ntp: Move adjtimex related compat syscalls to native counterparts

Get rid of set_fs() mess and sanitize compat_{get,put}_timex(),
while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170607084241.28657-9-viro@ZenIV.linux.org.uk

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 1c5f3152cbb57796caf1a587103ed3d092324a04..ecb8dd261d3674aef841099fe2e06080a5427641 100644 (file)
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -128,6 +128,10 @@ struct compat_timex {
        compat_int_t:32; compat_int_t:32; compat_int_t:32;
 };
 
+struct timex;
+int compat_get_timex(struct timex *, const struct compat_timex __user *);
+int compat_put_timex(struct compat_timex __user *, const struct timex *);
+
 #define _COMPAT_NSIG_WORDS     (_COMPAT_NSIG / _COMPAT_NSIG_BPW)
 
 typedef struct {

diff --git a/kernel/compat.c b/kernel/compat.c
index 23afa26f574bc4a93da642c1de3a7dfefb1c91f6..97087b3335438f3973e063998bb51000db7dbc5b 100644 (file)
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -30,60 +30,64 @@
 
 #include <linux/uaccess.h>
 
-static int compat_get_timex(struct timex *txc, struct compat_timex __user *utp)
+int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
 {
-       memset(txc, 0, sizeof(struct timex));
-
-       if (!access_ok(VERIFY_READ, utp, sizeof(struct compat_timex)) ||
-                       __get_user(txc->modes, &utp->modes) ||
-                       __get_user(txc->offset, &utp->offset) ||
-                       __get_user(txc->freq, &utp->freq) ||
-                       __get_user(txc->maxerror, &utp->maxerror) ||
-                       __get_user(txc->esterror, &utp->esterror) ||
-                       __get_user(txc->status, &utp->status) ||
-                       __get_user(txc->constant, &utp->constant) ||
-                       __get_user(txc->precision, &utp->precision) ||
-                       __get_user(txc->tolerance, &utp->tolerance) ||
-                       __get_user(txc->time.tv_sec, &utp->time.tv_sec) ||
-                       __get_user(txc->time.tv_usec, &utp->time.tv_usec) ||
-                       __get_user(txc->tick, &utp->tick) ||
-                       __get_user(txc->ppsfreq, &utp->ppsfreq) ||
-                       __get_user(txc->jitter, &utp->jitter) ||
-                       __get_user(txc->shift, &utp->shift) ||
-                       __get_user(txc->stabil, &utp->stabil) ||
-                       __get_user(txc->jitcnt, &utp->jitcnt) ||
-                       __get_user(txc->calcnt, &utp->calcnt) ||
-                       __get_user(txc->errcnt, &utp->errcnt) ||
-                       __get_user(txc->stbcnt, &utp->stbcnt))
+       struct compat_timex tx32;
+
+       if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
                return -EFAULT;
 
+       txc->modes = tx32.modes;
+       txc->offset = tx32.offset;
+       txc->freq = tx32.freq;
+       txc->maxerror = tx32.maxerror;
+       txc->esterror = tx32.esterror;
+       txc->status = tx32.status;
+       txc->constant = tx32.constant;
+       txc->precision = tx32.precision;
+       txc->tolerance = tx32.tolerance;
+       txc->time.tv_sec = tx32.time.tv_sec;
+       txc->time.tv_usec = tx32.time.tv_usec;
+       txc->tick = tx32.tick;
+       txc->ppsfreq = tx32.ppsfreq;
+       txc->jitter = tx32.jitter;
+       txc->shift = tx32.shift;
+       txc->stabil = tx32.stabil;
+       txc->jitcnt = tx32.jitcnt;
+       txc->calcnt = tx32.calcnt;
+       txc->errcnt = tx32.errcnt;
+       txc->stbcnt = tx32.stbcnt;
+
        return 0;
 }
 
-static int compat_put_timex(struct compat_timex __user *utp, struct timex *txc)
-{
-       if (!access_ok(VERIFY_WRITE, utp, sizeof(struct compat_timex)) ||
-                       __put_user(txc->modes, &utp->modes) ||
-                       __put_user(txc->offset, &utp->offset) ||
-                       __put_user(txc->freq, &utp->freq) ||
-                       __put_user(txc->maxerror, &utp->maxerror) ||
-                       __put_user(txc->esterror, &utp->esterror) ||
-                       __put_user(txc->status, &utp->status) ||
-                       __put_user(txc->constant, &utp->constant) ||
-                       __put_user(txc->precision, &utp->precision) ||
-                       __put_user(txc->tolerance, &utp->tolerance) ||
-                       __put_user(txc->time.tv_sec, &utp->time.tv_sec) ||
-                       __put_user(txc->time.tv_usec, &utp->time.tv_usec) ||
-                       __put_user(txc->tick, &utp->tick) ||
-                       __put_user(txc->ppsfreq, &utp->ppsfreq) ||
-                       __put_user(txc->jitter, &utp->jitter) ||
-                       __put_user(txc->shift, &utp->shift) ||
-                       __put_user(txc->stabil, &utp->stabil) ||
-                       __put_user(txc->jitcnt, &utp->jitcnt) ||
-                       __put_user(txc->calcnt, &utp->calcnt) ||
-                       __put_user(txc->errcnt, &utp->errcnt) ||
-                       __put_user(txc->stbcnt, &utp->stbcnt) ||
-                       __put_user(txc->tai, &utp->tai))
+int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
+{
+       struct compat_timex tx32;
+
+       memset(&tx32, 0, sizeof(struct compat_timex));
+       tx32.modes = txc->modes;
+       tx32.offset = txc->offset;
+       tx32.freq = txc->freq;
+       tx32.maxerror = txc->maxerror;
+       tx32.esterror = txc->esterror;
+       tx32.status = txc->status;
+       tx32.constant = txc->constant;
+       tx32.precision = txc->precision;
+       tx32.tolerance = txc->tolerance;
+       tx32.time.tv_sec = txc->time.tv_sec;
+       tx32.time.tv_usec = txc->time.tv_usec;
+       tx32.tick = txc->tick;
+       tx32.ppsfreq = txc->ppsfreq;
+       tx32.jitter = txc->jitter;
+       tx32.shift = txc->shift;
+       tx32.stabil = txc->stabil;
+       tx32.jitcnt = txc->jitcnt;
+       tx32.calcnt = txc->calcnt;
+       tx32.errcnt = txc->errcnt;
+       tx32.stbcnt = txc->stbcnt;
+       tx32.tai = txc->tai;
+       if (copy_to_user(utp, &tx32, sizeof(struct compat_timex)))
                return -EFAULT;
        return 0;
 }
@@ -705,29 +709,6 @@ COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
        return err;
 }
 
-COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
-                      struct compat_timex __user *, utp)
-{
-       struct timex txc;
-       mm_segment_t oldfs;
-       int err, ret;
-
-       err = compat_get_timex(&txc, utp);
-       if (err)
-               return err;
-
-       oldfs = get_fs();
-       set_fs(KERNEL_DS);
-       ret = sys_clock_adjtime(which_clock, (struct timex __user *) &txc);
-       set_fs(oldfs);
-
-       err = compat_put_timex(utp, &txc);
-       if (err)
-               return err;
-
-       return ret;
-}
-
 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
                       struct compat_timespec __user *, tp)
 {
@@ -944,24 +925,6 @@ COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr)
 
 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */
 
-COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp)
-{
-       struct timex txc;
-       int err, ret;
-
-       err = compat_get_timex(&txc, utp);
-       if (err)
-               return err;
-
-       ret = do_adjtimex(&txc);
-
-       err = compat_put_timex(utp, &txc);
-       if (err)
-               return err;
-
-       return ret;
-}
-
 #ifdef CONFIG_NUMA
 COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
                       compat_uptr_t __user *, pages32,

diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 749b76f2d7574e7b6a9448dcd309cdaeff9df7a1..954d1d8ff9e644af277ed67999486d787e558328 100644 (file)
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -28,6 +28,7 @@ asmlinkage long sys_ni_posix_timers(void)
 }
 
 #define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
+#define COMPAT_SYS_NI(name)  SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
 
 SYS_NI(timer_create);
 SYS_NI(timer_gettime);
@@ -40,6 +41,7 @@ SYS_NI(setitimer);
 #ifdef __ARCH_WANT_SYS_ALARM
 SYS_NI(alarm);
 #endif
+COMPAT_SYS_NI(clock_adjtime);
 
 /*
  * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index ea4a463436bff6648b06795cd2309d2c82f0f71d..b1b6d52d64255a890a8ed168c6b598791cb40725 100644 (file)
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -1018,6 +1018,33 @@ SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
        return err;
 }
 
+#ifdef CONFIG_COMPAT
+
+COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
+                      struct compat_timex __user *, utp)
+{
+       const struct k_clock *kc = clockid_to_kclock(which_clock);
+       struct timex ktx;
+       int err;
+
+       if (!kc)
+               return -EINVAL;
+       if (!kc->clock_adj)
+               return -EOPNOTSUPP;
+
+       err = compat_get_timex(&ktx, utp);
+       if (err)
+               return err;
+
+       err = kc->clock_adj(which_clock, &ktx);
+
+       if (err >= 0)
+               err = compat_put_timex(utp, &ktx);
+
+       return err;
+}
+#endif
+
 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
                struct timespec __user *, tp)
 {

diff --git a/kernel/time/time.c b/kernel/time/time.c
index 49c73c6ed648900d873190f9ebaefe9cb44f4f98..400662f16c5a788d37c3d94bad9fc2f05a5ca645 100644 (file)
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -39,6 +39,7 @@
 #include <linux/ptrace.h>
 
 #include <linux/uaccess.h>
+#include <linux/compat.h>
 #include <asm/unistd.h>
 
 #include <generated/timeconst.h>
@@ -224,12 +225,33 @@ SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p)
         * structure. But bear in mind that the structures
         * may change
         */
-       if(copy_from_user(&txc, txc_p, sizeof(struct timex)))
+       if (copy_from_user(&txc, txc_p, sizeof(struct timex)))
                return -EFAULT;
        ret = do_adjtimex(&txc);
        return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
 }
 
+#ifdef CONFIG_COMPAT
+
+COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp)
+{
+       struct timex txc;
+       int err, ret;
+
+       err = compat_get_timex(&txc, utp);
+       if (err)
+               return err;
+
+       ret = do_adjtimex(&txc);
+
+       err = compat_put_timex(utp, &txc);
+       if (err)
+               return err;
+
+       return ret;
+}
+#endif
+
 /*
  * Convert jiffies to milliseconds and back.
  *