This is a note to let you know that I've just added the patch titled
x86/signal: Fix restart_syscall number for x32 tasks
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-signal-fix-restart_syscall-number-for-x32-tasks.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 22eab1108781eff09961ae7001704f7bd8fb1dce Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@xxxxxxxxxxxx>
Date: Tue, 1 Dec 2015 00:54:36 +0300
Subject: x86/signal: Fix restart_syscall number for x32 tasks
From: "Dmitry V. Levin" <ldv@xxxxxxxxxxxx>
commit 22eab1108781eff09961ae7001704f7bd8fb1dce upstream.
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. This
issue has been there since the introduction of x32.
Reported-by: strace/tests/restart_syscall.test
Reported-and-tested-by: Elvira Khabirova <lineprinter0@xxxxxxxxx>
Signed-off-by: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
Cc: Elvira Khabirova <lineprinter0@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20151130215436.GA25996@xxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/signal.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -686,12 +686,15 @@ handle_signal(struct ksignal *ksig, stru
signal_setup_done(failed, ksig, test_thread_flag(TIF_SINGLESTEP));
}
-#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
@@ -720,7 +723,7 @@ static void do_signal(struct pt_regs *re
break;
case -ERESTART_RESTARTBLOCK:
- regs->ax = NR_restart_syscall;
+ regs->ax = get_nr_restart_syscall(regs);
regs->ip -= 2;
break;
}
Patches currently in stable-queue which might be from ldv@xxxxxxxxxxxx are
queue-3.10/x86-signal-fix-restart_syscall-number-for-x32-tasks.patch
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