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| author | Dmitry V. Levin <ldv@altlinux.org> | 2015-12-01 00:54:36 +0300 |
|---|---|---|
| committer | Zefan Li <lizefan@huawei.com> | 2016-10-26 23:15:33 +0800 |
| commit | e4d7eafcedc0e277421854577984009b51fb07ec (patch) | |
| tree | ed40a9bff0bc9ed6e9cb55f3ea272b6e8957f278 | |
| parent | 55d4174137baddba6a0291a9abd6fbc6c13c3302 (diff) | |
| download | lwn-e4d7eafcedc0e277421854577984009b51fb07ec.tar.gz lwn-e4d7eafcedc0e277421854577984009b51fb07ec.zip | |
x86/signal: Fix restart_syscall number for x32 tasks
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: Zefan Li <lizefan@huawei.com>
| -rw-r--r-- | arch/x86/kernel/signal.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 115eac431483..b2952cac860f 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -748,12 +748,15 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, return 0; } -#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 @@ -795,7 +798,7 @@ 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; } |