Commit b92adb74 authored Apr 16, 2018 by Eric W. Biederman

signal/ia64: Use the force_sig(SIGSEGV,...) in ia64_rt_sigreturn



The ia64 handling of failure to return from a signal frame has been trying
to set overlapping fields in struct siginfo since 2.3.43.  The si_code
corresponds to the fields that were stomped (not the field that is
actually written), so I can not imagine a piece of userspace code
making sense of the signal frame if it looks closely.

In practice failure to return from a signal frame is a rare event that
almost never happens.  Someone using an alternate signal stack to
recover and looking in detail is even more rare.  So I presume no one
has ever noticed and reported this ia64 nonsense.

Sort this out by causing ia64 to use force_sig(SIGSEGV) like other architectures.

Fixes: 2.3.43
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

parent 8b9c6b28

arch/ia64/kernel/signal.c

+1 −9

Original line number	Diff line number	Diff line
		@@ -110,7 +110,6 @@ ia64_rt_sigreturn (struct sigscratch *scr)
		{
		extern char ia64_strace_leave_kernel, ia64_leave_kernel;
		struct sigcontext __user *sc;
		struct siginfo si;
		sigset_t set;
		long retval;

		@@ -153,14 +152,7 @@ ia64_rt_sigreturn (struct sigscratch *scr)
		return retval;

		give_sigsegv:
		clear_siginfo(&si);
		si.si_signo = SIGSEGV;
		si.si_errno = 0;
		si.si_code = SI_KERNEL;
		si.si_pid = task_pid_vnr(current);
		si.si_uid = from_kuid_munged(current_user_ns(), current_uid());
		si.si_addr = sc;
		force_sig_info(SIGSEGV, &si, current);
		force_sig(SIGSEGV, current);
		return retval;
		}

Admin message