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Commit 6684ba20 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

compat: Add helper functions to read/write struct timeval, timespec 



Add helper functions to read and write struct timeval and struct
timespec from userspace.  We already had helper functions for reading
and writing struct compat_timespec; add a set of functions to do the
same with struct timeval, and add a second suite of functions which
can be sensitive to COMPAT_USE_64BIT_TIME and access either 32- or
64-bit time structures.

This also exports these helper functions to modules.

Rename the existing inlines for converting between struct
compat_timeval and native struct timespec so we can have a saner
naming convention for the exported functions.

Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 45e87781

include/linux/compat.h

+16 −0
Original line number Diff line number Diff line
@@ -87,10 +87,26 @@ typedef struct { 
	compat_sigset_word	sig[_COMPAT_NSIG_WORDS];

} compat_sigset_t;



/*

 * These functions operate strictly on struct compat_time*

 */

extern int get_compat_timespec(struct timespec *,

			       const struct compat_timespec __user *);

extern int put_compat_timespec(const struct timespec *,

			       struct compat_timespec __user *);

extern int get_compat_timeval(struct timeval *,

			      const struct compat_timeval __user *);

extern int put_compat_timeval(const struct timeval *,

			      struct compat_timeval __user *);

/*

 * These functions operate on 32- or 64-bit specs depending on

 * COMPAT_USE_64BIT_TIME, hence the void user pointer arguments and the

 * naming as compat_get/put_ rather than get/put_compat_.

 */

extern int compat_get_timespec(struct timespec *, const void __user *);

extern int compat_put_timespec(const struct timespec *, void __user *);

extern int compat_get_timeval(struct timeval *, const void __user *);

extern int compat_put_timeval(const struct timeval *, void __user *);



struct compat_iovec {

	compat_uptr_t	iov_base;

kernel/compat.c

+60 −8
Original line number Diff line number Diff line
@@ -31,10 +31,9 @@ 
#include <asm/uaccess.h>



/*

 * Note that the native side is already converted to a timespec, because

 * that's what we want anyway.

 * Get/set struct timeval with struct timespec on the native side

 */

static int compat_get_timeval(struct timespec *o,

static int compat_get_timeval_convert(struct timespec *o,

				      struct compat_timeval __user *i)

{

	long usec;
@@ -46,7 +45,7 @@ static int compat_get_timeval(struct timespec *o, 
	return 0;

}



static int compat_put_timeval(struct compat_timeval __user *o,

static int compat_put_timeval_convert(struct compat_timeval __user *o,

				      struct timeval *i)

{

	return (put_user(i->tv_sec, &o->tv_sec) ||
@@ -117,7 +116,7 @@ asmlinkage long compat_sys_gettimeofday(struct compat_timeval __user *tv, 
	if (tv) {

		struct timeval ktv;

		do_gettimeofday(&ktv);

		if (compat_put_timeval(tv, &ktv))

		if (compat_put_timeval_convert(tv, &ktv))

			return -EFAULT;

	}

	if (tz) {
@@ -135,7 +134,7 @@ asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv, 
	struct timezone ktz;



	if (tv) {

		if (compat_get_timeval(&kts, tv))

		if (compat_get_timeval_convert(&kts, tv))

			return -EFAULT;

	}

	if (tz) {
@@ -146,12 +145,29 @@ asmlinkage long compat_sys_settimeofday(struct compat_timeval __user *tv, 
	return do_sys_settimeofday(tv ? &kts : NULL, tz ? &ktz : NULL);

}



int get_compat_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)

{

	return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||

			__get_user(tv->tv_sec, &ctv->tv_sec) ||

			__get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;

}

EXPORT_SYMBOL_GPL(get_compat_timeval);



int put_compat_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)

{

	return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||

			__put_user(tv->tv_sec, &ctv->tv_sec) ||

			__put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;

}

EXPORT_SYMBOL_GPL(put_compat_timeval);



int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts)

{

	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||

			__get_user(ts->tv_sec, &cts->tv_sec) ||

			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;

}

EXPORT_SYMBOL_GPL(get_compat_timespec);



int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user *cts)

{
@@ -161,6 +177,42 @@ int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user 
}

EXPORT_SYMBOL_GPL(put_compat_timespec);



int compat_get_timeval(struct timeval *tv, const void __user *utv)

{

	if (COMPAT_USE_64BIT_TIME)

		return copy_from_user(tv, utv, sizeof *tv) ? -EFAULT : 0;

	else

		return get_compat_timeval(tv, utv);

}

EXPORT_SYMBOL_GPL(compat_get_timeval);



int compat_put_timeval(const struct timeval *tv, void __user *utv)

{

	if (COMPAT_USE_64BIT_TIME)

		return copy_to_user(utv, tv, sizeof *tv) ? -EFAULT : 0;

	else

		return put_compat_timeval(tv, utv);

}

EXPORT_SYMBOL_GPL(compat_put_timeval);



int compat_get_timespec(struct timespec *ts, const void __user *uts)

{

	if (COMPAT_USE_64BIT_TIME)

		return copy_from_user(ts, uts, sizeof *ts) ? -EFAULT : 0;

	else

		return get_compat_timespec(ts, uts);

}

EXPORT_SYMBOL_GPL(compat_get_timespec);



int compat_put_timespec(const struct timespec *ts, void __user *uts)

{

	if (COMPAT_USE_64BIT_TIME)

		return copy_to_user(uts, ts, sizeof *ts) ? -EFAULT : 0;

	else

		return put_compat_timespec(ts, uts);

}

EXPORT_SYMBOL_GPL(compat_put_timespec);



static long compat_nanosleep_restart(struct restart_block *restart)

{

	struct compat_timespec __user *rmtp;