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authorArnd Bergmann <arnd@arndb.de>2019-04-16 23:19:44 +0300
committerArnd Bergmann <arnd@arndb.de>2019-10-23 18:23:47 +0300
commit17c7e7f407085f510a815c0c99b3fd25d5b13110 (patch)
treeaa674e21bcd6b6380049c28333e6b70ab909de34 /drivers/net/ppp
parent5b6c02df50fb28d23c733a24df5a06d0a3f28b93 (diff)
downloadlinux-17c7e7f407085f510a815c0c99b3fd25d5b13110.tar.xz
compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t
The ppp_idle structure is defined in terms of __kernel_time_t, which is defined as 'long' on all architectures, and this usage is not affected by the y2038 problem since it transports a time interval rather than an absolute time. However, the ppp user space defines the same structure as time_t, which may be 64-bit wide on new libc versions even on 32-bit architectures. It's easy enough to just handle both possible structure layouts on all architectures, to deal with the possibility that a user space ppp implementation comes with its own ppp_idle structure definition, as well as to document the fact that the driver is y2038-safe. Doing this also avoids the need for a special compat mode translation, since 32-bit and 64-bit kernels now support the same interfaces. The old 32-bit structure is also available on native 64-bit architectures now, but this is harmless. Cc: netdev@vger.kernel.org Cc: linux-ppp@vger.kernel.org Cc: Paul Mackerras <paulus@samba.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/net/ppp')
-rw-r--r--drivers/net/ppp/ppp_generic.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index fb8e0ac099b8..ce4dd45c541d 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -612,7 +612,8 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct ppp_file *pf;
struct ppp *ppp;
int err = -EFAULT, val, val2, i;
- struct ppp_idle idle;
+ struct ppp_idle32 idle32;
+ struct ppp_idle64 idle64;
struct npioctl npi;
int unit, cflags;
struct slcompress *vj;
@@ -735,10 +736,18 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
err = 0;
break;
- case PPPIOCGIDLE:
- idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
- idle.recv_idle = (jiffies - ppp->last_recv) / HZ;
- if (copy_to_user(argp, &idle, sizeof(idle)))
+ case PPPIOCGIDLE32:
+ idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
+ idle32.recv_idle = (jiffies - ppp->last_recv) / HZ;
+ if (copy_to_user(argp, &idle32, sizeof(idle32)))
+ break;
+ err = 0;
+ break;
+
+ case PPPIOCGIDLE64:
+ idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ;
+ idle64.recv_idle = (jiffies - ppp->last_recv) / HZ;
+ if (copy_to_user(argp, &idle64, sizeof(idle64)))
break;
err = 0;
break;