CP0 register 26 is used as ECC register for legacy cores, but newer
cores (MIPS32/MIPS64) use it as an ErrCtl register. Since the kernel only
uses CP0 26 as ErrCtl register rename the access functions to the more
fitting name.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
With the expanded support for placing the kernel in XPHYS rather than
just KSEG0, scenarios where ebase doesn't belong to KSEG0 are more
likely to occur. In such cases, we currently experience a substantial
and perplexing stack dump without any accompanying explanation. To
rectify this, we aim to replace the uninformative stack dump with a
warning that offers a clear explanation of the issue.
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Use GPR number macros in uasm code generation parts to
reduce code duplication.
No functional change.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
"cpu_probe" is called both by BP and APs, but reserving exception vector
(like 0x0-0x1000) called by "cpu_probe" need once and calling on APs is
too late since memblock is unavailable at that time.
So, reserve exception vector ONLY by BP.
Suggested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Pull MIPS updates from Thomas Bogendoerfer:
"Just cleanups and fixes"
* tag 'mips_6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: Alchemy: Fix an out-of-bound access in db1550_dev_setup()
MIPS: Alchemy: Fix an out-of-bound access in db1200_dev_setup()
MIPS: Fix typos
MIPS: Remove unused shadow GPR support from vector irq setup
MIPS: Allow vectored interrupt handler to reside everywhere for 64bit
mips: Set dump-stack arch description
mips: mm: add slab availability checking in ioremap_prot
mips: Optimize max_mapnr init procedure
mips: Fix max_mapnr being uninitialized on early stages
mips: Fix incorrect max_low_pfn adjustment
mips: dmi: Fix early remap on MIPS32
MIPS: compressed: Use correct instruction for 64 bit code
MIPS: SGI-IP27: hubio: fix nasid kernel-doc warning
MAINTAINERS: Add myself as maintainer of the Ralink architecture
Setting up vector interrupts worked only with handlers, which resided
in CKSEG0 space. This limits the kernel placement for 64bit platforms.
By patching in the offset into vi_handlers[] instead of the full
handler address, the vectored exception handler can load the
address by itself and jump to it.
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
There are two definitions for tlb_init(), but no global declaration:
arch/mips/mm/tlb-r4k.c:552:6: error: no previous prototype for 'tlb_init' [-Werror=missing-prototypes]
arch/mips/mm/tlb-r3k.c:244:6: error: no previous prototype for 'tlb_init' [-Werror=missing-prototypes]
Move the declaration to asm/setup.h and included it as needed.
Link: https://lkml.kernel.org/r/20231204115710.2247097-12-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Rothwell <sfr@rothwell.id.au>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With KCFLAGS="-O3", I was able to trigger a fortify-source
memcpy() overflow panic on set_vi_srs_handler().
Although O3 level is not supported in the mainline, under some
conditions that may've happened with any optimization settings,
it's just a matter of inlining luck. The panic itself is correct,
more precisely, 50/50 false-positive and not at the same time.
From the one side, no real overflow happens. Exception handler
defined in asm just gets copied to some reserved places in the
memory.
But the reason behind is that C code refers to that exception
handler declares it as `char`, i.e. something of 1 byte length.
It's obvious that the asm function itself is way more than 1 byte,
so fortify logics thought we are going to past the symbol declared.
The standard way to refer to asm symbols from C code which is not
supposed to be called from C is to declare them as
`extern const u8[]`. This is fully correct from any point of view,
as any code itself is just a bunch of bytes (including 0 as it is
for syms like _stext/_etext/etc.), and the exact size is not known
at the moment of compilation.
Adjust the type of the except_vec_vi_*() and related variables.
Make set_handler() take `const` as a second argument to avoid
cast-away warnings and give a little more room for optimization.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
After making the brcmstb_gisb driver modular with 707a4cdf86 ("bus:
brcmstb_gisb: Allow building as module") Guenter reported that mips
allmodconfig failed to link because board_be_handler was referenced.
Thomas indicated that if we were to continue making the brcmstb_gisb
driver modular for MIPS we would need to introduce a function that
allows setting the board_be_handler and export that function towards
modules.
This is what is being done here: board_be_handler is made static and is
now settable with a mips_set_be_handler() function which is exported.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Suggested-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Fixes: 707a4cdf86 ("bus: brcmstb_gisb: Allow building as module")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
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 <tsbogend@alpha.franken.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
BMIPS is one of the few platforms that do change the exception base.
After commit 2dcb396454 ("memblock: do not start bottom-up allocations
with kernel_end") we started seeing BMIPS boards fail to boot with the
built-in FDT being corrupted.
Before the cited commit, early allocations would be in the [kernel_end,
RAM_END] range, but after commit they would be within [RAM_START +
PAGE_SIZE, RAM_END].
The custom exception base handler that is installed by
bmips_ebase_setup() done for BMIPS5000 CPUs ends-up trampling on the
memory region allocated by unflatten_and_copy_device_tree() thus
corrupting the FDT used by the kernel.
To fix this, we need to perform an early reservation of the custom
exception space. Additional we reserve the first 4k (1k for R3k) for
either normal exception vector space (legacy CPUs) or special vectors
like cache exceptions.
Huge thanks to Serge for analysing and proposing a solution to this
issue.
Fixes: 2dcb396454 ("memblock: do not start bottom-up allocations with kernel_end")
Reported-by: Kamal Dasu <kdasu.kdev@gmail.com>
Debugged-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Pull MIPS updates from Thomas Bogendoerfer:
- removed support for PNX833x alias NXT_STB22x
- included Ingenic SoC support into generic MIPS kernels
- added support for new Ingenic SoCs
- converted workaround selection to use Kconfig
- replaced old boot mem functions by memblock_*
- enabled COP2 usage in kernel for Loongson64 to make use
of 16byte load/stores possible
- cleanups and fixes
* tag 'mips_5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (92 commits)
MIPS: DEC: Restore bootmem reservation for firmware working memory area
MIPS: dec: fix section mismatch
bcm963xx_tag.h: fix duplicated word
mips: ralink: enable zboot support
MIPS: ingenic: Remove CPU_SUPPORTS_HUGEPAGES
MIPS: cpu-probe: remove MIPS_CPU_BP_GHIST option bit
MIPS: cpu-probe: introduce exclusive R3k CPU probe
MIPS: cpu-probe: move fpu probing/handling into its own file
MIPS: replace add_memory_region with memblock
MIPS: Loongson64: Clean up numa.c
MIPS: Loongson64: Select SMP in Kconfig to avoid build error
mips: octeon: Add Ubiquiti E200 and E220 boards
MIPS: SGI-IP28: disable use of ll/sc in kernel
MIPS: tx49xx: move tx4939_add_memory_regions into only user
MIPS: pgtable: Remove used PAGE_USERIO define
MIPS: alchemy: Share prom_init implementation
MIPS: alchemy: Fix build breakage, if TOUCHSCREEN_WM97XX is disabled
MIPS: process: include exec.h header in process.c
MIPS: process: Add prototype for function arch_dup_task_struct
MIPS: idle: Add prototype for function check_wait
...
Loongson-3's COP2 is Multi-Media coprocessor, it is disabled in kernel
mode by default. However, gslq/gssq (16-bytes load/store instructions)
overrides the instruction format of lwc2/swc2. If we wan't to use gslq/
gssq for optimization in kernel, we should enable COP2 usage in kernel.
Please pay attention that in this patch we only enable COP2 in kernel,
which means it will lose ST0_CU2 when a process go to user space (try
to use COP2 in user space will trigger an exception and then grab COP2,
which is similar to FPU). And as a result, we need to modify the context
switching code because the new scheduled process doesn't contain ST0_CU2
in its THERAD_STATUS probably.
For zboot, we disable gslq/gssq be generated by toolchain.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
In cc97ab235f ("MIPS: Simplify FP context initialization), init_fp_ctx
just initialize the fp/msa context, and own_fp_inatomic just restore
FCSR and 64bit FP regs from it, but miss MSACSR and upper MSA regs for
MSA, so MSACSR and MSA upper regs's value from previous task on current
cpu can leak into current task and cause unpredictable behavior when MSA
context not initialized.
Fixes: cc97ab235f ("MIPS: Simplify FP context initialization")
Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Pull MIPS upates from Thomas Bogendoerfer:
- improvements for Loongson64
- extended ingenic support
- removal of not maintained paravirt system type
- cleanups and fixes
* tag 'mips_5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (81 commits)
MIPS: SGI-IP27: always enable NUMA in Kconfig
MAINTAINERS: Update KVM/MIPS maintainers
MIPS: Update default config file for Loongson-3
MIPS: KVM: Add kvm guest support for Loongson-3
dt-bindings: mips: Document Loongson kvm guest board
MIPS: handle Loongson-specific GSExc exception
MIPS: add definitions for Loongson-specific CP0.Diag1 register
MIPS: only register FTLBPar exception handler for supported models
MIPS: ingenic: Hardcode mem size for qi,lb60 board
MIPS: DTS: ingenic/qi,lb60: Add model and memory node
MIPS: ingenic: Use fw_passed_dtb even if CONFIG_BUILTIN_DTB
MIPS: head.S: Init fw_passed_dtb to builtin DTB
of: address: Fix parser address/size cells initialization
of_address: Guard of_bus_pci_get_flags with CONFIG_PCI
MIPS: DTS: Fix number of msi vectors for Loongson64G
MIPS: Loongson64: Add ISA node for LS7A PCH
MIPS: Loongson64: DTS: Fix ISA and PCI I/O ranges for RS780E PCH
MIPS: Loongson64: Enlarge IO_SPACE_LIMIT
MIPS: Loongson64: Process ISA Node in DeviceTree
of_address: Add bus type match for pci ranges parser
...
Newer Loongson cores (Loongson-3A R2 and newer) use the
implementation-dependent ExcCode 16 to signal Loongson-specific
exceptions. The extended cause is put in the non-standard CP0.Diag1
register which is CP0 Register 22 Select 1, called GSCause in Loongson
manuals. Inside is an exception code bitfield called GSExcCode, only
codes 0 to 6 inclusive are documented (so far, in the Loongson 3A3000
User Manual, Volume 2).
During experiments, it was found that some undocumented unprivileged
instructions can trigger the also-undocumented GSExcCode 8 on Loongson
3A4000. Processor state is not corrupted, but we cannot continue without
further knowledge, and Loongson is not providing that information as of
this writing. So we send SIGILL on seeing this exception code to thwart
easy local DoS attacks.
Other exception codes are made fatal, partly because of insufficient
knowledge, also partly because they are not as easily reproduced. None
of them are encountered in the wild with upstream kernels and userspace
so far.
Some older cores (Loongson-3A1000 and Loongson-3B1500) have ExcCode 16
too, but the semantic is equivalent to GSExcCode 0. Because the
respective manuals did not mention the CP0.Diag1 register or its read
behavior, these cores are not covered in this patch, as MFC0 from
non-existent CP0 registers is UNDEFINED according to the MIPS
architecture spec.
Reviewed-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Previously ExcCode 16 is unconditionally treated as the FTLB parity
exception (FTLBPar), but in fact its semantic is implementation-
dependent. Looking at various manuals it seems the FTLBPar exception is
only present on some recent MIPS Technologies cores, so only register
the handler on these.
Fixes: 75b5b5e0a2 ("MIPS: Add support for FTLBs")
Reviewed-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Cc: Paul Burton <paulburton@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
