36 lines
1.3 KiB
Diff
36 lines
1.3 KiB
Diff
From d52bcb0a807dde87057f330dbe95aa6d221a4b85 Mon Sep 17 00:00:00 2001
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From: =?utf-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= <arve@android.com>
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Date: Mon, 9 Apr 2007 17:13:02 +0700
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Subject: [PATCH 060/134] [ARM] Add code to prevent system calls from being restarted muliple times before returning from the kernel.
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Fixes crashes with thumb syscalls.
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---
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arch/arm/kernel/signal.c | 9 +++++++++
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1 files changed, 9 insertions(+), 0 deletions(-)
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--- a/arch/arm/kernel/signal.c
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+++ b/arch/arm/kernel/signal.c
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@@ -534,6 +534,14 @@ setup_rt_frame(int usig, struct k_sigact
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static inline void restart_syscall(struct pt_regs *regs)
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{
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+ if (regs->ARM_ORIG_r0 == -ERESTARTNOHAND ||
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+ regs->ARM_ORIG_r0 == -ERESTARTSYS ||
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+ regs->ARM_ORIG_r0 == -ERESTARTNOINTR ||
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+ regs->ARM_ORIG_r0 == -ERESTART_RESTARTBLOCK) {
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+ /* the syscall cannot be safely restarted, return -EINTR instead */
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+ regs->ARM_r0 = -EINTR;
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+ return;
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+ }
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regs->ARM_r0 = regs->ARM_ORIG_r0;
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regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
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}
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@@ -650,6 +658,7 @@ static int do_signal(sigset_t *oldset, s
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*/
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if (syscall) {
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if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
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+ regs->ARM_r0 = -EAGAIN; /* prevent multiple restarts */
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if (thumb_mode(regs)) {
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regs->ARM_r7 = __NR_restart_syscall - __NR_SYSCALL_BASE;
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regs->ARM_pc -= 2;
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