linux/arch/cris/kernel/ptrace.c
Rabin Vincent 9a7449d3e9 CRISv32: handle multiple signals
Al Viro noted that CRIS fails to handle multiple signals.

This fixes the problem for CRISv32 by making it use a C work_pending
handling loop similar to the ARM implementation in 0a267fa6a1
("ARM: 7472/1: pull all work_pending logics into C function").

This also happens to fixes the warnings which currently trigger on
CRISv32 due to do_signal() being called with interrupts disabled.

Test case (should die of the SIGSEGV which gets raised when setting up
the stack for SIGALRM, but instead reaches and executes the _exit(1)):

  #include <unistd.h>
  #include <signal.h>
  #include <sys/time.h>
  #include <err.h>

  static void handler(int sig) { }

  int main(int argc, char *argv[])
  {
  	int ret;
  	struct itimerval t1 = { .it_value = {1} };
  	stack_t ss = {
  		.ss_sp = NULL,
  		.ss_size = SIGSTKSZ,
  	};
  	struct sigaction action = {
  		.sa_handler = handler,
  		.sa_flags = SA_ONSTACK,
  	};

  	ret = sigaltstack(&ss, NULL);
  	if (ret < 0)
  		err(1, "sigaltstack");

  	sigaction(SIGALRM, &action, NULL);
   	setitimer(ITIMER_REAL, &t1, NULL);

  	pause();

  	_exit(1);

  	return 0;
  }

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Link: http://lkml.kernel.org/r/20121208074429.GC4939@ZenIV.linux.org.uk
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Jesper Nilsson <jespern@axis.com>
2015-03-25 10:53:54 +01:00

68 lines
1.5 KiB
C

/*
* linux/arch/cris/kernel/ptrace.c
*
* Parts taken from the m68k port.
*
* Copyright (c) 2000, 2001, 2002 Axis Communications AB
*
* Authors: Bjorn Wesen
*
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/tracehook.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
/* notification of userspace execution resumption
* - triggered by current->work.notify_resume
*/
extern int do_signal(int canrestart, struct pt_regs *regs);
void do_notify_resume(int canrestart, struct pt_regs *regs,
__u32 thread_info_flags)
{
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(canrestart,regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}
void do_work_pending(int syscall, struct pt_regs *regs,
unsigned int thread_flags)
{
do {
if (likely(thread_flags & _TIF_NEED_RESCHED)) {
schedule();
} else {
if (unlikely(!user_mode(regs)))
return;
local_irq_enable();
if (thread_flags & _TIF_SIGPENDING) {
do_signal(syscall, regs);
syscall = 0;
} else {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}
local_irq_disable();
thread_flags = current_thread_info()->flags;
} while (thread_flags & _TIF_WORK_MASK);
}