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| author | Arnd Bergmann <arnd@arndb.de> | 2019-04-16 22:19:44 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2019-10-23 17:23:47 +0200 |
| commit | 17c7e7f407085f510a815c0c99b3fd25d5b13110 (patch) | |
| tree | aa674e21bcd6b6380049c28333e6b70ab909de34 /Documentation/networking | |
| parent | 5b6c02df50fb28d23c733a24df5a06d0a3f28b93 (diff) | |
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 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/ppp_generic.txt | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/networking/ppp_generic.txt b/Documentation/networking/ppp_generic.txt index 61daf4b39600..fd563aff5fc9 100644 --- a/Documentation/networking/ppp_generic.txt +++ b/Documentation/networking/ppp_generic.txt @@ -378,6 +378,8 @@ an interface unit are: CONFIG_PPP_FILTER option is enabled, the set of packets which reset the transmit and receive idle timers is restricted to those which pass the `active' packet filter. + Two versions of this command exist, to deal with user space + expecting times as either 32-bit or 64-bit time_t seconds. * PPPIOCSMAXCID sets the maximum connection-ID parameter (and thus the number of connection slots) for the TCP header compressor and |