Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 57/78] x86/signal: Fix restart_syscall number for x32 tasks | Date | Wed, 16 Dec 2015 16:39:41 -0800 |
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3.13.11-ckt32 -stable review patch. If anyone has any objections, please let me know.
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From: "Dmitry V. Levin" <ldv@altlinux.org>
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@gmail.com> Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Cc: Elvira Khabirova <lineprinter0@gmail.com> Link: http://lkml.kernel.org/r/20151130215436.GA25996@altlinux.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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 b88fc86..5d3e601 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -682,12 +682,15 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs) 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 @@ -716,7 +719,7 @@ static 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; } -- 1.9.1
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