linux.git/arch/mips/kernel/unaligned.c, branch v6.12.80

mips: add missing declarations for trap handlers

2023-12-11T01:21:38+00:00

These exception handlers are all called from assembly code, so they don't
normally need a declaration, but without one we now get warnings:

arch/mips/mm/fault.c:323:17: error: no previous prototype for 'do_page_fault' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:447:17: error: no previous prototype for 'do_be' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:752:17: error: no previous prototype for 'do_ov' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:874:17: error: no previous prototype for 'do_fpe' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1027:17: error: no previous prototype for 'do_bp' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1114:17: error: no previous prototype for 'do_tr' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1151:17: error: no previous prototype for 'do_ri' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1402:17: error: no previous prototype for 'do_cpu' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1507:17: error: no previous prototype for 'do_msa_fpe' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1527:17: error: no previous prototype for 'do_msa' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1548:17: error: no previous prototype for 'do_mdmx' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1560:17: error: no previous prototype for 'do_watch' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1587:17: error: no previous prototype for 'do_mcheck' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1612:17: error: no previous prototype for 'do_mt' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1648:17: error: no previous prototype for 'do_dsp' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1656:17: error: no previous prototype for 'do_reserved' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1832:17: error: no previous prototype for 'cache_parity_error' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1880:17: error: no previous prototype for 'do_ftlb' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1909:17: error: no previous prototype for 'do_gsexc' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1944:6: error: no previous prototype for 'ejtag_exception_handler' [-Werror=missing-prototypes]
arch/mips/kernel/traps.c:1989:17: error: no previous prototype for 'nmi_exception_handler' [-Werror=missing-prototypes]
arch/mips/kernel/unaligned.c:1516:17: error: no previous prototype for 'do_ade' [-Werror=missing-prototypes]

Link: https://lkml.kernel.org/r/20231204115710.2247097-4-arnd@kernel.org
Signed-off-by: Arnd Bergmann 
Cc: Stephen Rothwell 
Cc: Thomas Bogendoerfer 
Signed-off-by: Andrew Morton

MIPS: uaccess: emulate Ingenic LXW/LXH/LXHU uaccess

2023-06-09T07:54:17+00:00

The LXW, LXH, LXHU opcodes are part of the MXU ASE found in Ingenic
XBurst based SoCs.

While technically part of the MXU ASE, they do not touch any of the SIMD
registers, and can be used even when the MXU ASE is disabled.

This patch makes it possible to emulate unaligned access for those
instructions.

Signed-off-by: Siarhei Volkau 
Signed-off-by: Thomas Bogendoerfer

MIPS: Handle address errors for accesses above CPU max virtual user address

2022-02-25T08:36:05+00:00

Address errors have always been treated as unaliged accesses and handled
as such. But address errors are also issued for illegal accesses like
user to kernel space or accesses outside of implemented spaces. This
change implements Linux exception handling for accesses to the illegal
space above the CPU implemented maximum virtual user address and the
MIPS 64bit architecture maximum. With this we can now use a fixed value
for the maximum task size on every MIPS CPU and get a more optimized
access_ok().

Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Arnd Bergmann

MIPS: Fix new sparse warnings

2021-04-07T14:11:05+00:00

Commit 45deb5faeb9e ("MIPS: uaccess: Remove get_fs/set_fs call sites")
caused a few new sparse warnings, fix them.

Signed-off-by: Thomas Bogendoerfer

MIPS: uaccess: Remove get_fs/set_fs call sites

2021-04-06T12:36:56+00:00

Use new helpers to access user/kernel for functions, which are used with
user/kernel pointers. Instead of dealing with get_fs/set_fs select
user/kernel access via parameter.

Signed-off-by: Thomas Bogendoerfer 
Reviewed-by: Christoph Hellwig

uaccess: add force_uaccess_{begin,end} helpers

2020-08-12T17:57:59+00:00

Add helpers to wrap the get_fs/set_fs magic for undoing any damange done
by set_fs(KERNEL_DS).  There is no real functional benefit, but this
documents the intent of these calls better, and will allow stubbing the
functions out easily for kernels builds that do not allow address space
overrides in the future.

[hch@lst.de: drop two incorrect hunks, fix a commit log typo]
  Link: http://lkml.kernel.org/r/20200714105505.935079-6-hch@lst.de

Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Acked-by: Linus Torvalds 
Acked-by: Mark Rutland 
Acked-by: Greentime Hu 
Acked-by: Geert Uytterhoeven 
Cc: Nick Hu 
Cc: Vincent Chen 
Cc: Paul Walmsley 
Cc: Palmer Dabbelt 
Link: http://lkml.kernel.org/r/20200710135706.537715-6-hch@lst.de
Signed-off-by: Linus Torvalds

MIPS: Fix build warning about "PTR_STR" redefinition

2020-05-30T08:58:30+00:00

PTR_STR is redefined when CONFIG_TEST_PRINTF is set. This causes the
following build warning:

  CC      lib/test_printf.o
lib/test_printf.c:214:0: warning: "PTR_STR" redefined
 #define PTR_STR "ffff0123456789ab"
 ^
In file included from ./arch/mips/include/asm/dsemul.h:11:0,
                 from ./arch/mips/include/asm/processor.h:22,
                 from ./arch/mips/include/asm/thread_info.h:16,
                 from ./include/linux/thread_info.h:38,
                 from ./include/asm-generic/preempt.h:5,
                 from ./arch/mips/include/generated/asm/preempt.h:1,
                 from ./include/linux/preempt.h:78,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/seqlock.h:36,
                 from ./include/linux/time.h:6,
                 from ./include/linux/stat.h:19,
                 from ./include/linux/module.h:13,
                 from lib/test_printf.c:10:
./arch/mips/include/asm/inst.h:20:0: note: this is the location of the previous definition
 #define PTR_STR  ".dword"
 ^

Instead of renaming PTR_STR we move the unaligned macros to a new file,
which is only included inside MIPS code. This way we can safely include
asm.h and can use STR(PTR) again.

Fixes: e701656ec4db ("MIPS: inst.h: Stop including asm.h to avoid various build failures")
Cc: Maciej W. Rozycki" 
Reported-by: Tiezhu Yang 
Co-developed-by: Huacai Chen 
Signed-off-by: Huacai Chen 
Signed-off-by: Thomas Bogendoerfer

MIPS: Move unaligned load/store helpers to inst.h

2020-04-24T16:18:06+00:00

Move unaligned load/store helpers from unaligned.c to inst.h, then
other parts of the kernel can use these helpers.

Use __ASSEMBLY__ to guard the definition of "LONG" in asm.h to avoid
build error on IPxx platforms.

Signed-off-by: Huacai Chen 
Signed-off-by: Pei Huang 
Reviewed-by: Jiaxun Yang 
Signed-off-by: Thomas Bogendoerfer

MIPS: make CPU_HAS_LOAD_STORE_LR opt-out

2020-01-22T18:16:47+00:00

CPU_HAS_LOAD_STORE_LR was introduced in 932afdeec18b ("MIPS: Add Kconfig
variable for CPUs with unaligned load/store instructions") to make code
in kernel/unaligned.c and lib/mem{cpy,set}.S more intuitive and give a
possibility to easily add new CPUs without these instruction sets in
future.

Hovewer, this variant is not optimal for mainly two reasons:
* For now, we have 20+ CPUs with such instructions and only two (MIPS R6)
  without. It will obviously be more effective and straightforward to
  have an option for these two rather than for the rest.
* You can easily miss the fact that you need to select this option when
  adding a new CPU, while all processors lacking these sets are
  well-known, so the probability of missing something is way much lower.

We can address both points by turning CPU_HAS_LOAD_STORE_LR into opt-out
CPU_NO_LOAD_STORE_LR. This also makes MIPS root Kconfig more clear and
understandable.

Signed-off-by: Alexander Lobakin 
Signed-off-by: Paul Burton 
Cc: Ralf Baechle 
Cc: Alexandre Belloni 
Cc: Microchip Linux Driver Support 
Cc: Will Deacon 
Cc: Greg Kroah-Hartman 
Cc: Masahiro Yamada 
Cc: Paul Walmsley 
Cc: Michal Simek 
Cc: Allison Randal 
Cc: Thomas Gleixner 
Cc: Eric W. Biederman 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

signal: Remove task parameter from force_sig

2019-05-27T14:36:28+00:00

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"