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>
When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so
there's no need to save & restore floating point context around signals.
This prepares us for the removal of FP context from struct task_struct
later.
Since MSA context is a superset of FP context support for it similarly
needs to be removed when MSA/FP support is disabled.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21009/
Cc: linux-mips@linux-mips.org
An overview of the general architecture changes:
- Massive DMA ops refactoring from Christoph Hellwig (huzzah for
deleting crufty code!).
- We introduce NT_MIPS_DSP & NT_MIPS_FP_MODE ELF notes & corresponding
regsets to expose DSP ASE & floating point mode state respectively,
both for live debugging & core dumps.
- We better optimize our code by hard-coding cpu_has_* macros at
compile time where their values are known due to the ISA revision
that the kernel build is targeting.
- The EJTAG exception handler now better handles SMP systems, where it
was previously possible for CPUs to clobber a register value saved
by another CPU.
- Our implementation of memset() gained a couple of fixes for MIPSr6
systems to return correct values in some cases where stores fault.
- We now implement ioremap_wc() using the uncached-accelerated cache
coherency attribute where supported, which is detected during boot,
and fall back to plain uncached access where necessary. The
MIPS-specific (and unused in tree) ioremap_uncached_accelerated() &
ioremap_cacheable_cow() are removed.
- The prctl(PR_SET_FP_MODE, ...) syscall is better supported for SMP
systems by reworking the way we ensure remote CPUs that may be
running threads within the affected process switch mode.
- Systems using the MIPS Coherence Manager will now set the
MIPS_IC_SNOOPS_REMOTE flag to avoid some unnecessary cache
maintenance overhead when flushing the icache.
- A few fixes were made for building with clang/LLVM, which
now sucessfully builds kernels for many of our platforms.
- Miscellaneous cleanups all over.
And some platform-specific changes:
- ar7 gained stubs for a few clock API functions to fix build failures
for some drivers.
- ath79 gained support for a few new SoCs, a few fixes & better
gpio-keys support.
- Ci20 now exposes its SPI bus using the spi-gpio driver.
- The generic platform can now auto-detect a suitable value for
PHYS_OFFSET based upon the memory map described by the device tree,
allowing us to avoid wasting memory on page book-keeping for systems
where RAM starts at a non-zero physical address.
- Ingenic systems using the jz4740 platform code now link their
vmlinuz higher to allow for kernels of a realistic size.
- Loongson32 now builds the kernel targeting MIPSr1 rather than MIPSr2
to avoid CPU errata.
- Loongson64 gains a couple of fixes, a workaround for a write
buffering issue & support for the Loongson 3A R3.1 CPU.
- Malta now uses the piix4-poweroff driver to handle powering down.
- Microsemi Ocelot gained support for its SPI bus & NOR flash, its
second MDIO bus and can now be supported by a FIT/.itb image.
- Octeon saw a bunch of header cleanups which remove a lot of
duplicate or unused code.
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Merge tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS updates from Paul Burton:
"Here are the main MIPS changes for 4.19.
An overview of the general architecture changes:
- Massive DMA ops refactoring from Christoph Hellwig (huzzah for
deleting crufty code!).
- We introduce NT_MIPS_DSP & NT_MIPS_FP_MODE ELF notes &
corresponding regsets to expose DSP ASE & floating point mode state
respectively, both for live debugging & core dumps.
- We better optimize our code by hard-coding cpu_has_* macros at
compile time where their values are known due to the ISA revision
that the kernel build is targeting.
- The EJTAG exception handler now better handles SMP systems, where
it was previously possible for CPUs to clobber a register value
saved by another CPU.
- Our implementation of memset() gained a couple of fixes for MIPSr6
systems to return correct values in some cases where stores fault.
- We now implement ioremap_wc() using the uncached-accelerated cache
coherency attribute where supported, which is detected during boot,
and fall back to plain uncached access where necessary. The
MIPS-specific (and unused in tree) ioremap_uncached_accelerated() &
ioremap_cacheable_cow() are removed.
- The prctl(PR_SET_FP_MODE, ...) syscall is better supported for SMP
systems by reworking the way we ensure remote CPUs that may be
running threads within the affected process switch mode.
- Systems using the MIPS Coherence Manager will now set the
MIPS_IC_SNOOPS_REMOTE flag to avoid some unnecessary cache
maintenance overhead when flushing the icache.
- A few fixes were made for building with clang/LLVM, which now
sucessfully builds kernels for many of our platforms.
- Miscellaneous cleanups all over.
And some platform-specific changes:
- ar7 gained stubs for a few clock API functions to fix build
failures for some drivers.
- ath79 gained support for a few new SoCs, a few fixes & better
gpio-keys support.
- Ci20 now exposes its SPI bus using the spi-gpio driver.
- The generic platform can now auto-detect a suitable value for
PHYS_OFFSET based upon the memory map described by the device tree,
allowing us to avoid wasting memory on page book-keeping for
systems where RAM starts at a non-zero physical address.
- Ingenic systems using the jz4740 platform code now link their
vmlinuz higher to allow for kernels of a realistic size.
- Loongson32 now builds the kernel targeting MIPSr1 rather than
MIPSr2 to avoid CPU errata.
- Loongson64 gains a couple of fixes, a workaround for a write
buffering issue & support for the Loongson 3A R3.1 CPU.
- Malta now uses the piix4-poweroff driver to handle powering down.
- Microsemi Ocelot gained support for its SPI bus & NOR flash, its
second MDIO bus and can now be supported by a FIT/.itb image.
- Octeon saw a bunch of header cleanups which remove a lot of
duplicate or unused code"
* tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (123 commits)
MIPS: Remove remnants of UASM_ISA
MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send()
MIPS: VDSO: Force link endianness
MIPS: Always specify -EB or -EL when using clang
MIPS: Use dins to simplify __write_64bit_c0_split()
MIPS: Use read-write output operand in __write_64bit_c0_split()
MIPS: Avoid using array as parameter to write_c0_kpgd()
MIPS: vdso: Allow clang's --target flag in VDSO cflags
MIPS: genvdso: Remove GOT checks
MIPS: Remove obsolete MIPS checks for DST node "chosen@0"
MIPS: generic: Remove input symbols from defconfig
MIPS: Delete unused code in linux32.c
MIPS: Remove unused sys_32_mmap2
MIPS: Remove nabi_no_regargs
mips: dts: mscc: enable spi and NOR flash support on ocelot PCB123
mips: dts: mscc: Add spi on Ocelot
MIPS: Loongson: Merge load addresses
MIPS: Loongson: Set Loongson32 to MIPS32R1
MIPS: mscc: ocelot: add interrupt controller properties to GPIO controller
MIPS: generic: Select MIPS_AUTO_PFN_OFFSET
...
Our sigreturn functions make use of a macro named nabi_no_regargs to
declare 8 dummy arguments to a function, forcing the compiler to expect
a pt_regs structure on the stack rather than in argument registers. This
is an ugly hack which unnecessarily causes these sigreturn functions to
need to care about the calling convention of the ABI the kernel is built
for. Although this is abstracted via nabi_no_regargs, it's still ugly &
unnecessary.
Remove nabi_no_regargs & the struct pt_regs argument from sigreturn
functions, and instead use current_pt_regs() to find the struct pt_regs
on the stack, which works cleanly regardless of ABI.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20106/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Commit 784e0300fe ("rseq: Avoid infinite recursion when delivering
SIGSEGV") added a new ksig argument to the rseq_signal_deliver() &
rseq_handle_notify_resume() functions, and was merged in v4.18-rc2.
Meanwhile MIPS support for restartable sequences was also merged in
v4.18-rc2 with commit 9ea141ad54 ("MIPS: Add support for restartable
sequences"), and therefore didn't get updated for the API change.
This results in build failures like the following:
CC arch/mips/kernel/signal.o
arch/mips/kernel/signal.c: In function 'handle_signal':
arch/mips/kernel/signal.c:804:22: error: passing argument 1 of
'rseq_signal_deliver' from incompatible pointer type
[-Werror=incompatible-pointer-types]
rseq_signal_deliver(regs);
^~~~
In file included from ./include/linux/context_tracking.h:5,
from arch/mips/kernel/signal.c:12:
./include/linux/sched.h:1811:56: note: expected 'struct ksignal *' but
argument is of type 'struct pt_regs *'
static inline void rseq_signal_deliver(struct ksignal *ksig,
~~~~~~~~~~~~~~~~^~~~
arch/mips/kernel/signal.c:804:2: error: too few arguments to function
'rseq_signal_deliver'
rseq_signal_deliver(regs);
^~~~~~~~~~~~~~~~~~~
Fix this by adding the ksig argument as was done for other architectures
in commit 784e0300fe ("rseq: Avoid infinite recursion when delivering
SIGSEGV").
Signed-off-by: Paul Burton <paul.burton@mips.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Patchwork: https://patchwork.linux-mips.org/patch/19603/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Implement support for restartable sequences on MIPS, which requires 3
simple things:
- Call rseq_handle_notify_resume() on return to userspace if
TIF_NOTIFY_RESUME is set.
- Call rseq_signal_deliver() to fixup the pre-signal stack frame when
a signal is delivered whilst executing a restartable sequence
critical section.
- Select CONFIG_HAVE_RSEQ.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: James Hogan <jhogan@kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/19523/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.8. Also includes is a
minor SSB cleanup as SSB code traditionally is merged through the MIPS
tree:
ATH25:
- MIPS: Add default configuration for ath25
Boot:
- For zboot, copy appended dtb to the end of the kernel
- store the appended dtb address in a variable
BPF:
- Fix off by one error in offset allocation
Cobalt code:
- Fix typos
Core code:
- debugfs_create_file returns NULL on error, so don't use IS_ERR for
testing for errors.
- Fix double locking issue in RM7000 S-cache code. This would only
affect RM7000 ARC systems on reboot.
- Fix page table corruption on THP permission changes.
- Use compat_sys_keyctl for 32 bit userspace on 64 bit kernels.
David says, there are no compatibility issues raised by this fix.
- Move some signal code around.
- Rewrite r4k count/compare clockevent device registration such that
min_delta_ticks/max_delta_ticks files are guaranteed to be
initialized.
- Only register r4k count/compare as clockevent device if we can
assume the clock to be constant.
- Fix MSA asm warnings in control reg accessors
- uasm and tlbex fixes and tweaking.
- Print segment physical address when EU=1.
- Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFO.
- CP: Allow booting by VP other than VP 0
- Cache handling fixes and optimizations for r4k class caches
- Add hotplug support for R6 processors
- Cleanup hotplug bits in kconfig
- traps: return correct si code for accessing nonmapped addresses
- Remove cpu_has_safe_index_cacheops
Lantiq:
- Register IRQ handler for virtual IRQ number
- Fix EIU interrupt loading code
- Use the real EXIN count
- Fix build error.
Loongson 3:
- Increase HPET_MIN_PROG_DELTA and decrease HPET_MIN_CYCLES
Octeon:
- Delete built-in DTB pruning code for D-Link DSR-1000N.
- Clean up GPIO definitions in dlink_dsr-1000n.dts.
- Add more LEDs to the DSR-100n DTS
- Fix off by one in octeon_irq_gpio_map()
- Typo fixes
- Enable SATA by default in cavium_octeon_defconfig
- Support readq/writeq()
- Remove forced mappings of USB interrupts.
- Ensure DMA descriptors are always in the low 4GB
- Improve USB reset code for OCTEON II.
Pistachio:
- Add maintainers entry for pistachio SoC Support
- Remove plat_setup_iocoherency
Ralink:
- Fix pwm UART in spis group pinmux.
SSB:
- Change bare unsigned to unsigned int to suit coding style
Tools:
- Fix reloc tool compiler warnings.
Other:
- Delete use of ARCH_WANT_OPTIONAL_GPIOLIB"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (61 commits)
MIPS: mm: Fix definition of R6 cache instruction
MIPS: tools: Fix relocs tool compiler warnings
MIPS: Cobalt: Fix typo
MIPS: Octeon: Fix typo
MIPS: Lantiq: Fix build failure
MIPS: Use CPHYSADDR to implement mips32 __pa
MIPS: Octeon: Dlink_dsr-1000n.dts: add more leds.
MIPS: Octeon: Clean up GPIO definitions in dlink_dsr-1000n.dts.
MIPS: Octeon: Delete built-in DTB pruning code for D-Link DSR-1000N.
MIPS: store the appended dtb address in a variable
MIPS: ZBOOT: copy appended dtb to the end of the kernel
MIPS: ralink: fix spis group pinmux
MIPS: Factor o32 specific code into signal_o32.c
MIPS: non-exec stack & heap when non-exec PT_GNU_STACK is present
MIPS: Use per-mm page to execute branch delay slot instructions
MIPS: Modify error handling
MIPS: c-r4k: Use SMP calls for CM indexed cache ops
MIPS: c-r4k: Avoid small flush_icache_range SMP calls
MIPS: c-r4k: Local flush_icache_range cache op override
MIPS: c-r4k: Split r4k_flush_kernel_vmap_range()
...
The use of config_enabled() against config options is ambiguous. In
practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the
author might have used it for the meaning of IS_ENABLED(). Using
IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention
clearer.
This commit replaces config_enabled() with IS_ENABLED() where possible.
This commit is only touching bool config options.
I noticed two cases where config_enabled() is used against a tristate
option:
- config_enabled(CONFIG_HWMON)
[ drivers/net/wireless/ath/ath10k/thermal.c ]
- config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE)
[ drivers/gpu/drm/gma500/opregion.c ]
I did not touch them because they should be converted to IS_BUILTIN()
in order to keep the logic, but I was not sure it was the authors'
intention.
Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Stas Sergeev <stsp@list.ru>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: "Dmitry V. Levin" <ldv@altlinux.org>
Cc: yu-cheng yu <yu-cheng.yu@intel.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Will Drewry <wad@chromium.org>
Cc: Nikolay Martynov <mar.kolya@gmail.com>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Rafal Milecki <zajec5@gmail.com>
Cc: James Cowgill <James.Cowgill@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Tony Wu <tung7970@gmail.com>
Cc: Huaitong Han <huaitong.han@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Gelmini <andrea.gelmini@gelma.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In some cases the kernel needs to execute an instruction from the delay
slot of an emulated branch instruction. These cases include:
- Emulated floating point branch instructions (bc1[ft]l?) for systems
which don't include an FPU, or upon which the kernel is run with the
"nofpu" parameter.
- MIPSr6 systems running binaries targeting older revisions of the
architecture, which may include branch instructions whose encodings
are no longer valid in MIPSr6.
Executing instructions from such delay slots is done by writing the
instruction to memory followed by a trap, as part of an "emuframe", and
executing it. This avoids the requirement of an emulator for the entire
MIPS instruction set. Prior to this patch such emuframes are written to
the user stack and executed from there.
This patch moves FP branch delay emuframes off of the user stack and
into a per-mm page. Allocating a page per-mm leaves userland with access
to only what it had access to previously, and compared to other
solutions is relatively simple.
When a thread requires a delay slot emulation, it is allocated a frame.
A thread may only have one frame allocated at any one time, since it may
only ever be executing one instruction at any one time. In order to
ensure that we can free up allocated frame later, its index is recorded
in struct thread_struct. In the typical case, after executing the delay
slot instruction we'll execute a break instruction with the BRK_MEMU
code. This traps back to the kernel & leads to a call to do_dsemulret
which frees the allocated frame & moves the user PC back to the
instruction that would have executed following the emulated branch.
In some cases the delay slot instruction may be invalid, such as a
branch, or may trigger an exception. In these cases the BRK_MEMU break
instruction will not be hit. In order to ensure that frames are freed
this patch introduces dsemul_thread_cleanup() and calls it to free any
allocated frame upon thread exit. If the instruction generated an
exception & leads to a signal being delivered to the thread, or indeed
if a signal simply happens to be delivered to the thread whilst it is
executing from the struct emuframe, then we need to take care to exit
the frame appropriately. This is done by either rolling back the user PC
to the branch or advancing it to the continuation PC prior to signal
delivery, using dsemul_thread_rollback(). If this were not done then a
sigreturn would return to the struct emuframe, and if that frame had
meanwhile been used in response to an emulated branch instruction within
the signal handler then we would execute the wrong user code.
Whilst a user could theoretically place something like a compact branch
to self in a delay slot and cause their thread to become stuck in an
infinite loop with the frame never being deallocated, this would:
- Only affect the users single process.
- Be architecturally invalid since there would be a branch in the
delay slot, which is forbidden.
- Be extremely unlikely to happen by mistake, and provide a program
with no more ability to harm the system than a simple infinite loop
would.
If a thread requires a delay slot emulation & no frame is available to
it (ie. the process has enough other threads that all frames are
currently in use) then the thread joins a waitqueue. It will sleep until
a frame is freed by another thread in the process.
Since we now know whether a thread has an allocated frame due to our
tracking of its index, the cookie field of struct emuframe is removed as
we can be more certain whether we have a valid frame. Since a thread may
only ever have a single frame at any given time, the epc field of struct
emuframe is also removed & the PC to continue from is instead stored in
struct thread_struct. Together these changes simplify & shrink struct
emuframe somewhat, allowing twice as many frames to fit into the page
allocated for them.
The primary benefit of this patch is that we are now free to mark the
user stack non-executable where that is possible.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: Maciej Rozycki <maciej.rozycki@imgtec.com>
Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13764/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In microMIPS kernels, handle_signal() sets the isa16 mode bit in the
vdso address so that the sigreturn trampolines (which are offset from
the VDSO) get executed as microMIPS.
However commit ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
changed the offsets to come from the VDSO image, which already have the
isa16 mode bit set correctly since they're extracted from the VDSO
shared library symbol table.
Drop the isa16 mode bit handling from handle_signal() to fix sigreturn
for cores which support both microMIPS and normal MIPS. This doesn't fix
microMIPS only cores, since the VDSO is still built for normal MIPS, but
thats a separate problem.
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/13348/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
If a kernel doesn't support MSA context (ie. CONFIG_CPU_HAS_MSA=n) then
it will only keep 64 bits per FP register in thread context, and the
calls to set_fpr64 in restore_msa_extcontext will overrun the end of the
FP register context into the FCSR & MSACSR values. GCC 6.x has become
smart enough to detect this & complain like so:
arch/mips/kernel/signal.c: In function 'protected_restore_fp_context':
./arch/mips/include/asm/processor.h:114:17: error: array subscript is above array bounds [-Werror=array-bounds]
fpr->val##width[FPR_IDX(width, idx)] = val; \
~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
./arch/mips/include/asm/processor.h:118:1: note: in expansion of macro 'BUILD_FPR_ACCESS'
BUILD_FPR_ACCESS(64)
The only way to trigger this code to run would be for a program to set
up an artificial extended MSA context structure following a sigframe &
execute sigreturn. Whilst this doesn't allow a program to write to any
state that it couldn't already, it makes little sense to allow this
"restoration" of MSA context in a system that doesn't support MSA.
Fix this by killing a program with SIGSYS if it tries something as crazy
as "restoring" fake MSA context in this way, also fixing the build error
& allowing for most of restore_msa_extcontext to be optimised out of
kernels without support for MSA.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: Michal Toman <michal.toman@imgtec.com>
Fixes: bf82cb30c7 ("MIPS: Save MSA extended context around signals")
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Toman <michal.toman@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable <stable@vger.kernel.org> # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/13164/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add an initial implementation of a proper (i.e. an ELF shared library)
VDSO. With this commit it does not export any symbols, it only replaces
the current signal return trampoline page. A later commit will add user
implementations of gettimeofday()/clock_gettime().
To support both new toolchains and old ones which don't generate ABI
flags section, we define its content manually and then use a tool
(genvdso) to patch up the section to have the correct name and type.
genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the
kernel, and generates a C file containing a "struct mips_vdso_image"
containing both the VDSO data and these offsets. This C file is
compiled into the kernel.
On 64-bit kernels we require a different VDSO for each supported ABI,
so we may build up to 3 different VDSOs. The VDSO to use is selected by
the mips_abi structure.
A kernel/user shared data page is created and mapped below the VDSO
image. This is currently empty, but will be used by the user time
function implementations which are added later.
[markos.chandras@imgtec.com:
- Add more comments
- Move abi detection in genvdso.h since it's the get_symbol function
that needs it.
- Add an R6 specific way to calculate the base address of VDSO in order
to avoid the branch instruction which affects performance.
- Do not patch .gnu.attributes since it's not needed for dynamic linking.
- Simplify Makefile a little bit.
- checkpatch fixes
- Restrict VDSO support for binutils < 2.25 for pre-R6
- Include atomic64.h for O32 variant on MIPS64]
Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11337/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
It is desirable for signal handlers to be allowed to make use of MSA,
particularly if auto vectorisation is used when compiling a program.
The MSA context must therefore be saved & restored before & after
invoking the signal handler. Make use of the extended context structs
defined in the preceding patch to save MSA context after the sigframe
when appropriate.
[ralf@linux-mips.org: Fixed conflicts.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10796/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The context introduced by MSA needs to be saved around signals. However,
we can't increase the size of struct sigcontext because that will change
the offset of the signal mask in struct sigframe or struct ucontext.
This patch instead places the new context immediately after the struct
sigframe for traditional signals, or similarly after struct ucontext for
RT signals. The layout of struct sigframe & struct ucontext is identical
from their sigcontext fields onwards, so the offset from the sigcontext
to the extended context will always be the same regardless of the type
of signal.
Userland will be able to search through the extended context by using
the magic values to detect which types of context are present. Any
unrecognised context can be skipped over using the size field of struct
extcontext. Once the magic value END_EXTCONTEXT_MAGIC is seen it is
known that there are no further extended context structures to examine.
This approach is somewhat similar to that taken by ARM to save VFP &
other context at the end of struct ucontext.
Userland can determine whether extended context is present by checking
for the USED_EXTCONTEXT bit in the sc_used_math field of struct
sigcontext. Whilst this could potentially change the historic semantics
of sc_used_math if further extended context which does not imply FP
context were to be introduced in the future, I have been unable to find
any userland code making use of sc_used_math at all. Using one of the
fields described as unused in struct sigcontext was considered, but the
kernel does not already write to those fields so there would be no
guarantee of the field being clear on older kernels. Other alternatives
would be to have userland check the kernel version, or to have a HWCAP
bit indicating presence of extended context. However there is a desire
to have the context & information required to decode it be self
contained such that, for example, debuggers could decode the saved
context easily.
[ralf@linux-mips.org: Fixed conflict.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10795/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The sc_used_math field of struct sigcontext & its variants has
traditionally been used as a boolean value indicating only whether or
not floating point context is saved within the sigcontext. With various
supported FP modes & the ability to switch between them this information
will no longer be enough to decode the meaning of the data stored in the
sc_fpregs fields of struct sigcontext.
To make that possible 3 bits are defined within sc_used_math:
- Bit 0 (USED_FP) represents whether FP was used, essentially
providing the boolean flag which sc_used_math as a whole provided
previously.
- Bit 1 (USED_FR1) provides the value of the Status.FR bit at the time
the FP context was saved.
- Bit 2 (USED_HYBRID_FPRS) indicates whether the FP context was saved
under the hybrid FPR scheme. Essentially, when set the odd singles
are located in bits 63:32 of the preceding even indexed sc_fpregs
element.
Any userland that tests whether the sc_used_math field is zero or
non-zero will continue to function as expected. Having said that, I
could not find any userland which uses the sc_used_math field at all.
[ralf@linux-mips.org: Fixed rejects.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10794/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Make use of the common FP sigcontext code for O32 binaries running on
MIPS64 kernels now that it is taking appropriate offsets into struct
sigcontext(32) from struct mips_abi.
[ralf@linux-mips.org: Fixed reject.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10792/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When a task uses 32 bit floating point, the odd indexed 32b register
values are stored in bits 63:32 of the preceding even indexed 64b
FP register field in saved context. Thus there is no point in
preserving the odd indexed 64b register fields since they hold no
valid context. This patch will cause them to be skipped, as is
already done in arch/mips/kernel/signal32.c.
[ralf@linux-mips.org: Fixed reject.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Patchwork: https://patchwork.linux-mips.org/patch/10791/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In preparation for sharing protected_{save,restore}_fp_context with
compat ABIs, move the FP usage checks into said functions. This will
both enable that code to be shared, and allow for extensions of it in
further patches to also be shared.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10790/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When saving FP state to struct sigcontext, make use of the offsets
provided by struct mips_abi to obtain appropriate addresses for the
sc_fpregs & sc_fpc_csr fields of the sigcontext. This is done only for
the native struct sigcontext in this patch (ie. for O32 in CONFIG_32BIT
kernels or for N64 in CONFIG_64BIT kernels) but is done in preparation
for sharing this code with compat ABIs in further patches.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10789/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add fields to struct mips_abi, which holds information regarding the
kernel-userland ABI regarding signals, to specify the offsets to the FP
related fields within the appropriate variant of struct sigcontext.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10788/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The protected_{save,restore}_fp_context functions had effectively
different implementations for EVA. Simplify & unify the code somewhat
such that EVA configurations simply guarantee the FPU-not-owned path
through the standard code path.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-kernel@vger.kernel.org
Cc: Richard Weinberger <richard@nod.at>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Maciej W. Rozycki <macro@codesourcery.com>
Patchwork: https://patchwork.linux-mips.org/patch/10787/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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>
Pull MIPS updates from Ralf Baechle:
"This is an unusually large pull request for MIPS - in parts because
lots of patches missed the 3.18 deadline but primarily because some
folks opened the flood gates.
- Retire the MIPS-specific phys_t with the generic phys_addr_t.
- Improvments for the backtrace code used by oprofile.
- Better backtraces on SMP systems.
- Cleanups for the Octeon platform code.
- Cleanups and fixes for the Loongson platform code.
- Cleanups and fixes to the firmware library.
- Switch ATH79 platform to use the firmware library.
- Grand overhault to the SEAD3 and Malta interrupt code.
- Move the GIC interrupt code to drivers/irqchip
- Lots of GIC cleanups and updates to the GIC code to use modern IRQ
infrastructures and features of the kernel.
- OF documentation updates for the GIC bindings
- Move GIC clocksource driver to drivers/clocksource
- Merge GIC clocksource driver with clockevent driver.
- Further updates to bring the GIC clocksource driver up to date.
- R3000 TLB code cleanups
- Improvments to the Loongson 3 platform code.
- Convert pr_warning to pr_warn.
- Merge a bunch of small lantiq and ralink fixes that have been
staged/lingering inside the openwrt tree for a while.
- Update archhelp for IP22/IP32
- Fix a number of issues for Loongson 1B.
- New clocksource and clockevent driver for Loongson 1B.
- Further work on clk handling for Loongson 1B.
- Platform work for Broadcom BMIPS.
- Error handling cleanups for TurboChannel.
- Fixes and optimization to the microMIPS support.
- Option to disable the FTLB.
- Dump more relevant information on machine check exception
- Change binfmt to allow arch to examine PT_*PROC headers
- Support for new style FPU register model in O32
- VDSO randomization.
- BCM47xx cleanups
- BCM47xx reimplement the way the kernel accesses NVRAM information.
- Random cleanups
- Add support for ATH25 platforms
- Remove pointless locking code in some PCI platforms.
- Some improvments to EVA support
- Minor Alchemy cleanup"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (185 commits)
MIPS: Add MFHC0 and MTHC0 instructions to uasm.
MIPS: Cosmetic cleanups of page table headers.
MIPS: Add CP0 macros for extended EntryLo registers
MIPS: Remove now unused definition of phys_t.
MIPS: Replace use of phys_t with phys_addr_t.
MIPS: Replace MIPS-specific 64BIT_PHYS_ADDR with generic PHYS_ADDR_T_64BIT
PCMCIA: Alchemy Don't select 64BIT_PHYS_ADDR in Kconfig.
MIPS: lib: memset: Clean up some MIPS{EL,EB} ifdefery
MIPS: iomap: Use __mem_{read,write}{b,w,l} for MMIO
MIPS: <asm/types.h> fix indentation.
MAINTAINERS: Add entry for BMIPS multiplatform kernel
MIPS: Enable VDSO randomization
MIPS: Remove a temporary hack for debugging cache flushes in SMTC configuration
MIPS: Remove declaration of obsolete arch_init_clk_ops()
MIPS: atomic.h: Reformat to fit in 79 columns
MIPS: Apply `.insn' to fixup labels throughout
MIPS: Fix microMIPS LL/SC immediate offsets
MIPS: Kconfig: Only allow 32-bit microMIPS builds
MIPS: signal.c: Fix an invalid cast in ISA mode bit handling
MIPS: mm: Only build one microassembler that is suitable
...
Fix:
arch/mips/kernel/signal.c: In function 'handle_signal':
arch/mips/kernel/signal.c:533:21: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
unsigned int tmp = (unsigned int)current->mm->context.vdso;
^
arch/mips/kernel/signal.c:536:9: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
vdso = (void *)tmp;
^
cc1: all warnings being treated as errors
when building a 64-bit kernel.
This is not really a supported configuration, but the cast is wrong
either way, Linux makes the assumption that sizeof(void *) equals
sizeof(unsigned long) and therefore the latter type is expected to be
used where integer operations have to be applied to pointers for some
reason.
Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8480/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The save_fp_context & restore_fp_context pointers were being assigned
to the wrong variables if either:
- The kernel is configured for UP & runs on a system without an FPU,
since b2ead52828 "MIPS: Move & rename
fpu_emulator_{save,restore}_context".
- The kernel is configured for EVA, since ca750649e0 "MIPS: kernel:
signal: Prevent save/restore FPU context in user memory".
This would lead to FP context being clobbered incorrectly when setting
up a sigcontext, then the garbage values being saved uselessly when
returning from the signal.
Fix by swapping the pointer assignments appropriately.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: stable@vger.kernel.org # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8230/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This reverts commit eec43a224c "MIPS: Save/restore MSA context around
signals" and the MSA parts of ca750649e0 "MIPS: kernel: signal:
Prevent save/restore FPU context in user memory" (the restore path of
which appears incorrect anyway...).
The reverted patch took care not to break compatibility with userland
users of struct sigcontext, but inadvertantly changed the offset of the
uc_sigmask field of struct ucontext. Thus Linux v3.15 breaks the
userland ABI. The MSA context will need to be saved via some other
opt-in mechanism, but for now revert the change to reduce the fallout.
This will have minimal impact upon use of MSA since the only supported
CPU which includes it (the P5600) is 32-bit and therefore requires that
the experimental CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option be selected
before the kernel will set FR=1 for a task, a requirement for MSA use.
Thus the users of MSA are limited to known small groups of people & this
patch won't be breaking any previously working MSA-using userland
outside of experimental settings.
[ralf@linux-mips.org: Fixed rejects.]
Cc: stable@vger.kernel.org
Reported-by: Joseph S. Myers <joseph@codesourcery.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7107/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
EVA does not have FPU specific instructions for reading or writing
FPU registers from userspace memory.
Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
This patch extends sigcontext in order to hold the most significant 64
bits of each vector register in addition to the MSA control & status
register. The least significant 64 bits are already saved as the scalar
FP context. This makes things a little awkward since the least & most
significant 64 bits of each vector register are not contiguous in
memory. Thus the copy_u & insert instructions are used to transfer the
values of the most significant 64 bits via GP registers.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6533/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
NUM_FPU_REGS just makes it clearer what's going on, rather than the
magic hard coded 32.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6424/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When a task which has used the FPU at some point in its past takes a
signal the kernel would previously always require the task to take
ownership of the FPU whilst setting up or restoring from the sigcontext.
That means that if the task has not used the FPU within this timeslice
then the kernel would enable the FPU, restore the task's FP context into
FPU registers and then save them into the sigcontext. This seems
inefficient, and if the signal handler doesn't use FP then enabling the
FPU & the extra memory accesses are entirely wasted work.
This patch modifies the sigcontext setup & restore code to copy directly
between the tasks saved FP context & the sigcontext for any tasks which
have used FP in the past but are not currently the FPU owner (ie. have
not used FP in this timeslice).
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6423/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
These functions aren't directly related to the FPU emulator at all, they
simply copy between a thread's saved context & a sigcontext. Thus move
them to the appropriate signal files & rename them accordingly. This
makes it clearer that the functions don't require the FPU emulator in
any way.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6422/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
CPUs implementing MIPS32 R2 may include a 64-bit FPU, just as MIPS64 CPUs
do. In order to preserve backwards compatibility a 64-bit FPU will act
like a 32-bit FPU (by accessing doubles from the least significant 32
bits of an even-odd pair of FP registers) when the Status.FR bit is
zero, again just like a mips64 CPU. The standard O32 ABI is defined
expecting a 32-bit FPU, however recent toolchains support use of a
64-bit FPU from an O32 MIPS32 executable. When an ELF executable is
built to use a 64-bit FPU a new flag (EF_MIPS_FP64) is set in the ELF
header.
With this patch the kernel will check the EF_MIPS_FP64 flag when
executing an O32 binary, and set Status.FR accordingly. The addition
of O32 64-bit FP support lessens the opportunity for optimisation in
the FPU emulator, so a CONFIG_MIPS_O32_FP64_SUPPORT Kconfig option is
introduced to allow this support to be disabled for those that don't
require it.
Inspired by an earlier patch by Leonid Yegoshin, but implemented more
cleanly & correctly.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/6154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull MIPS updates from Ralf Baechle:
o Add basic support for the Mediatek/Ralink Wireless SoC family.
o The Qualcomm Atheros platform is extended by support for the new
QCA955X SoC series as well as a bunch of patches that get the code
ready for OF support.
o Lantiq and BCM47XX platform have a few improvements and bug fixes.
o MIPS has sent a few patches that get the kernel ready for the
upcoming microMIPS support.
o The rest of the series is made up of small bug fixes and cleanups
that relate to various parts of the MIPS code. The biggy in there is
a whitespace cleanup. After I was sent another set of whitespace
cleanup patches I decided it was the time to clean the whitespace
"issues" for once and and that touches many files below arch/mips/.
Fix up silly conflicts, mostly due to whitespace cleanups.
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (105 commits)
MIPS: Quit exporting kernel internel break codes to uapi/asm/break.h
MIPS: remove broken conditional inside vpe loader code
MIPS: SMTC: fix implicit declaration of set_vi_handler
MIPS: early_printk: drop __init annotations
MIPS: Probe for and report hardware virtualization support.
MIPS: ath79: add support for the Qualcomm Atheros AP136-010 board
MIPS: ath79: add USB controller registration code for the QCA955X SoCs
MIPS: ath79: add PCI controller registration code for the QCA955X SoCs
MIPS: ath79: add WMAC registration code for the QCA955X SoCs
MIPS: ath79: register UART for the QCA955X SoCs
MIPS: ath79: add QCA955X specific glue to ath79_device_reset_{set, clear}
MIPS: ath79: add GPIO setup code for the QCA955X SoCs
MIPS: ath79: add IRQ handling code for the QCA955X SoCs
MIPS: ath79: add clock setup code for the QCA955X SoCs
MIPS: ath79: add SoC detection code for the QCA955X SoCs
MIPS: ath79: add early printk support for the QCA955X SoCs
MIPS: ath79: fix WMAC IRQ resource assignment
mips: reserve elfcorehdr
mips: Make sure kernel memory is in iomem
MIPS: ath79: use dynamically allocated USB platform devices
...
mips was the last architecture not using the generic variant.
Both native and compat variants switched to generic, which is
made unconditional now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
we want to do that before branchpoint for arch-* to be able to
consolidate sys_rt_sigsuspend() declarations.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
The actual bug is a missing else statement - but really this should be
expressed using a switch() statement.
Found by Al Viro who writes "the funny thing is, it *does* work only
because r2 is syscall number and syscall number around 512 => return
value being ENOSYS and not one of ERESTART... so we really can't hit
the first if and emerge from it with ERESTART_RESTARTBLOCK. still
wrong to write it that way..."
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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>
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>
Linus Torvalds