fcfc2aa018
There are a few system calls (pselect, ppoll, etc) which replace a task sigmask while they are running in a kernel-space When a task calls one of these syscalls, the kernel saves a current sigmask in task->saved_sigmask and sets a syscall sigmask. On syscall-exit-stop, ptrace traps a task before restoring the saved_sigmask, so PTRACE_GETSIGMASK returns the syscall sigmask and PTRACE_SETSIGMASK does nothing, because its sigmask is replaced by saved_sigmask, when the task returns to user-space. This patch fixes this problem. PTRACE_GETSIGMASK returns saved_sigmask if it's set. PTRACE_SETSIGMASK drops the TIF_RESTORE_SIGMASK flag. Link: http://lkml.kernel.org/r/20181120060616.6043-1-avagin@gmail.com Fixes: 29000caecbe8 ("ptrace: add ability to get/set signal-blocked mask") Signed-off-by: Andrei Vagin <avagin@gmail.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.