Commit Graph

575 Commits

Author SHA1 Message Date
Tong Tiangen
78a743cd82
riscv/vdso: Move vdso data page up front
As commit 601255ae3c ("arm64: vdso: move data page before code pages"), the
same issue exists on riscv, testcase is shown below, make sure that vdso.so is
bigger than page size,

  struct timespec tp;
  clock_gettime(5, &tp);
  printf("tv_sec: %ld, tv_nsec: %ld\n", tp.tv_sec, tp.tv_nsec);

without this patch, test result : tv_sec: 0, tv_nsec: 0
   with this patch, test result : tv_sec: 1629271537, tv_nsec: 748000000

Move the vdso data page in front of the VDSO area to fix the issue.

Fixes: ad5d1122b8 ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-02 13:42:25 -07:00
Tong Tiangen
bb4a23c994
riscv/vdso: Refactor asm/vdso.h
The asm/vdso.h will be included in vdso.lds.S in the next patch, the
following cleanup is needed to avoid syntax error:

 1.the declaration of sys_riscv_flush_icache() is moved into asm/syscall.h.
 2.the definition of struct vdso_data is moved into kernel/vdso.c.
 2.the definition of VDSO_SYMBOL is placed under "#ifndef __ASSEMBLY__".

Also remove the redundant linux/types.h include.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-10-02 13:42:23 -07:00
Masami Hiramatsu
adf8a61a94 kprobes: treewide: Make it harder to refer kretprobe_trampoline directly
Since now there is kretprobe_trampoline_addr() for referring the
address of kretprobe trampoline code, we don't need to access
kretprobe_trampoline directly.

Make it harder to refer by renaming it to __kretprobe_trampoline().

Link: https://lkml.kernel.org/r/163163045446.489837.14510577516938803097.stgit@devnote2

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30 21:24:06 -04:00
Masami Hiramatsu
96fed8ac2b kprobes: treewide: Remove trampoline_address from kretprobe_trampoline_handler()
The __kretprobe_trampoline_handler() callback, called from low level
arch kprobes methods, has the 'trampoline_address' parameter, which is
entirely superfluous as it basically just replicates:

  dereference_kernel_function_descriptor(kretprobe_trampoline)

In fact we had bugs in arch code where it wasn't replicated correctly.

So remove this superfluous parameter and use kretprobe_trampoline_addr()
instead.

Link: https://lkml.kernel.org/r/163163044546.489837.13505751885476015002.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30 21:24:06 -04:00
Masami Hiramatsu
9c89bb8e32 kprobes: treewide: Cleanup the error messages for kprobes
This clean up the error/notification messages in kprobes related code.
Basically this defines 'pr_fmt()' macros for each files and update
the messages which describes

 - what happened,
 - what is the kernel going to do or not do,
 - is the kernel fine,
 - what can the user do about it.

Also, if the message is not needed (e.g. the function returns unique
error code, or other error message is already shown.) remove it,
and replace the message with WARN_*() macros if suitable.

Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-09-30 21:24:05 -04:00
Ard Biesheuvel
8aa0fb0fbb riscv: rely on core code to keep thread_info::cpu updated
Now that the core code switched back to using thread_info::cpu to keep
a task's CPU number, we no longer need to keep it in sync explicitly. So
just drop the code that does this.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
2021-09-30 16:13:11 +02:00
Linus Torvalds
f306b90c69 Updates for the SMP and CPU hotplug:
- Remove DEFINE_SMP_CALL_CACHE_FUNCTION() which is a left over of the
    original hotplug code and now causing trouble with the ARM64 cache
    topology setup due to the pointless SMP function call. It's not longer
    required as the hotplug callbacks are guaranteed to be invoked on the
    upcoming CPU.
 
  - Remove the deprecated and now unused CPU hotplug functions
 
  - Rewrite the CPU hotplug API documentation
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Merge tag 'smp-urgent-2021-09-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull CPU hotplug updates from Thomas Gleixner:
 "Updates for the SMP and CPU hotplug:

   - Remove DEFINE_SMP_CALL_CACHE_FUNCTION() which is a left over of the
     original hotplug code and now causing trouble with the ARM64 cache
     topology setup due to the pointless SMP function call.

     It's not longer required as the hotplug callbacks are guaranteed to
     be invoked on the upcoming CPU.

   - Remove the deprecated and now unused CPU hotplug functions

   - Rewrite the CPU hotplug API documentation"

* tag 'smp-urgent-2021-09-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation: core-api/cpuhotplug: Rewrite the API section
  cpu/hotplug: Remove deprecated CPU-hotplug functions.
  thermal: Replace deprecated CPU-hotplug functions.
  drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()
2021-09-12 12:42:51 -07:00
Linus Torvalds
b79bd0d510 RISC-V Patches for the 5.15 Merge Window, Part 2
* A pair of defconfig additions, for NVMe and the EFI filesystem
   localization options.
 * A larger address space for stack randomization.
 * A cleanup to our install rules.
 * A DTS update for the Microchip Icicle board, to fix the serial
   console.
 * Support for build-time table sorting, which allows us to have
   __ex_table read-only.
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Merge tag 'riscv-for-linus-5.15-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:

 - A pair of defconfig additions, for NVMe and the EFI filesystem
   localization options.

 - A larger address space for stack randomization.

 - A cleanup to our install rules.

 - A DTS update for the Microchip Icicle board, to fix the serial
   console.

 - Support for build-time table sorting, which allows us to have
   __ex_table read-only.

* tag 'riscv-for-linus-5.15-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Move EXCEPTION_TABLE to RO_DATA segment
  riscv: Enable BUILDTIME_TABLE_SORT
  riscv: dts: microchip: mpfs-icicle: Fix serial console
  riscv: move the (z)install rules to arch/riscv/Makefile
  riscv: Improve stack randomisation on RV64
  riscv: defconfig: enable NLS_CODEPAGE_437, NLS_ISO8859_1
  riscv: defconfig: enable BLK_DEV_NVME
2021-09-11 14:29:42 -07:00
Jisheng Zhang
6f55ab36be
riscv: Move EXCEPTION_TABLE to RO_DATA segment
_ex_table section is read-only, so move it to RO_DATA.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-09-10 23:59:48 -07:00
Thomas Gleixner
c2f4954c2d Merge branch 'linus' into smp/urgent
Ensure that all usage sites of get/put_online_cpus() except for the
struggler in drivers/thermal are gone. So the last user and the deprecated
inlines can be removed.
2021-09-11 00:38:47 +02:00
Linus Torvalds
2d338201d5 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "147 patches, based on 7d2a07b769.

  Subsystems affected by this patch series: mm (memory-hotplug, rmap,
  ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
  alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
  checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
  selftests, ipc, and scripts"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
  scripts: check_extable: fix typo in user error message
  mm/workingset: correct kernel-doc notations
  ipc: replace costly bailout check in sysvipc_find_ipc()
  selftests/memfd: remove unused variable
  Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
  configs: remove the obsolete CONFIG_INPUT_POLLDEV
  prctl: allow to setup brk for et_dyn executables
  pid: cleanup the stale comment mentioning pidmap_init().
  kernel/fork.c: unexport get_{mm,task}_exe_file
  coredump: fix memleak in dump_vma_snapshot()
  fs/coredump.c: log if a core dump is aborted due to changed file permissions
  nilfs2: use refcount_dec_and_lock() to fix potential UAF
  nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
  nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
  nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
  nilfs2: fix NULL pointer in nilfs_##name##_attr_release
  nilfs2: fix memory leak in nilfs_sysfs_create_device_group
  trap: cleanup trap_init()
  init: move usermodehelper_enable() to populate_rootfs()
  ...
2021-09-08 12:55:35 -07:00
Kefeng Wang
8b097881b5 trap: cleanup trap_init()
There are some empty trap_init() definitions in different ARCHs, Introduce
a new weak trap_init() function to clean them up.

Link: https://lkml.kernel.org/r/20210812123602.76356-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>	[arm32]
Acked-by: Vineet Gupta						[arc]
Acked-by: Michael Ellerman <mpe@ellerman.id.au>			[powerpc]
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <palmerdabbelt@google.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-08 11:50:27 -07:00
Linus Torvalds
063df71a57 RISC-V Patches for the 5.15 Merge Window, Part 1
* Support for PC-relative instructions (auipc and branches) in kprobes.
 * Support for forced IRQ threading.
 * Support for the hlt/nohlt kernel command line options, via the generic
   idle loop.
 * Support for showing the edge/level triggered behavior of interrupts in
   /proc/interrupts.
 * A handful of cleanups to our address mapping mechanisms.
 * Support for allocating gigantic hugepages via CMA.
 * Support for the undefined behavior sanitizer.
 * A handful of cleanups to the VDSO that allow the kernel to build with
   LLD.
 * Support for hugepage migration.
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Merge tag 'riscv-for-linus-5.15-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - support PC-relative instructions (auipc and branches) in kprobes

 - support for forced IRQ threading

 - support for the hlt/nohlt kernel command line options, via the
   generic idle loop

 - show the edge/level triggered behavior of interrupts
   in /proc/interrupts

 - a handful of cleanups to our address mapping mechanisms

 - support for allocating gigantic hugepages via CMA

 - support for the undefined behavior sanitizer (UBSAN)

 - a handful of cleanups to the VDSO that allow the kernel to build with
   LLD.

 - support for hugepage migration

* tag 'riscv-for-linus-5.15-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (21 commits)
  riscv: add support for hugepage migration
  RISC-V: Fix VDSO build for !MMU
  riscv: use strscpy to replace strlcpy
  riscv: explicitly use symbol offsets for VDSO
  riscv: Enable Undefined Behavior Sanitizer UBSAN
  riscv: Keep the riscv Kconfig selects sorted
  riscv: Support allocating gigantic hugepages using CMA
  riscv: fix the global name pfn_base confliction error
  riscv: Move early fdt mapping creation in its own function
  riscv: Simplify BUILTIN_DTB device tree mapping handling
  riscv: Use __maybe_unused instead of #ifdefs around variable declarations
  riscv: Get rid of map_size parameter to create_kernel_page_table
  riscv: Introduce va_kernel_pa_offset for 32-bit kernel
  riscv: Optimize kernel virtual address conversion macro
  dt-bindings: riscv: add starfive jh7100 bindings
  riscv: Enable GENERIC_IRQ_SHOW_LEVEL
  riscv: Enable idle generic idle loop
  riscv: Allow forced irq threading
  riscv: Implement thread_struct whitelist for hardened usercopy
  riscv: kprobes: implement the branch instructions
  ...
2021-09-05 11:31:23 -07:00
Thomas Gleixner
4b92d4add5 drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()
DEFINE_SMP_CALL_CACHE_FUNCTION() was usefel before the CPU hotplug rework
to ensure that the cache related functions are called on the upcoming CPU
because the notifier itself could run on any online CPU.

The hotplug state machine guarantees that the callbacks are invoked on the
upcoming CPU. So there is no need to have this SMP function call
obfuscation. That indirection was missed when the hotplug notifiers were
converted.

This also solves the problem of ARM64 init_cache_level() invoking ACPI
functions which take a semaphore in that context. That's invalid as SMP
function calls run with interrupts disabled. Running it just from the
callback in context of the CPU hotplug thread solves this.

Fixes: 8571890e15 ("arm64: Add support for ACPI based firmware tables")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/871r69ersb.ffs@tglx
2021-09-01 10:29:10 +02:00
Jason Wang
803930ee35
riscv: use strscpy to replace strlcpy
The strlcpy should not be used because it doesn't limit the source
length. As linus says, it's a completely useless function if you
can't implicitly trust the source string - but that is almost always
why people think they should use it! All in all the BSD function
will lead some potential bugs.

But the strscpy doesn't require reading memory from the src string
beyond the specified "count" bytes, and since the return value is
easier to error-check than strlcpy()'s. In addition, the implementation
is robust to the string changing out from underneath it, unlike the
current strlcpy() implementation.

Thus, We prefer using strscpy instead of strlcpy.

Signed-off-by: Jason Wang <wangborong@cdjrlc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-25 21:52:47 -07:00
Saleem Abdulrasool
fde9c59aeb
riscv: explicitly use symbol offsets for VDSO
The current implementation of the `__rt_sigaction` reference computed an
absolute offset relative to the mapped base of the VDSO.  While this can
be handled in the medlow model, the medany model cannot handle this as
it is meant to be position independent.  The current implementation
relied on the BFD linker relaxing the PC-relative relocation into an
absolute relocation as it was a near-zero address allowing it to be
referenced relative to `zero`.

We now extract the offsets and create a generated header allowing the
build with LLVM and lld to succeed as we no longer depend on the linker
rewriting address references near zero.  This change was largely
modelled after the ARM64 target which does something similar.

Signed-off-by: Saleem Abdulrasool <abdulras@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24 21:45:47 -07:00
Jisheng Zhang
8341dcfbd8
riscv: Enable Undefined Behavior Sanitizer UBSAN
Select ARCH_HAS_UBSAN_SANITIZE_ALL in order to allow the user to
enable CONFIG_UBSAN_SANITIZE_ALL and instrument the entire kernel for
ubsan checks.

VDSO is excluded because its build doesn't include the
__ubsan_handle_*() functions from lib/ubsan.c, and the VDSO has no
sane way to report errors even if it has definitions of these functions.

Passed lib/test_ubsan.c test.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24 20:59:10 -07:00
Vincent Chen
379eb01c21
riscv: Ensure the value of FP registers in the core dump file is up to date
The value of FP registers in the core dump file comes from the
thread.fstate. However, kernel saves the FP registers to the thread.fstate
only before scheduling out the process. If no process switch happens
during the exception handling process, kernel will not have a chance to
save the latest value of FP registers to thread.fstate. It will cause the
value of FP registers in the core dump file may be incorrect. To solve this
problem, this patch force lets kernel save the FP register into the
thread.fstate if the target task_struct equals the current.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Fixes: b8c8a9590e ("RISC-V: Add FP register ptrace support for gdb.")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24 20:54:10 -07:00
Petr Pavlu
aa3e1ba32e
riscv: Fix a number of free'd resources in init_resources()
Function init_resources() allocates a boot memory block to hold an array of
resources which it adds to iomem_resource. The array is filled in from its
end and the function then attempts to free any unused memory at the
beginning. The problem is that size of the unused memory is incorrectly
calculated and this can result in releasing memory which is in use by
active resources. Their data then gets corrupted later when the memory is
reused by a different part of the system.

Fix the size of the released memory to correctly match the number of unused
resource entries.

Fixes: ffe0e52612 ("RISC-V: Improve init_resources()")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
Acked-by: Nick Kossifidis <mick@ics.forth.gr>
Tested-by: Sunil V L <sunilvl@ventanamicro.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-20 10:15:51 -07:00
Changbin Du
030d6dbf0c
riscv: kexec: do not add '-mno-relax' flag if compiler doesn't support it
The RISC-V special option '-mno-relax' which to disable linker relaxations
is supported by GCC8+. For GCC7 and lower versions do not support this
option.

Fixes: fba8a8674f ("RISC-V: Add kexec support")
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-12 07:16:52 -07:00
Jisheng Zhang
78d9d8005e
riscv: stacktrace: Fix NULL pointer dereference
When CONFIG_FRAME_POINTER=y, calling dump_stack() can always trigger
NULL pointer dereference panic similar as below:

[    0.396060] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc5+ #47
[    0.396692] Hardware name: riscv-virtio,qemu (DT)
[    0.397176] Call Trace:
[    0.398191] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000960
[    0.399487] Oops [#1]
[    0.399739] Modules linked in:
[    0.400135] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc5+ #47
[    0.400570] Hardware name: riscv-virtio,qemu (DT)
[    0.400926] epc : walk_stackframe+0xc4/0xdc
[    0.401291]  ra : dump_backtrace+0x30/0x38
[    0.401630] epc : ffffffff80004922 ra : ffffffff8000496a sp : ffffffe000f3bd00
[    0.402115]  gp : ffffffff80cfdcb8 tp : ffffffe000f30000 t0 : ffffffff80d0b0cf
[    0.402602]  t1 : ffffffff80d0b0c0 t2 : 0000000000000000 s0 : ffffffe000f3bd60
[    0.403071]  s1 : ffffffff808bc2e8 a0 : 0000000000001000 a1 : 0000000000000000
[    0.403448]  a2 : ffffffff803d7088 a3 : ffffffff808bc2e8 a4 : 6131725dbc24d400
[    0.403820]  a5 : 0000000000001000 a6 : 0000000000000002 a7 : ffffffffffffffff
[    0.404226]  s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
[    0.404634]  s5 : ffffffff803d7088 s6 : ffffffff808bc2e8 s7 : ffffffff80630650
[    0.405085]  s8 : ffffffff80912a80 s9 : 0000000000000008 s10: ffffffff804000fc
[    0.405388]  s11: 0000000000000000 t3 : 0000000000000043 t4 : ffffffffffffffff
[    0.405616]  t5 : 000000000000003d t6 : ffffffe000f3baa8
[    0.405793] status: 0000000000000100 badaddr: 0000000000000960 cause: 000000000000000d
[    0.406135] [<ffffffff80004922>] walk_stackframe+0xc4/0xdc
[    0.407032] [<ffffffff8000496a>] dump_backtrace+0x30/0x38
[    0.407797] [<ffffffff803d7100>] show_stack+0x40/0x4c
[    0.408234] [<ffffffff803d9e5c>] dump_stack+0x90/0xb6
[    0.409019] [<ffffffff8040423e>] ptdump_init+0x20/0xc4
[    0.409681] [<ffffffff800015b6>] do_one_initcall+0x4c/0x226
[    0.410110] [<ffffffff80401094>] kernel_init_freeable+0x1f4/0x258
[    0.410562] [<ffffffff803dba88>] kernel_init+0x22/0x148
[    0.410959] [<ffffffff800029e2>] ret_from_exception+0x0/0x14
[    0.412241] ---[ end trace b2ab92c901b96251 ]---
[    0.413099] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

The reason is the task is NULL when we finally call walk_stackframe()
the NULL is passed from __dump_stack():

|static void __dump_stack(void)
|{
|        dump_stack_print_info(KERN_DEFAULT);
|        show_stack(NULL, NULL, KERN_DEFAULT);
|}

Fix this issue by checking "task == NULL" case in walk_stackframe().

Fixes: eac2f3059e ("riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabled")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Wende Tan <twd2.me@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-24 12:58:51 -07:00
Jisheng Zhang
76f5dfacfb
riscv: stacktrace: pin the task's stack in get_wchan
Pin the task's stack before calling walk_stackframe() in get_wchan().
This can fix the panic as reported by Andreas when CONFIG_VMAP_STACK=y:

[   65.609696] Unable to handle kernel paging request at virtual address ffffffd0003bbde8
[   65.610460] Oops [#1]
[   65.610626] Modules linked in: virtio_blk virtio_mmio rtc_goldfish btrfs blake2b_generic libcrc32c xor raid6_pq sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua efivarfs
[   65.611670] CPU: 2 PID: 1 Comm: systemd Not tainted 5.14.0-rc1-1.g34fe32a-default #1 openSUSE Tumbleweed (unreleased) c62f7109153e5a0897ee58ba52393ad99b070fd2
[   65.612334] Hardware name: riscv-virtio,qemu (DT)
[   65.613008] epc : get_wchan+0x5c/0x88
[   65.613334]  ra : get_wchan+0x42/0x88
[   65.613625] epc : ffffffff800048a4 ra : ffffffff8000488a sp : ffffffd00021bb90
[   65.614008]  gp : ffffffff817709f8 tp : ffffffe07fe91b80 t0 : 00000000000001f8
[   65.614411]  t1 : 0000000000020000 t2 : 0000000000000000 s0 : ffffffd00021bbd0
[   65.614818]  s1 : ffffffd0003bbdf0 a0 : 0000000000000001 a1 : 0000000000000002
[   65.615237]  a2 : ffffffff81618008 a3 : 0000000000000000 a4 : 0000000000000000
[   65.615637]  a5 : ffffffd0003bc000 a6 : 0000000000000002 a7 : ffffffe27d370000
[   65.616022]  s2 : ffffffd0003bbd90 s3 : ffffffff8071a81e s4 : 0000000000003fff
[   65.616407]  s5 : ffffffffffffc000 s6 : 0000000000000000 s7 : ffffffff81618008
[   65.616845]  s8 : 0000000000000001 s9 : 0000000180000040 s10: 0000000000000000
[   65.617248]  s11: 000000000000016b t3 : 000000ff00000000 t4 : 0c6aec92de5e3fd7
[   65.617672]  t5 : fff78f60608fcfff t6 : 0000000000000078
[   65.618088] status: 0000000000000120 badaddr: ffffffd0003bbde8 cause: 000000000000000d
[   65.618621] [<ffffffff800048a4>] get_wchan+0x5c/0x88
[   65.619008] [<ffffffff8022da88>] do_task_stat+0x7a2/0xa46
[   65.619325] [<ffffffff8022e87e>] proc_tgid_stat+0xe/0x16
[   65.619637] [<ffffffff80227dd6>] proc_single_show+0x46/0x96
[   65.619979] [<ffffffff801ccb1e>] seq_read_iter+0x190/0x31e
[   65.620341] [<ffffffff801ccd70>] seq_read+0xc4/0x104
[   65.620633] [<ffffffff801a6bfe>] vfs_read+0x6a/0x112
[   65.620922] [<ffffffff801a701c>] ksys_read+0x54/0xbe
[   65.621206] [<ffffffff801a7094>] sys_read+0xe/0x16
[   65.621474] [<ffffffff8000303e>] ret_from_syscall+0x0/0x2
[   65.622169] ---[ end trace f24856ed2b8789c5 ]---
[   65.622832] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-23 17:29:03 -07:00
Chen Lifu
67979e927d
riscv: kprobes: implement the branch instructions
This has been tested by probing a module that contains each of the
flavors of branches we have.

Signed-off-by: Chen Lifu <chenlifu@huawei.com>
[Palmer: commit message, fix kconfig errors]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-21 23:22:34 -07:00
Chen Lifu
b7d2be48cc
riscv: kprobes: implement the auipc instruction
This has been tested by probing a module that contains an auipc
instruction.

Signed-off-by: Chen Lifu <chenlifu@huawei.com>
[Palmer: commit message]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-21 23:22:25 -07:00
Linus Torvalds
9b76d71fa8 RISC-V Patches for the 5.14 Merge Window, Part 1
In addition to We have a handful of new features for 5.14:
 
 * Support for transparent huge pages.
 * Support for generic PCI resources mapping.
 * Support for the mem= kernel parameter.
 * Support for KFENCE.
 * A handful of fixes to avoid W+X mappings in the kernel.
 * Support for VMAP_STACK based overflow detection.
 * An optimized copy_{to,from}_user.
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Merge tag 'riscv-for-linus-5.14-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "We have a handful of new features for 5.14:

   - Support for transparent huge pages.

   - Support for generic PCI resources mapping.

   - Support for the mem= kernel parameter.

   - Support for KFENCE.

   - A handful of fixes to avoid W+X mappings in the kernel.

   - Support for VMAP_STACK based overflow detection.

   - An optimized copy_{to,from}_user"

* tag 'riscv-for-linus-5.14-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (37 commits)
  riscv: xip: Fix duplicate included asm/pgtable.h
  riscv: Fix PTDUMP output now BPF region moved back to module region
  riscv: __asm_copy_to-from_user: Optimize unaligned memory access and pipeline stall
  riscv: add VMAP_STACK overflow detection
  riscv: ptrace: add argn syntax
  riscv: mm: fix build errors caused by mk_pmd()
  riscv: Introduce structure that group all variables regarding kernel mapping
  riscv: Map the kernel with correct permissions the first time
  riscv: Introduce set_kernel_memory helper
  riscv: Enable KFENCE for riscv64
  RISC-V: Use asm-generic for {in,out}{bwlq}
  riscv: add ASID-based tlbflushing methods
  riscv: pass the mm_struct to __sbi_tlb_flush_range
  riscv: Add mem kernel parameter support
  riscv: Simplify xip and !xip kernel address conversion macros
  riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED
  riscv: Only initialize swiotlb when necessary
  riscv: fix typo in init.c
  riscv: Cleanup unused functions
  riscv: mm: Use better bitmap_zalloc()
  ...
2021-07-09 10:36:29 -07:00
Kefeng Wang
723a42f4f6 riscv: convert to setup_initial_init_mm()
Use setup_initial_init_mm() helper to simplify code.

Link: https://lkml.kernel.org/r/20210608083418.137226-13-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-08 11:48:21 -07:00
Jiapeng Chong
1958e5aef5
riscv: xip: Fix duplicate included asm/pgtable.h
Clean up the following includecheck warning:

./arch/riscv/kernel/vmlinux-xip.lds.S: asm/pgtable.h is included more
than once.

No functional change.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-06 16:17:40 -07:00
Tong Tiangen
31da94c25a
riscv: add VMAP_STACK overflow detection
This patch adds stack overflow detection to riscv, usable when
CONFIG_VMAP_STACK=y.

Overflow is detected in kernel exception entry(kernel/entry.S), if the
kernel stack is overflow and been detected, the overflow handler is
invoked on a per-cpu overflow stack. This approach preserves GPRs and
the original exception information.

The overflow detect is performed before any attempt is made to access
the stack and the principle of stack overflow detection: kernel stacks
are aligned to double their size, enabling overflow to be detected with
a single bit test. For example, a 16K stack is aligned to 32K, ensuring
that bit 14 of the SP must be zero. On an overflow (or underflow), this
bit is flipped. Thus, overflow (of less than the size of the stack) can
be detected by testing whether this bit is set.

This gives us a useful error message on stack overflow, as can be
trigger with the LKDTM overflow test:

[  388.053267] lkdtm: Performing direct entry EXHAUST_STACK
[  388.053663] lkdtm: Calling function with 1024 frame size to depth 32 ...
[  388.054016] lkdtm: loop 32/32 ...
[  388.054186] lkdtm: loop 31/32 ...
[  388.054491] lkdtm: loop 30/32 ...
[  388.054672] lkdtm: loop 29/32 ...
[  388.054859] lkdtm: loop 28/32 ...
[  388.055010] lkdtm: loop 27/32 ...
[  388.055163] lkdtm: loop 26/32 ...
[  388.055309] lkdtm: loop 25/32 ...
[  388.055481] lkdtm: loop 24/32 ...
[  388.055653] lkdtm: loop 23/32 ...
[  388.055837] lkdtm: loop 22/32 ...
[  388.056015] lkdtm: loop 21/32 ...
[  388.056188] lkdtm: loop 20/32 ...
[  388.058145] Insufficient stack space to handle exception!
[  388.058153] Task stack:     [0xffffffd014260000..0xffffffd014264000]
[  388.058160] Overflow stack: [0xffffffe1f8d2c220..0xffffffe1f8d2d220]
[  388.058168] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90
[  388.058175] Hardware name: riscv-virtio,qemu (DT)
[  388.058187] epc : number+0x32/0x2c0
[  388.058247]  ra : vsnprintf+0x2ae/0x3f0
[  388.058255] epc : ffffffe0002d38f6 ra : ffffffe0002d814e sp : ffffffd01425ffc0
[  388.058263]  gp : ffffffe0012e4010 tp : ffffffe08014da00 t0 : ffffffd0142606e8
[  388.058271]  t1 : 0000000000000000 t2 : 0000000000000000 s0 : ffffffd014260070
[  388.058303]  s1 : ffffffd014260158 a0 : ffffffd01426015e a1 : ffffffd014260158
[  388.058311]  a2 : 0000000000000013 a3 : ffff0a01ffffff10 a4 : ffffffe000c398e0
[  388.058319]  a5 : 511b02ec65f3e300 a6 : 0000000000a1749a a7 : 0000000000000000
[  388.058327]  s2 : ffffffff000000ff s3 : 00000000ffff0a01 s4 : ffffffe0012e50a8
[  388.058335]  s5 : 0000000000ffff0a s6 : ffffffe0012e50a8 s7 : ffffffe000da1cc0
[  388.058343]  s8 : ffffffffffffffff s9 : ffffffd0142602b0 s10: ffffffd0142602a8
[  388.058351]  s11: ffffffd01426015e t3 : 00000000000f0000 t4 : ffffffffffffffff
[  388.058359]  t5 : 000000000000002f t6 : ffffffd014260158
[  388.058366] status: 0000000000000100 badaddr: ffffffd01425fff8 cause: 000000000000000f
[  388.058374] Kernel panic - not syncing: Kernel stack overflow
[  388.058381] CPU: 0 PID: 89 Comm: bash Not tainted 5.12.0-rc8-dirty #90
[  388.058387] Hardware name: riscv-virtio,qemu (DT)
[  388.058393] Call Trace:
[  388.058400] [<ffffffe000004944>] walk_stackframe+0x0/0xce
[  388.058406] [<ffffffe0006f0b28>] dump_backtrace+0x38/0x46
[  388.058412] [<ffffffe0006f0b46>] show_stack+0x10/0x18
[  388.058418] [<ffffffe0006f3690>] dump_stack+0x74/0x8e
[  388.058424] [<ffffffe0006f0d52>] panic+0xfc/0x2b2
[  388.058430] [<ffffffe0006f0acc>] print_trace_address+0x0/0x24
[  388.058436] [<ffffffe0002d814e>] vsnprintf+0x2ae/0x3f0
[  388.058956] SMP: stopping secondary CPUs

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-06 12:11:38 -07:00
Alexandre Ghiti
658e2c5125
riscv: Introduce structure that group all variables regarding kernel mapping
We have a lot of variables that are used to hold kernel mapping addresses,
offsets between physical and virtual mappings and some others used for XIP
kernels: they are all defined at different places in mm/init.c, so group
them into a single structure with, for some of them, more explicit and concise
names.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-07-05 18:04:00 -07:00
Palmer Dabbelt
01112e5e20
Merge branch 'riscv-wx-mappings' into for-next
This contains both the short-term fix for the W+X boot mappings and the
larger cleanup.

* riscv-wx-mappings:
  riscv: Map the kernel with correct permissions the first time
  riscv: Introduce set_kernel_memory helper
  riscv: Simplify xip and !xip kernel address conversion macros
  riscv: Remove CONFIG_PHYS_RAM_BASE_FIXED
  riscv: mm: Fix W+X mappings at boot
2021-06-30 21:50:32 -07:00
Alexandre Ghiti
e5c35fa040
riscv: Map the kernel with correct permissions the first time
For 64-bit kernels, we map all the kernel with write and execute
permissions and afterwards remove writability from text and executability
from data.

For 32-bit kernels, the kernel mapping resides in the linear mapping, so we
map all the linear mapping as writable and executable and afterwards we
remove those properties for unused memory and kernel mapping as
described above.

Change this behavior to directly map the kernel with correct permissions
and avoid going through the whole mapping to fix the permissions.

At the same time, this fixes an issue introduced by commit 2bfc6cd81b
("riscv: Move kernel mapping outside of linear mapping") as reported
here https://github.com/starfive-tech/linux/issues/17.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-30 21:18:58 -07:00
Linus Torvalds
54a728dc5e Scheduler udpates for this cycle:
- Changes to core scheduling facilities:
 
     - Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables
       coordinated scheduling across SMT siblings. This is a much
       requested feature for cloud computing platforms, to allow
       the flexible utilization of SMT siblings, without exposing
       untrusted domains to information leaks & side channels, plus
       to ensure more deterministic computing performance on SMT
       systems used by heterogenous workloads.
 
       There's new prctls to set core scheduling groups, which
       allows more flexible management of workloads that can share
       siblings.
 
     - Fix task->state access anti-patterns that may result in missed
       wakeups and rename it to ->__state in the process to catch new
       abuses.
 
  - Load-balancing changes:
 
      - Tweak newidle_balance for fair-sched, to improve
        'memcache'-like workloads.
 
      - "Age" (decay) average idle time, to better track & improve workloads
        such as 'tbench'.
 
      - Fix & improve energy-aware (EAS) balancing logic & metrics.
 
      - Fix & improve the uclamp metrics.
 
      - Fix task migration (taskset) corner case on !CONFIG_CPUSET.
 
      - Fix RT and deadline utilization tracking across policy changes
 
      - Introduce a "burstable" CFS controller via cgroups, which allows
        bursty CPU-bound workloads to borrow a bit against their future
        quota to improve overall latencies & batching. Can be tweaked
        via /sys/fs/cgroup/cpu/<X>/cpu.cfs_burst_us.
 
      - Rework assymetric topology/capacity detection & handling.
 
  - Scheduler statistics & tooling:
 
      - Disable delayacct by default, but add a sysctl to enable
        it at runtime if tooling needs it. Use static keys and
        other optimizations to make it more palatable.
 
      - Use sched_clock() in delayacct, instead of ktime_get_ns().
 
  - Misc cleanups and fixes.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler udpates from Ingo Molnar:

 - Changes to core scheduling facilities:

    - Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables
      coordinated scheduling across SMT siblings. This is a much
      requested feature for cloud computing platforms, to allow the
      flexible utilization of SMT siblings, without exposing untrusted
      domains to information leaks & side channels, plus to ensure more
      deterministic computing performance on SMT systems used by
      heterogenous workloads.

      There are new prctls to set core scheduling groups, which allows
      more flexible management of workloads that can share siblings.

    - Fix task->state access anti-patterns that may result in missed
      wakeups and rename it to ->__state in the process to catch new
      abuses.

 - Load-balancing changes:

    - Tweak newidle_balance for fair-sched, to improve 'memcache'-like
      workloads.

    - "Age" (decay) average idle time, to better track & improve
      workloads such as 'tbench'.

    - Fix & improve energy-aware (EAS) balancing logic & metrics.

    - Fix & improve the uclamp metrics.

    - Fix task migration (taskset) corner case on !CONFIG_CPUSET.

    - Fix RT and deadline utilization tracking across policy changes

    - Introduce a "burstable" CFS controller via cgroups, which allows
      bursty CPU-bound workloads to borrow a bit against their future
      quota to improve overall latencies & batching. Can be tweaked via
      /sys/fs/cgroup/cpu/<X>/cpu.cfs_burst_us.

    - Rework assymetric topology/capacity detection & handling.

 - Scheduler statistics & tooling:

    - Disable delayacct by default, but add a sysctl to enable it at
      runtime if tooling needs it. Use static keys and other
      optimizations to make it more palatable.

    - Use sched_clock() in delayacct, instead of ktime_get_ns().

 - Misc cleanups and fixes.

* tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  sched/doc: Update the CPU capacity asymmetry bits
  sched/topology: Rework CPU capacity asymmetry detection
  sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag
  psi: Fix race between psi_trigger_create/destroy
  sched/fair: Introduce the burstable CFS controller
  sched/uclamp: Fix uclamp_tg_restrict()
  sched/rt: Fix Deadline utilization tracking during policy change
  sched/rt: Fix RT utilization tracking during policy change
  sched: Change task_struct::state
  sched,arch: Remove unused TASK_STATE offsets
  sched,timer: Use __set_current_state()
  sched: Add get_current_state()
  sched,perf,kvm: Fix preemption condition
  sched: Introduce task_is_running()
  sched: Unbreak wakeups
  sched/fair: Age the average idle time
  sched/cpufreq: Consider reduced CPU capacity in energy calculation
  sched/fair: Take thermal pressure into account while estimating energy
  thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure
  sched/fair: Return early from update_tg_cfs_load() if delta == 0
  ...
2021-06-28 12:14:19 -07:00
Linus Torvalds
28a27cbd86 Perf events updates for this cycle:
- Platform PMU driver updates:
 
      - x86 Intel uncore driver updates for Skylake (SNR) and Icelake (ICX) servers
      - Fix RDPMC support
      - Fix [extended-]PEBS-via-PT support
      - Fix Sapphire Rapids event constraints
      - Fix :ppp support on Sapphire Rapids
      - Fix fixed counter sanity check on Alder Lake & X86_FEATURE_HYBRID_CPU
      - Other heterogenous-PMU fixes
 
  - Kprobes:
 
      - Remove the unused and misguided kprobe::fault_handler callbacks.
      - Warn about kprobes taking a page fault.
      - Fix the 'nmissed' stat counter.
 
  - Misc cleanups and fixes.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf events updates from Ingo Molnar:

 - Platform PMU driver updates:

     - x86 Intel uncore driver updates for Skylake (SNR) and Icelake (ICX) servers
     - Fix RDPMC support
     - Fix [extended-]PEBS-via-PT support
     - Fix Sapphire Rapids event constraints
     - Fix :ppp support on Sapphire Rapids
     - Fix fixed counter sanity check on Alder Lake & X86_FEATURE_HYBRID_CPU
     - Other heterogenous-PMU fixes

 - Kprobes:

     - Remove the unused and misguided kprobe::fault_handler callbacks.
     - Warn about kprobes taking a page fault.
     - Fix the 'nmissed' stat counter.

 - Misc cleanups and fixes.

* tag 'perf-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix task context PMU for Hetero
  perf/x86/intel: Fix instructions:ppp support in Sapphire Rapids
  perf/x86/intel: Add more events requires FRONTEND MSR on Sapphire Rapids
  perf/x86/intel: Fix fixed counter check warning for some Alder Lake
  perf/x86/intel: Fix PEBS-via-PT reload base value for Extended PEBS
  perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task
  kprobes: Do not increment probe miss count in the fault handler
  x86,kprobes: WARN if kprobes tries to handle a fault
  kprobes: Remove kprobe::fault_handler
  uprobes: Update uprobe_write_opcode() kernel-doc comment
  perf/hw_breakpoint: Fix DocBook warnings in perf hw_breakpoint
  perf/core: Fix DocBook warnings
  perf/core: Make local function perf_pmu_snapshot_aux() static
  perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on ICX
  perf/x86/intel/uncore: Enable I/O stacks to IIO PMON mapping on SNR
  perf/x86/intel/uncore: Generalize I/O stacks to PMON mapping procedure
  perf/x86/intel/uncore: Drop unnecessary NULL checks after container_of()
2021-06-28 12:03:20 -07:00
Peter Zijlstra
b03fbd4ff2 sched: Introduce task_is_running()
Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
2021-06-18 11:43:07 +02:00
Ingo Molnar
b2c0931a07 Merge branch 'sched/urgent' into sched/core, to resolve conflicts
This commit in sched/urgent moved the cfs_rq_is_decayed() function:

  a7b359fc6a: ("sched/fair: Correctly insert cfs_rq's to list on unthrottle")

and this fresh commit in sched/core modified it in the old location:

  9e077b52d8: ("sched/pelt: Check that *_avg are null when *_sum are")

Merge the two variants.

Conflicts:
	kernel/sched/fair.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-18 11:31:25 +02:00
Kefeng Wang
ce3aca0465
riscv: Only initialize swiotlb when necessary
The SWIOTLB buffer is not needed unless the physical address space
is beyond the limit of dma, only initialize swiotlb when swiotlb_force
is true or not all system memory is DMA-able.

Also move the swiotlb_init() into mem_init().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-11 13:42:26 -07:00
Vitaly Wool
5e63215c2f
riscv: xip: support runtime trap patching
RISCV_ERRATA_ALTERNATIVE patches text at runtime which is currently
not possible when the kernel is executed from the flash in XIP mode.
Since runtime patching concerns only traps at the moment, let's just
have all the traps reside in RAM anyway if RISCV_ERRATA_ALTERNATIVE
is set. Thus, these functions will be patch-able even when the .text
section is in flash.

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-10 16:16:06 -07:00
Ingo Molnar
a9e906b71f Merge branch 'sched/urgent' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-03 19:00:49 +02:00
Naveen N. Rao
2e38eb04c9 kprobes: Do not increment probe miss count in the fault handler
Kprobes has a counter 'nmissed', that is used to count the number of
times a probe handler was not called. This generally happens when we hit
a kprobe while handling another kprobe.

However, if one of the probe handlers causes a fault, we are currently
incrementing 'nmissed'. The comment in fault handler indicates that this
can be used to account faults taken by the probe handlers. But, this has
never been the intention as is evident from the comment above 'nmissed'
in 'struct kprobe':

	/*count the number of times this probe was temporarily disarmed */
	unsigned long nmissed;

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lkml.kernel.org/r/20210601120150.672652-1-naveen.n.rao@linux.vnet.ibm.com
2021-06-03 15:47:26 +02:00
Wende Tan
da2d48808f
RISC-V: Fix memblock_free() usages in init_resources()
`memblock_free()` takes a physical address as its first argument.
Fix the wrong usages in `init_resources()`.

Fixes: ffe0e52612 ("RISC-V: Improve init_resources()")
Fixes: 797f0375dd ("RISC-V: Do not allocate memblock while iterating reserved memblocks")
Signed-off-by: Wende Tan <twd2.me@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-06-01 21:16:42 -07:00
Peter Zijlstra
ec6aba3d2b kprobes: Remove kprobe::fault_handler
The reason for kprobe::fault_handler(), as given by their comment:

 * We come here because instructions in the pre/post
 * handler caused the page_fault, this could happen
 * if handler tries to access user space by
 * copy_from_user(), get_user() etc. Let the
 * user-specified handler try to fix it first.

Is just plain bad. Those other handlers are ran from non-preemptible
context and had better use _nofault() functions. Also, there is no
upstream usage of this.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20210525073213.561116662@infradead.org
2021-06-01 16:00:08 +02:00
Jisheng Zhang
3df952ae2a
riscv: Add __init section marker to some functions again
These functions are not needed after booting, so mark them as __init
to move them to the __init section.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-29 13:39:27 -07:00
Jisheng Zhang
8c9f4940c2
riscv: kprobes: Remove redundant kprobe_step_ctx
Inspired by commit ba090f9caf ("arm64: kprobes: Remove redundant
kprobe_step_ctx"), the ss_pending and match_addr of kprobe_step_ctx
are redundant because those can be replaced by KPROBE_HIT_SS and
&cur_kprobe->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode)
respectively.

Remove the kprobe_step_ctx to simplify the code.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-29 11:17:08 -07:00
Jisheng Zhang
37a7a2a10e
riscv: Turn has_fpu into a static key if FPU=y
The has_fpu check sits at hot code path: switch_to(). Currently, has_fpu
is a bool variable if FPU=y, switch_to() checks it each time, we can
optimize out this check by turning the has_fpu into a static key.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-25 22:56:57 -07:00
Kefeng Wang
f842f5ff6a
riscv: Move setup_bootmem into paging_init
Make setup_bootmem() static.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-25 22:50:50 -07:00
Jisheng Zhang
bab0d47c0e
riscv: kexec: Fix W=1 build warnings
Fixes the following W=1 build warning(s):

In file included from include/linux/kexec.h:28,
                 from arch/riscv/kernel/machine_kexec.c:7:
arch/riscv/include/asm/kexec.h:45:1: warning: ‘extern’ is not at beginning of declaration [-Wold-style-declaration]
   45 | const extern unsigned char riscv_kexec_relocate[];
      | ^~~~~
arch/riscv/include/asm/kexec.h:46:1: warning: ‘extern’ is not at beginning of declaration [-Wold-style-declaration]
   46 | const extern unsigned int riscv_kexec_relocate_size;
      | ^~~~~
arch/riscv/kernel/machine_kexec.c:125:6: warning: no previous prototype for ‘machine_shutdown’ [-Wmissing-prototypes]
  125 | void machine_shutdown(void)
      |      ^~~~~~~~~~~~~~~~
arch/riscv/kernel/machine_kexec.c:147:1: warning: no previous prototype for ‘machine_crash_shutdown’ [-Wmissing-prototypes]
  147 | machine_crash_shutdown(struct pt_regs *regs)
      | ^~~~~~~~~~~~~~~~~~~~~~
arch/riscv/kernel/machine_kexec.c:23: warning: Function parameter or member 'image' not described in 'kexec_image_info'
arch/riscv/kernel/machine_kexec.c:53: warning: Function parameter or member 'image' not described in 'machine_kexec_prepare'
arch/riscv/kernel/machine_kexec.c:114: warning: Function parameter or member 'image' not described in 'machine_kexec_cleanup'
arch/riscv/kernel/machine_kexec.c:148: warning: Function parameter or member 'regs' not described in 'machine_crash_shutdown'
arch/riscv/kernel/machine_kexec.c:167: warning: Function parameter or member 'image' not described in 'machine_kexec'

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-22 22:05:30 -07:00
Jisheng Zhang
02ccdeed18
riscv: kprobes: Fix build error when MMU=n
lkp reported a randconfig failure:

arch/riscv/kernel/probes/kprobes.c:90:22: error: use of undeclared identifier 'PAGE_KERNEL_READ_EXEC'

We implemented the alloc_insn_page() to allocate PAGE_KERNEL_READ_EXEC
page for kprobes insn page for STRICT_MODULE_RWX. But if MMU=n, we
should fall back to the generic weak alloc_insn_page() by generic
kprobe subsystem.

Fixes: cdd1b2bd35 ("riscv: kprobes: Implement alloc_insn_page()")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-22 22:04:58 -07:00
Chen Huang
eac2f3059e
riscv: stacktrace: fix the riscv stacktrace when CONFIG_FRAME_POINTER enabled
As [1] and [2] said, the arch_stack_walk should not to trace itself, or it will
leave the trace unexpectedly when called. The example is when we do "cat
/sys/kernel/debug/page_owner", all pages' stack is the same.

arch_stack_walk+0x18/0x20
stack_trace_save+0x40/0x60
register_dummy_stack+0x24/0x5e
init_page_owner+0x2e

So we use __builtin_frame_address(1) as the first frame to be walked. And mark
the arch_stack_walk() noinline.

We found that pr_cont will affact pages' stack whose task state is RUNNING when
testing "echo t > /proc/sysrq-trigger". So move the place of pr_cont and mark
the function dump_backtrace() noinline.

Also we move the case when task == NULL into else branch, and test for it in
"echo c > /proc/sysrq-trigger".

[1] https://lore.kernel.org/lkml/20210319184106.5688-1-mark.rutland@arm.com/
[2] https://lore.kernel.org/lkml/20210317142050.57712-1-chenjun102@huawei.com/

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
Fixes: 5d8544e2d0 ("RISC-V: Generic library routines and assembly")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-22 18:59:20 -07:00
Valentin Schneider
f1a0a376ca sched/core: Initialize the idle task with preemption disabled
As pointed out by commit

  de9b8f5dcb ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

  @begone@
  @@

  -preempt_disable();
  ...
  cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
2021-05-12 13:01:45 +02:00
Rouven Czerwinski
beaf5ae15a
riscv: remove unused handle_exception symbol
Since commit 79b1feba54 ("RISC-V: Setup exception vector early")
exception vectors are setup early and the handle_exception symbol from
the asm files is no longer referenced in traps.c. Remove it.

Signed-off-by: Rouven Czerwinski <rouven@czerwinskis.de>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-06 09:40:16 -07:00
Geert Uytterhoeven
8d91b09733
riscv: Consistify protect_kernel_linear_mapping_text_rodata() use
The various uses of protect_kernel_linear_mapping_text_rodata() are
not consistent:
  - Its definition depends on "64BIT && !XIP_KERNEL",
  - Its forward declaration depends on MMU,
  - Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU &&
    !XIP_KERNEL".

Fix this by settling on the dependencies of the caller, which can be
simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL".
Provide a dummy definition, as the caller is protected by
"IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef
CONFIG_STRICT_KERNEL_RWX".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-06 09:40:15 -07:00
Linus Torvalds
939b7cbc00 RISC-V Patches for the 5.13 Merge Window, Part 1
* Support for the memtest= kernel command-line argument.
 * Support for building the kernel with FORTIFY_SOURCE.
 * Support for generic clockevent broadcasts.
 * Support for the buildtar build target.
 * Some build system cleanups to pass more LLVM-friendly arguments.
 * Support for kprobes.
 * A rearranged kernel memory map, the first part of supporting sv48
   systems.
 * Improvements to kexec, along with support for kdump and crash kernels.
 * An alternatives-based errata framework, along with support for
   handling a pair of errata that manifest on some SiFive designs
   (including the HiFive Unmatched).
 * Support for XIP.
 * A device tree for the Microchip PolarFire ICICLE SoC and associated
   dev board.
 
 Along with a bunch of cleanups.  There are already a handful of fixes
 on the list so there will likely be a part 2.
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Merge tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the memtest= kernel command-line argument.

 - Support for building the kernel with FORTIFY_SOURCE.

 - Support for generic clockevent broadcasts.

 - Support for the buildtar build target.

 - Some build system cleanups to pass more LLVM-friendly arguments.

 - Support for kprobes.

 - A rearranged kernel memory map, the first part of supporting sv48
   systems.

 - Improvements to kexec, along with support for kdump and crash
   kernels.

 - An alternatives-based errata framework, along with support for
   handling a pair of errata that manifest on some SiFive designs
   (including the HiFive Unmatched).

 - Support for XIP.

 - A device tree for the Microchip PolarFire ICICLE SoC and associated
   dev board.

... along with a bunch of cleanups.  There are already a handful of fixes
on the list so there will likely be a part 2.

* tag 'riscv-for-linus-5.13-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (45 commits)
  RISC-V: Always define XIP_FIXUP
  riscv: Remove 32b kernel mapping from page table dump
  riscv: Fix 32b kernel build with CONFIG_DEBUG_VIRTUAL=y
  RISC-V: Fix error code returned by riscv_hartid_to_cpuid()
  RISC-V: Enable Microchip PolarFire ICICLE SoC
  RISC-V: Initial DTS for Microchip ICICLE board
  dt-bindings: riscv: microchip: Add YAML documentation for the PolarFire SoC
  RISC-V: Add Microchip PolarFire SoC kconfig option
  RISC-V: enable XIP
  RISC-V: Add crash kernel support
  RISC-V: Add kdump support
  RISC-V: Improve init_resources()
  RISC-V: Add kexec support
  RISC-V: Add EM_RISCV to kexec UAPI header
  riscv: vdso: fix and clean-up Makefile
  riscv/mm: Use BUG_ON instead of if condition followed by BUG.
  riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe
  riscv: Set ARCH_HAS_STRICT_MODULE_RWX if MMU
  riscv: module: Create module allocations without exec permissions
  riscv: bpf: Avoid breaking W^X
  ...
2021-05-06 09:24:18 -07:00
Anup Patel
533b4f3a78
RISC-V: Fix error code returned by riscv_hartid_to_cpuid()
We should return a negative error code upon failure in
riscv_hartid_to_cpuid() instead of NR_CPUS. This is also
aligned with all uses of riscv_hartid_to_cpuid() which
expect negative error code upon failure.

Fixes: 6825c7a80f ("RISC-V: Add logical CPU indexing for RISC-V")
Fixes: f99fb607fb ("RISC-V: Use Linux logical CPU number instead of hartid")
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-01 08:53:19 -07:00
Vitaly Wool
44c9225729
RISC-V: enable XIP
Introduce XIP (eXecute In Place) support for RISC-V platforms.
It allows code to be executed directly from non-volatile storage
directly addressable by the CPU, such as QSPI NOR flash which can
be found on many RISC-V platforms. This makes way for significant
optimization of RAM footprint. The XIP kernel is not compressed
since it has to run directly from flash, so it will occupy more
space on the non-volatile storage. The physical flash address used
to link the kernel object files and for storing it has to be known
at compile time and is represented by a Kconfig option.

XIP on RISC-V will for the time being only work on MMU-enabled
kernels.

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
[Alex: Rebase on top of "Move kernel mapping outside the linear mapping" ]
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
[Palmer: disable XIP for allyesconfig]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:31:28 -07:00
Nick Kossifidis
5640975003
RISC-V: Add crash kernel support
This patch allows Linux to act as a crash kernel for use with
kdump. Userspace will let the crash kernel know about the
memory region it can use through linux,usable-memory property
on the /memory node (overriding its reg property), and about the
memory region where the elf core header of the previous kernel
is saved, through a reserved-memory node with a compatible string
of "linux,elfcorehdr". This approach is the least invasive and
re-uses functionality already present.

I tested this on riscv64 qemu and it works as expected, you
may test it by retrieving the dmesg of the previous kernel
through /proc/vmcore, using the vmcore-dmesg utility from
kexec-tools.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:24 -07:00
Nick Kossifidis
e53d28180d
RISC-V: Add kdump support
This patch adds support for kdump, the kernel will reserve a
region for the crash kernel and jump there on panic. In order
for userspace tools (kexec-tools) to prepare the crash kernel
kexec image, we also need to expose some information on
/proc/iomem for the memory regions used by the kernel and for
the region reserved for crash kernel. Note that on userspace
the device tree is used to determine the system's memory
layout so the "System RAM" on /proc/iomem is ignored.

I tested this on riscv64 qemu and works as expected, you may
test it by triggering a crash through /proc/sysrq_trigger:

echo c > /proc/sysrq_trigger

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:23 -07:00
Nick Kossifidis
ffe0e52612
RISC-V: Improve init_resources()
The kernel region is always present and we know where it is, no need to
look for it inside the loop, just ignore it like the rest of the
reserved regions within system's memory.

Additionally, we don't need to call memblock_free inside the loop, as if
called it'll split the region of pre-allocated resources in two parts,
messing things up, just re-use the previous pre-allocated resource and
free any unused resources after both loops finish.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
[Palmer: commit text]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:22 -07:00
Nick Kossifidis
fba8a8674f
RISC-V: Add kexec support
This patch adds support for kexec on RISC-V. On SMP systems it depends
on HOTPLUG_CPU in order to be able to bring up all harts after kexec.
It also needs a recent OpenSBI version that supports the HSM extension.
I tested it on riscv64 QEMU on both an smp and a non-smp system.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:21 -07:00
Jisheng Zhang
772d7891e8
riscv: vdso: fix and clean-up Makefile
Running "make" on an already compiled kernel tree will rebuild the
kernel even without any modifications:

  CALL    linux/scripts/checksyscalls.sh
  CALL    linux/scripts/atomic/check-atomics.sh
  CHK     include/generated/compile.h
  SO2S    arch/riscv/kernel/vdso/vdso-syms.S
  AS      arch/riscv/kernel/vdso/vdso-syms.o
  AR      arch/riscv/kernel/vdso/built-in.a
  AR      arch/riscv/kernel/built-in.a
  AR      arch/riscv/built-in.a
  GEN     .version
  CHK     include/generated/compile.h
  UPD     include/generated/compile.h
  CC      init/version.o
  AR      init/built-in.a
  LD      vmlinux.o

The reason is "Any target that utilizes if_changed must be listed in
$(targets), otherwise the command line check will fail, and the target
will always be built" as explained by Documentation/kbuild/makefiles.rst

Fix this build bug by adding vdso-syms.S to $(targets)

At the same time, there are two trivial clean up modifications:

- the vdso-dummy.o is not needed any more after so remove it.

- vdso.lds is a generated file, so it should be prefixed with
  $(obj)/ instead of $(src)/

Fixes: c2c81bb2f6 ("RISC-V: Fix the VDSO symbol generaton for binutils-2.35+")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:19 -07:00
Liao Chang
b1ebaa0e13
riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe
The execution of sys_read end up hitting a BUG_ON() in __find_get_block
after installing kprobe at sys_read, the BUG message like the following:

[   65.708663] ------------[ cut here ]------------
[   65.709987] kernel BUG at fs/buffer.c:1251!
[   65.711283] Kernel BUG [#1]
[   65.712032] Modules linked in:
[   65.712925] CPU: 0 PID: 51 Comm: sh Not tainted 5.12.0-rc4 #1
[   65.714407] Hardware name: riscv-virtio,qemu (DT)
[   65.715696] epc : __find_get_block+0x218/0x2c8
[   65.716835]  ra : __getblk_gfp+0x1c/0x4a
[   65.717831] epc : ffffffe00019f11e ra : ffffffe00019f56a sp : ffffffe002437930
[   65.719553]  gp : ffffffe000f06030 tp : ffffffe0015abc00 t0 : ffffffe00191e038
[   65.721290]  t1 : ffffffe00191e038 t2 : 000000000000000a s0 : ffffffe002437960
[   65.723051]  s1 : ffffffe00160ad00 a0 : ffffffe00160ad00 a1 : 000000000000012a
[   65.724772]  a2 : 0000000000000400 a3 : 0000000000000008 a4 : 0000000000000040
[   65.726545]  a5 : 0000000000000000 a6 : ffffffe00191e000 a7 : 0000000000000000
[   65.728308]  s2 : 000000000000012a s3 : 0000000000000400 s4 : 0000000000000008
[   65.730049]  s5 : 000000000000006c s6 : ffffffe00240f800 s7 : ffffffe000f080a8
[   65.731802]  s8 : 0000000000000001 s9 : 000000000000012a s10: 0000000000000008
[   65.733516]  s11: 0000000000000008 t3 : 00000000000003ff t4 : 000000000000000f
[   65.734434]  t5 : 00000000000003ff t6 : 0000000000040000
[   65.734613] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003
[   65.734901] Call Trace:
[   65.735076] [<ffffffe00019f11e>] __find_get_block+0x218/0x2c8
[   65.735417] [<ffffffe00020017a>] __ext4_get_inode_loc+0xb2/0x2f6
[   65.735618] [<ffffffe000201b6c>] ext4_get_inode_loc+0x3a/0x8a
[   65.735802] [<ffffffe000203380>] ext4_reserve_inode_write+0x2e/0x8c
[   65.735999] [<ffffffe00020357a>] __ext4_mark_inode_dirty+0x4c/0x18e
[   65.736208] [<ffffffe000206bb0>] ext4_dirty_inode+0x46/0x66
[   65.736387] [<ffffffe000192914>] __mark_inode_dirty+0x12c/0x3da
[   65.736576] [<ffffffe000180dd2>] touch_atime+0x146/0x150
[   65.736748] [<ffffffe00010d762>] filemap_read+0x234/0x246
[   65.736920] [<ffffffe00010d834>] generic_file_read_iter+0xc0/0x114
[   65.737114] [<ffffffe0001f5d7a>] ext4_file_read_iter+0x42/0xea
[   65.737310] [<ffffffe000163f2c>] new_sync_read+0xe2/0x15a
[   65.737483] [<ffffffe000165814>] vfs_read+0xca/0xf2
[   65.737641] [<ffffffe000165bae>] ksys_read+0x5e/0xc8
[   65.737816] [<ffffffe000165c26>] sys_read+0xe/0x16
[   65.737973] [<ffffffe000003972>] ret_from_syscall+0x0/0x2
[   65.738858] ---[ end trace fe93f985456c935d ]---

A simple reproducer looks like:
	echo 'p:myprobe sys_read fd=%a0 buf=%a1 count=%a2' > /sys/kernel/debug/tracing/kprobe_events
	echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable
	cat /sys/kernel/debug/tracing/trace

Here's what happens to hit that BUG_ON():

1) After installing kprobe at entry of sys_read, the first instruction
   is replaced by 'ebreak' instruction on riscv64 platform.

2) Once kernel reach the 'ebreak' instruction at the entry of sys_read,
   it trap into the riscv breakpoint handler, where it do something to
   setup for coming single-step of origin instruction, including backup
   the 'sstatus' in pt_regs, followed by disable interrupt during single
   stepping via clear 'SIE' bit of 'sstatus' in pt_regs.

3) Then kernel restore to the instruction slot contains two instructions,
   one is original instruction at entry of sys_read, the other is 'ebreak'.
   Here it trigger a 'Instruction page fault' exception (value at 'scause'
   is '0xc'), if PF is not filled into PageTabe for that slot yet.

4) Again kernel trap into page fault exception handler, where it choose
   different policy according to the state of running kprobe. Because
   afte 2) the state is KPROBE_HIT_SS, so kernel reset the current kprobe
   and 'pc' points back to the probe address.

5) Because 'epc' point back to 'ebreak' instrution at sys_read probe,
   kernel trap into breakpoint handler again, and repeat the operations
   at 2), however 'sstatus' without 'SIE' is keep at 4), it cause the
   real 'sstatus' saved at 2) is overwritten by the one withou 'SIE'.

6) When kernel cross the probe the 'sstatus' CSR restore with value
   without 'SIE', and reach __find_get_block where it requires the
   interrupt must be enabled.

Fix this is very trivial, just restore the value of 'sstatus' in pt_regs
with backup one at 2) when the instruction being single stepped cause a
page fault.

Fixes: c22b0bcb1d ("riscv: Add kprobes supported")
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:17 -07:00
Jisheng Zhang
5387054b98
riscv: module: Create module allocations without exec permissions
The core code manages the executable permissions of code regions of
modules explicitly, it is not necessary to create the module vmalloc
regions with RWX permissions. Create them with RW- permissions instead.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:15 -07:00
Jisheng Zhang
cdd1b2bd35
riscv: kprobes: Implement alloc_insn_page()
Allocate PAGE_KERNEL_READ_EXEC(read only, executable) page for kprobes
insn page. This is to prepare for STRICT_MODULE_RWX.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:11 -07:00
Jisheng Zhang
300f62c37d
riscv: Constify sbi_ipi_ops
Constify the sbi_ipi_ops so that it will be placed in the .rodata
section. This will cause attempts to modify it to fail when strict
page permissions are in place.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:10 -07:00
Jisheng Zhang
e6a302248c
riscv: Constify sys_call_table
Constify the sys_call_table so that it will be placed in the .rodata
section. This will cause attempts to modify the table to fail when
strict page permissions are in place.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:09 -07:00
Jisheng Zhang
de31ea4a11
riscv: Mark some global variables __ro_after_init
All of these are never modified after init, so they can be
__ro_after_init.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:08 -07:00
Jisheng Zhang
1987501b11
riscv: add __init section marker to some functions
They are not needed after booting, so mark them as __init to move them
to the __init section.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:07 -07:00
Alexandre Ghiti
2bfc6cd81b
riscv: Move kernel mapping outside of linear mapping
This is a preparatory patch for relocatable kernel and sv48 support.

The kernel used to be linked at PAGE_OFFSET address therefore we could use
the linear mapping for the kernel mapping. But the relocated kernel base
address will be different from PAGE_OFFSET and since in the linear mapping,
two different virtual addresses cannot point to the same physical address,
the kernel mapping needs to lie outside the linear mapping so that we don't
have to copy it at the same physical offset.

The kernel mapping is moved to the last 2GB of the address space, BPF
is now always after the kernel and modules use the 2GB memory range right
before the kernel, so BPF and modules regions do not overlap. KASLR
implementation will simply have to move the kernel in the last 2GB range
and just take care of leaving enough space for BPF.

In addition, by moving the kernel to the end of the address space, both
sv39 and sv48 kernels will be exactly the same without needing to be
relocated at runtime.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
[Palmer: Squash the STRICT_RWX fix, and a !MMU fix]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:04 -07:00
Nathan Chancellor
7ce0477150
riscv: Workaround mcount name prior to clang-13
Prior to clang 13.0.0, the RISC-V name for the mcount symbol was
"mcount", which differs from the GCC version of "_mcount", which results
in the following errors:

riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_level':
main.c:(.text+0xe): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_start':
main.c:(.text+0x4e): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `__traceiter_initcall_finish':
main.c:(.text+0x92): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `.LBB32_28':
main.c:(.text+0x30c): undefined reference to `mcount'
riscv64-linux-gnu-ld: init/main.o: in function `free_initmem':
main.c:(.text+0x54c): undefined reference to `mcount'

This has been corrected in https://reviews.llvm.org/D98881 but the
minimum supported clang version is 10.0.1. To avoid build errors and to
gain a working function tracer, adjust the name of the mcount symbol for
older versions of clang in mount.S and recordmcount.pl.

Link: https://github.com/ClangBuiltLinux/linux/issues/1331
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:25:01 -07:00
Nathan Chancellor
7f3d349065
riscv: Use $(LD) instead of $(CC) to link vDSO
Currently, the VDSO is being linked through $(CC). This does not match
how the rest of the kernel links objects, which is through the $(LD)
variable.

When linking with clang, there are a couple of warnings about flags that
will not be used during the link:

clang-12: warning: argument unused during compilation: '-no-pie' [-Wunused-command-line-argument]
clang-12: warning: argument unused during compilation: '-pg' [-Wunused-command-line-argument]

'-no-pie' was added in commit 85602bea29 ("RISC-V: build vdso-dummy.o
with -no-pie") to override '-pie' getting added to the ld command from
distribution versions of GCC that enable PIE by default. It is
technically no longer needed after commit c2c81bb2f6 ("RISC-V: Fix the
VDSO symbol generaton for binutils-2.35+"), which removed vdso-dummy.o
in favor of generating vdso-syms.S from vdso.so with $(NM) but this also
resolves the issue in case it ever comes back due to having full control
over the $(LD) command. '-pg' is for function tracing, it is not used
during linking as clang states.

These flags could be removed/filtered to fix the warnings but it is
easier to just match the rest of the kernel and use $(LD) directly for
linking. See commits

  fe00e50b2d ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO")
  691efbedc6 ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO")
  2ff906994b ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO")
  2b2a25845d ("s390/vdso: Use $(LD) instead of $(CC) to link vDSO")

for more information.

The flags are converted to linker flags and '--eh-frame-hdr' is added to
match what is added by GCC implicitly, which can be seen by adding '-v'
to GCC's invocation.

Additionally, since this area is being modified, use the $(OBJCOPY)
variable instead of an open coded $(CROSS_COMPILE)objcopy so that the
user's choice of objcopy binary is respected.

Link: https://github.com/ClangBuiltLinux/linux/issues/803
Link: https://github.com/ClangBuiltLinux/linux/issues/970
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:24:59 -07:00
Vincent Chen
800149a77c
riscv: sifive: Apply errata "cip-453" patch
Add sign extension to the $badaddr before addressing the instruction page
fault and instruction access fault to workaround the issue "cip-453".

To avoid affecting the existing code sequence, this patch will creates two
trampolines to add sign extension to the $badaddr. By the "alternative"
mechanism, these two trampolines will replace the original exception
handler of instruction page fault and instruction access fault in the
excp_vect_table. In this case, only the specific SiFive CPU core jumps to
the do_page_fault and do_trap_insn_fault through these two trampolines.
Other CPUs are not affected.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:24:57 -07:00
Vincent Chen
6f4eea9046
riscv: Introduce alternative mechanism to apply errata solution
Introduce the "alternative" mechanism from ARM64 and x86 to apply the CPU
vendors' errata solution at runtime. The main purpose of this patch is
to provide a framework. Therefore, the implementation is quite basic for
now so that some scenarios could not use this schemei, such as patching
code to a module, relocating the patching code and heterogeneous CPU
topology.

Users could use the macro ALTERNATIVE to apply an errata to the existing
code flow. In the macro ALTERNATIVE, users need to specify the manufacturer
information(vendorid, archid, and impid) for this errata. Therefore, kernel
will know this errata is suitable for which CPU core. During the booting
procedure, kernel will select the errata required by the CPU core and then
patch it. It means that the kernel only applies the errata to the specified
CPU core. In this case, the vendor's errata does not affect each other at
runtime. The above patching procedure only occurs during the booting phase,
so we only take the overhead of the "alternative" mechanism once.

This "alternative" mechanism is enabled by default to ensure that all
required errata will be applied. However, users can disable this feature by
the Kconfig "CONFIG_RISCV_ERRATA_ALTERNATIVE".

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:24:55 -07:00
Vincent Chen
183787c6fc
riscv: Add 3 SBI wrapper functions to get cpu manufacturer information
Add 3 wrapper functions to get vendor id, architecture id and implement id
from M-mode

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-26 08:24:54 -07:00
Jisheng Zhang
7ae11635ec
riscv: keep interrupts disabled for BREAKPOINT exception
Current riscv's kprobe handlers are run with both preemption and
interrupt enabled, this violates kprobe requirements. Fix this issue
by keeping interrupts disabled for BREAKPOINT exception.

Fixes: c22b0bcb1d ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
[Palmer: add a comment]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-15 21:32:40 -07:00
Jisheng Zhang
e31be8d343
riscv: kprobes/ftrace: Add recursion protection to the ftrace callback
Currently, the riscv's kprobes(powerred by ftrace) handler is
preemptible. Futher check indicates we miss something similar as the
commit c536aa1c5b ("kprobes/ftrace: Add recursion protection to the
ftrace callback"), so do similar modifications as the commit does.

Fixes: 829adda597 ("riscv: Add KPROBES_ON_FTRACE supported")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-15 21:32:34 -07:00
Jisheng Zhang
2349a3b26e
riscv: add do_page_fault and do_trap_break into the kprobes blacklist
These two functions are used to implement the kprobes feature so they
can't be kprobed.

Fixes: c22b0bcb1d ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-15 21:32:28 -07:00
Zihao Yu
ac8d0b901f
riscv,entry: fix misaligned base for excp_vect_table
In RV64, the size of each entry in excp_vect_table is 8 bytes. If the
base of the table is not 8-byte aligned, loading an entry in the table
will raise a misaligned exception. Although such exception will be
handled by opensbi/bbl, this still causes performance degradation.

Signed-off-by: Zihao Yu <yuzihao@ict.ac.cn>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-01 21:37:05 -07:00
Kefeng Wang
23c1075ae8
riscv: Drop const annotation for sp
The const annotation should not be used for 'sp', or it will
become read only and lead to bad stack output.

Fixes: dec822771b ("riscv: stacktrace: Move register keyword to beginning of declaration")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-04-01 21:37:03 -07:00
Anup Patel
f35bb4b8d1
RISC-V: Don't print SBI version for all detected extensions
The sbi_init() already prints SBI version before detecting
various SBI extensions so we don't need to print SBI version
for all detected SBI extensions.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-29 23:13:28 -07:00
Geert Uytterhoeven
ce989f1472
RISC-V: Fix out-of-bounds accesses in init_resources()
init_resources() allocates an array of resources, based on the current
total number of memory regions and reserved memory regions.  However,
allocating this array using memblock_alloc() might increase the number
of reserved memory regions.  If that happens, populating the array later
based on the new number of regions will cause out-of-bounds writes
beyond the end of the allocated array.

Fix this by allocating one more entry, which may or may not be used.

Fixes: 797f0375dd ("RISC-V: Do not allocate memblock while iterating reserved memblocks")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-16 21:55:11 -07:00
Colin Ian King
bab1770a2c
ftrace: Fix spelling mistake "disabed" -> "disabled"
There is a spelling mistake in a comment, fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-16 21:19:40 -07:00
Guo Ren
2f100585d0
riscv: Enable generic clockevent broadcast
When percpu-timers are stopped by deep power saving mode, we
need system timer help to broadcast IPI_TIMER.

This is first introduced by broken x86 hardware, where the local apic
timer stops in C3 state. But many other architectures(powerpc, mips,
arm, hexagon, openrisc, sh) have supported the infrastructure to
deal with Power Management issues.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-16 20:40:06 -07:00
kernel test robot
6e9070dc2e
riscv: fix bugon.cocci warnings
Use BUG_ON instead of a if condition followed by BUG.

Generated by: scripts/coccinelle/misc/bugon.cocci

Fixes: c22b0bcb1d ("riscv: Add kprobes supported")
CC: Guo Ren <guoren@linux.alibaba.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-16 20:34:19 -07:00
Nanyong Sun
288f6775a0
riscv: ftrace: Use ftrace_get_regs helper
Use ftrace_get_regs() helper call to get pt_regs from ftrace_regs struct,
this makes the code simpler.

Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09 20:46:06 -08:00
Nanyong Sun
86b276c1dd
riscv: process: Fix no prototype for show_regs
Include header file to fix the following W=1 compilation warning:
arch/riscv/kernel/process.c:78:6: warning: no previous prototype for ‘show_regs’ [-Wmissing-prototypes]
   78 | void show_regs(struct pt_regs *regs)
      |      ^~~~~~~~~

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09 20:46:05 -08:00
Nanyong Sun
a6a58ecf98
riscv: syscall_table: Reduce W=1 compilation warnings noise
Building riscv syscall table with W=1 throws the warning as
following pattern:
arch/riscv/kernel/syscall_table.c:14:36: warning: initialized field overwritten [-Woverride-init]
   14 | #define __SYSCALL(nr, call) [nr] = (call),
      |                                    ^
./include/uapi/asm-generic/unistd.h:29:37: note: in expansion of macro ‘__SYSCALL’
   29 | #define __SC_COMP(_nr, _sys, _comp) __SYSCALL(_nr, _sys)
      |                                     ^~~~~~~~~
./include/uapi/asm-generic/unistd.h:34:1: note: in expansion of macro ‘__SC_COMP’
   34 | __SC_COMP(__NR_io_setup, sys_io_setup, compat_sys_io_setup)
      | ^~~~~~~~~
arch/riscv/kernel/syscall_table.c:14:36: note: (near initialization for ‘sys_call_table[0]’)
   14 | #define __SYSCALL(nr, call) [nr] = (call),
      |                                    ^
./include/uapi/asm-generic/unistd.h:29:37: note: in expansion of macro ‘__SYSCALL’
   29 | #define __SC_COMP(_nr, _sys, _comp) __SYSCALL(_nr, _sys)
      |                                     ^~~~~~~~~
./include/uapi/asm-generic/unistd.h:34:1: note: in expansion of macro ‘__SC_COMP’
   34 | __SC_COMP(__NR_io_setup, sys_io_setup, compat_sys_io_setup)
      | ^~~~~~~~~
arch/riscv/kernel/syscall_table.c:14:36: warning: initialized field overwritten [-Woverride-init]
...

Since we intentionally build the syscall tables this way,ignore the warning.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09 20:46:04 -08:00
Nanyong Sun
db2a8f9256
riscv: time: Fix no prototype for time_init
Fix the following W=1 compilation warning:
arch/riscv/kernel/time.c:16:13: warning: no previous prototype for ‘time_init’ [-Wmissing-prototypes]
   16 | void __init time_init(void)
      |             ^~~~~~~~~

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09 20:46:03 -08:00
Nanyong Sun
56a6c37f6e
riscv: sbi: Fix comment of __sbi_set_timer_v01
Fix the comment of __sbi_set_timer_v01, the function name in comment
is missing '__'

Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09 20:46:01 -08:00
Nanyong Sun
030f1dfa85
riscv: traps: Fix no prototype warnings
Fix all W=1 compilation warnings:'no previous prototype for' in arch/riscv/kernel/traps.c:
arch/riscv/kernel/traps.c:96:15: warning: no previous prototype for ‘do_trap_unknown’ [-Wmissing-prototypes]
   96 | DO_ERROR_INFO(do_trap_unknown,
      |               ^~~~~~~~~~~~~~~
arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’
   91 | asmlinkage __visible void name(struct pt_regs *regs)   \
      |                           ^~~~
arch/riscv/kernel/traps.c:98:15: warning: no previous prototype for ‘do_trap_insn_misaligned’ [-Wmissing-prototypes]
   98 | DO_ERROR_INFO(do_trap_insn_misaligned,
      |               ^~~~~~~~~~~~~~~~~~~~~~~
arch/riscv/kernel/traps.c:91:27: note: in definition of macro ‘DO_ERROR_INFO’
   91 | asmlinkage __visible void name(struct pt_regs *regs)   \
      |                           ^~~~
arch/riscv/kernel/traps.c💯15: warning: no previous prototype for ‘do_trap_insn_fault’ [-Wmissing-prototypes]
...

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
[Palmer: fix checkpatch warnings]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-03-09 20:45:51 -08:00
Linus Torvalds
5695e51619 io_uring-worker.v3-2021-02-25
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Merge tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block

Pull io_uring thread rewrite from Jens Axboe:
 "This converts the io-wq workers to be forked off the tasks in question
  instead of being kernel threads that assume various bits of the
  original task identity.

  This kills > 400 lines of code from io_uring/io-wq, and it's the worst
  part of the code. We've had several bugs in this area, and the worry
  is always that we could be missing some pieces for file types doing
  unusual things (recent /dev/tty example comes to mind, userfaultfd
  reads installing file descriptors is another fun one... - both of
  which need special handling, and I bet it's not the last weird oddity
  we'll find).

  With these identical workers, we can have full confidence that we're
  never missing anything. That, in itself, is a huge win. Outside of
  that, it's also more efficient since we're not wasting space and code
  on tracking state, or switching between different states.

  I'm sure we're going to find little things to patch up after this
  series, but testing has been pretty thorough, from the usual
  regression suite to production. Any issue that may crop up should be
  manageable.

  There's also a nice series of further reductions we can do on top of
  this, but I wanted to get the meat of it out sooner rather than later.
  The general worry here isn't that it's fundamentally broken. Most of
  the little issues we've found over the last week have been related to
  just changes in how thread startup/exit is done, since that's the main
  difference between using kthreads and these kinds of threads. In fact,
  if all goes according to plan, I want to get this into the 5.10 and
  5.11 stable branches as well.

  That said, the changes outside of io_uring/io-wq are:

   - arch setup, simple one-liner to each arch copy_thread()
     implementation.

   - Removal of net and proc restrictions for io_uring, they are no
     longer needed or useful"

* tag 'io_uring-worker.v3-2021-02-25' of git://git.kernel.dk/linux-block: (30 commits)
  io-wq: remove now unused IO_WQ_BIT_ERROR
  io_uring: fix SQPOLL thread handling over exec
  io-wq: improve manager/worker handling over exec
  io_uring: ensure SQPOLL startup is triggered before error shutdown
  io-wq: make buffered file write hashed work map per-ctx
  io-wq: fix race around io_worker grabbing
  io-wq: fix races around manager/worker creation and task exit
  io_uring: ensure io-wq context is always destroyed for tasks
  arch: ensure parisc/powerpc handle PF_IO_WORKER in copy_thread()
  io_uring: cleanup ->user usage
  io-wq: remove nr_process accounting
  io_uring: flag new native workers with IORING_FEAT_NATIVE_WORKERS
  net: remove cmsg restriction from io_uring based send/recvmsg calls
  Revert "proc: don't allow async path resolution of /proc/self components"
  Revert "proc: don't allow async path resolution of /proc/thread-self components"
  io_uring: move SQPOLL thread io-wq forked worker
  io-wq: make io_wq_fork_thread() available to other users
  io-wq: only remove worker from free_list, if it was there
  io_uring: remove io_identity
  io_uring: remove any grabbing of context
  ...
2021-02-27 08:29:02 -08:00
Linus Torvalds
8b83369ddc RISC-V Patches for the 5.12 Merge Window
I have a handful of new RISC-V related patches for this merge window:
 
 * A check to ensure drivers are properly using uaccess.  This isn't
   manifesting with any of the drivers I'm currently using, but may catch
   errors in new drivers.
 * Some preliminary support for the FU740, along with the HiFive
   Unleashed it will appear on.
 * NUMA support for RISC-V, which involves making the arm64 code generic.
 * Support for kasan on the vmalloc region.
 * A handful of new drivers for the Kendryte K210, along with the DT
   plumbing required to boot on a handful of K210-based boards.
 * Support for allocating ASIDs.
 * Preliminary support for kernels larger than 128MiB.
 * Various other improvements to our KASAN support, including the
   utilization of huge pages when allocating the KASAN regions.
 
 We may have already found a bug with the KASAN_VMALLOC code, but it's
 passing my tests.  There's a fix in the works, but that will probably
 miss the merge window.
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Merge tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "A handful of new RISC-V related patches for this merge window:

   - A check to ensure drivers are properly using uaccess. This isn't
     manifesting with any of the drivers I'm currently using, but may
     catch errors in new drivers.

   - Some preliminary support for the FU740, along with the HiFive
     Unleashed it will appear on.

   - NUMA support for RISC-V, which involves making the arm64 code
     generic.

   - Support for kasan on the vmalloc region.

   - A handful of new drivers for the Kendryte K210, along with the DT
     plumbing required to boot on a handful of K210-based boards.

   - Support for allocating ASIDs.

   - Preliminary support for kernels larger than 128MiB.

   - Various other improvements to our KASAN support, including the
     utilization of huge pages when allocating the KASAN regions.

  We may have already found a bug with the KASAN_VMALLOC code, but it's
  passing my tests. There's a fix in the works, but that will probably
  miss the merge window.

* tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (75 commits)
  riscv: Improve kasan population by using hugepages when possible
  riscv: Improve kasan population function
  riscv: Use KASAN_SHADOW_INIT define for kasan memory initialization
  riscv: Improve kasan definitions
  riscv: Get rid of MAX_EARLY_MAPPING_SIZE
  soc: canaan: Sort the Makefile alphabetically
  riscv: Disable KSAN_SANITIZE for vDSO
  riscv: Remove unnecessary declaration
  riscv: Add Canaan Kendryte K210 SD card defconfig
  riscv: Update Canaan Kendryte K210 defconfig
  riscv: Add Kendryte KD233 board device tree
  riscv: Add SiPeed MAIXDUINO board device tree
  riscv: Add SiPeed MAIX GO board device tree
  riscv: Add SiPeed MAIX DOCK board device tree
  riscv: Add SiPeed MAIX BiT board device tree
  riscv: Update Canaan Kendryte K210 device tree
  dt-bindings: add resets property to dw-apb-timer
  dt-bindings: fix sifive gpio properties
  dt-bindings: update sifive uart compatible string
  dt-bindings: update sifive clint compatible string
  ...
2021-02-26 10:28:35 -08:00
Tobias Klauser
f3d60f2a25
riscv: Disable KSAN_SANITIZE for vDSO
We use the generic C VDSO implementations of a handful of clock-related
functions.  When kasan is enabled this results in asan stub calls that
are unlikely to be resolved by userspace, this just disables KASAN
when building the VDSO.

Verified the fix on a kernel with KASAN enabled using vDSO selftests.

Link: https://lore.kernel.org/lkml/CACT4Y+ZNJBnkKHXUf=tm_yuowvZvHwN=0rmJ=7J+xFd+9r_6pQ@mail.gmail.com/
Tested-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
[Palmer: commit text]
Fixes: ad5d1122b8 ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-22 17:51:23 -08:00
Atish Patra
4bb875632a
RISC-V: Add a non-void return for sbi v02 functions
SBI v0.2 functions can return an error code from SBI implementation.
We are already processing the SBI error code and coverts it to the Linux
error code.

Propagate to the error code to the caller as well. As of now, kvm is the
only user of these error codes.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-22 17:51:03 -08:00
Jens Axboe
4727dc20e0 arch: setup PF_IO_WORKER threads like PF_KTHREAD
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-21 17:25:22 -07:00
Palmer Dabbelt
5dd6713331
RISC-V: probes: Treat the instruction stream as host-endian
Neither of these are actually correct: the instruction stream is defined
(for versions of the ISA manual newer than 2.2) as a stream of 16-bit
little-endian parcels, which is different than just being little-endian.
In theory we should represent this as a type, but we don't have any
concrete plans for the big endian stuff so it doesn't seem worth the
time -- we've got variants of this all over the place.

Instead I'm just dropping the unnecessary type conversion, which is a
NOP on LE systems but causes an sparse error as the types are all mixed
up.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-18 23:18:02 -08:00
tangchunyou
5da9cbd2b2
arch/riscv:fix typo in a comment in arch/riscv/kernel/image-vars.h
"kerne" -> "kernel"

Signed-off-by: WenZhang <zhangwen@yulong.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-18 23:18:00 -08:00
Vitaly Wool
f105aa940e
riscv: add BUILTIN_DTB support for MMU-enabled targets
Sometimes, especially in a production system we may not want to
use a "smart bootloader" like u-boot to load kernel, ramdisk and
device tree from a filesystem on eMMC, but rather load the kernel
from a NAND partition and just run it as soon as we can, and in
this case it is convenient to have device tree compiled into the
kernel binary. Since this case is not limited to MMU-less systems,
let's support it for these which have MMU enabled too.

While at it, provide __dtb_start as a parameter to setup_vm() in
BUILTIN_DTB case, so we don't have to duplicate BUILTIN_DTB specific
processing in MMU-enabled and MMU-disabled versions of setup_vm().

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-18 23:17:54 -08:00
Atish Patra
f105ea9890
RISC-V: Fix .init section permission update
.init section permission should only updated to non-execute if
STRICT_KERNEL_RWX is enabled. Otherwise, this will lead to a kernel hang.

Fixes: 19a0086902 ("RISC-V: Protect all kernel sections including init early")
Cc: stable@vger.kernel.org
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-02 18:35:42 -08:00
Atish Patra
797f0375dd
RISC-V: Do not allocate memblock while iterating reserved memblocks
Currently, resource tree allocates memory blocks while iterating on the
list. It leads to following kernel warning because memblock allocation
also invokes memory block reservation API.

[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: CPU: 0 PID: 0 at kernel/resource.c:795
__insert_resource+0x8e/0xd0
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted
5.10.0-00022-ge20097fb37e2-dirty #549
[    0.000000] epc: c00125c2 ra : c001262c sp : c1c01f50
[    0.000000]  gp : c1d456e0 tp : c1c0a980 t0 : ffffcf20
[    0.000000]  t1 : 00000000 t2 : 00000000 s0 : c1c01f60
[    0.000000]  s1 : ffffcf00 a0 : ffffff00 a1 : c1c0c0c4
[    0.000000]  a2 : 80c12b15 a3 : 80402000 a4 : 80402000
[    0.000000]  a5 : c1c0c0c4 a6 : 80c12b15 a7 : f5faf600
[    0.000000]  s2 : c1c0c0c4 s3 : c1c0e000 s4 : c1009a80
[    0.000000]  s5 : c1c0c000 s6 : c1d48000 s7 : c1613b4c
[    0.000000]  s8 : 00000fff s9 : 80000200 s10: c1613b40
[    0.000000]  s11: 00000000 t3 : c1d4a000 t4 : ffffffff

This is also unnecessary as we can pre-compute the total memblocks required
for each memory region and allocate it before the loop. It save precious
boot time not going through memblock allocation code every time.

Fixes: 00ab027a3b ("RISC-V: Add kernel image sections to the resource tree")

Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-15 21:35:46 -08:00
Kefeng Wang
dec822771b
riscv: stacktrace: Move register keyword to beginning of declaration
Using global sp_in_global directly to fix the following warning,

arch/riscv/kernel/stacktrace.c:31:3: warning: ‘register’ is not at beginning of declaration [-Wold-style-declaration]
31 |   const register unsigned long current_sp = sp_in_global;
   |   ^~~~~

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 18:31:47 -08:00
Chen Huang
f766f77a74
riscv/stacktrace: Fix stack output without ra on the stack top
When a function doesn't have a callee, then it will not
push ra into the stack, such as lkdtm_BUG() function,

addi	sp,sp,-16
sd	s0,8(sp)
addi	s0,sp,16
ebreak

The struct stackframe use {fp,ra} to get information from
stack, if walk_stackframe() with pr_regs, we will obtain
wrong value and bad stacktrace,

[<ffffffe00066c56c>] lkdtm_BUG+0x6/0x8
---[ end trace 18da3fbdf08e25d5 ]---

Correct the next fp and pc, after that, full stacktrace
shown as expects,

[<ffffffe00066c56c>] lkdtm_BUG+0x6/0x8
[<ffffffe0008b24a4>] lkdtm_do_action+0x14/0x1c
[<ffffffe00066c372>] direct_entry+0xc0/0x10a
[<ffffffe000439f86>] full_proxy_write+0x42/0x6a
[<ffffffe000309626>] vfs_write+0x7e/0x214
[<ffffffe00030992a>] ksys_write+0x98/0xc0
[<ffffffe000309960>] sys_write+0xe/0x16
[<ffffffe0002014bc>] ret_from_syscall+0x0/0x2
---[ end trace 61917f3d9a9fadcd ]---

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 15:09:13 -08:00