openrisc: Declare do_signal function as static

When compiling with W=1 enabling -Wmissing-prototypes the compiler
warns:

arch/openrisc/kernel/signal.c:227:5: error: no previous prototype for 'do_signal' [-Werror=missing-prototypes]

Fix this by declaring the function a static as it is not used outside of
the scope of this file.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/linux-kernel/20230810141947.1236730-17-arnd@kernel.org/
Signed-off-by: Stafford Horne <shorne@gmail.com>

openrisc: Add missing prototypes for assembly called fnctions

These functions are all called from assembly files so there is no need
for a prototype in a header file, but when compiling with W=1 enabling
-Wmissing-prototypes the compiler warns:

arch/openrisc/kernel/ptrace.c:191:17: error: no previous prototype for 'do_syscall_trace_enter' [-Werror=missing-prototypes]
arch/openrisc/kernel/ptrace.c:210:17: error: no previous prototype for 'do_syscall_trace_leave' [-Werror=missing-prototypes]
arch/openrisc/kernel/signal.c:293:1: error: no previous prototype for 'do_work_pending' [-Werror=missing-prototypes]
arch/openrisc/kernel/signal.c:68:17: error: no previous prototype for '_sys_rt_sigreturn' [-Werror=missing-prototypes]
arch/openrisc/kernel/time.c:111:25: error: no previous prototype for 'timer_interrupt' [-Werror=missing-prototypes]
arch/openrisc/kernel/traps.c:239:17: error: no previous prototype for 'unhandled_exception' [-Werror=missing-prototypes]
arch/openrisc/kernel/traps.c:246:17: error: no previous prototype for 'do_fpe_trap' [-Werror=missing-prototypes]
arch/openrisc/kernel/traps.c:268:17: error: no previous prototype for 'do_trap' [-Werror=missing-prototypes]
arch/openrisc/kernel/traps.c:273:17: error: no previous prototype for 'do_unaligned_access' [-Werror=missing-prototypes]
arch/openrisc/kernel/traps.c:286:17: error: no previous prototype for 'do_bus_fault' [-Werror=missing-prototypes]
arch/openrisc/kernel/traps.c:462:17: error: no previous prototype for 'do_illegal_instruction' [-Werror=missing-prototypes]
arch/openrisc/mm/fault.c:44:17: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]

Since these are not needed in header files, fix these by adding
prototypes to the top of the respective C files.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/linux-kernel/20230810141947.1236730-17-arnd@kernel.org/
Signed-off-by: Stafford Horne <shorne@gmail.com>

openrisc: Union fpcsr and oldmask in sigcontext to unbreak userspace ABI

With commit 27267655c531 ("openrisc: Support floating point user api") I
added an entry to the struct sigcontext which caused an unwanted change
to the userspace ABI.

To fix this we use the previously unused oldmask field space for the
floating point fpcsr state. We do this with a union to restore the ABI
back to the pre kernel v6.4 ABI and keep API compatibility.

This does mean if there is some code somewhere that is setting oldmask
in an OpenRISC specific userspace sighandler it would end up setting the
floating point register status, but I think it's unlikely as oldmask was
never functional before.

Fixes: 27267655c531 ("openrisc: Support floating point user api")
Reported-by: Szabolcs Nagy <nsz@port70.net>
Closes: https://lore.kernel.org/openrisc/20230626213840.GA1236108@port70.net/
Signed-off-by: Stafford Horne <shorne@gmail.com>

openrisc: Support floating point user api

Add support for handling floating point exceptions and forwarding the
SIGFPE signal to processes. Also, add fpu state to sigcontext.

Signed-off-by: Stafford Horne <shorne@gmail.com>

resume_user_mode: Move to resume_user_mode.h

Move set_notify_resume and tracehook_notify_resume into resume_user_mode.h.
While doing that rename tracehook_notify_resume to resume_user_mode_work.

Update all of the places that included tracehook.h for these functions to
include resume_user_mode.h instead.

Update all of the callers of tracehook_notify_resume to call
resume_user_mode_work.

Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20220309162454.123006-12-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

openrisc: Snapshot thread flags

Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.

To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.

Convert them all to the new flag accessor helpers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Link: https://lore.kernel.org/r/20211129130653.2037928-9-mark.rutland@arm.com

openrisc: signal: remove unused DEBUG_SIG macro

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>

openrisc: add support for TIF_NOTIFY_SIGNAL

Wire up TIF_NOTIFY_SIGNAL handling for openrisc.

Cc: openrisc@lists.librecores.org
Acked-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

tracehook: clear TIF_NOTIFY_RESUME in tracehook_notify_resume()

All the callers currently do this, clean it up and move the clearing
into tracehook_notify_resume() instead.

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

openrisc: signal: Fix sparse address space warnings

The __user annotations in signal.c were mostly missing. The missing
annotations caused the warnings listed below. This patch fixes them up
by adding the __user annotations.

arch/openrisc/kernel/signal.c:71:38: warning: incorrect type in initializer (different address spaces)
arch/openrisc/kernel/signal.c:71:38: expected struct rt_sigframe *frame
arch/openrisc/kernel/signal.c:71:38: got struct rt_sigframe [noderef] __user *
arch/openrisc/kernel/signal.c:82:14: warning: incorrect type in argument 1 (different address spaces)
arch/openrisc/kernel/signal.c:82:14: expected void const volatile [noderef] __user *
arch/openrisc/kernel/signal.c:82:14: got struct rt_sigframe *frame
arch/openrisc/kernel/signal.c:84:37: warning: incorrect type in argument 2 (different address spaces)
arch/openrisc/kernel/signal.c:84:37: expected void const [noderef] __user *from
arch/openrisc/kernel/signal.c:84:37: got struct sigset_t *
arch/openrisc/kernel/signal.c:89:39: warning: incorrect type in argument 2 (different address spaces)
arch/openrisc/kernel/signal.c:89:39: expected struct sigcontext [noderef] __user *sc
arch/openrisc/kernel/signal.c:89:39: got struct sigcontext *
arch/openrisc/kernel/signal.c:92:31: warning: incorrect type in argument 1 (different address spaces)
arch/openrisc/kernel/signal.c:92:31: expected struct sigaltstack const [noderef] [usertype] __user *
arch/openrisc/kernel/signal.c:92:31: got struct sigaltstack *
arch/openrisc/kernel/signal.c:158:15: warning: incorrect type in assignment (different address spaces)
arch/openrisc/kernel/signal.c:158:15: expected struct rt_sigframe *frame
arch/openrisc/kernel/signal.c:158:15: got void [noderef] __user *
arch/openrisc/kernel/signal.c:160:14: warning: incorrect type in argument 1 (different address spaces)
arch/openrisc/kernel/signal.c:160:14: expected void const volatile [noderef] __user *
arch/openrisc/kernel/signal.c:160:14: got struct rt_sigframe *frame
arch/openrisc/kernel/signal.c:165:46: warning: incorrect type in argument 1 (different address spaces)
arch/openrisc/kernel/signal.c:165:46: expected struct siginfo [noderef] [usertype] __user *to
arch/openrisc/kernel/signal.c:165:46: got struct siginfo *
arch/openrisc/kernel/signal.c:170:33: warning: incorrect type in argument 1 (different address spaces)
arch/openrisc/kernel/signal.c:170:33: expected struct sigaltstack [noderef] [usertype] __user *
arch/openrisc/kernel/signal.c:170:33: got struct sigaltstack *
arch/openrisc/kernel/signal.c:171:40: warning: incorrect type in argument 2 (different address spaces)
arch/openrisc/kernel/signal.c:171:40: expected struct sigcontext [noderef] __user *sc
arch/openrisc/kernel/signal.c:171:40: got struct sigcontext *
arch/openrisc/kernel/signal.c:173:32: warning: incorrect type in argument 1 (different address spaces)
arch/openrisc/kernel/signal.c:173:32: expected void [noderef] __user *to
arch/openrisc/kernel/signal.c:173:32: got struct sigset_t *

Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

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

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

signal: Remove task parameter from force_sig

All of the remaining callers pass current into force_sig so
remove the task parameter to make this obvious and to make
misuse more difficult in the future.

This also makes it clear force_sig passes current into force_sig_info.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Remove 'type' argument from access_ok() function

Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

- csky still had the old "verify_area()" name as an alias.

- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)

- microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

This was entirely automated, using the script by Al:

PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch: Remove exec_domain from remaining archs

Signed-off-by: Richard Weinberger <richard@nod.at>

all arches, signal: move restart_block to struct task_struct

If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target. This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

openrisc: Use sigsp()

Use sigsp() instead of the open coded variant.

Signed-off-by: Richard Weinberger <richard@nod.at>

openrisc: Use get_signal() signal_setup_done()

Use the more generic functions get_signal() signal_setup_done()
for signal delivery.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

openrisc: Rework signal handling

The mainline signal handling code for OpenRISC has been buggy since day
one with respect to syscall restart. This patch significantly reworks
the signal handling code:

i) Move the "work pending" loop to C code (borrowed from ARM arch)

ii) Allow a tracer to muck about with the IP and skip syscall restart
in that case (again, borrowed from ARM)

iii) Make signal handling WRT syscall restart actually work

v) Make the signal handling code look more like that of other
architectures so that it's easier for others to follow

Reported-by: Anders Nystrom <anders@southpole.se>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

openrisc: switch to generic sigaltstack

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

openrisk: fix altstack switching on sigreturn

do_sigaltstack() expects _userland_ address, TYVM...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

new helper: signal_delivered()

Does block_sigmask() + tracehook_signal_handler(); called when
sigframe has been successfully built. All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set

Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

pull clearing RESTORE_SIGMASK into block_sigmask()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

openrisc: tracehook_signal_handler() is supposed to be called on success

... not if sigframe couldn't have been built.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

new helper: sigmask_to_save()

replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

new helper: restore_saved_sigmask()

first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper. Open-coded instances switched...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

move key_repace_session_keyring() into tracehook_notify_resume()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

openrisc: sanitize use of orig_gpr11

The pt_regs struct had both a 'syscallno' field and an 'orig_gpr11' field
and it wasn't really clear how these were supposed to be used. This patch
removes the syscallno field altogether and makes orig_gpr11 work more
like other architectures: keep track of syscall number in progress or
hold -1 for non-syscall exceptions.

Signed-off-by: Jonas Bonn <jonas@southpole.se>

OpenRISC: Use set_current_blocked() and block_sigmask()

As described in e6fa16ab ("signal: sigprocmask() should do
retarget_shared_pending()") the modification of current->blocked is
incorrect as we need to check whether the signal we're about to block
is pending in the shared queue.

Also, use the new helper function introduced in commit 5e6292c0f28f
("signal: add block_sigmask() for adding sigmask to current->blocked")
which centralises the code for updating current->blocked after
successfully delivering a signal and reduces the amount of duplicate
code across architectures. In the past some architectures got this
code wrong, so using this helper function should stop that from
happening again.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

OpenRISC: Don't mask signals if we fail to setup signal stack

setup_rt_frame() needs to return an indication of whether it succeeded
or failed in setting up the signal stack frame. If setup_rt_frame()
fails then we must not modify current->blocked.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

OpenRISC: No need to reset handler if SA_ONESHOT

get_signal_to_deliver() already resets the signal handler if
SA_ONESHOT is set in ka->sa.sa_flags, there's no need to do it again
in handle_signal(). Furthermore, because we were modifying
ka->sa.sa_handler (which is a copy of sighand->action[]) instead of
sighand->action[] the original code actually had no effect on signal
delivery.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

OpenRISC: Don't reimplement force_sigsegv()

Instead of open coding the sequence from force_sigsegv() just call
it. This also fixes a bug because we were modifying ka->sa.sa_handler
(which is a copy of sighand->action[]), whereas the intention of the
code was to modify sighand->action[] directly.

As the original code was working with a copy it had no effect on
signal delivery.

Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux@lists.openrisc.net
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>

openrisc: don't use pt_regs in struct sigcontext

As it was decided not to export struct pt_regs to userspace, struct
sigcontext shouldn't be using it either. The pt_regs struct for OpenRISC
is kernel internal and the layout of the registers may change in the
future. The struct user_regs_struct is what is guaranteed to remain
stable, so struct sigcontext may use that instead.

This patch removes the usage of struct pt_regs in struct sigcontext and
makes according changes in signal.c to get the register layout right.

The usp field is removed from the sigcontext structure as this information
is already contained in the user_regs_struct.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Emilio Cota <cota@braap.org>

OpenRISC: Signal handling

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>