target/linux/goldfish/patches-2.6.30/0060--ARM-Add-code-to-prevent-system-calls-from-being-re.patch

   1 From d52bcb0a807dde87057f330dbe95aa6d221a4b85 Mon Sep 17 00:00:00 2001
   2 From: =?utf-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= <arve@android.com>
   3 Date: Mon, 9 Apr 2007 17:13:02 +0700
   4 Subject: [PATCH 060/134] [ARM] Add code to prevent system calls from being restarted muliple times before returning from the kernel.
   5
   6 Fixes crashes with thumb syscalls.
   7 ---
   8  arch/arm/kernel/signal.c |    9 +++++++++
   9  1 files changed, 9 insertions(+), 0 deletions(-)
  10
  11 --- a/arch/arm/kernel/signal.c
  12 +++ b/arch/arm/kernel/signal.c
  13 @@ -499,6 +499,14 @@ setup_rt_frame(int usig, struct k_sigact
  14
  15  static inline void restart_syscall(struct pt_regs *regs)
  16  {
  17 +       if (regs->ARM_ORIG_r0 == -ERESTARTNOHAND ||
  18 +           regs->ARM_ORIG_r0 == -ERESTARTSYS ||
  19 +           regs->ARM_ORIG_r0 == -ERESTARTNOINTR ||
  20 +           regs->ARM_ORIG_r0 == -ERESTART_RESTARTBLOCK) {
  21 +               /* the syscall cannot be safely restarted, return -EINTR instead */
  22 +               regs->ARM_r0 = -EINTR;
  23 +               return;
  24 +       }
  25         regs->ARM_r0 = regs->ARM_ORIG_r0;
  26         regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
  27  }
  28 @@ -631,6 +639,7 @@ static void do_signal(struct pt_regs *re
  29          */
  30         if (syscall) {
  31                 if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
  32 +                       regs->ARM_r0 = -EAGAIN; /* prevent multiple restarts */
  33                         if (thumb_mode(regs)) {
  34                                 regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
  35                                 regs->ARM_pc -= 2;