Benjamin Herrenschmidt | 22e38f2 | 2007-06-04 15:15:49 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Common signal handling code for both 32 and 64 bits |
| 3 | * |
| 4 | * Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration |
| 5 | * Extracted from signal_32.c and signal_64.c |
| 6 | * |
| 7 | * This file is subject to the terms and conditions of the GNU General |
| 8 | * Public License. See the file README.legal in the main directory of |
| 9 | * this archive for more details. |
| 10 | */ |
| 11 | |
Roland McGrath | 6558ba2 | 2008-07-27 16:49:50 +1000 | [diff] [blame] | 12 | #include <linux/tracehook.h> |
Benjamin Herrenschmidt | 22e38f2 | 2007-06-04 15:15:49 +1000 | [diff] [blame] | 13 | #include <linux/signal.h> |
Ananth N Mavinakayanahalli | 8b7b80b | 2012-08-23 21:31:32 +0000 | [diff] [blame] | 14 | #include <linux/uprobes.h> |
Benjamin Herrenschmidt | 18b246f | 2012-02-22 16:48:32 +1100 | [diff] [blame] | 15 | #include <linux/key.h> |
K.Prasad | 06532a6 | 2010-06-15 11:35:41 +0530 | [diff] [blame] | 16 | #include <asm/hw_breakpoint.h> |
Benjamin Herrenschmidt | a3f61dc | 2007-06-04 17:22:48 +1000 | [diff] [blame] | 17 | #include <asm/uaccess.h> |
Benjamin Herrenschmidt | 22e38f2 | 2007-06-04 15:15:49 +1000 | [diff] [blame] | 18 | #include <asm/unistd.h> |
David Howells | ae3a197 | 2012-03-28 18:30:02 +0100 | [diff] [blame] | 19 | #include <asm/debug.h> |
Benjamin Herrenschmidt | 22e38f2 | 2007-06-04 15:15:49 +1000 | [diff] [blame] | 20 | |
Christoph Hellwig | db277e9 | 2007-06-04 15:15:51 +1000 | [diff] [blame] | 21 | #include "signal.h" |
| 22 | |
Olof Johansson | d0c3d53 | 2007-10-12 10:20:07 +1000 | [diff] [blame] | 23 | /* Log an error when sending an unhandled signal to a process. Controlled |
| 24 | * through debug.exception-trace sysctl. |
| 25 | */ |
| 26 | |
| 27 | int show_unhandled_signals = 0; |
| 28 | |
Benjamin Herrenschmidt | a3f61dc | 2007-06-04 17:22:48 +1000 | [diff] [blame] | 29 | /* |
| 30 | * Allocate space for the signal frame |
| 31 | */ |
| 32 | void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, |
Josh Boyer | efbda86 | 2009-03-25 06:23:59 +0000 | [diff] [blame] | 33 | size_t frame_size, int is_32) |
Benjamin Herrenschmidt | a3f61dc | 2007-06-04 17:22:48 +1000 | [diff] [blame] | 34 | { |
| 35 | unsigned long oldsp, newsp; |
| 36 | |
| 37 | /* Default to using normal stack */ |
Josh Boyer | efbda86 | 2009-03-25 06:23:59 +0000 | [diff] [blame] | 38 | oldsp = get_clean_sp(regs, is_32); |
Benjamin Herrenschmidt | a3f61dc | 2007-06-04 17:22:48 +1000 | [diff] [blame] | 39 | |
| 40 | /* Check for alt stack */ |
| 41 | if ((ka->sa.sa_flags & SA_ONSTACK) && |
| 42 | current->sas_ss_size && !on_sig_stack(oldsp)) |
| 43 | oldsp = (current->sas_ss_sp + current->sas_ss_size); |
| 44 | |
| 45 | /* Get aligned frame */ |
| 46 | newsp = (oldsp - frame_size) & ~0xFUL; |
| 47 | |
| 48 | /* Check access */ |
| 49 | if (!access_ok(VERIFY_WRITE, (void __user *)newsp, oldsp - newsp)) |
| 50 | return NULL; |
| 51 | |
| 52 | return (void __user *)newsp; |
| 53 | } |
| 54 | |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 55 | static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka, |
| 56 | int has_handler) |
Benjamin Herrenschmidt | 22e38f2 | 2007-06-04 15:15:49 +1000 | [diff] [blame] | 57 | { |
| 58 | unsigned long ret = regs->gpr[3]; |
| 59 | int restart = 1; |
| 60 | |
| 61 | /* syscall ? */ |
| 62 | if (TRAP(regs) != 0x0C00) |
| 63 | return; |
| 64 | |
| 65 | /* error signalled ? */ |
| 66 | if (!(regs->ccr & 0x10000000)) |
| 67 | return; |
| 68 | |
| 69 | switch (ret) { |
| 70 | case ERESTART_RESTARTBLOCK: |
| 71 | case ERESTARTNOHAND: |
| 72 | /* ERESTARTNOHAND means that the syscall should only be |
| 73 | * restarted if there was no handler for the signal, and since |
| 74 | * we only get here if there is a handler, we dont restart. |
| 75 | */ |
| 76 | restart = !has_handler; |
| 77 | break; |
| 78 | case ERESTARTSYS: |
| 79 | /* ERESTARTSYS means to restart the syscall if there is no |
| 80 | * handler or the handler was registered with SA_RESTART |
| 81 | */ |
| 82 | restart = !has_handler || (ka->sa.sa_flags & SA_RESTART) != 0; |
| 83 | break; |
| 84 | case ERESTARTNOINTR: |
| 85 | /* ERESTARTNOINTR means that the syscall should be |
| 86 | * called again after the signal handler returns. |
| 87 | */ |
| 88 | break; |
| 89 | default: |
| 90 | return; |
| 91 | } |
| 92 | if (restart) { |
| 93 | if (ret == ERESTART_RESTARTBLOCK) |
| 94 | regs->gpr[0] = __NR_restart_syscall; |
| 95 | else |
| 96 | regs->gpr[3] = regs->orig_gpr3; |
| 97 | regs->nip -= 4; |
| 98 | regs->result = 0; |
| 99 | } else { |
| 100 | regs->result = -EINTR; |
| 101 | regs->gpr[3] = EINTR; |
| 102 | regs->ccr |= 0x10000000; |
| 103 | } |
| 104 | } |
Christoph Hellwig | 69d15f6 | 2007-06-04 15:15:50 +1000 | [diff] [blame] | 105 | |
Benjamin Herrenschmidt | 18b246f | 2012-02-22 16:48:32 +1100 | [diff] [blame] | 106 | static int do_signal(struct pt_regs *regs) |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 107 | { |
Al Viro | b7f9a11 | 2012-05-02 09:59:21 -0400 | [diff] [blame] | 108 | sigset_t *oldset = sigmask_to_save(); |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 109 | siginfo_t info; |
| 110 | int signr; |
| 111 | struct k_sigaction ka; |
| 112 | int ret; |
| 113 | int is32 = is_32bit_task(); |
| 114 | |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 115 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| 116 | |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 117 | /* Is there any syscall restart business here ? */ |
| 118 | check_syscall_restart(regs, &ka, signr > 0); |
| 119 | |
| 120 | if (signr <= 0) { |
| 121 | /* No signal to deliver -- put the saved sigmask back */ |
Al Viro | 51a7b44 | 2012-05-21 23:33:55 -0400 | [diff] [blame] | 122 | restore_saved_sigmask(); |
Al Viro | 9a81c16 | 2010-09-20 21:48:57 +0100 | [diff] [blame] | 123 | regs->trap = 0; |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 124 | return 0; /* no signals delivered */ |
| 125 | } |
| 126 | |
Dave Kleikamp | 3bffb65 | 2010-02-08 11:51:18 +0000 | [diff] [blame] | 127 | #ifndef CONFIG_PPC_ADV_DEBUG_REGS |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 128 | /* |
| 129 | * Reenable the DABR before delivering the signal to |
| 130 | * user space. The DABR will have been cleared if it |
| 131 | * triggered inside the kernel. |
| 132 | */ |
Dave Kleikamp | 3bffb65 | 2010-02-08 11:51:18 +0000 | [diff] [blame] | 133 | if (current->thread.dabr) |
Michael Neuling | 4474ef0 | 2012-09-06 21:24:56 +0000 | [diff] [blame] | 134 | set_dabr(current->thread.dabr, current->thread.dabrx); |
Luis Machado | d6a61bf | 2008-07-24 02:10:41 +1000 | [diff] [blame] | 135 | #endif |
K.Prasad | 06532a6 | 2010-06-15 11:35:41 +0530 | [diff] [blame] | 136 | /* Re-enable the breakpoints for the signal stack */ |
| 137 | thread_change_pc(current, regs); |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 138 | |
| 139 | if (is32) { |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 140 | if (ka.sa.sa_flags & SA_SIGINFO) |
| 141 | ret = handle_rt_signal32(signr, &ka, &info, oldset, |
Benjamin Herrenschmidt | a3f61dc | 2007-06-04 17:22:48 +1000 | [diff] [blame] | 142 | regs); |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 143 | else |
| 144 | ret = handle_signal32(signr, &ka, &info, oldset, |
Benjamin Herrenschmidt | a3f61dc | 2007-06-04 17:22:48 +1000 | [diff] [blame] | 145 | regs); |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 146 | } else { |
| 147 | ret = handle_rt_signal64(signr, &ka, &info, oldset, regs); |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 148 | } |
| 149 | |
Al Viro | 9a81c16 | 2010-09-20 21:48:57 +0100 | [diff] [blame] | 150 | regs->trap = 0; |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 151 | if (ret) { |
Al Viro | efee984 | 2012-04-28 02:04:15 -0400 | [diff] [blame] | 152 | signal_delivered(signr, &info, &ka, regs, |
Roland McGrath | 6558ba2 | 2008-07-27 16:49:50 +1000 | [diff] [blame] | 153 | test_thread_flag(TIF_SINGLESTEP)); |
Christoph Hellwig | f478f54 | 2007-06-04 15:15:52 +1000 | [diff] [blame] | 154 | } |
| 155 | |
| 156 | return ret; |
| 157 | } |
| 158 | |
Benjamin Herrenschmidt | 18b246f | 2012-02-22 16:48:32 +1100 | [diff] [blame] | 159 | void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) |
Roland McGrath | 7d6d637 | 2008-07-27 16:52:52 +1000 | [diff] [blame] | 160 | { |
Oleg Nesterov | f57d56d | 2012-10-28 18:17:11 +0100 | [diff] [blame] | 161 | if (thread_info_flags & _TIF_UPROBE) |
Ananth N Mavinakayanahalli | 8b7b80b | 2012-08-23 21:31:32 +0000 | [diff] [blame] | 162 | uprobe_notify_resume(regs); |
Ananth N Mavinakayanahalli | 8b7b80b | 2012-08-23 21:31:32 +0000 | [diff] [blame] | 163 | |
Roland McGrath | 7d6d637 | 2008-07-27 16:52:52 +1000 | [diff] [blame] | 164 | if (thread_info_flags & _TIF_SIGPENDING) |
Benjamin Herrenschmidt | 18b246f | 2012-02-22 16:48:32 +1100 | [diff] [blame] | 165 | do_signal(regs); |
Roland McGrath | 7d6d637 | 2008-07-27 16:52:52 +1000 | [diff] [blame] | 166 | |
| 167 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
| 168 | clear_thread_flag(TIF_NOTIFY_RESUME); |
| 169 | tracehook_notify_resume(regs); |
| 170 | } |
| 171 | } |
| 172 | |
Christoph Hellwig | 69d15f6 | 2007-06-04 15:15:50 +1000 | [diff] [blame] | 173 | long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, |
| 174 | unsigned long r5, unsigned long r6, unsigned long r7, |
| 175 | unsigned long r8, struct pt_regs *regs) |
| 176 | { |
| 177 | return do_sigaltstack(uss, uoss, regs->gpr[1]); |
| 178 | } |