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linux/arch/csky/Kconfig
Linus Torvalds 9471f1f2f5 Merge branch 'expand-stack' 
This modifies our user mode stack expansion code to always take the
mmap_lock for writing before modifying the VM layout.

It's actually something we always technically should have done, but
because we didn't strictly need it, we were being lazy ("opportunistic"
sounds so much better, doesn't it?) about things, and had this hack in
place where we would extend the stack vma in-place without doing the
proper locking.

And it worked fine.  We just needed to change vm_start (or, in the case
of grow-up stacks, vm_end) and together with some special ad-hoc locking
using the anon_vma lock and the mm->page_table_lock, it all was fairly
straightforward.

That is, it was all fine until Ruihan Li pointed out that now that the
vma layout uses the maple tree code, we *really* don't just change
vm_start and vm_end any more, and the locking really is broken.  Oops.

It's not actually all _that_ horrible to fix this once and for all, and
do proper locking, but it's a bit painful.  We have basically three
different cases of stack expansion, and they all work just a bit
differently:

 - the common and obvious case is the page fault handling. It's actually
   fairly simple and straightforward, except for the fact that we have
   something like 24 different versions of it, and you end up in a maze
   of twisty little passages, all alike.

 - the simplest case is the execve() code that creates a new stack.
   There are no real locking concerns because it's all in a private new
   VM that hasn't been exposed to anybody, but lockdep still can end up
   unhappy if you get it wrong.

 - and finally, we have GUP and page pinning, which shouldn't really be
   expanding the stack in the first place, but in addition to execve()
   we also use it for ptrace(). And debuggers do want to possibly access
   memory under the stack pointer and thus need to be able to expand the
   stack as a special case.

None of these cases are exactly complicated, but the page fault case in
particular is just repeated slightly differently many many times.  And
ia64 in particular has a fairly complicated situation where you can have
both a regular grow-down stack _and_ a special grow-up stack for the
register backing store.

So to make this slightly more manageable, the bulk of this series is to
first create a helper function for the most common page fault case, and
convert all the straightforward architectures to it.

Thus the new 'lock_mm_and_find_vma()' helper function, which ends up
being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa.  So we not only convert more
than half the architectures, we now have more shared code and avoid some
of those twisty little passages.

And largely due to this common helper function, the full diffstat of
this series ends up deleting more lines than it adds.

That still leaves eight architectures (ia64, m68k, microblaze, openrisc,
parisc, s390, sparc64 and um) that end up doing 'expand_stack()'
manually because they are doing something slightly different from the
normal pattern.  Along with the couple of special cases in execve() and
GUP.

So there's a couple of patches that first create 'locked' helper
versions of the stack expansion functions, so that there's a obvious
path forward in the conversion.  The execve() case is then actually
pretty simple, and is a nice cleanup from our old "grow-up stackls are
special, because at execve time even they grow down".

The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because
it's just more straightforward to write out the stack expansion there
manually, instead od having get_user_pages_remote() do it for us in some
situations but not others and have to worry about locking rules for GUP.

And the final step is then to just convert the remaining odd cases to a
new world order where 'expand_stack()' is called with the mmap_lock held
for reading, but where it might drop it and upgrade it to a write, only
to return with it held for reading (in the success case) or with it
completely dropped (in the failure case).

In the process, we remove all the stack expansion from GUP (where
dropping the lock wouldn't be ok without special rules anyway), and add
it in manually to __access_remote_vm() for ptrace().

Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases.
Everything else here felt pretty straightforward, but the ia64 rules for
stack expansion are really quite odd and very different from everything
else.  Also thanks to Vegard Nossum who caught me getting one of those
odd conditions entirely the wrong way around.

Anyway, I think I want to actually move all the stack expansion code to
a whole new file of its own, rather than have it split up between
mm/mmap.c and mm/memory.c, but since this will have to be backported to
the initial maple tree vma introduction anyway, I tried to keep the
patches _fairly_ minimal.

Also, while I don't think it's valid to expand the stack from GUP, the
final patch in here is a "warn if some crazy GUP user wants to try to
expand the stack" patch.  That one will be reverted before the final
release, but it's left to catch any odd cases during the merge window
and release candidates.

Reported-by: Ruihan Li <lrh2000@pku.edu.cn>

* branch 'expand-stack':
  gup: add warning if some caller would seem to want stack expansion
  mm: always expand the stack with the mmap write lock held
  execve: expand new process stack manually ahead of time
  mm: make find_extend_vma() fail if write lock not held
  powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
  mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
  arm/mm: Convert to using lock_mm_and_find_vma()
  riscv/mm: Convert to using lock_mm_and_find_vma()
  mips/mm: Convert to using lock_mm_and_find_vma()
  powerpc/mm: Convert to using lock_mm_and_find_vma()
  arm64/mm: Convert to using lock_mm_and_find_vma()
  mm: make the page fault mmap locking killable
  mm: introduce new 'lock_mm_and_find_vma()' page fault helper
2023-06-28 20:35:21 -07:00

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# SPDX-License-Identifier: GPL-2.0-only
config CSKY
def_bool y
select ARCH_32BIT_OFF_T
select ARCH_HAS_DMA_PREP_COHERENT
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_INLINE_READ_LOCK if !PREEMPTION
select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION
select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION
select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION
select ARCH_INLINE_READ_UNLOCK if !PREEMPTION
select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION
select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION
select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION
select ARCH_INLINE_WRITE_LOCK if !PREEMPTION
select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION
select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION
select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION
select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION
select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION
select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION
select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION
select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION
select ARCH_INLINE_SPIN_LOCK if !PREEMPTION
select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION
select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION
select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION
select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION
select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION
select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION
select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION
select ARCH_WANT_FRAME_POINTERS if !CPU_CK610 && $(cc-option,-mbacktrace)
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
select COMMON_CLK
select CLKSRC_MMIO
select CSKY_MPINTC if CPU_CK860
select CSKY_MP_TIMER if CPU_CK860
select CSKY_APB_INTC
select DMA_DIRECT_REMAP
select IRQ_DOMAIN
select DW_APB_TIMER_OF
select GENERIC_IOREMAP
select GENERIC_LIB_ASHLDI3
select GENERIC_LIB_ASHRDI3
select GENERIC_LIB_LSHRDI3
select GENERIC_LIB_MULDI3
select GENERIC_LIB_CMPDI2
select GENERIC_LIB_UCMPDI2
select GENERIC_ALLOCATOR
select GENERIC_ATOMIC64
select GENERIC_CPU_DEVICES
select GENERIC_IRQ_CHIP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_MULTI_HANDLER
select GENERIC_SCHED_CLOCK
select GENERIC_SMP_IDLE_THREAD
select GENERIC_TIME_VSYSCALL
select GENERIC_VDSO_32
select GENERIC_GETTIMEOFDAY
select GX6605S_TIMER if CPU_CK610
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL if !CPU_CK610
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_MMAP_RND_BITS
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_CONTEXT_TRACKING_USER
select HAVE_VIRT_CPU_ACCOUNTING_GEN
select HAVE_DEBUG_BUGVERBOSE
select HAVE_DEBUG_KMEMLEAK
select HAVE_DYNAMIC_FTRACE
select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_GENERIC_VDSO
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_LZO
select HAVE_KERNEL_LZMA
select HAVE_KPROBES if !CPU_CK610
select HAVE_KPROBES_ON_FTRACE if !CPU_CK610
select HAVE_KRETPROBES if !CPU_CK610
select HAVE_PERF_EVENTS
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
select HAVE_DMA_CONTIGUOUS
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU
select LOCK_MM_AND_FIND_VMA
select MAY_HAVE_SPARSE_IRQ
select MODULES_USE_ELF_RELA if MODULES
select OF
select OF_EARLY_FLATTREE
select PERF_USE_VMALLOC if CPU_CK610
select RTC_LIB
select TIMER_OF
select GENERIC_PCI_IOMAP
select HAVE_PCI
select PCI_DOMAINS_GENERIC if PCI
select PCI_SYSCALL if PCI
select PCI_MSI if PCI
select TRACE_IRQFLAGS_SUPPORT
config LOCKDEP_SUPPORT
def_bool y
config ARCH_SUPPORTS_UPROBES
def_bool y if !CPU_CK610
config CPU_HAS_CACHEV2
bool
config CPU_HAS_FPUV2
bool
config CPU_HAS_HILO
bool
config CPU_HAS_TLBI
bool
config CPU_HAS_LDSTEX
bool
help
For SMP, CPU needs "ldex&stex" instructions for atomic operations.
config CPU_NEED_TLBSYNC
bool
config CPU_NEED_SOFTALIGN
bool
config CPU_NO_USER_BKPT
bool
help
For abiv2 we couldn't use "trap 1" as user space bkpt in gdbserver, because
abiv2 is 16/32bit instruction set and "trap 1" is 32bit.
So we need a 16bit instruction as user space bkpt, and it will cause an illegal
instruction exception.
In kernel we parse the *regs->pc to determine whether to send SIGTRAP or not.
config GENERIC_CALIBRATE_DELAY
def_bool y
config GENERIC_CSUM
def_bool y
config GENERIC_HWEIGHT
def_bool y
config MMU
def_bool y
config STACKTRACE_SUPPORT
def_bool y
config TIME_LOW_RES
def_bool y
config CPU_ASID_BITS
int
default "8" if (CPU_CK610 || CPU_CK807 || CPU_CK810)
default "12" if (CPU_CK860)
config L1_CACHE_SHIFT
int
default "4" if (CPU_CK610)
default "5" if (CPU_CK807 || CPU_CK810)
default "6" if (CPU_CK860)
config ARCH_MMAP_RND_BITS_MIN
default 8
# max bits determined by the following formula:
# VA_BITS - PAGE_SHIFT - 3
config ARCH_MMAP_RND_BITS_MAX
default 17
menu "Processor type and features"
choice
prompt "CPU MODEL"
default CPU_CK807
config CPU_CK610
bool "CSKY CPU ck610"
select CPU_NEED_TLBSYNC
select CPU_NEED_SOFTALIGN
select CPU_NO_USER_BKPT
config CPU_CK810
bool "CSKY CPU ck810"
select CPU_HAS_HILO
select CPU_NEED_TLBSYNC
config CPU_CK807
bool "CSKY CPU ck807"
select CPU_HAS_HILO
config CPU_CK860
bool "CSKY CPU ck860"
select CPU_HAS_TLBI
select CPU_HAS_CACHEV2
select CPU_HAS_LDSTEX
select CPU_HAS_FPUV2
endchoice
choice
prompt "PAGE OFFSET"
default PAGE_OFFSET_80000000
config PAGE_OFFSET_80000000
bool "PAGE OFFSET 2G (user:kernel = 2:2)"
config PAGE_OFFSET_A0000000
bool "PAGE OFFSET 2.5G (user:kernel = 2.5:1.5)"
endchoice
config PAGE_OFFSET
hex
default 0x80000000 if PAGE_OFFSET_80000000
default 0xa0000000 if PAGE_OFFSET_A0000000
choice
prompt "C-SKY PMU type"
depends on PERF_EVENTS
depends on CPU_CK807 || CPU_CK810 || CPU_CK860
config CPU_PMU_NONE
bool "None"
config CSKY_PMU_V1
bool "Performance Monitoring Unit Ver.1"
endchoice
choice
prompt "Power Manager Instruction (wait/doze/stop)"
default CPU_PM_NONE
config CPU_PM_NONE
bool "None"
config CPU_PM_WAIT
bool "wait"
config CPU_PM_DOZE
bool "doze"
config CPU_PM_STOP
bool "stop"
endchoice
menuconfig HAVE_TCM
bool "Tightly-Coupled/Sram Memory"
depends on !COMPILE_TEST
help
The implementation are not only used by TCM (Tightly-Coupled Memory)
but also used by sram on SOC bus. It follow existed linux tcm
software interface, so that old tcm application codes could be
re-used directly.
if HAVE_TCM
config ITCM_RAM_BASE
hex "ITCM ram base"
default 0xffffffff
config ITCM_NR_PAGES
int "Page count of ITCM size: NR*4KB"
range 1 256
default 32
config HAVE_DTCM
bool "DTCM Support"
config DTCM_RAM_BASE
hex "DTCM ram base"
depends on HAVE_DTCM
default 0xffffffff
config DTCM_NR_PAGES
int "Page count of DTCM size: NR*4KB"
depends on HAVE_DTCM
range 1 256
default 32
endif
config CPU_HAS_VDSP
bool "CPU has VDSP coprocessor"
depends on CPU_HAS_FPU && CPU_HAS_FPUV2
config CPU_HAS_FPU
bool "CPU has FPU coprocessor"
depends on CPU_CK807 || CPU_CK810 || CPU_CK860
config CPU_HAS_ICACHE_INS
bool "CPU has Icache invalidate instructions"
depends on CPU_HAS_CACHEV2
config CPU_HAS_TEE
bool "CPU has Trusted Execution Environment"
depends on CPU_CK810
config SMP
bool "Symmetric Multi-Processing (SMP) support for C-SKY"
depends on CPU_CK860
default n
config NR_CPUS
int "Maximum number of CPUs (2-32)"
range 2 32
depends on SMP
default "4"
config HIGHMEM
bool "High Memory Support"
depends on !CPU_CK610
select KMAP_LOCAL
default y
config DRAM_BASE
hex "DRAM start addr (the same with memory-section in dts)"
default 0x0
config HOTPLUG_CPU
bool "Support for hot-pluggable CPUs"
select GENERIC_IRQ_MIGRATION
depends on SMP
help
Say Y here to allow turning CPUs off and on. CPUs can be
controlled through /sys/devices/system/cpu/cpu1/hotplug/target.
Say N if you want to disable CPU hotplug.
config HAVE_EFFICIENT_UNALIGNED_STRING_OPS
bool "Enable EFFICIENT_UNALIGNED_STRING_OPS for abiv2"
depends on CPU_CK807 || CPU_CK810 || CPU_CK860
help
Say Y here to enable EFFICIENT_UNALIGNED_STRING_OPS. Some CPU models could
deal with unaligned access by hardware.
endmenu
source "arch/csky/Kconfig.platforms"
source "kernel/Kconfig.hz"
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