linux-toradex.git/arch/powerpc/kernel/sys_ppc32.c, branch v6.7

powerpc/32: fix syscall wrappers with 64-bit arguments

2022-10-31T23:24:09+00:00

With the introduction of syscall wrappers all wrappers for syscalls with
64-bit arguments must be handled specially, not only those that have
unaligned 64-bit arguments. This left out the fallocate() and
sync_file_range2() syscalls.

Fixes: 7e92e01b7245 ("powerpc: Provide syscall wrapper")
Fixes: e23750623835 ("powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs")
Signed-off-by: Andreas Schwab 
Reviewed-by: Arnd Bergmann 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/87mt9cxd6g.fsf_-_@igel.home

powerpc/32: fix syscall wrappers with 64-bit arguments of unaligned register-pairs

2022-10-12T13:49:58+00:00

powerpc 32-bit system call (and function) calling convention for 64-bit
arguments requires the next available odd-pair (two sequential registers
with the first being odd-numbered) from the standard register argument
allocation.

The first argument register is r3, so a 64-bit argument that appears at
an even position in the argument list must skip a register (unless there
were preceding 64-bit arguments, which might throw things off). This
requires non-standard compat definitions to deal with the holes in the
argument register allocation.

With pt_regs syscall wrappers which use a standard mapper to map pt_regs
GPRs to function arguments, 32-bit kernels hit the same basic problem,
the standard definitions don't cope with the unused argument registers.

Fix this by having 32-bit kernels share those syscall definitions with
compat.

Thanks to Jason for spending a lot of time finding and bisecting this
and developing a trivial reproducer. The perfect bug report.

Reported-by: Jason A. Donenfeld 
Signed-off-by: Nicholas Piggin 
Fixes: 7e92e01b72452 ("powerpc: Provide syscall wrapper")
Reviewed-by: Arnd Bergmann 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20221012035335.866440-1-npiggin@gmail.com

powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers

2022-09-28T09:22:08+00:00

Arch-specific implementations of syscall handlers are currently used
over generic implementations for the following reasons:

1. Semantics unique to powerpc
2. Compatibility syscalls require 'argument padding' to comply with
   64-bit argument convention in ELF32 abi.
3. Parameter types or order is different in other architectures.

These syscall handlers have been defined prior to this patch series
without invoking the SYSCALL_DEFINE or COMPAT_SYSCALL_DEFINE macros with
custom input and output types. We remove every such direct definition in
favour of the aforementioned macros.

Also update syscalls.tbl in order to refer to the symbol names generated
by each of these macros. Since ppc64_personality can be called by both
64 bit and 32 bit binaries through compatibility, we must generate both
both compat_sys_ and sys_ symbols for this handler.

As an aside:
A number of architectures including arm and powerpc agree on an
alternative argument order and numbering for most of these arch-specific
handlers. A future patch series may allow for asm/unistd.h to signal
through its defines that a generic implementation of these syscall
handlers with the correct calling convention be emitted, through the
__ARCH_WANT_COMPAT_SYS_... convention.

Signed-off-by: Rohan McLure 
Reviewed-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220921065605.1051927-16-rmclure@linux.ibm.com

powerpc: Remove direct call to mmap2 syscall handlers

2022-09-28T09:21:26+00:00

Syscall handlers should not be invoked internally by their symbol names,
as these symbols defined by the architecture-defined SYSCALL_DEFINE
macro. Move the compatibility syscall definition for mmap2 to
syscalls.c, so that all mmap implementations can share a helper function.

Remove 'inline' on static mmap helper.

Signed-off-by: Rohan McLure 
Reviewed-by: Nicholas Piggin 
[mpe: Fix compat_sys_mmap2() prototype and offset handling]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220921065605.1051927-14-rmclure@linux.ibm.com

powerpc: Use generic fallocate compatibility syscall

2022-09-26T13:00:15+00:00

The powerpc fallocate compat syscall handler is identical to the
generic implementation provided by commit 59c10c52f573f ("riscv:
compat: syscall: Add compat_sys_call_table implementation"), and as
such can be removed in favour of the generic implementation.

A future patch series will replace more architecture-defined syscall
handlers with generic implementations, dependent on introducing generic
implementations that are compatible with powerpc and arm's parameter
reorderings.

Reported-by: Arnd Bergmann 
Signed-off-by: Rohan McLure 
Reviewed-by: Arnd Bergmann 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220921065605.1051927-11-rmclure@linux.ibm.com

powerpc: Fix fallocate and fadvise64_64 compat parameter combination

2022-09-26T13:00:15+00:00

As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate
compatibility handlers assume parameters are passed with 32-bit
big-endian ABI. This affects the assignment of odd-even parameter pairs
to the high or low words of a 64-bit syscall parameter.

Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower
32 bits conditioned on endianness.

A future patch will replace the arch-specific compat fallocate with an
asm-generic implementation. This patch is intended for ease of
back-port.

[1]: https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/

Fixes: 57f48b4b74e7 ("powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode")
Reported-by: Arnd Bergmann 
Signed-off-by: Rohan McLure 
Reviewed-by: Arnd Bergmann 
Reviewed-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com

powerpc: Remove asmlinkage from syscall handler definitions

2022-09-26T13:00:14+00:00

The asmlinkage macro has no special meaning in powerpc, and prior to
this patch is used sporadically on some syscall handler definitions. On
architectures that do not define asmlinkage, it resolves to extern "C"
for C++ compilers and a nop otherwise. The current invocations of
asmlinkage provide far from complete support for C++ toolchains, and so
the macro serves no purpose in powerpc.

Remove all invocations of asmlinkage in arch/powerpc. These incidentally
only occur in syscall definitions and prototypes.

Signed-off-by: Rohan McLure 
Reviewed-by: Nicholas Piggin 
Reviewed-by: Andrew Donnellan 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220921065605.1051927-2-rmclure@linux.ibm.com

powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode

2021-02-11T12:35:07+00:00

Swap upper/lower 32 bits for 64-bit compat syscalls, conditioned on
endianness. This is modeled after the same functionality in
arch/mips/kernel/linux32.c.

This fixes compat_sys on ppc64le, when called by 32-bit little-endian
processes.

Tested with `file /bin/bash` (pread64) and `truncate -s 5G test`
(ftruncate64).

Signed-off-by: Will Springer 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/2765111.e9J7NaK4W3@sheen

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

2019-05-30T18:26:32+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

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 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

powerpc/syscalls: kill ppc32_select()

2018-05-10T13:25:15+00:00

it had always been pointless - compat_sys_select() sign-extends
the first argument just fine on its own.

Signed-off-by: Al Viro 
[mpe: Use COMPAT_SPU_NEW() to keep systbl_chk.sh happy]
Signed-off-by: Michael Ellerman