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From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
	Jan Kratochvil <jan.kratochvil@redhat.com>,
	Pedro Alves <palves@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 0/1] get_nr_restart_syscall() should return __NR_ia32_restart_syscall if __USER32_CS
Date: Tue, 28 Mar 2017 16:54:13 +0200	[thread overview]
Message-ID: <20170328145413.GA3164@redhat.com> (raw)

Hello,

get_nr_restart_syscall() is still buggy, TS_I386_REGS_POKED can't
really help and should probably die.

The fix just adds the __USER32_CS check, but perhaps we can avoid
these "fundamentally broken" checks altogether?

Is __NR_ia32_restart_syscall/__NR_restart_syscall the part of ABI?
OK, we probaly can't remove them, at least right now. But what if
we simply add the new syscall number,

	#define __NR_new_restart_syscall	383
	#define __NR_ia32_new_restart_syscall	383

so that it doesn't depends on bitness and we can just do

	static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
	{
		BUILD_BUG_ON(__NR_ia32_new_restart_syscall != __NR_new_restart_syscall);
	#ifdef CONFIG_X86_X32_ABI
		return __NR_new_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
	#else
		return __NR_new_restart_syscall;
	#endif
	}

?

Oleg.

             reply	other threads:[~2017-03-28 15:05 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-28 14:54 Oleg Nesterov [this message]
2017-03-28 14:54 ` [PATCH 1/1] get_nr_restart_syscall() should return __NR_ia32_restart_syscall if __USER32_CS Oleg Nesterov
2017-03-28 15:03   ` Andy Lutomirski
2017-03-28 16:27     ` Oleg Nesterov
2017-03-28 17:10       ` Andy Lutomirski
2017-03-29 15:05       ` Oleg Nesterov
2017-03-29 16:59         ` Andy Lutomirski
2017-03-30 15:28           ` Oleg Nesterov
2017-03-30 18:36             ` Andy Lutomirski
2017-03-29 16:33 ` syscall_get_error() && TS_ checks Oleg Nesterov
2017-03-29 16:45   ` Linus Torvalds
2017-03-29 16:55     ` Oleg Nesterov
2017-03-29 16:59       ` Linus Torvalds
2017-03-29 17:04         ` Oleg Nesterov
2017-03-29 17:16           ` Linus Torvalds
2017-03-29 18:50             ` Oleg Nesterov
2017-03-29 18:56               ` Linus Torvalds
2017-03-30 13:51                 ` Oleg Nesterov
2017-03-30 15:49                   ` Oleg Nesterov
2017-03-30 17:46                     ` Linus Torvalds
2017-03-30 18:23                       ` Andy Lutomirski
2017-03-30 18:35                         ` Linus Torvalds
2017-03-30 18:59                           ` Andy Lutomirski
2017-03-30 19:11                             ` Linus Torvalds
2017-03-30 19:21                               ` Andy Lutomirski
2017-03-30 19:29                                 ` Linus Torvalds
2017-03-29 16:56     ` Andy Lutomirski

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