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