linux.git/arch/parisc/kernel/signal32.h, branch v6.6.118

parisc: Add vDSO support

2022-03-11T18:49:30+00:00

Add minimal vDSO support, which provides the signal trampoline helpers,
but none of the userspace syscall helpers like time wrappers.

The big benefit of this vDSO implementation is, that we now don't need
an executeable stack any longer. PA-RISC is one of the last
architectures where an executeable stack was needed in oder to implement
the signal trampolines by putting assembly instructions on the stack
which then gets executed. Instead the kernel will provide the relevant
code in the vDSO page and only put the pointers to the signal
information on the stack.

By dropping the need for executable stacks we avoid running into issues
with applications which want non executable stacks for security reasons.
Additionally, alternative stacks on memory areas without exec
permissions are supported too.

This code is based on an initial implementation by Randolph Chung from 2006:
https://lore.kernel.org/linux-parisc/4544A34A.6080700@tausq.org/

I did the porting and lifted the code to current code base. Dave fixed
the unwind code so that gdb and glibc are able to backtrace through the
code. An additional patch to gdb will be pushed upstream by Dave.

Signed-off-by: Helge Deller 
Signed-off-by: Dave Anglin 
Cc: Randolph Chung 
Signed-off-by: Helge Deller

Revert "parisc: Reduce sigreturn trampoline to 3 instructions"

2021-11-18T08:02:32+00:00

This reverts commit e4f2006f1287e7ea17660490569cff323772dac4.

This patch shows problems with signal handling. Revert it for now.

Signed-off-by: Helge Deller 
Cc:  # v5.15

parisc: Reduce sigreturn trampoline to 3 instructions

2021-09-09T10:44:31+00:00

We can move the INSN_LDI_R20 instruction into the branch delay slot.

Signed-off-by: Helge Deller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

signal: Unify and correct copy_siginfo_to_user32

2018-01-16T01:56:20+00:00

Among the existing architecture specific versions of
copy_siginfo_to_user32 there are several different implementation
problems.  Some architectures fail to handle all of the cases in in
the siginfo union.  Some architectures perform a blind copy of the
siginfo union when the si_code is negative.  A blind copy suggests the
data is expected to be in 32bit siginfo format, which means that
receiving such a signal via signalfd won't work, or that the data is
in 64bit siginfo and the code is copying nonsense to userspace.

Create a single instance of copy_siginfo_to_user32 that all of the
architectures can share, and teach it to handle all of the cases in
the siginfo union correctly, with the assumption that siginfo is
stored internally to the kernel is 64bit siginfo format.

A special case is made for x86 x32 format.  This is needed as presence
of both x32 and ia32 on x86_64 results in two different 32bit signal
formats.  By allowing this small special case there winds up being
exactly one code base that needs to be maintained between all of the
architectures.  Vastly increasing the testing base and the chances of
finding bugs.

As the x86 copy of copy_siginfo_to_user32 the call of the x86
signal_compat_build_tests were moved into sigaction_compat_abi, so
that they will keep running.

Signed-off-by: "Eric W. Biederman"

signal: Unify and correct copy_siginfo_from_user32

2018-01-15T23:55:59+00:00

The function copy_siginfo_from_user32 is used for two things, in ptrace
since the dawn of siginfo for arbirarily modifying a signal that
user space sees, and in sigqueueinfo to send a signal with arbirary
siginfo data.

Create a single copy of copy_siginfo_from_user32 that all architectures
share, and teach it to handle all of the cases in the siginfo union.

In the generic version of copy_siginfo_from_user32 ensure that all
of the fields in siginfo are initialized so that the siginfo structure
can be safely copied to userspace if necessary.

When copying the embedded sigval union copy the si_int member.  That
ensures the 32bit values passes through the kernel unchanged.

Signed-off-by: "Eric W. Biederman"

parisc: switch to {get,put}_compat_sigset()

2017-09-19T21:56:02+00:00

Signed-off-by: Al Viro

constify copy_siginfo_to_user{,32}()

2013-11-09T05:16:29+00:00

Signed-off-by: Al Viro

parisc: switch to generic compat rt_sigaction()

2013-02-03T23:16:07+00:00

Signed-off-by: Al Viro

parisc: switch to generic sigaltstack

2013-02-03T23:16:05+00:00

Signed-off-by: Al Viro