ARM: 5793/1: ARM: Check put_user fail in do_signal when enable OABI_COMPAT
Using OABI, the call to put_user in do_signal can fail causing the
calling app to hang.
The solution is to check if put_user fails and force the app to
seg fault in that case.
Tested with multiple sleeping apps/threads (using the nanosleep syscall)
and suspend/resume.
Signed-off-by: janboe <janboe.ye at gmail.com>
Signed-off-by: Jean Pihet <jpihet@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 2a573d4..e7714f3 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -662,8 +662,12 @@
regs->ARM_sp -= 4;
usp = (u32 __user *)regs->ARM_sp;
- put_user(regs->ARM_pc, usp);
- regs->ARM_pc = KERN_RESTART_CODE;
+ if (put_user(regs->ARM_pc, usp) == 0) {
+ regs->ARM_pc = KERN_RESTART_CODE;
+ } else {
+ regs->ARM_sp += 4;
+ force_sigsegv(0, current);
+ }
#endif
}
}