recipes/linux/omap3-pandora-kernel/0001-implement-TIF_RESTORE_SIGMASK-support-and-enable-the.patch

   1 From 000afb0c667a638d5dd2eede868ec2e7e852f0bb Mon Sep 17 00:00:00 2001\r
   2 From: Steven Newbury <s_j_newbury@yahoo.co.uk>\r
   3 Date: Fri, 22 May 2009 14:25:40 +0200\r
   4 Subject: [PATCH] implement TIF_RESTORE_SIGMASK support and enable the related\r
   5  syscalls:\r
   6 \r
   7 pselect6\r
   8 ppoll\r
   9 epoll_pwait\r
  10 \r
  11 Based on http://www.spinics.net/lists/arm-kernel/msg38114.html\r
  12 ---\r
  13  arch/arm/include/asm/unistd.h |    7 ++-\r
  14  arch/arm/kernel/calls.S       |    6 +-\r
  15  arch/arm/kernel/signal.c      |   90 +++++++++++++++++------------------------\r
  16  3 files changed, 44 insertions(+), 59 deletions(-)\r
  17 \r
  18 diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h\r
  19 index 94cc58e..cd1eaa0 100644\r
  20 --- a/arch/arm/include/asm/unistd.h\r
  21 +++ b/arch/arm/include/asm/unistd.h\r
  22 @@ -360,8 +360,8 @@\r
  23  #define __NR_readlinkat                        (__NR_SYSCALL_BASE+332)\r
  24  #define __NR_fchmodat                  (__NR_SYSCALL_BASE+333)\r
  25  #define __NR_faccessat                 (__NR_SYSCALL_BASE+334)\r
  26 -                                       /* 335 for pselect6 */\r
  27 -                                       /* 336 for ppoll */\r
  28 +#define __NR_pselect6                  (__NR_SYSCALL_BASE+335)\r
  29 +#define __NR_ppoll                     (__NR_SYSCALL_BASE+336)\r
  30  #define __NR_unshare                   (__NR_SYSCALL_BASE+337)\r
  31  #define __NR_set_robust_list           (__NR_SYSCALL_BASE+338)\r
  32  #define __NR_get_robust_list           (__NR_SYSCALL_BASE+339)\r
  33 @@ -372,7 +372,7 @@\r
  34  #define __NR_vmsplice                  (__NR_SYSCALL_BASE+343)\r
  35  #define __NR_move_pages                        (__NR_SYSCALL_BASE+344)\r
  36  #define __NR_getcpu                    (__NR_SYSCALL_BASE+345)\r
  37 -                                       /* 346 for epoll_pwait */\r
  38 +#define __NR_epoll_pwait               (__NR_SYSCALL_BASE+346)\r
  39  #define __NR_kexec_load                        (__NR_SYSCALL_BASE+347)\r
  40  #define __NR_utimensat                 (__NR_SYSCALL_BASE+348)\r
  41  #define __NR_signalfd                  (__NR_SYSCALL_BASE+349)\r
  42 @@ -430,6 +430,7 @@\r
  43  #define __ARCH_WANT_SYS_SIGPENDING\r
  44  #define __ARCH_WANT_SYS_SIGPROCMASK\r
  45  #define __ARCH_WANT_SYS_RT_SIGACTION\r
  46 +#define __ARCH_WANT_SYS_RT_SIGSUSPEND\r
  47  \r
  48  #if !defined(CONFIG_AEABI) || defined(CONFIG_OABI_COMPAT)\r
  49  #define __ARCH_WANT_SYS_TIME\r
  50 diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S\r
  51 index 1680e9e..d9edf33 100644\r
  52 --- a/arch/arm/kernel/calls.S\r
  53 +++ b/arch/arm/kernel/calls.S\r
  54 @@ -344,8 +344,8 @@\r
  55                 CALL(sys_readlinkat)\r
  56                 CALL(sys_fchmodat)\r
  57                 CALL(sys_faccessat)\r
  58 -/* 335 */      CALL(sys_ni_syscall)            /* eventually pselect6 */\r
  59 -               CALL(sys_ni_syscall)            /* eventually ppoll */\r
  60 +/* 335 */      CALL(sys_pselect6)\r
  61 +               CALL(ys_ppoll)\r
  62                 CALL(sys_unshare)\r
  63                 CALL(sys_set_robust_list)\r
  64                 CALL(sys_get_robust_list)\r
  65 @@ -355,7 +355,7 @@\r
  66                 CALL(sys_vmsplice)\r
  67                 CALL(sys_move_pages)\r
  68  /* 345 */      CALL(sys_getcpu)\r
  69 -               CALL(sys_ni_syscall)            /* eventually epoll_pwait */\r
  70 +               CALL(sys_epoll_pwait)\r
  71                 CALL(sys_kexec_load)\r
  72                 CALL(sys_utimensat)\r
  73                 CALL(sys_signalfd)\r
  74 diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c\r
  75 index 80b8b5c..014703d 100644\r
  76 --- a/arch/arm/kernel/signal.c\r
  77 +++ b/arch/arm/kernel/signal.c\r
  78 @@ -47,57 +47,23 @@ const unsigned long sigreturn_codes[7] = {\r
  79         MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,\r
  80  };\r
  81  \r
  82 -static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);\r
  83 +static void fastcall do_signal(struct pt_regs * regs, int syscall);\r
  84  \r
  85  /*\r
  86   * atomically swap in the new signal mask, and wait for a signal.\r
  87   */\r
  88 -asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)\r
  89 +asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask)\r
  90  {\r
  91 -       sigset_t saveset;\r
  92 -\r
  93         mask &= _BLOCKABLE;\r
  94         spin_lock_irq(&current->sighand->siglock);\r
  95 -       saveset = current->blocked;\r
  96 +       current->saved_sigmask = current->blocked;\r
  97         siginitset(&current->blocked, mask);\r
  98         recalc_sigpending();\r
  99         spin_unlock_irq(&current->sighand->siglock);\r
 100 -       regs->ARM_r0 = -EINTR;\r
 101 -\r
 102 -       while (1) {\r
 103 -               current->state = TASK_INTERRUPTIBLE;\r
 104 -               schedule();\r
 105 -               if (do_signal(&saveset, regs, 0))\r
 106 -                       return regs->ARM_r0;\r
 107 -       }\r
 108 -}\r
 109 -\r
 110 -asmlinkage int\r
 111 -sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)\r
 112 -{\r
 113 -       sigset_t saveset, newset;\r
 114 -\r
 115 -       /* XXX: Don't preclude handling different sized sigset_t's. */\r
 116 -       if (sigsetsize != sizeof(sigset_t))\r
 117 -               return -EINVAL;\r
 118 -\r
 119 -       if (copy_from_user(&newset, unewset, sizeof(newset)))\r
 120 -               return -EFAULT;\r
 121 -       sigdelsetmask(&newset, ~_BLOCKABLE);\r
 122 -\r
 123 -       spin_lock_irq(&current->sighand->siglock);\r
 124 -       saveset = current->blocked;\r
 125 -       current->blocked = newset;\r
 126 -       recalc_sigpending();\r
 127 -       spin_unlock_irq(&current->sighand->siglock);\r
 128 -       regs->ARM_r0 = -EINTR;\r
 129 -\r
 130 -       while (1) {\r
 131 -               current->state = TASK_INTERRUPTIBLE;\r
 132 -               schedule();\r
 133 -               if (do_signal(&saveset, regs, 0))\r
 134 -                       return regs->ARM_r0;\r
 135 -       }\r
 136 +       current->state = TASK_INTERRUPTIBLE;\r
 137 +       schedule();\r
 138 +       set_thread_flag(TIF_RESTORE_SIGMASK);\r
 139 +       return -ERESTARTNOHAND;\r
 140  }\r
 141  \r
 142  asmlinkage int \r
 143 @@ -290,7 +256,7 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs)\r
 144  \r
 145  badframe:\r
 146         force_sig(SIGSEGV, current);\r
 147 -       return 0;\r
 148 +       return -EFAULT;\r
 149  }\r
 150  \r
 151  asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)\r
 152 @@ -325,7 +291,7 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)\r
 153  \r
 154  badframe:\r
 155         force_sig(SIGSEGV, current);\r
 156 -       return 0;\r
 157 +       return -EFAULT;\r
 158  }\r
 159  \r
 160  static int\r
 161 @@ -541,7 +507,7 @@ static inline void restart_syscall(struct pt_regs *regs)\r
 162  /*\r
 163   * OK, we're invoking a handler\r
 164   */    \r
 165 -static void\r
 166 +static int\r
 167  handle_signal(unsigned long sig, struct k_sigaction *ka,\r
 168               siginfo_t *info, sigset_t *oldset,\r
 169               struct pt_regs * regs, int syscall)\r
 170 @@ -592,7 +558,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,\r
 171  \r
 172         if (ret != 0) {\r
 173                 force_sigsegv(sig, tsk);\r
 174 -               return;\r
 175 +               return ret;\r
 176         }\r
 177  \r
 178         /*\r
 179 @@ -606,6 +572,7 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,\r
 180         recalc_sigpending();\r
 181         spin_unlock_irq(&tsk->sighand->siglock);\r
 182  \r
 183 +       return ret;\r
 184  }\r
 185  \r
 186  /*\r
 187 @@ -617,11 +584,12 @@ handle_signal(unsigned long sig, struct k_sigaction *ka,\r
 188   * the kernel can handle, and then we build all the user-level signal handling\r
 189   * stack-frames in one go after that.\r
 190   */\r
 191 -static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)\r
 192 +static void fastcall do_signal(struct pt_regs *regs, int syscall)\r
 193  {\r
 194         struct k_sigaction ka;\r
 195         siginfo_t info;\r
 196         int signr;\r
 197 +       sigset_t *oldset;\r
 198  \r
 199         /*\r
 200          * We want the common case to go fast, which\r
 201 @@ -630,18 +598,29 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)\r
 202          * if so.\r
 203          */\r
 204         if (!user_mode(regs))\r
 205 -               return 0;\r
 206 +               return;\r
 207  \r
 208         if (try_to_freeze())\r
 209                 goto no_signal;\r
 210  \r
 211         single_step_clear(current);\r
 212  \r
 213 +       if (test_thread_flag(TIF_RESTORE_SIGMASK))\r
 214 +               oldset = &current->saved_sigmask;\r
 215 +       else\r
 216 +               oldset = &current->blocked;\r
 217 +\r
 218         signr = get_signal_to_deliver(&info, &ka, regs, NULL);\r
 219         if (signr > 0) {\r
 220 -               handle_signal(signr, &ka, &info, oldset, regs, syscall);\r
 221 +               if (handle_signal(signr, &ka, &info, oldset, regs, syscall) == 0) {\r
 222 +                       /* a signal was successfully delivered; the saved\r
 223 +                        * sigmask will have been stored in the signal frame,\r
 224 +                        * and will be restored by sigreturn, so we can simply\r
 225 +                        * clear the TIF_RESTORE_SIGMASK flag */\r
 226 +                       clear_thread_flag(TIF_RESTORE_SIGMASK);\r
 227 +               }\r
 228                 single_step_set(current);\r
 229 -               return 1;\r
 230 +               return;\r
 231         }\r
 232  \r
 233   no_signal:\r
 234 @@ -665,7 +644,7 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)\r
 235                                 usp = (u32 __user *)regs->ARM_sp;\r
 236  \r
 237                                 /*\r
 238 -                                * Either we supports OABI only, or we have\r
 239 +                                * Either we support OABI only, or we have\r
 240                                  * EABI with the OABI compat layer enabled.\r
 241                                  * In the later case we don't know if user\r
 242                                  * space is EABI or not, and if not we must\r
 243 @@ -695,12 +674,17 @@ static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall)\r
 244                 }\r
 245         }\r
 246         single_step_set(current);\r
 247 -       return 0;\r
 248 +        /* if there's no signal to deliver, we just put the saved sigmask\r
 249 +           back. */\r
 250 +               if (test_thread_flag(TIF_RESTORE_SIGMASK)) {\r
 251 +                       clear_thread_flag(TIF_RESTORE_SIGMASK);\r
 252 +                       sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);\r
 253 +               }\r
 254  }\r
 255  \r
 256  asmlinkage void\r
 257  do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)\r
 258  {\r
 259 -       if (thread_flags & _TIF_SIGPENDING)\r
 260 -               do_signal(&current->blocked, regs, syscall);\r
 261 +       if (thread_flags & (_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK))\r
 262 +               do_signal(regs, syscall);\r
 263  }\r
 264 -- \r
 265 1.6.2.4\r
 266 \r