On 06/03/2015 05:09 AM, Greg Kroah-Hartman wrote: > 4.0-stable review patch. If anyone has any objections, please let me know.
I sent a copycat patch for arm64, but I think it may be a problem to leave interrupts disabled for __sys_trace_return. Thoughts, Russell? > ------------------ > > From: Russell King <rmk+ker...@arm.linux.org.uk> > > commit 1b97937246d8b97c0760d16d8992c7937bdf5e6a upstream. > > Josh Stone reports: > > I've discovered a case where both arm and arm64 will miss a ptrace > syscall-exit that they should report. If the syscall is entered > without TIF_SYSCALL_TRACE set, then it goes on the fast path. It's > then possible to have TIF_SYSCALL_TRACE added in the middle of the > syscall, but ret_fast_syscall doesn't check this flag again. > > Fix this by always checking for a syscall trace in the fast exit path. > > Reported-by: Josh Stone <jist...@redhat.com> > Signed-off-by: Russell King <rmk+ker...@arm.linux.org.uk> > Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> > > --- > arch/arm/kernel/entry-common.S | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > --- a/arch/arm/kernel/entry-common.S > +++ b/arch/arm/kernel/entry-common.S > @@ -33,7 +33,9 @@ ret_fast_syscall: > UNWIND(.fnstart ) > UNWIND(.cantunwind ) > disable_irq @ disable interrupts > - ldr r1, [tsk, #TI_FLAGS] > + ldr r1, [tsk, #TI_FLAGS] @ re-check for syscall tracing > + tst r1, #_TIF_SYSCALL_WORK > + bne __sys_trace_return > tst r1, #_TIF_WORK_MASK > bne fast_work_pending > asm_trace_hardirqs_on > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
