diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-01 11:53:44 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-06-01 11:53:44 -0700 |
commit | 86c47b70f62a7072d441ba212aab33c2f82627c2 (patch) | |
tree | d03988bd2226966352bb7f3c2e82ff545353d2c4 | |
parent | 1193755ac6328ad240ba987e6ec41d5e8baf0680 (diff) | |
parent | 44fbbb3dc687c9709a6f2236197316e5c79ab1eb (diff) |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull third pile of signal handling patches from Al Viro:
"This time it's mostly helpers and conversions to them; there's a lot
of stuff remaining in the tree, but that'll either go in -rc2
(isolated bug fixes, ideally via arch maintainers' trees) or will sit
there until the next cycle."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
x86: get rid of calling do_notify_resume() when returning to kernel mode
blackfin: check __get_user() return value
whack-a-mole with TIF_FREEZE
FRV: Optimise the system call exit path in entry.S [ver #2]
FRV: Shrink TIF_WORK_MASK [ver #2]
FRV: Prevent syscall exit tracing and notify_resume at end of kernel exceptions
new helper: signal_delivered()
powerpc: get rid of restore_sigmask()
most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
set_restore_sigmask() is never called without SIGPENDING (and never should be)
TIF_RESTORE_SIGMASK can be set only when TIF_SIGPENDING is set
don't call try_to_freeze() from do_signal()
pull clearing RESTORE_SIGMASK into block_sigmask()
sh64: failure to build sigframe != signal without handler
openrisc: tracehook_signal_handler() is supposed to be called on success
new helper: sigmask_to_save()
new helper: restore_saved_sigmask()
new helpers: {clear,test,test_and_clear}_restore_sigmask()
HAVE_RESTORE_SIGMASK is defined on all architectures now
68 files changed, 482 insertions, 1091 deletions
diff --git a/arch/alpha/kernel/signal.c b/arch/alpha/kernel/signal.c index f6db3032ddf0..a8c97d42ec8e 100644 --- a/arch/alpha/kernel/signal.c +++ b/arch/alpha/kernel/signal.c @@ -226,7 +226,6 @@ do_sigreturn(struct sigcontext __user *sc, struct pt_regs *regs, if (__get_user(set.sig[0], &sc->sc_mask)) goto give_sigsegv; - sigdelsetmask(&set, ~_BLOCKABLE); set_current_blocked(&set); if (restore_sigcontext(sc, regs, sw)) @@ -261,7 +260,6 @@ do_rt_sigreturn(struct rt_sigframe __user *frame, struct pt_regs *regs, if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto give_sigsegv; - sigdelsetmask(&set, ~_BLOCKABLE); set_current_blocked(&set); if (restore_sigcontext(&frame->uc.uc_mcontext, regs, sw)) @@ -468,12 +466,9 @@ static inline void handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, struct pt_regs * regs, struct switch_stack *sw) { - sigset_t *oldset = ¤t->blocked; + sigset_t *oldset = sigmask_to_save(); int ret; - if (test_thread_flag(TIF_RESTORE_SIGMASK)) - oldset = ¤t->saved_sigmask; - if (ka->sa.sa_flags & SA_SIGINFO) ret = setup_rt_frame(sig, ka, info, oldset, regs, sw); else @@ -483,12 +478,7 @@ handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, force_sigsegv(sig, current); return; } - block_sigmask(ka, sig); - /* A signal was successfully delivered, and the - saved sigmask was stored on the signal frame, - and will be restored by sigreturn. So we can - simply clear the restore sigmask flag. */ - clear_thread_flag(TIF_RESTORE_SIGMASK); + signal_delivered(sig, info, ka, regs, 0); } static inline void @@ -572,9 +562,7 @@ do_signal(struct pt_regs * regs, struct switch_stack * sw, } /* If there's no signal to deliver, we just restore the saved mask. */ - if (test_and_clear_thread_flag(TIF_RESTORE_SIGMASK)) - set_current_blocked(¤t->saved_sigmask); - + restore_saved_sigmask(); if (single_stepping) ptrace_set_bpt(current); /* re-set breakpoint */ } diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index 63f327dd5198..fd2392a17ac1 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -22,8 +22,6 @@ #include "signal.h" -#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) - /* * For ARM syscalls, we encode the syscall number into the instruction. */ @@ -210,10 +208,8 @@ static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) int err; err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); - if (err == 0) { - sigdelsetmask(&set, ~_BLOCKABLE); + if (err == 0) set_current_blocked(&set); - } __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); @@ -528,13 +524,13 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, /* * OK, we're invoking a handler */ -static int +static void handle_signal(unsigned long sig, struct k_sigaction *ka, - siginfo_t *info, sigset_t *oldset, - struct pt_regs * regs) + siginfo_t *info, struct pt_regs *regs) { struct thread_info *thread = current_thread_info(); struct task_struct *tsk = current; + sigset_t *oldset = sigmask_to_save(); int usig = sig; int ret; @@ -559,17 +555,9 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, if (ret != 0) { force_sigsegv(sig, tsk); - return ret; + return; } - - /* - * Block the signal if we were successful. - */ - block_sigmask(ka, sig); - - tracehook_signal_handler(sig, info, ka, regs, 0); - - return 0; + signal_delivered(sig, info, ka, regs, 0); } /* @@ -617,8 +605,6 @@ static void do_signal(struct pt_regs *regs, int syscall) */ signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { - sigset_t *oldset; - /* * Depending on the signal settings we may need to revert the * decision to restart the system call. But skip this if a @@ -635,20 +621,7 @@ static void do_signal(struct pt_regs *regs, int syscall) clear_thread_flag(TIF_SYSCALL_RESTARTSYS); } - if (test_thread_flag(TIF_RESTORE_SIGMASK)) - oldset = ¤t->saved_sigmask; - else - oldset = ¤t->blocked; - if (handle_signal(signr, &ka, &info, oldset, regs) == 0) { - /* - * A signal was successfully delivered; the saved - * sigmask will have been stored in the signal frame, - * and will be restored by sigreturn, so we can simply - * clear the TIF_RESTORE_SIGMASK flag. - */ - if (test_thread_flag(TIF_RESTORE_SIGMASK)) - clear_thread_flag(TIF_RESTORE_SIGMASK); - } + handle_signal(signr, &ka, &info, regs); return; } @@ -663,11 +636,7 @@ static void do_signal(struct pt_regs *regs, int syscall) set_thread_flag(TIF_SYSCALL_RESTARTSYS); } - /* If there's no signal to deliver, we just put the saved sigmask - * back. - */ - if (test_and_clear_thread_flag(TIF_RESTORE_SIGMASK)) - set_current_blocked(¤t->saved_sigmask); + restore_saved_sigmask(); } asmlinkage void diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S index 5e6beb2597a8..df2884181313 100644 --- a/arch/avr32/kernel/entry-avr32b.S +++ b/arch/avr32/kernel/entry-avr32b.S @@ -281,7 +281,7 @@ syscall_exit_work: ld.w r1, r0[TI_flags] rjmp 1b -2: mov r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NOTIFY_RESUME +2: mov r2, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME tst r1, r2 breq 3f unmask_interrupts @@ -587,7 +587,7 @@ fault_exit_work: ld.w r1, r0[TI_flags] rjmp fault_exit_work -1: mov r2, _TIF_SIGPENDING | _TIF_RESTORE_SIGMASK | _TIF_NOTIFY_RESUME +1: mov r2, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME tst r1, r2 breq 2f unmask_interrupts diff --git a/arch/avr32/kernel/signal.c b/arch/avr32/kernel/signal.c index e7595ef74f51..c140f9b41dce 100644 --- a/arch/avr32/kernel/signal.c +++ b/arch/avr32/kernel/signal.c @@ -22,8 +22,6 @@ #include <asm/ucontext.h> #include <asm/syscalls.h> -#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) - asmlinkage int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, struct pt_regs *regs) { @@ -89,7 +87,6 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; - sigdelsetmask(&set, ~_BLOCKABLE); set_current_blocked(&set); if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) @@ -224,30 +221,27 @@ static inline void setup_syscall_restart(struct pt_regs *regs) static inline void handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, - sigset_t *oldset, struct pt_regs *regs, int syscall) + struct pt_regs *regs, int syscall) { int ret; /* * Set up the stack frame */ - ret = setup_rt_frame(sig, ka, info, oldset, regs); + ret = setup_rt_frame(sig, ka, info, sigmask_to_save(), regs); /* * Check that the resulting registers are sane */ ret |= !valid_user_regs(regs); - if (ret != 0) { - force_sigsegv(sig, current); - return; - } - /* * Block the signal if we were successful. */ - block_sigmask(ka, sig); - clear_thread_flag(TIF_RESTORE_SIGMASK); + if (ret != 0) + force_sigsegv(sig, current); + else + signal_delivered(sig, info, ka, regs, 0); } /* @@ -255,7 +249,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, * doesn't want to handle. Thus you cannot kill init even with a * SIGKILL even by mistake. */ -int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall) +static void do_signal(struct pt_regs *regs, int syscall) { siginfo_t info; int signr; @@ -267,12 +261,7 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall) * without doing anything if so. */ if (!user_mode(regs)) - return 0; - - if (test_thread_flag(TIF_RESTORE_SIGMASK)) - oldset = ¤t->saved_sigmask; - else if (!oldset) - oldset = ¤t->blocked; + return; signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (syscall) { @@ -297,15 +286,11 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset, int syscall) if (signr == 0) { /* No signal to deliver -- put the saved sigmask back */ - if (test_thread_flag(TIF_RESTORE_SIGMASK)) { - clear_thread_flag(TIF_RESTORE_SIGMASK); - sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); - } - return 0; + restore_saved_sigmask(); + return; } - handle_signal(signr, &ka, &info, oldset, regs, syscall); - return 1; + handle_signal(signr, &ka, &info, regs, syscall); } asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti) @@ -315,8 +300,8 @@ asmlinkage void do_notify_resume(struct pt_regs *regs, struct thread_info *ti) if ((sysreg_read(SR) & MODE_MASK) == MODE_SUPERVISOR) syscall = 1; - if (ti->flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) - do_signal(regs, ¤t->blocked, syscall); + if (ti->flags & _TIF_SIGPENDING)) + do_signal(regs, syscall); if (ti->flags & _TIF_NOTIFY_RESUME) { clear_thread_flag(TIF_NOTIFY_RESUME); diff --git a/arch/blackfin/include/asm/thread_info.h b/arch/blackfin/include/asm/thread_info.h index 02560fd8a121..53ad10005ae3 100644 --- a/arch/blackfin/include/asm/thread_info.h +++ b/arch/blackfin/include/asm/thread_info.h @@ -100,7 +100,6 @@ static inline struct thread_info *current_thread_info(void) TIF_NEED_RESCHED */ #define TIF_MEMDIE 4 /* is terminating due to OOM killer */ #define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */ -#define TIF_FREEZE 6 /* is freezing for suspend */ #define TIF_IRQ_SYNC 7 /* sync pipeline stage */ #define TIF_NOTIFY_RESUME 8 /* callback before returning to user */ #define TIF_SINGLESTEP 9 @@ -111,7 +110,6 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) #define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG) #define _TIF_RESTORE_SIGMASK (1<<TIF_RESTORE_SIGMASK) -#define _TIF_FREEZE (1<<TIF_FREEZE) #define _TIF_IRQ_SYNC (1<<TIF_IRQ_SYNC) #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP) diff --git a/arch/blackfin/kernel/signal.c b/arch/blackfin/kernel/signal.c index fc9ecce8b6ce..6682b73a8523 100644 --- a/arch/blackfin/kernel/signal.c +++ b/arch/blackfin/kernel/signal.c @@ -19,8 +19,6 @@ #include <asm/fixed_code.h> #include <asm/syscall.h> -#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) - /* Location of the trace bit in SYSCFG. */ #define TRACE_BITS 0x0001 @@ -98,7 +96,6 @@ asmlinkage int do_rt_sigreturn(unsigned long __unused) if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; - sigdelsetmask(&set, ~_BLOCKABLE); set_current_blocked(&set); if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) @@ -190,17 +187,22 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info, err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); if (err) - goto give_sigsegv; + return -EFAULT; /* Set up registers for signal handler */ - wrusp((unsigned long)frame); if (current->personality & FDPIC_FUNCPTRS) { struct fdpic_func_descriptor __user *funcptr = (struct fdpic_func_descriptor *) ka->sa.sa_handler; - __get_user(regs->pc, &funcptr->text); - __get_user(regs->p3, &funcptr->GOT); + u32 pc, p3; + err |= __get_user(pc, &funcptr->text); + err |= __get_user(p3, &funcptr->GOT); + if (err) + return -EFAULT; + regs->pc = pc; + regs->p3 = p3; } else regs->pc = (unsigned long)ka->sa.sa_handler; + wrusp((unsigned long)frame); regs->rets = SIGRETURN_STUB; regs->r0 = frame->sig; @@ -208,10 +210,6 @@ setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t * info, regs->r2 = (unsigned long)(&frame->uc); return 0; - - give_sigsegv: - force_sigsegv(sig, current); - return -EFAULT; } static inline void @@ -247,24 +245,21 @@ handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) /* * OK, we're invoking a handler */ -static int +static void handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka, - sigset_t *oldset, struct pt_regs *regs) + struct pt_regs *regs) { - int ret; - /* are we from a system call? to see pt_regs->orig_p0 */ if (regs->orig_p0 >= 0) /* If so, check system call restarting.. */ handle_restart(regs, ka, 1); /* set up the stack frame */ - ret = setup_rt_frame(sig, ka, info, oldset, regs); - - if (ret == 0) - block_sigmask(ka, sig); - - return ret; + if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs) < 0) + force_sigsegv(sig, current); + else + signal_delivered(sig, info, ka, regs, + test_thread_flag(TIF_SINGLESTEP)); } /* @@ -281,37 +276,16 @@ asmlinkage void do_signal(struct pt_regs *regs) siginfo_t info; int signr; struct k_sigaction ka; - sigset_t *oldset; current->thread.esp0 = (unsigned long)regs; - if (try_to_freeze()) - goto no_signal; - - if (test_thread_flag(TIF_RESTORE_SIGMASK)) - oldset = ¤t->saved_sigmask; - else - oldset = ¤t->blocked; - signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { /* Whee! Actually deliver the signal. */ - if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { - /* a signal was successfully delivered; the saved - * sigmask will have been stored in the signal frame, - * and will be restored by sigreturn, so we can simply - * clear the TIF_RESTORE_SIGMASK flag */ - if (test_thread_flag(TIF_RESTORE_SIGMASK)) - clear_thread_flag(TIF_RESTORE_SIGMASK); - - tracehook_signal_handler(signr, &info, &ka, regs, - test_thread_flag(TIF_SINGLESTEP)); - } - + handle_signal(signr, &info, &ka, regs); return; } - no_signal: /* Did we come from a system call? */ if (regs->orig_p0 >= 0) /* Restart the system call - no handlers present */ @@ -319,10 +293,7 @@ asmlinkage void do_signal(struct pt_regs *regs) /* if there's no signal to deliver, we just put the saved sigmask * back */ - if (test_thread_flag(TIF_RESTORE_SIGMASK)) { - clear_thread_flag(TIF_RESTORE_SIGMASK); - sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); - } + restore_saved_sigmask(); } /* @@ -330,7 +301,7 @@ asmlinkage void do_signal(struct pt_regs *regs) */ asmlinkage void do_notify_resume(struct pt_regs *regs) { - if (test_thread_flag(TIF_SIGPENDING) || test_thread_flag(TIF_RESTORE_SIGMASK)) + if (test_thread_flag(TIF_SIGPENDING)) do_signal(regs); if (test_thread_flag(TIF_NOTIFY_RESUME)) { diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S index 80aa2535e2c9..04c2fbe41a7f 100644 --- a/arch/blackfin/mach-common/entry.S +++ b/arch/blackfin/mach-common/entry.S @@ -711,8 +711,6 @@ ENTRY(_system_call) jump .Lresume_userspace_1; .Lsyscall_sigpending: - cc = BITTST(r7, TIF_RESTORE_SIGMASK); - if cc jump .Lsyscall_do_signals; cc = BITTST(r7, TIF_SIGPENDING); if cc jump .Lsyscall_do_signals; cc = BITTST(r7, TIF_NOTIFY_RESUME); diff --git a/arch/c6x/kernel/signal.c b/arch/c6x/kernel/signal.c index 9493f0bbf0a6..3d8f3c22a94f 100644 --- a/arch/c6x/kernel/signal.c +++ b/arch/c6x/kernel/signal.c @@ -20,8 +20,6 @@ #include <asm/cacheflush.h> -#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) - /* * Do a signal return, undo the signal stack. */ @@ -87,7 +85,6 @@ asmlinkage int do_rt_sigreturn(struct pt_regs *regs) if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) goto badframe; - sigdelsetmask(&set, ~_BLOCKABLE); set_current_blocked(&set); if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) @@ -248,10 +245,9 @@ do_restart: /* * handle the actual delivery of a signal to userspace */ -static int handle_signal(int sig, +static void handle_signal(int sig, siginfo_t *info, struct k_sigaction *ka, - sigset_t *oldset, struct pt_regs *regs, - int syscall) + struct pt_regs *regs, int syscall) { int ret; @@ -278,11 +274,9 @@ static int handle_signal(int sig, } /* Set up the stack frame */ - ret = setup_rt_frame(sig, ka, info, oldset, regs); - if (ret == 0) - block_sigmask(ka, sig); - - return ret; + if (setup_rt_frame(sig, ka, info, sigmask_to_save(), regs) < 0) + return; + signal_delivered(sig, info, ka, regs, 0); } /* @@ -292,7 +286,6 @@ static void do_signal(struct pt_regs *regs, int syscall) { struct k_sigaction ka; siginfo_t info; - sigset_t *oldset; int signr; /* we want the common case to go fast, which is why we may in certain @@ -300,25 +293,9 @@ stat |