};
-
-#define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32)
-#define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32)
-
-static int ppp_sock_fprog_ioctl_trans(struct file *file,
- unsigned int cmd, struct sock_fprog32 __user *u_fprog32)
-{
- struct sock_fprog __user *u_fprog64 = compat_alloc_user_space(sizeof(struct sock_fprog));
- void __user *fptr64;
- u32 fptr32;
- u16 flen;
-
- if (get_user(flen, &u_fprog32->len) ||
- get_user(fptr32, &u_fprog32->filter))
- return -EFAULT;
-
- fptr64 = compat_ptr(fptr32);
-
- if (put_user(flen, &u_fprog64->len) ||
- put_user(fptr64, &u_fprog64->filter))
- return -EFAULT;
-
- if (cmd == PPPIOCSPASS32)
- cmd = PPPIOCSPASS;
- else
- cmd = PPPIOCSACTIVE;
-
- return do_ioctl(file, cmd, (unsigned long) u_fprog64);
-}
-
struct ppp_idle32 {
compat_time_t xmit_idle;
compat_time_t recv_idle;
@@ -874,9 +840,6 @@ static long do_ioctl_trans(unsigned int cmd,
switch (cmd) {
case PPPIOCGIDLE32:
return ppp_gidle(file, cmd, argp);
- case PPPIOCSPASS32:
- case PPPIOCSACTIVE32:
- return ppp_sock_fprog_ioctl_trans(file, cmd, argp);
#ifdef CONFIG_BLOCK
case SG_IO:
return sg_ioctl_trans(file, cmd, argp);
--
2.20.0