Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-27 05:11:48 +00:00
Code Issues Packages Projects Releases Wiki Activity

ppoll: use __kernel_timespec

Browse Source 
struct timespec is not y2038 safe.
struct __kernel_timespec is the new y2038 safe structure for all
syscalls that are using struct timespec.
Update ppoll interfaces to use struct __kernel_timespec.

sigset_t also has different representations on 32 bit and 64 bit
architectures. Hence, we need to support the following different
syscalls:

New y2038 safe syscalls:
(Controlled by CONFIG_64BIT_TIME for 32 bit ABIs)

Native 64 bit(unchanged) and native 32 bit : sys_ppoll
Compat : compat_sys_ppoll_time64

Older y2038 unsafe syscalls:
(Controlled by CONFIG_32BIT_COMPAT_TIME for 32 bit ABIs)

Native 32 bit : ppoll_time32
Compat : compat_sys_ppoll

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Deepa Dinamani 2018-09-19 21:41:06 -07:00 committed by Arnd Bergmann
parent 854a6ed568
commit 8bd27a3004
3 changed files with 131 additions and 67 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

188
fs/select.c
View File

@ -287,12 +287,18 @@ int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec)
return 0;
}
enum poll_time_type {
PT_TIMEVAL = 0,
PT_OLD_TIMEVAL = 1,
PT_TIMESPEC = 2,
PT_OLD_TIMESPEC = 3,
};
static int poll_select_copy_remaining(struct timespec64 *end_time,
void __user *p,
int timeval, int ret)
enum poll_time_type pt_type, int ret)
{
struct timespec64 rts;
struct timeval rtv;
if (!p)
return ret;
@ -310,18 +316,40 @@ static int poll_select_copy_remaining(struct timespec64 *end_time,
rts.tv_sec = rts.tv_nsec = 0;
if (timeval) {
if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec))
memset(&rtv, 0, sizeof(rtv));
rtv.tv_sec = rts.tv_sec;
rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
switch (pt_type) {
case PT_TIMEVAL:
{
struct timeval rtv;
if (!copy_to_user(p, &rtv, sizeof(rtv)))
if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec))
memset(&rtv, 0, sizeof(rtv));
rtv.tv_sec = rts.tv_sec;
rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
if (!copy_to_user(p, &rtv, sizeof(rtv)))
return ret;
}
break;
case PT_OLD_TIMEVAL:
{
struct old_timeval32 rtv;
rtv.tv_sec = rts.tv_sec;
rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
if (!copy_to_user(p, &rtv, sizeof(rtv)))
return ret;
}
break;
case PT_TIMESPEC:
if (!put_timespec64(&rts, p))
return ret;
} else if (!put_timespec64(&rts, p))
return ret;
break;
case PT_OLD_TIMESPEC:
if (!put_old_timespec32(&rts, p))
return ret;
break;
default:
BUG();
}
/*
* If an application puts its timeval in read-only memory, we
* don't want the Linux-specific update to the timeval to
@ -689,7 +717,7 @@ static int kern_select(int n, fd_set __user *inp, fd_set __user *outp,
}
ret = core_sys_select(n, inp, outp, exp, to);
ret = poll_select_copy_remaining(&end_time, tvp, 1, ret);
ret = poll_select_copy_remaining(&end_time, tvp, PT_TIMEVAL, ret);
return ret;
}
@ -722,7 +750,7 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp,
return ret;
ret = core_sys_select(n, inp, outp, exp, to);
ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret);
restore_user_sigmask(sigmask, &sigsaved);
@ -1026,7 +1054,7 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
}
SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
struct timespec __user *, tsp, const sigset_t __user *, sigmask,
struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask,
size_t, sigsetsize)
{
sigset_t ksigmask, sigsaved;
@ -1054,61 +1082,51 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);
ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret);
return ret;
}
#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds,
struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask,
size_t, sigsetsize)
{
sigset_t ksigmask, sigsaved;
struct timespec64 ts, end_time, *to = NULL;
int ret;
if (tsp) {
if (get_old_timespec32(&ts, tsp))
return -EFAULT;
to = &end_time;
if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
return -EINVAL;
}
ret = set_user_sigmask(sigmask, &ksigmask, &sigsaved, sigsetsize);
if (ret)
return ret;
ret = do_sys_poll(ufds, nfds, to);
restore_user_sigmask(sigmask, &sigsaved);
/* We can restart this syscall, usually */
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret);
return ret;
}
#endif
#ifdef CONFIG_COMPAT
#define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t))
static
int compat_poll_select_copy_remaining(struct timespec64 *end_time, void __user *p,
int timeval, int ret)
{
struct timespec64 ts;
if (!p)
return ret;
if (current->personality & STICKY_TIMEOUTS)
goto sticky;
/* No update for zero timeout */
if (!end_time->tv_sec && !end_time->tv_nsec)
return ret;
ktime_get_ts64(&ts);
ts = timespec64_sub(*end_time, ts);
if (ts.tv_sec < 0)
ts.tv_sec = ts.tv_nsec = 0;
if (timeval) {
struct old_timeval32 rtv;
rtv.tv_sec = ts.tv_sec;
rtv.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
if (!copy_to_user(p, &rtv, sizeof(rtv)))
return ret;
} else {
if (!put_old_timespec32(&ts, p))
return ret;
}
/*
* If an application puts its timeval in read-only memory, we
* don't want the Linux-specific update to the timeval to
* cause a fault after the select has completed
* successfully. However, because we're not updating the
* timeval, we can't restart the system call.
*/
sticky:
if (ret == -ERESTARTNOHAND)
ret = -EINTR;
return ret;
}
/*
* Ooo, nasty. We need here to frob 32-bit unsigned longs to
* 64-bit unsigned longs.
@ -1239,7 +1257,7 @@ static int do_compat_select(int n, compat_ulong_t __user *inp,
}
ret = compat_core_sys_select(n, inp, outp, exp, to);
ret = compat_poll_select_copy_remaining(&end_time, tvp, 1, ret);
ret = poll_select_copy_remaining(&end_time, tvp, PT_OLD_TIMEVAL, ret);
return ret;
}
@ -1292,7 +1310,7 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp,
return ret;
ret = compat_core_sys_select(n, inp, outp, exp, to);
ret = compat_poll_select_copy_remaining(&end_time, tsp, 0, ret);
ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret);
restore_user_sigmask(sigmask, &sigsaved);
@ -1318,6 +1336,7 @@ COMPAT_SYSCALL_DEFINE6(pselect6, int, n, compat_ulong_t __user *, inp,
sigsetsize);
}
#if defined(CONFIG_COMPAT_32BIT_TIME)
COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds,
unsigned int, nfds, struct old_timespec32 __user *, tsp,
const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
@ -1347,8 +1366,45 @@ COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds,
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
ret = compat_poll_select_copy_remaining(&end_time, tsp, 0, ret);
ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret);
return ret;
}
#endif
/* New compat syscall for 64 bit time_t*/
COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds,
unsigned int, nfds, struct __kernel_timespec __user *, tsp,
const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
{
sigset_t ksigmask, sigsaved;
struct timespec64 ts, end_time, *to = NULL;
int ret;
if (tsp) {
if (get_timespec64(&ts, tsp))
return -EFAULT;
to = &end_time;
if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
return -EINVAL;
}
ret = set_compat_user_sigmask(sigmask, &ksigmask, &sigsaved, sigsetsize);
if (ret)
return ret;
ret = do_sys_poll(ufds, nfds, to);
restore_user_sigmask(sigmask, &sigsaved);
/* We can restart this syscall, usually */
if (ret == -EINTR)
ret = -ERESTARTNOHAND;
ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret);
return ret;
}
#endif

5
include/linux/compat.h
View File

@ -652,6 +652,11 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
struct old_timespec32 __user *tsp,
const compat_sigset_t __user *sigmask,
compat_size_t sigsetsize);
asmlinkage long compat_sys_ppoll_time64(struct pollfd __user *ufds,
unsigned int nfds,
struct __kernel_timespec __user *tsp,
const compat_sigset_t __user *sigmask,
compat_size_t sigsetsize);
/* fs/signalfd.c */
asmlinkage long compat_sys_signalfd4(int ufd,

5
include/linux/syscalls.h
View File

@ -469,7 +469,10 @@ asmlinkage long sys_pselect6(int, fd_set __user *, fd_set __user *,
fd_set __user *, struct timespec __user *,
void __user *);
asmlinkage long sys_ppoll(struct pollfd __user *, unsigned int,
struct timespec __user *, const sigset_t __user *,
struct __kernel_timespec __user *, const sigset_t __user *,
size_t);
asmlinkage long sys_ppoll_time32(struct pollfd __user *, unsigned int,
struct old_timespec32 __user *, const sigset_t __user *,
size_t);
/* fs/signalfd.c */