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Commit afe05d41 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-curr' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc 

Pull ARC fix from Vineet Gupta:
 "Chrisitian found/fixed issue with SA_SIGINFO based signal handler
  corrupting the user space registers post after signal handling"

* 'for-curr' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Fix signal frame management for SA_SIGINFO
parents c15f5bbc 10469350

arch/arc/kernel/signal.c

+13 −12
Original line number Diff line number Diff line
@@ -101,7 +101,6 @@ SYSCALL_DEFINE0(rt_sigreturn) 
{

	struct rt_sigframe __user *sf;

	unsigned int magic;

	int err;

	struct pt_regs *regs = current_pt_regs();



	/* Always make any pending restarted system calls return -EINTR */
@@ -119,15 +118,16 @@ SYSCALL_DEFINE0(rt_sigreturn) 
	if (!access_ok(VERIFY_READ, sf, sizeof(*sf)))

		goto badframe;



	err = restore_usr_regs(regs, sf);

	err |= __get_user(magic, &sf->sigret_magic);

	if (err)

	if (__get_user(magic, &sf->sigret_magic))

		goto badframe;



	if (unlikely(is_do_ss_needed(magic)))

		if (restore_altstack(&sf->uc.uc_stack))

			goto badframe;



	if (restore_usr_regs(regs, sf))

		goto badframe;



	/* Don't restart from sigreturn */

	syscall_wont_restart(regs);
@@ -190,6 +190,15 @@ setup_rt_frame(int signo, struct k_sigaction *ka, siginfo_t *info, 
	if (!sf)

		return 1;



	/*

	 * w/o SA_SIGINFO, struct ucontext is partially populated (only

	 * uc_mcontext/uc_sigmask) for kernel's normal user state preservation

	 * during signal handler execution. This works for SA_SIGINFO as well

	 * although the semantics are now overloaded (the same reg state can be

	 * inspected by userland: but are they allowed to fiddle with it ?

	 */

	err |= stash_usr_regs(sf, regs, set);



	/*

	 * SA_SIGINFO requires 3 args to signal handler:

	 *  #1: sig-no (common to any handler)
@@ -213,14 +222,6 @@ setup_rt_frame(int signo, struct k_sigaction *ka, siginfo_t *info, 
		magic = MAGIC_SIGALTSTK;

	}



	/*

	 * w/o SA_SIGINFO, struct ucontext is partially populated (only

	 * uc_mcontext/uc_sigmask) for kernel's normal user state preservation

	 * during signal handler execution. This works for SA_SIGINFO as well

	 * although the semantics are now overloaded (the same reg state can be

	 * inspected by userland: but are they allowed to fiddle with it ?

	 */

	err |= stash_usr_regs(sf, regs, set);

	err |= __put_user(magic, &sf->sigret_magic);

	if (err)

		return err;