From: "Dmitry V. Levin" <ldv@altlinux.org>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Elvira Khabirova <lineprinter0@gmail.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] x86/signal: fix restart_syscall number for x32 tasks
Date: Tue, 1 Dec 2015 00:54:36 +0300 [thread overview]
Message-ID: <20151130215436.GA25996@altlinux.org> (raw)
When restarting a syscall with regs->ax == -ERESTART_RESTARTBLOCK,
regs->ax is assigned to a restart_syscall number. For x32 tasks,
this syscall number must have __X32_SYSCALL_BIT set, otherwise it
will be an x86_64 syscall number instead of a valid x32 syscall number.
Reported-by: strace/tests/restart_syscall.test
Reported-and-tested-by: Elvira Khabirova <lineprinter0@gmail.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: stable@vger.kernel.org
---
arch/x86/kernel/signal.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index b7ffb7c..cb6282c 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -690,12 +690,15 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
signal_setup_done(failed, ksig, stepping);
}
-#ifdef CONFIG_X86_32
-#define NR_restart_syscall __NR_restart_syscall
-#else /* !CONFIG_X86_32 */
-#define NR_restart_syscall \
- test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
-#endif /* CONFIG_X86_32 */
+static inline unsigned long get_nr_restart_syscall(const struct pt_regs *regs)
+{
+#if defined(CONFIG_X86_32) || !defined(CONFIG_X86_64)
+ return __NR_restart_syscall;
+#else /* !CONFIG_X86_32 && CONFIG_X86_64 */
+ return test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall :
+ __NR_restart_syscall | (regs->orig_ax & __X32_SYSCALL_BIT);
+#endif /* CONFIG_X86_32 || !CONFIG_X86_64 */
+}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
@@ -724,7 +727,7 @@ void do_signal(struct pt_regs *regs)
break;
case -ERESTART_RESTARTBLOCK:
- regs->ax = NR_restart_syscall;
+ regs->ax = get_nr_restart_syscall(regs);
regs->ip -= 2;
break;
}
--
ldv
next reply other threads:[~2015-11-30 21:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-30 21:54 Dmitry V. Levin [this message]
2015-12-05 17:55 ` [tip:x86/urgent] x86/signal: Fix restart_syscall number for x32 tasks tip-bot for Dmitry V. Levin
2015-12-07 23:22 [PATCH] x86/signal: fix " Andy Lutomirski
2015-12-13 3:44 ` Dmitry V. Levin
2015-12-17 20:27 ` Andy Lutomirski
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