Attachment #225031 for bug #255947

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	struct timespec uts, *ts;
	int error, save;
	uint32_t flags, val;
	int no_compare;

	if (args->op & LINUX_FUTEX_PRIVATE_FLAG) {
		flags = 0;


	error = 0;
	f = f2 = NULL;
	no_compare = 0;		// for FUTEX_REQUEUE

	switch (args->op) {
	case LINUX_FUTEX_WAIT:

		futex_put(f, NULL);
		break;

	case LINUX_FUTEX_REQUEUE:
		/*
		 * Glibc does not use this operation since version 2.3.3,
		 * as it is racy and replaced by FUTEX_CMP_REQUEUE operation.
		 * Glibc versions prior to 2.3.3 fall back to FUTEX_WAKE when
		 * FUTEX_REQUEUE returned EINVAL.
		 */
		pem = pem_find(td->td_proc);
		if ((pem->flags & LINUX_XDEPR_REQUEUEOP) == 0) {
			linux_msg(td, "warn: deprecated FUTEX_REQUEUE");
			pem->flags |= LINUX_XDEPR_REQUEUEOP;
			LIN_SDT_PROBE0(futex, linux_sys_futex,
					deprecated_requeue);
		}
		/*
		 * The above is true, however musl libc does make use of the
		 * futex requeue operation, so we add support for it.
		 */
		no_compare = 1;
		/* FALLTHROUGH */

	case LINUX_FUTEX_CMP_REQUEUE:
		LIN_SDT_PROBE5(futex, linux_sys_futex, debug_cmp_requeue,
		    args->uaddr, args->val, args->val3, args->uaddr2,

			    error);
			return (error);
		}
		if ((no_compare == 0) && val != args->val3) {
			LIN_SDT_PROBE2(futex, linux_sys_futex,
			    debug_cmp_requeue_value_neq, args->val, val);
			LINUX_CTR2(sys_futex, "CMP_REQUEUE val 0x%x != uval 0x%x",

		}
		return (ENOSYS);

	case LINUX_FUTEX_REQUEUE:
		/*
		 * Glibc does not use this operation since version 2.3.3,
		 * as it is racy and replaced by FUTEX_CMP_REQUEUE operation.
		 * Glibc versions prior to 2.3.3 fall back to FUTEX_WAKE when
		 * FUTEX_REQUEUE returned EINVAL.
		 */
		pem = pem_find(td->td_proc);
		if ((pem->flags & LINUX_XDEPR_REQUEUEOP) == 0) {
			linux_msg(td, "unsupported FUTEX_REQUEUE");
			pem->flags |= LINUX_XDEPR_REQUEUEOP;
			LIN_SDT_PROBE0(futex, linux_sys_futex,
			    deprecated_requeue);
		}
		return (EINVAL);

	case LINUX_FUTEX_WAIT_REQUEUE_PI:
		/* not yet implemented */
		pem = pem_find(td->td_proc);

Return to bug 255947

Lines 664-669 linux_sys_futex(struct thread td, struct linux_sys_futex_args args) Link Here

(-)b/sys/compat/linux/linux_futex.c (-17 / +24 lines)
664	struct timespec uts, *ts;	664	struct timespec uts, *ts;
665	int error, save;	665	int error, save;
666	uint32_t flags, val;	666	uint32_t flags, val;
		667	int no_compare;
667		668
668	if (args->op & LINUX_FUTEX_PRIVATE_FLAG) {	669	if (args->op & LINUX_FUTEX_PRIVATE_FLAG) {
669	flags = 0;	670	flags = 0;
Lines 688-693 linux_sys_futex(struct thread td, struct linux_sys_futex_args args) Link Here
688		689
689	error = 0;	690	error = 0;
690	f = f2 = NULL;	691	f = f2 = NULL;
		692	no_compare = 0; // for FUTEX_REQUEUE
691		693
692	switch (args->op) {	694	switch (args->op) {
693	case LINUX_FUTEX_WAIT:	695	case LINUX_FUTEX_WAIT:
Lines 767-772 linux_sys_futex(struct thread td, struct linux_sys_futex_args args) Link Here
767	futex_put(f, NULL);	769	futex_put(f, NULL);
768	break;	770	break;
769		771
		772	case LINUX_FUTEX_REQUEUE:
		773	/*
		774	* Glibc does not use this operation since version 2.3.3,
		775	* as it is racy and replaced by FUTEX_CMP_REQUEUE operation.
		776	* Glibc versions prior to 2.3.3 fall back to FUTEX_WAKE when
		777	* FUTEX_REQUEUE returned EINVAL.
		778	*/
		779	pem = pem_find(td->td_proc);
		780	if ((pem->flags & LINUX_XDEPR_REQUEUEOP) == 0) {
		781	linux_msg(td, "warn: deprecated FUTEX_REQUEUE");
		782	pem->flags \|= LINUX_XDEPR_REQUEUEOP;
		783	LIN_SDT_PROBE0(futex, linux_sys_futex,
		784	deprecated_requeue);
		785	}
		786	/*
		787	* The above is true, however musl libc does make use of the
		788	* futex requeue operation, so we add support for it.
		789	*/
		790	no_compare = 1;
		791	/* FALLTHROUGH */
		792
770	case LINUX_FUTEX_CMP_REQUEUE:	793	case LINUX_FUTEX_CMP_REQUEUE:
771	LIN_SDT_PROBE5(futex, linux_sys_futex, debug_cmp_requeue,	794	LIN_SDT_PROBE5(futex, linux_sys_futex, debug_cmp_requeue,
772	args->uaddr, args->val, args->val3, args->uaddr2,	795	args->uaddr, args->val, args->val3, args->uaddr2,
Lines 819-825 linux_sys_futex(struct thread td, struct linux_sys_futex_args args) Link Here
819	error);	842	error);
820	return (error);	843	return (error);
821	}	844	}
822	if (val != args->val3) {	845	if ((no_compare == 0) && val != args->val3) {
823	LIN_SDT_PROBE2(futex, linux_sys_futex,	846	LIN_SDT_PROBE2(futex, linux_sys_futex,
824	debug_cmp_requeue_value_neq, args->val, val);	847	debug_cmp_requeue_value_neq, args->val, val);
825	LINUX_CTR2(sys_futex, "CMP_REQUEUE val 0x%x != uval 0x%x",	848	LINUX_CTR2(sys_futex, "CMP_REQUEUE val 0x%x != uval 0x%x",
Lines 931-952 linux_sys_futex(struct thread td, struct linux_sys_futex_args args) Link Here
931	}	954	}
932	return (ENOSYS);	955	return (ENOSYS);
933		956
934	case LINUX_FUTEX_REQUEUE:
935	/*
936	* Glibc does not use this operation since version 2.3.3,
937	* as it is racy and replaced by FUTEX_CMP_REQUEUE operation.
938	* Glibc versions prior to 2.3.3 fall back to FUTEX_WAKE when
939	* FUTEX_REQUEUE returned EINVAL.
940	*/
941	pem = pem_find(td->td_proc);
942	if ((pem->flags & LINUX_XDEPR_REQUEUEOP) == 0) {
943	linux_msg(td, "unsupported FUTEX_REQUEUE");
944	pem->flags \|= LINUX_XDEPR_REQUEUEOP;
945	LIN_SDT_PROBE0(futex, linux_sys_futex,
946	deprecated_requeue);
947	}
948	return (EINVAL);
949
950	case LINUX_FUTEX_WAIT_REQUEUE_PI:	957	case LINUX_FUTEX_WAIT_REQUEUE_PI:
951	/* not yet implemented */	958	/* not yet implemented */
952	pem = pem_find(td->td_proc);	959	pem = pem_find(td->td_proc);