Commit Graph

12 Commits

Author SHA1 Message Date
Maciej W. Rozycki
8e0780d30b MIPS: Fix big-endian stack argument fetching in o32 wrapper
Fix an issue in call_o32() where the upper 32-bit half of incoming n64
stack arguments is fetched and used for outgoing o32 stack arguments on
big-endian platforms.

This code was adapted from arch/mips/dec/prom/call_o32.S which was meant
for a little-endian platform only and therefore using 32-bit loads from
64-bit stack slot locations holding incoming stack arguments resulted in
correct values being retrieved for data that is expected to be 32-bit.

This works on little-endian platforms where the lower 32-bit half of the
64-bit value is located at every 64-bit stack slot location.  However on
big-endian platforms the lower 32-bit half is instead located at offset
4 from every 64-bit stack slot location.

So to fix the issue the offset of 4 would have to be used on big-endian
platforms only, or alternatively a 64-bit load from the 64-bit stack
slot location can be used across the board, as the subsequent 32-bit
store to the corresponding outgoing stack argument slot will correctly
truncate the value and cause no unpredictable result.  We already take
advantage of this architectural feature for the incoming arguments held
in $a6 and $a7 registers, since the o32 wrapper does not know how many
incoming arguments there are and consequently propagates incoming data
which may not be 32-bit.

Since this code is generally supposed to be used with the stack located
in cached memory there is no extra overhead expected for 64-bit loads as
opposed to 32-bit ones, so pick this variant for code simplicity.

Fixes: 231a35d372 ("[MIPS] RM: Collected changes")
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2026-05-26 16:35:36 +02:00
Jiaxun Yang
ee1809ed7b MIPS: fw: Allow firmware to pass a empty env
fw_getenv will use env entry to determine style of env,
however it is legal for firmware to just pass a empty list.

Check if first entry exist before running strchr to avoid
null pointer dereference.

Cc: stable@vger.kernel.org
Link: https://github.com/clbr/n64bootloader/issues/5
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2023-04-12 15:07:36 +02:00
Masahiro Yamada
78bdbbac08 MIPS: do not compile generic functions for CONFIG_CAVIUM_OCTEON_SOC
MIPS provides multiple definitions for the following functions:

  fw_init_cmdline
  __delay
  __udelay
  __ndelay
  memmove
  __rmemcpy
  memcpy
  __copy_user

The generic ones are defined in lib-y objects, which are overridden by
the Octeon ones when CONFIG_CAVIUM_OCTEON_SOC is enabled.

The use of EXPORT_SYMBOL in static libraries potentially causes a
problem for the llvm linker [1]. So, I want to forcibly link lib-y
objects to vmlinux when CONFIG_MODULES=y.

As a groundwork, we must fix multiple definitions that have previously
been hidden by lib-y.

If you look at lib/string.c, arch can define __HAVE_ARCH_* to opt out
the generic implementation.

Similarly, this commit adds CONFIG_HAVE_PLAT_* to allow a platform
to opt out the MIPS generic code.

[1]: https://github.com/ClangBuiltLinux/linux/issues/515

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2020-03-25 16:07:13 +01:00
Thomas Gleixner
2874c5fd28 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>
2019-05-30 11:26:32 -07:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Alban Bedel
484c344985 MIPS: FW: Use kstrtoul() to parse unsigned long from the fw environment
Fix some value corruptions with values that can't be represented in a
signed long.

Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8358/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:26 +01:00
Alban Bedel
4a792e56cf MIPS: FW: Fix parsing u-boot environment
When reading u-boot's key=value pairs it should skip the '=' and not
use the next argument.

Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8357/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24 07:45:25 +01:00
Maciej W. Rozycki
824122a319 MIPS: DEC/SNI: O32 wrapper stack switching fixes
Commit 231a35d372 [[MIPS] RM: Collected
changes] broke DECstation support by introducing an incompatible copy of
arch/mips/dec/prom/call_o32.S in arch/mips/fw/lib/, built unconditionally.
The copy happens to land earlier of the two among the modules used in the
link and is therefore chosen for the DECstation rather than the intended
original.  As a result random kernel data is corrupted because a pointer
to the "%s" formatted output template is used as a temporary stack pointer
rather than being passed down to prom_printf.  This also explains why
prom_printf still works, up to a point -- the next argument is the actual
string to output so it works just fine as the output template until enough
kernel data has been corrupted to cause a crash.

This change adjusts the modified wrapper in arch/mips/fw/lib/call_o32.S to
let callers request no stack switching by passing a null temporary stack
pointer in $a1, reworks the DECstation callers to work with the updated
interface and removes the old copy from arch/mips/dec/prom/call_o32.S.  A
few minor readability adjustments are included as well, most importantly
O32_SZREG is now used throughout where applicable rather than hardcoded
multiplies of 4 and $fp is used to access the argument save area as a more
usual register to operate the stack with rather than $s0.

Finally an update is made to the temporary stack space used by the SNI
platform to guarantee 8-byte alignment as per o32 requirements.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6668/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-13 00:29:35 +02:00
Steven J. Hill
14aecdd419 MIPS: FW: Add environment variable processing.
Add parsing of the environment and command line variables passed to
the kernel to the firmware library.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
2013-05-08 12:30:09 +02:00
Ralf Baechle
7034228792 MIPS: Whitespace cleanup.
Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-01 10:00:22 +01:00
Ralf Baechle
49316cbf0a MIPS: Eleminate filenames from comments
They tend to get not updated when files are moved around or copied and
lack any obvious use.  While at it zap some only too obvious comments and
as per Shinya's suggestion, add a copyright header to extable.c.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
2009-08-03 17:52:40 +01:00
Thomas Bogendoerfer
231a35d372 [MIPS] RM: Collected changes
- EISA support for non PCI RMs (RM200 and RM400-xxx). The major part
  is the splitting of the EISA and onboard ISA of the RM200, which
  makes the EISA bus on the RM200 look like on other RMs.
- 64bit kernel support
- system type detection is now common for big and little endian
- moved sniprom code to arch/mips/fw
- added call_o32 function to arch/mips/fw/lib, which uses a private
  stack for calling prom functions
- fix problem with ISA interrupts, which makes using PIT clockevent
  possible

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-01-29 10:14:59 +00:00