Pandora Sourcecodes - openembedded.git/blob

   1 From 8a7643b09856f4f661403dcedbe0455b3cbeeea9 Mon Sep 17 00:00:00 2001
   2 From: Steven Newbury <s_j_newbury@yahoo.co.uk>
   3 Date: Fri, 22 May 2009 14:25:40 +0200
   4 Subject: [PATCH] implement TIF_RESTORE_SIGMASK support and enable the related
   5  syscalls:
   6
   7 pselect6
   8 ppoll
   9 epoll_pwait
  10
  11 Based on http://www.spinics.net/lists/arm-kernel/msg38114.html
  12 ---
  13  arch/arm/include/asm/thread_info.h |    2 +
  14  arch/arm/include/asm/unistd.h      |    7 ++-
  15  arch/arm/kernel/calls.S            |    6 +-
  16  arch/arm/kernel/signal.c           |   90 +++++++++++++++---------------------
  17  4 files changed, 46 insertions(+), 59 deletions(-)
  18
  19 diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
  20 index 4f88482..2cf0917 100644
  21 --- a/arch/arm/include/asm/thread_info.h
  22 +++ b/arch/arm/include/asm/thread_info.h
  23 @@ -136,6 +136,7 @@ extern void vfp_sync_state(struct thread_info *thread);
  24  #define TIF_SIGPENDING         0
  25  #define TIF_NEED_RESCHED       1
  26  #define TIF_SYSCALL_TRACE      8
  27 +#define TIF_RESTORE_SIGMASK    9       /* restore signal mask in do_signal */
  28  #define TIF_POLLING_NRFLAG     16
  29  #define TIF_USING_IWMMXT       17
  30  #define TIF_MEMDIE             18
  31 @@ -144,6 +145,7 @@ extern void vfp_sync_state(struct thread_info *thread);
  32  #define _TIF_SIGPENDING                (1 << TIF_SIGPENDING)
  33  #define _TIF_NEED_RESCHED      (1 << TIF_NEED_RESCHED)
  34  #define _TIF_SYSCALL_TRACE     (1 << TIF_SYSCALL_TRACE)
  35 +#define _TIF_RESTORE_SIGMASK   (1 << TIF_RESTORE_SIGMASK)
  36  #define _TIF_POLLING_NRFLAG    (1 << TIF_POLLING_NRFLAG)
  37  #define _TIF_USING_IWMMXT      (1 << TIF_USING_IWMMXT)
  38  #define _TIF_FREEZE            (1 << TIF_FREEZE)
  39 diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
  40 index 94cc58e..cd1eaa0 100644
  41 --- a/arch/arm/include/asm/unistd.h
  42 +++ b/arch/arm/include/asm/unistd.h
  43 @@ -360,8 +360,8 @@
  44  #define __NR_readlinkat                        (__NR_SYSCALL_BASE+332)
  45  #define __NR_fchmodat                  (__NR_SYSCALL_BASE+333)
  46  #define __NR_faccessat                 (__NR_SYSCALL_BASE+334)
  47 -                                       /* 335 for pselect6 */
  48 -                                       /* 336 for ppoll */
  49 +#define __NR_pselect6                  (__NR_SYSCALL_BASE+335)
  50 +#define __NR_ppoll                     (__NR_SYSCALL_BASE+336)
  51  #define __NR_unshare                   (__NR_SYSCALL_BASE+337)
  52  #define __NR_set_robust_list           (__NR_SYSCALL_BASE+338)
  53  #define __NR_get_robust_list           (__NR_SYSCALL_BASE+339)
  54 @@ -372,7 +372,7 @@
  55  #define __NR_vmsplice                  (__NR_SYSCALL_BASE+343)
  56  #define __NR_move_pages                        (__NR_SYSCALL_BASE+344)
  57  #define __NR_getcpu                    (__NR_SYSCALL_BASE+345)
  58 -                                       /* 346 for epoll_pwait */
  59 +#define __NR_epoll_pwait               (__NR_SYSCALL_BASE+346)
  60  #define __NR_kexec_load                        (__NR_SYSCALL_BASE+347)
  61  #define __NR_utimensat                 (__NR_SYSCALL_BASE+348)
  62  #define __NR_signalfd                  (__NR_SYSCALL_BASE+349)
  63 @@ -430,6 +430,7 @@
  64  #define __ARCH_WANT_SYS_SIGPENDING
  65  #define __ARCH_WANT_SYS_SIGPROCMASK
  66  #define __ARCH_WANT_SYS_RT_SIGACTION
  67 +#define __ARCH_WANT_SYS_RT_SIGSUSPEND
  68
  69  #if !defined(CONFIG_AEABI) || defined(CONFIG_OABI_COMPAT)
  70  #define __ARCH_WANT_SYS_TIME
  71 diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
  72 index 1680e9e..534000d 100644
  73 --- a/arch/arm/kernel/calls.S
  74 +++ b/arch/arm/kernel/calls.S
  75 @@ -344,8 +344,8 @@
  76                 CALL(sys_readlinkat)
  77                 CALL(sys_fchmodat)
  78                 CALL(sys_faccessat)
  79 -/* 335 */      CALL(sys_ni_syscall)            /* eventually pselect6 */
  80 -               CALL(sys_ni_syscall)            /* eventually ppoll */
  81 +/* 335 */      CALL(sys_pselect6)
  82 +               CALL(sys_ppoll)
  83                 CALL(sys_unshare)
  84                 CALL(sys_set_robust_list)
  85                 CALL(sys_get_robust_list)
  86 @@ -355,7 +355,7 @@
  87                 CALL(sys_vmsplice)
  88                 CALL(sys_move_pages)
  89  /* 345 */      CALL(sys_getcpu)
  90 -               CALL(sys_ni_syscall)            /* eventually epoll_pwait */
  91 +               CALL(sys_epoll_pwait)
  92                 CALL(sys_kexec_load)
  93                 CALL(sys_utimensat)
  94                 CALL(sys_signalfd)
  95 diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
  96 index 80b8b5c..7645048 100644
  97 --- a/arch/arm/kernel/signal.c
  98 +++ b/arch/arm/kernel/signal.c
  99 @@ -47,57 +47,23 @@ const unsigned long sigreturn_codes[7] = {
 100         MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
 101  };
 102
 103 -static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);
 104 +static void do_signal(struct pt_regs * regs, int syscall);
 105
 106  /*
 107   * atomically swap in the new signal mask, and wait for a signal.
 108   */
 109 -asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
 110 +asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)
 111  {
 112 -       sigset_t saveset;
 113 -
 114         mask &= _BLOCKABLE;
 115         spin_lock_irq(&current->sighand->siglock);
 116 -       saveset = current->blocked;
 117 +       current->saved_sigmask = current->blocked;
 118         siginitset(&current->blocked, mask);
 119         recalc_sigpending();
 120         spin_unlock_irq(&current->sighand->siglock);
 121 -       regs->ARM_r0 = -EINTR;
 122 -
 123 -       while (1) {
 124 -               current->state = TASK_INTERRUPTIBLE;
 125 -               schedule();
 126 -               if (do_signal(&saveset, regs, 0))
 127 -                       return regs->ARM_r0;
 128 -       }
 129 -}
 130 -
 131 -asmlinkage int
 132 -sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
 133 -{
 134 -       sigset_t saveset, newset;
 135 -
 136 -       /* XXX: Don't preclude handling different sized sigset_t's. */
 137 -       if (sigsetsize != sizeof(sigset_t))
 138 -               return -EINVAL;
 139 -
 140 -       if (copy_from_user(&newset, unewset, sizeof(newset)))
 141 -               return -EFAULT;
 142 -       sigdelsetmask(&newset, ~_BLOCKABLE);
 143 -
 144 -       spin_lock_irq(&current->sighand->siglock);
 145 -       saveset = current->blocked;
 146 -       current->blocked = newset;
 147 -       recalc_sigpending();
 148 -       spin_unlock_irq(&current->sighand->siglock);
 149 -       regs->ARM_r0 = -EINTR;
 150 -
 151 -       while (1) {
 152 -               current->state = TASK_INTERRUPTIBLE;
 153 -               schedule();
 154 -               if (do_signal(&saveset, regs, 0))
 155 -                       return regs->ARM_r0;
 156 -       }
 157 +       current->state = TASK_INTERRUPTIBLE;
 158 +       schedule();
 159 +       set_thread_flag(TIF_RESTORE_SIGMASK);
 160 +       return -ERESTARTNOHAND;
 161  }
 162
 163  asmlinkage int
 164 @@ -290,7 +256,7 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs)
 165
 166  badframe:
 167         force_sig(SIGSEGV, current);
 168 -       return 0;
 169 +       return -EFAULT;
 170  }
 171
 172  asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 173 @@ -325,7 +291,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
 174
 175  badframe:
 176         force_sig(SIGSEGV, current);
 177 -       return 0;
 178 +       return -EFAULT;
 179  }
 180
 181  static int
 182 @@ -541,7 +507,7 @@ static inline void restart_syscall(struct pt_regs *regs)
 183  /*
 184   * OK, we're invoking a handler
 185   */
 186 -static void
 187 +static int
 188  handle_signal(unsigned long sig, struct k_sigaction *ka,
 189               siginfo_t *info, sigset_t *oldset,
 190               struct pt_regs * regs, int syscall)
 191 @@ -592,7 +558,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 192
 193         if (ret != 0) {
 194                 force_sigsegv(sig, tsk);
 195 -               return;
 196 +               return ret;
 197         }
 198
 199         /*
 200 @@ -606,6 +572,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 201         recalc_sigpending();
 202         spin_unlock_irq(&tsk->sighand->siglock);
 203
 204 +       return ret;
 205  }
 206
 207  /*
 208 @@ -617,11 +584,12 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,
 209   * the kernel can handle, and then we build all the user-level signal handling
 210   * stack-frames in one go after that.
 211   */
 212 -static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
 213 +static void do_signal(struct pt_regs *regs, int syscall)
 214  {
 215         struct k_sigaction ka;
 216         siginfo_t info;
 217         int signr;
 218 +       sigset_t *oldset;
 219
 220         /*
 221          * We want the common case to go fast, which
 222 @@ -630,18 +598,29 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
 223          * if so.
 224          */
 225         if (!user_mode(regs))
 226 -               return 0;
 227 +               return;
 228
 229         if (try_to_freeze())
 230                 goto no_signal;
 231
 232         single_step_clear(current);
 233
 234 +       if (test_thread_flag(TIF_RESTORE_SIGMASK))
 235 +               oldset = &current->saved_sigmask;
 236 +       else
 237 +               oldset = &current->blocked;
 238 +
 239         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 240         if (signr > 0) {
 241 -               handle_signal(signr, &ka, &info, oldset, regs, syscall);
 242 +               if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 0) {
 243 +                       /* a signal was successfully delivered; the saved
 244 +                        * sigmask will have been stored in the signal frame,
 245 +                        * and will be restored by sigreturn, so we can simply
 246 +                        * clear the TIF_RESTORE_SIGMASK flag */
 247 +                       clear_thread_flag(TIF_RESTORE_SIGMASK);
 248 +               }
 249                 single_step_set(current);
 250 -               return 1;
 251 +               return;
 252         }
 253
 254   no_signal:
 255 @@ -665,7 +644,7 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
 256                                 usp = (u32 __user *)regs->ARM_sp;
 257
 258                                 /*
 259 -                                * Either we supports OABI only, or we have
 260 +                                * Either we support OABI only, or we have
 261                                  * EABI with the OABI compat layer enabled.
 262                                  * In the later case we don't know if user
 263                                  * space is EABI or not, and if not we must
 264 @@ -695,12 +674,17 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)
 265                 }
 266         }
 267         single_step_set(current);
 268 -       return 0;
 269 +        /* if there's no signal to deliver, we just put the saved sigmask
 270 +           back. */
 271 +               if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
 272 +                       clear_thread_flag(TIF_RESTORE_SIGMASK);
 273 +                       sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 274 +               }
 275  }
 276
 277  asmlinkage void
 278  do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 279  {
 280 -       if (thread_flags & _TIF_SIGPENDING)
 281 -               do_signal(&current->blocked, regs, syscall);
 282 +       if (thread_flags & (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK))
 283 +               do_signal(regs, syscall);
 284  }
 285 --
 286 1.6.2.4
 287