From 30b4ae8a4498543863501f707879b7220b649602 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 4 Apr 2009 21:01:01 +0000 Subject: [PATCH 1/3] signals: split do_tkill Split out the code from do_tkill to make it reusable by the follow up patch which implements sys_rt_tgsigqueueinfo Signed-off-by: Thomas Gleixner Reviewed-by: Oleg Nesterov --- kernel/signal.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index d8034737db4c..56d27acad87e 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2278,24 +2278,17 @@ SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) return kill_something_info(sig, &info, pid); } -static int do_tkill(pid_t tgid, pid_t pid, int sig) +static int +do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) { - int error; - struct siginfo info; struct task_struct *p; unsigned long flags; - - error = -ESRCH; - info.si_signo = sig; - info.si_errno = 0; - info.si_code = SI_TKILL; - info.si_pid = task_tgid_vnr(current); - info.si_uid = current_uid(); + int error = -ESRCH; rcu_read_lock(); p = find_task_by_vpid(pid); if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { - error = check_kill_permission(sig, &info, p); + error = check_kill_permission(sig, info, p); /* * The null signal is a permissions and process existence * probe. No signal is actually delivered. @@ -2305,7 +2298,7 @@ static int do_tkill(pid_t tgid, pid_t pid, int sig) * signal is private anyway. */ if (!error && sig && lock_task_sighand(p, &flags)) { - error = specific_send_sig_info(sig, &info, p); + error = specific_send_sig_info(sig, info, p); unlock_task_sighand(p, &flags); } } @@ -2314,6 +2307,19 @@ static int do_tkill(pid_t tgid, pid_t pid, int sig) return error; } +static int do_tkill(pid_t tgid, pid_t pid, int sig) +{ + struct siginfo info; + + info.si_signo = sig; + info.si_errno = 0; + info.si_code = SI_TKILL; + info.si_pid = task_tgid_vnr(current); + info.si_uid = current_uid(); + + return do_send_specific(tgid, pid, sig, &info); +} + /** * sys_tgkill - send signal to one specific thread * @tgid: the thread group ID of the thread From 62ab4505e3efaf67784f84059e0fb9cedb1728ea Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 4 Apr 2009 21:01:06 +0000 Subject: [PATCH 2/3] signals: implement sys_rt_tgsigqueueinfo sys_kill has the per thread counterpart sys_tgkill. sigqueueinfo is missing a thread directed counterpart. Such an interface is important for migrating applications from other OSes which have the per thread delivery implemented. Signed-off-by: Thomas Gleixner Reviewed-by: Oleg Nesterov Acked-by: Roland McGrath Acked-by: Ulrich Drepper --- include/linux/compat.h | 2 ++ include/linux/signal.h | 2 ++ kernel/compat.c | 11 +++++++++++ kernel/signal.c | 26 ++++++++++++++++++++++++++ 4 files changed, 41 insertions(+) diff --git a/include/linux/compat.h b/include/linux/compat.h index f2ded21f9a3c..af931ee43dd8 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -222,6 +222,8 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from); int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from); int get_compat_sigevent(struct sigevent *event, const struct compat_sigevent __user *u_event); +long compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, compat_pid_t pid, int sig, + struct compat_siginfo __user *uinfo); static inline int compat_timeval_compare(struct compat_timeval *lhs, struct compat_timeval *rhs) diff --git a/include/linux/signal.h b/include/linux/signal.h index 84f997f8aa53..c7552836bd95 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -235,6 +235,8 @@ static inline int valid_signal(unsigned long sig) extern int next_signal(struct sigpending *pending, sigset_t *mask); extern int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p); extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *); +extern long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, + siginfo_t *info); extern long do_sigpending(void __user *, unsigned long); extern int sigprocmask(int, sigset_t *, sigset_t *); extern int show_unhandled_signals; diff --git a/kernel/compat.c b/kernel/compat.c index 42d56544460f..f6c204f07ea6 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -882,6 +882,17 @@ compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese, } +asmlinkage long +compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid, compat_pid_t pid, int sig, + struct compat_siginfo __user *uinfo) +{ + siginfo_t info; + + if (copy_siginfo_from_user32(&info, uinfo)) + return -EFAULT; + return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); +} + #ifdef __ARCH_WANT_COMPAT_SYS_TIME /* compat_time_t is a 32 bit "long" and needs to get converted. */ diff --git a/kernel/signal.c b/kernel/signal.c index 56d27acad87e..f79b3b9f8375 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2369,6 +2369,32 @@ SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, return kill_proc_info(sig, &info, pid); } +long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) +{ + /* This is only valid for single tasks */ + if (pid <= 0 || tgid <= 0) + return -EINVAL; + + /* Not even root can pretend to send signals from the kernel. + Nor can they impersonate a kill(), which adds source info. */ + if (info->si_code >= 0) + return -EPERM; + info->si_signo = sig; + + return do_send_specific(tgid, pid, sig, info); +} + +SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, + siginfo_t __user *, uinfo) +{ + siginfo_t info; + + if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) + return -EFAULT; + + return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); +} + int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) { struct task_struct *t = current; From 12d161147f828192b5bcc33166f468a827832767 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 4 Apr 2009 21:01:10 +0000 Subject: [PATCH 3/3] x86: hookup sys_rt_tgsigqueueinfo Make the new sys_rt_tgsigqueueinfo available for x86. Signed-off-by: Thomas Gleixner --- arch/x86/ia32/ia32entry.S | 1 + arch/x86/include/asm/unistd_32.h | 1 + arch/x86/include/asm/unistd_64.h | 2 ++ arch/x86/kernel/syscall_table_32.S | 1 + 4 files changed, 5 insertions(+) diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index a505202086e8..dcef387ddc36 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -830,4 +830,5 @@ ia32_sys_call_table: .quad sys_inotify_init1 .quad compat_sys_preadv .quad compat_sys_pwritev + .quad compat_sys_rt_tgsigqueueinfo /* 335 */ ia32_syscall_end: diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/asm/unistd_32.h index 6e72d74cf8dc..708dae61262d 100644 --- a/arch/x86/include/asm/unistd_32.h +++ b/arch/x86/include/asm/unistd_32.h @@ -340,6 +340,7 @@ #define __NR_inotify_init1 332 #define __NR_preadv 333 #define __NR_pwritev 334 +#define __NR_rt_tgsigqueueinfo 335 #ifdef __KERNEL__ diff --git a/arch/x86/include/asm/unistd_64.h b/arch/x86/include/asm/unistd_64.h index f81829462325..4e2b05404400 100644 --- a/arch/x86/include/asm/unistd_64.h +++ b/arch/x86/include/asm/unistd_64.h @@ -657,6 +657,8 @@ __SYSCALL(__NR_inotify_init1, sys_inotify_init1) __SYSCALL(__NR_preadv, sys_preadv) #define __NR_pwritev 296 __SYSCALL(__NR_pwritev, sys_pwritev) +#define __NR_rt_tgsigqueueinfo 297 +__SYSCALL(__NR_rt_tgsigqueueinfo, sys_rt_tgsigqueueinfo) #ifndef __NO_STUBS diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S index ff5c8736b491..734f92c02dde 100644 --- a/arch/x86/kernel/syscall_table_32.S +++ b/arch/x86/kernel/syscall_table_32.S @@ -334,3 +334,4 @@ ENTRY(sys_call_table) .long sys_inotify_init1 .long sys_preadv .long sys_pwritev + .long sys_rt_tgsigqueueinfo /* 335 */