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69 Commits

Author SHA1 Message Date
Linus Torvalds
e0152e7481 RISC-V Patches for the 6.6 Merge Window, Part 1
* Support for the new "riscv,isa-extensions" and "riscv,isa-base" device
   tree interfaces for probing extensions.
 * Support for userspace access to the performance counters.
 * Support for more instructions in kprobes.
 * Crash kernels can be allocated above 4GiB.
 * Support for KCFI.
 * Support for ELFs in !MMU configurations.
 * ARCH_KMALLOC_MINALIGN has been reduced to 8.
 * mmap() defaults to sv48-sized addresses, with longer addresses hidden
   behind a hint (similar to Arm and Intel).
 * Also various fixes and cleanups.
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Merge tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the new "riscv,isa-extensions" and "riscv,isa-base"
   device tree interfaces for probing extensions

 - Support for userspace access to the performance counters

 - Support for more instructions in kprobes

 - Crash kernels can be allocated above 4GiB

 - Support for KCFI

 - Support for ELFs in !MMU configurations

 - ARCH_KMALLOC_MINALIGN has been reduced to 8

 - mmap() defaults to sv48-sized addresses, with longer addresses hidden
   behind a hint (similar to Arm and Intel)

 - Also various fixes and cleanups

* tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits)
  lib/Kconfig.debug: Restrict DEBUG_INFO_SPLIT for RISC-V
  riscv: support PREEMPT_DYNAMIC with static keys
  riscv: Move create_tmp_mapping() to init sections
  riscv: Mark KASAN tmp* page tables variables as static
  riscv: mm: use bitmap_zero() API
  riscv: enable DEBUG_FORCE_FUNCTION_ALIGN_64B
  riscv: remove redundant mv instructions
  RISC-V: mm: Document mmap changes
  RISC-V: mm: Update pgtable comment documentation
  RISC-V: mm: Add tests for RISC-V mm
  RISC-V: mm: Restrict address space for sv39,sv48,sv57
  riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent
  riscv: allow kmalloc() caches aligned to the smallest value
  riscv: support the elf-fdpic binfmt loader
  binfmt_elf_fdpic: support 64-bit systems
  riscv: Allow CONFIG_CFI_CLANG to be selected
  riscv/purgatory: Disable CFI
  riscv: Add CFI error handling
  riscv: Add ftrace_stub_graph
  riscv: Add types to indirectly called assembly functions
  ...
2023-09-01 08:09:48 -07:00
Sami Tolvanen
af0ead42f6
riscv: Add CFI error handling
With CONFIG_CFI_CLANG, the compiler injects a type preamble immediately
before each function and a check to validate the target function type
before indirect calls:

  ; type preamble
    .word <id>
  function:
    ...
  ; indirect call check
    lw      t1, -4(a0)
    lui     t2, <hi20>
    addiw   t2, t2, <lo12>
    beq     t1, t2, .Ltmp0
    ebreak
  .Ltmp0:
    jarl    a0

Implement error handling code for the ebreak traps emitted for the
checks. This produces the following oops on a CFI failure (generated
using lkdtm):

[   21.177245] CFI failure at lkdtm_indirect_call+0x22/0x32 [lkdtm]
(target: lkdtm_increment_int+0x0/0x18 [lkdtm]; expected type: 0x3ad55aca)
[   21.178483] Kernel BUG [#1]
[   21.178671] Modules linked in: lkdtm
[   21.179037] CPU: 1 PID: 104 Comm: sh Not tainted
6.3.0-rc6-00037-g37d5ec6297ab #1
[   21.179511] Hardware name: riscv-virtio,qemu (DT)
[   21.179818] epc : lkdtm_indirect_call+0x22/0x32 [lkdtm]
[   21.180106]  ra : lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm]
[   21.180426] epc : ffffffff01387092 ra : ffffffff01386f14 sp : ff20000000453cf0
[   21.180792]  gp : ffffffff81308c38 tp : ff6000000243f080 t0 : ff20000000453b78
[   21.181157]  t1 : 000000003ad55aca t2 : 000000007e0c52a5 s0 : ff20000000453d00
[   21.181506]  s1 : 0000000000000001 a0 : ffffffff0138d170 a1 : ffffffff013870bc
[   21.181819]  a2 : b5fea48dd89aa700 a3 : 0000000000000001 a4 : 0000000000000fff
[   21.182169]  a5 : 0000000000000004 a6 : 00000000000000b7 a7 : 0000000000000000
[   21.182591]  s2 : ff20000000453e78 s3 : ffffffffffffffea s4 : 0000000000000012
[   21.183001]  s5 : ff600000023c7000 s6 : 0000000000000006 s7 : ffffffff013882a0
[   21.183653]  s8 : 0000000000000008 s9 : 0000000000000002 s10: ffffffff0138d878
[   21.184245]  s11: ffffffff0138d878 t3 : 0000000000000003 t4 : 0000000000000000
[   21.184591]  t5 : ffffffff8133df08 t6 : ffffffff8133df07
[   21.184858] status: 0000000000000120 badaddr: 0000000000000000
cause: 0000000000000003
[   21.185415] [<ffffffff01387092>] lkdtm_indirect_call+0x22/0x32 [lkdtm]
[   21.185772] [<ffffffff01386f14>] lkdtm_CFI_FORWARD_PROTO+0x48/0x7c [lkdtm]
[   21.186093] [<ffffffff01383552>] lkdtm_do_action+0x22/0x34 [lkdtm]
[   21.186445] [<ffffffff0138350c>] direct_entry+0x128/0x13a [lkdtm]
[   21.186817] [<ffffffff8033ed8c>] full_proxy_write+0x58/0xb2
[   21.187352] [<ffffffff801d4fe8>] vfs_write+0x14c/0x33a
[   21.187644] [<ffffffff801d5328>] ksys_write+0x64/0xd4
[   21.187832] [<ffffffff801d53a6>] sys_write+0xe/0x1a
[   21.188171] [<ffffffff80003996>] ret_from_syscall+0x0/0x2
[   21.188595] Code: 0513 0f65 a303 ffc5 53b7 7e0c 839b 2a53 0363 0073 (9002) 9582
[   21.189178] ---[ end trace 0000000000000000 ]---
[   21.189590] Kernel panic - not syncing: Fatal exception

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com> # ISA bits
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230710183544.999540-12-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-23 14:16:39 -07:00
Guo Ren
8d0be64154
riscv: stack: Fixup independent irq stack for CONFIG_FRAME_POINTER=n
The independent irq stack uses s0 to save & restore sp, but s0 would be
corrupted when CONFIG_FRAME_POINTER=n. So add s0 in the clobber list to
fix the problem.

Fixes: 163e76cc6e ("riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK")
Cc: stable@vger.kernel.org
Reported-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Tested-by: Drew Fustini <dfustini@baylibre.com>
Link: https://lore.kernel.org/r/20230716001506.3506041-2-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16 07:26:28 -07:00
Celeste Liu
52449c17bd
riscv: entry: set a0 = -ENOSYS only when syscall != -1
When we test seccomp with 6.4 kernel, we found errno has wrong value.
If we deny NETLINK_AUDIT with EAFNOSUPPORT, after f0bddf5058, we will
get ENOSYS instead. We got same result with commit 9c2598d435 ("riscv:
entry: Save a0 prior syscall_enter_from_user_mode()").

After analysing code, we think that regs->a0 = -ENOSYS should only be
executed when syscall != -1. In __seccomp_filter, when seccomp rejected
this syscall with specified errno, they will set a0 to return number as
syscall ABI, and then return -1. This return number is finally pass as
return number of syscall_enter_from_user_mode, and then is compared with
NR_syscalls after converted to ulong (so it will be ULONG_MAX). The
condition syscall < NR_syscalls will always be false, so regs->a0 = -ENOSYS
is always executed. It covered a0 set by seccomp, so we always get
ENOSYS when match seccomp RET_ERRNO rule.

Fixes: f0bddf5058 ("riscv: entry: Convert to generic entry")
Reported-by: Felix Yan <felixonmars@archlinux.org>
Co-developed-by: Ruizhe Pan <c141028@gmail.com>
Signed-off-by: Ruizhe Pan <c141028@gmail.com>
Co-developed-by: Shiqi Zhang <shiqi@isrc.iscas.ac.cn>
Signed-off-by: Shiqi Zhang <shiqi@isrc.iscas.ac.cn>
Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com>
Tested-by: Felix Yan <felixonmars@archlinux.org>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230801141607.435192-1-CoelacanthusHex@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16 07:19:49 -07:00
Björn Töpel
9657e9b7d2
riscv: Discard vector state on syscalls
The RISC-V vector specification states:
  Executing a system call causes all caller-saved vector registers
  (v0-v31, vl, vtype) and vstart to become unspecified.

The vector registers are set to all 1s, vill is set (invalid), and the
vector status is set to Dirty.

That way we can prevent userspace from accidentally relying on the
stated save.

Rémi pointed out [1] that writing to the registers might be
superfluous, and setting vill is sufficient.

Link: https://lore.kernel.org/linux-riscv/12784326.9UPPK3MAeB@basile.remlab.net/ # [1]
Suggested-by: Darius Rad <darius@bluespec.com>
Suggested-by: Palmer Dabbelt <palmer@rivosinc.com>
Suggested-by: Rémi Denis-Courmont <remi@remlab.net>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230629142228.1125715-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-04 08:59:24 -07:00
Andy Chiu
26c38cd802
riscv: vector: only enable interrupts in the first-use trap
The function irqentry_exit_to_user_mode() must be called with interrupt
disabled. The caller of do_trap_insn_illegal() also assumes running
without interrupts. So, we should turn off interrupts after
riscv_v_first_use_handler() returns.

Fixes: cd05483724 ("riscv: Allocate user's vector context in the first-use trap")
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230625155416.18629-1-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-07-01 07:38:20 -07:00
Guo Ren
163e76cc6e
riscv: stack: Support HAVE_IRQ_EXIT_ON_IRQ_STACK
Add independent irq stacks for percpu to prevent kernel stack overflows.
It is also compatible with VMAP_STACK by arch_alloc_vmap_stack.

Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Clément Léger <cleger@rivosinc.com>
Link: https://lore.kernel.org/r/20230614013018.2168426-2-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-22 10:38:35 -07:00
Andy Chiu
cd05483724
riscv: Allocate user's vector context in the first-use trap
Vector unit is disabled by default for all user processes. Thus, a
process will take a trap (illegal instruction) into kernel at the first
time when it uses Vector. Only after then, the kernel allocates V
context and starts take care of the context for that user process.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230605110724.21391-12-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08 07:16:44 -07:00
Björn Töpel
9c2598d435
riscv: entry: Save a0 prior syscall_enter_from_user_mode()
The RISC-V calling convention passes the first argument, and the
return value in the a0 register. For this reason, the a0 register
needs some extra care; When handling syscalls, the a0 register is
saved into regs->orig_a0, so a0 can be properly restored for,
e.g. interrupted syscalls.

This functionality was broken with the introduction of the generic
entry patches. Here, a0 was saved into orig_a0 after calling
syscall_enter_from_user_mode(), which can change regs->a0 for some
paths, incorrectly restoring a0.

This is resolved, by saving a0 prior doing the
syscall_enter_from_user_mode() call.

Fixes: f0bddf5058 ("riscv: entry: Convert to generic entry")
Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20230403065207.1070974-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-11 08:25:29 -07:00
Guo Ren
f0bddf5058
riscv: entry: Convert to generic entry
This patch converts riscv to use the generic entry infrastructure from
kernel/entry/*. The generic entry makes maintainers' work easier and
codes more elegant. Here are the changes:

 - More clear entry.S with handle_exception and ret_from_exception
 - Get rid of complex custom signal implementation
 - Move syscall procedure from assembly to C, which is much more
   readable.
 - Connect ret_from_fork & ret_from_kernel_thread to generic entry.
 - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode
 - Use the standard preemption code instead of custom

Suggested-by: Huacai Chen <chenhuacai@kernel.org>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Yipeng Zou <zouyipeng@huawei.com>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Link: https://lore.kernel.org/r/20230222033021.983168-5-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-23 08:47:00 -07:00
Guo Ren
d0db02c628
riscv: entry: Add noinstr to prevent instrumentation inserted
Without noinstr the compiler is free to insert instrumentation (think
all the k*SAN, KCov, GCov, ftrace etc..) which can call code we're not
yet ready to run this early in the entry path, for instance it could
rely on RCU which isn't on yet, or expect lockdep state. (by peterz)

Link: https://lore.kernel.org/linux-riscv/YxcQ6NoPf3AH0EXe@hirez.programming.kicks-ass.net/
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230222033021.983168-4-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-23 08:46:59 -07:00
Palmer Dabbelt
b19aa282c5
Merge patch series "riscv: Dump faulting instructions in oops handler"
Björn Töpel <bjorn@kernel.org> says:

From: Björn Töpel <bjorn@rivosinc.com>

RISC-V does not dump faulting instructions in the oops handler. This
series adds "Code:" dumps to the oops output together with
scripts/decodecode support.

* b4-shazam-merge:
  scripts/decodecode: Add support for RISC-V
  riscv: Add instruction dump to RISC-V splats

Link: https://lore.kernel.org/r/20230119074738.708301-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-21 17:21:51 -08:00
Mattias Nissler
130aee3fd9
riscv: Avoid enabling interrupts in die()
While working on something else, I noticed that the kernel would start
accepting interrupts again after crashing in an interrupt handler. Since
the kernel is already in inconsistent state, enabling interrupts is
dangerous and opens up risk of kernel state deteriorating further.
Interrupts do get enabled via what looks like an unintended side effect of
spin_unlock_irq, so switch to the more cautious
spin_lock_irqsave/spin_unlock_irqrestore instead.

Fixes: 76d2a0493a ("RISC-V: Init and Halt Code")
Signed-off-by: Mattias Nissler <mnissler@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230215144828.3370316-1-mnissler@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-21 17:21:45 -08:00
Björn Töpel
eb165bfa8e
riscv: Add instruction dump to RISC-V splats
Add instruction dump (Code:) output to RISC-V splats. Dump 16b
parcels.

An example:
  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
  Oops [#1]
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc3-00302-g840ff44c571d-dirty #27
  Hardware name: riscv-virtio,qemu (DT)
  epc : kernel_init+0xc8/0x10e
   ra : kernel_init+0x70/0x10e
  epc : ffffffff80bd9a40 ra : ffffffff80bd99e8 sp : ff2000000060bec0
   gp : ffffffff81730b28 tp : ff6000007ff00000 t0 : 7974697275636573
   t1 : 0000000000000000 t2 : 3030303270393d6e s0 : ff2000000060bee0
   s1 : ffffffff81732028 a0 : 0000000000000000 a1 : ff60000080dd1780
   a2 : 0000000000000002 a3 : ffffffff8176a470 a4 : 0000000000000000
   a5 : 000000000000000a a6 : 0000000000000081 a7 : ff60000080dd1780
   s2 : 0000000000000000 s3 : 0000000000000000 s4 : 0000000000000000
   s5 : 0000000000000000 s6 : 0000000000000000 s7 : 0000000000000000
   s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000000000000000
   s11: 0000000000000000 t3 : ffffffff81186018 t4 : 0000000000000022
   t5 : 000000000000003d t6 : 0000000000000000
  status: 0000000200000120 badaddr: 0000000000000000 cause: 000000000000000f
  [<ffffffff80003528>] ret_from_exception+0x0/0x16
  Code: 862a d179 608c a517 0069 0513 2be5 d0ef db2e 47a9 (c11c) a517
  ---[ end trace 0000000000000000 ]---
  Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
  SMP: stopping secondary CPUs
  ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---

Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230119074738.708301-2-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-02-21 16:53:53 -08:00
Palmer Dabbelt
c3ec1e8964
Merge patch series "RISC-V: Align the shadow stack"
Palmer Dabbelt <palmer@rivosinc.com> says:

This contains a pair of cleanups that depend on a fix that has already
landed upstream.

* b4-shazam-merge:
  RISC-V: Add some comments about the shadow and overflow stacks
  RISC-V: Align the shadow stack
  riscv: fix race when vmap stack overflow

Link: https://lore.kernel.org/r/20221130023515.20217-1-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-12 09:30:37 -08:00
Palmer Dabbelt
de57ecc476
RISC-V: Add some comments about the shadow and overflow stacks
It took me a while to page all this back in when trying to review the
recent spin_shadow_stack, so I figured I'd just write up some comments.

Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20221130023515.20217-2-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-12 09:30:35 -08:00
Palmer Dabbelt
b003b3b77d
RISC-V: Align the shadow stack
The standard RISC-V ABIs all require 16-byte stack alignment.  We're
only calling that one function on the shadow stack so I doubt it'd
result in a real issue, but might as well keep this lined up.

Fixes: 31da94c25a ("riscv: add VMAP_STACK overflow detection")
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20221130023515.20217-1-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-12 09:30:34 -08:00
Jisheng Zhang
7e1864332f
riscv: fix race when vmap stack overflow
Currently, when detecting vmap stack overflow, riscv firstly switches
to the so called shadow stack, then use this shadow stack to call the
get_overflow_stack() to get the overflow stack. However, there's
a race here if two or more harts use the same shadow stack at the same
time.

To solve this race, we introduce spin_shadow_stack atomic var, which
will be swap between its own address and 0 in atomic way, when the
var is set, it means the shadow_stack is being used; when the var
is cleared, it means the shadow_stack isn't being used.

Fixes: 31da94c25a ("riscv: add VMAP_STACK overflow detection")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Suggested-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20221030124517.2370-1-jszhang@kernel.org
[Palmer: Add AQ to the swap, and also some comments.]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-11-29 18:16:55 -08:00
Palmer Dabbelt
f2913d006f
RISC-V: Avoid dereferening NULL regs in die()
I don't think we can actually die() without a regs pointer, but the
compiler was warning about a NULL check after a dereference.  It seems
prudent to just avoid the possibly-NULL dereference, given that when
die()ing the system is already toast so who knows how we got there.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220920200037.6727-1-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-12 22:02:49 -07:00
Conor Dooley
d951b20b9d
riscv: traps: add missing prototype
Sparse complains:
arch/riscv/kernel/traps.c:213:6: warning: symbol 'shadow_stack' was not declared. Should it be static?

The variable is used in entry.S, so declare shadow_stack there
alongside SHADOW_OVERFLOW_STACK_SIZE.

Fixes: 31da94c25a ("riscv: add VMAP_STACK overflow detection")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220814141237.493457-5-mail@conchuod.ie
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-18 14:42:58 -07:00
Xianting Tian
3f1901110a
RISC-V: Add fast call path of crash_kexec()
Currently, almost all archs (x86, arm64, mips...) support fast call
of crash_kexec() when "regs && kexec_should_crash()" is true. But
RISC-V not, it can only enter crash system via panic(). However panic()
doesn't pass the regs of the real accident scene to crash_kexec(),
it caused we can't get accurate backtrace via gdb,
	$ riscv64-linux-gnu-gdb vmlinux vmcore
	Reading symbols from vmlinux...
	[New LWP 95]
	#0  console_unlock () at kernel/printk/printk.c:2557
	2557                    if (do_cond_resched)
	(gdb) bt
	#0  console_unlock () at kernel/printk/printk.c:2557
	#1  0x0000000000000000 in ?? ()

With the patch we can get the accurate backtrace,
	$ riscv64-linux-gnu-gdb vmlinux vmcore
	Reading symbols from vmlinux...
	[New LWP 95]
	#0  0xffffffe00063a4e0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81
	81             *(int *)p = 0xdead;
	(gdb)
	(gdb) bt
	#0  0xffffffe00064d5c0 in test_thread (data=<optimized out>) at drivers/test_crash.c:81
	#1  0x0000000000000000 in ?? ()

Test code to produce NULL address dereference in test_crash.c,
	void *p = NULL;
	*(int *)p = 0xdead;

Reviewed-by: Guo Ren <guoren@kernel.org>
Tested-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220606082308.2883458-1-xianting.tian@linux.alibaba.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-21 16:40:03 -07:00
Heiko Stuebner
e64f737ad7
riscv: integrate alternatives better into the main architecture
Right now the alternatives need to be explicitly enabled and
erratas are limited to SiFive ones.

We want to use alternatives not only for patching soc erratas,
but in the future also for handling different behaviour depending
on the existence of future extensions.

So move the core alternatives over to the kernel subdirectory
and move the CONFIG_RISCV_ALTERNATIVE to be a hidden symbol
which we expect relevant erratas and extensions to just select
if needed.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Link: https://lore.kernel.org/r/20220511192921.2223629-2-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-05-11 21:36:31 -07:00
Eric W. Biederman
0e25498f8c exit: Add and use make_task_dead.
There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-12-13 12:04:45 -06:00
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
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
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
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
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
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
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
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
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
Kefeng Wang
091b945085
riscv: Add dump stack in show_regs
Like commit 1149aad10b ("arm64: Add dump_backtrace() in show_regs"),
dump the stack in riscv show_regs as common code expects.

Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 15:09:11 -08:00
Guo Ren
74784081aa
riscv: Add uprobes supported
This patch adds support for uprobes on riscv architecture.

Just like kprobe, it support single-step and simulate instructions.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 15:09:08 -08:00
Guo Ren
c22b0bcb1d
riscv: Add kprobes supported
This patch enables "kprobe & kretprobe" to work with ftrace
interface. It utilized software breakpoint as single-step
mechanism.

Some instructions which can't be single-step executed must be
simulated in kernel execution slot, such as: branch, jal, auipc,
la ...

Some instructions should be rejected for probing and we use a
blacklist to filter, such as: ecall, ebreak, ...

We use ebreak & c.ebreak to replace origin instruction and the
kprobe handler prepares an executable memory slot for out-of-line
execution with a copy of the original instruction being probed.
In execution slot we add ebreak behind original instruction to
simulate a single-setp mechanism.

The patch is based on packi's work [1] and csky's work [2].
 - The kprobes_trampoline.S is all from packi's patch
 - The single-step mechanism is new designed for riscv without hw
   single-step trap
 - The simulation codes are from csky
 - Frankly, all codes refer to other archs' implementation

 [1] https://lore.kernel.org/linux-riscv/20181113195804.22825-1-me@packi.ch/
 [2] https://lore.kernel.org/linux-csky/20200403044150.20562-9-guoren@kernel.org/

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Patrick Stählin <me@packi.ch>
Signed-off-by: Patrick Stählin <me@packi.ch>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Patrick Stählin <me@packi.ch>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Björn Töpel <bjorn.topel@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-01-14 15:09:06 -08:00
Atish Patra
79b1feba54
RISC-V: Setup exception vector early
The trap vector is set only in trap_init which may be too late in some
cases. Early ioremap/efi spits many warning messages which may be useful.

Setup the trap vector early so that any warning/bug can be handled before
generic code invokes trap_init.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-07-30 11:37:48 -07:00
Christoph Hellwig
25f12ae45f maccess: rename probe_kernel_address to get_kernel_nofault
Better describe what this helper does, and match the naming of
copy_from_kernel_nofault.

Also switch the argument order around, so that it acts and looks
like get_user().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-18 11:14:40 -07:00
Anup Patel
6b7ce8927b
irqchip: RISC-V per-HART local interrupt controller driver
The RISC-V per-HART local interrupt controller manages software
interrupts, timer interrupts, external interrupts (which are routed
via the platform level interrupt controller) and other per-HART
local interrupts.

We add a driver for the RISC-V local interrupt controller, which
eventually replaces the RISC-V architecture code, allowing for a
better split between arch code and drivers.

The driver is compliant with RISC-V Hart-Level Interrupt Controller
DT bindings located at:
Documentation/devicetree/bindings/interrupt-controller/riscv,cpu-intc.txt

Co-developed-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
[Palmer: Cleaned up warnings]
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2020-06-09 19:11:21 -07:00
Vincent Chen
fe89bd2be8
riscv: Add KGDB support
The skeleton of RISC-V KGDB port.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-05-18 11:38:10 -07:00
Linus Torvalds
eab4002660 RISC-V Patches for the 5.7 Merge Window, Part 1
This tag contains the patches I'd like to target for 5.7.  It has a handful of
 new features:
 
 * Partial support for the Kendryte K210.  There are still a few outstanding
   issues that I have patches for, but I don't actually have a board to test
   them so they're not included yet.
 * SBI v0.2 support.
 * Fixes to support for building with LLVM-based toolchains.  The resulting
   images are known not to boot yet.
 
 This builds and boots for me.  There is one merge conflict, it's just a Kconfig
 merge issue.  I can publish a resolved branch if you'd like.
 
 I don't anticipate a part two, but I'll probably have something early in the
 RCs to finish up the K210 support.
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Merge tag 'riscv-for-linus-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:
 "This contains a handful of new features:

   - Partial support for the Kendryte K210.

     There are still a few outstanding issues that I have patches for,
     but I don't actually have a board to test them so they're not
     included yet.

   - SBI v0.2 support.

   - Fixes to support for building with LLVM-based toolchains. The
     resulting images are known not to boot yet.

  I don't anticipate a part two, but I'll probably have something early
  in the RCs to finish up the K210 support"

* tag 'riscv-for-linus-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (38 commits)
  riscv: create a loader.bin boot image for Kendryte SoC
  riscv: Kendryte K210 default config
  riscv: Add Kendryte K210 device tree
  riscv: Select required drivers for Kendryte SOC
  riscv: Add Kendryte K210 SoC support
  riscv: Add SOC early init support
  riscv: Unaligned load/store handling for M_MODE
  RISC-V: Support cpu hotplug
  RISC-V: Add supported for ordered booting method using HSM
  RISC-V: Add SBI HSM extension definitions
  RISC-V: Export SBI error to linux error mapping function
  RISC-V: Add cpu_ops and modify default booting method
  RISC-V: Move relocate and few other functions out of __init
  RISC-V: Implement new SBI v0.2 extensions
  RISC-V: Introduce a new config for SBI v0.1
  RISC-V: Add SBI v0.2 extension definitions
  RISC-V: Add basic support for SBI v0.2
  RISC-V: Mark existing SBI as 0.1 SBI.
  riscv: Use macro definition instead of magic number
  riscv: Add support to dump the kernel page tables
  ...
2020-04-09 10:51:30 -07:00
Damien Le Moal
956d705dd2
riscv: Unaligned load/store handling for M_MODE
Add handlers for unaligned load and store traps that may be generated
by applications. Code heavily inspired from the OpenSBI project.
Handling of the unaligned access traps is suitable for applications
compiled with or without compressed instructions and is independent of
the kernel CONFIG_RISCV_ISA_C option value.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-04-03 10:45:33 -07:00
Atish Patra
cfafe26013
RISC-V: Add supported for ordered booting method using HSM
Currently, all harts have to jump Linux in RISC-V. This complicates the
multi-stage boot process as every transient stage also has to ensure all
harts enter to that stage and jump to Linux afterwards. It also obstructs
a clean Kexec implementation.

SBI HSM extension provides alternate solutions where only a single hart
need to boot and enter Linux. The booting hart can bring up secondary
harts one by one afterwards.

Add SBI HSM based cpu_ops that implements an ordered booting method in
RISC-V. This change is also backward compatible with older firmware not
implementing HSM extension. If a latest kernel is used with older
firmware, it will continue to use the default spinning booting method.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-31 11:27:50 -07:00
Zong Li
b42d763a2d
riscv: add macro to get instruction length
Extract the calculation of instruction length for common use.

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-03-26 09:24:49 -07:00
Atish Patra
ccbe80bad5 irqchip/sifive-plic: Enable/Disable external interrupts upon cpu online/offline
Currently, PLIC threshold is only initialized once in the beginning.
However, threshold can be set to disabled if a CPU is marked offline with
CPU hotplug feature. This will not allow to change the irq affinity to a
CPU that just came online.

Add PLIC specific CPU hotplug callbacks and enable the threshold when a CPU
comes online. Take this opportunity to move the external interrupt enable
code from trap init to PLIC driver as well. On cpu offline path, the driver
performs the exact opposite operations i.e. disable the interrupt and
the threshold.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20200302231146.15530-2-atish.patra@wdc.com
2020-03-16 15:48:54 +00:00
Anup Patel
6a1ce99dc4
RISC-V: Don't enable all interrupts in trap_init()
Historically, we have been enabling all interrupts for each
HART in trap_init(). Ideally, we should only enable M-mode
interrupts for M-mode kernel and S-mode interrupts for S-mode
kernel in trap_init().

Currently, we get suprious S-mode interrupts on Kendryte K210
board running M-mode NO-MMU kernel because we are enabling all
interrupts in trap_init(). To fix this, we only enable software
and external interrupt in trap_init(). In future, trap_init()
will only enable software interrupt and PLIC driver will enable
external interrupt using CPU notifiers.

Fixes: a4c3733d32 ("riscv: abstract out CSR names for supervisor vs machine mode")
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Palmer Dabbelt <palmerdabbelt@google.com> [QMEU virt machine with SMP]
[Palmer: Move the Fixes up to a newer commit]
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-18 10:34:04 -08:00
Christoph Hellwig
a4c3733d32 riscv: abstract out CSR names for supervisor vs machine mode
Many of the privileged CSRs exist in a supervisor and machine version
that are used very similarly.  Provide versions of the CSR names and
fields that map to either the S-mode or M-mode variant depending on
a new CONFIG_RISCV_M_MODE kconfig symbol.

Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com>
and Paul Walmsley <paul.walmsley@sifive.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip
[paul.walmsley@sifive.com: updated to apply]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-05 09:20:42 -08:00
Paul Walmsley
f307307992 riscv: for C functions called only from assembly, mark with __visible
Rather than adding prototypes for C functions called only by assembly
code, mark them as __visible.  This avoids adding prototypes that will
never be used by the callers.  Resolves the following sparse warnings:

arch/riscv/kernel/irq.c:27:29: warning: symbol 'do_IRQ' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:151:6: warning: symbol 'do_syscall_trace_enter' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:165:6: warning: symbol 'do_syscall_trace_exit' was not declared. Should it be static?
arch/riscv/kernel/signal.c:295:17: warning: symbol 'do_notify_resume' was not declared. Should it be static?
arch/riscv/kernel/traps.c:92:1: warning: symbol 'do_trap_unknown' was not declared. Should it be static?
arch/riscv/kernel/traps.c:94:1: warning: symbol 'do_trap_insn_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:96:1: warning: symbol 'do_trap_insn_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:98:1: warning: symbol 'do_trap_insn_illegal' was not declared. Should it be static?
arch/riscv/kernel/traps.c💯1: warning: symbol 'do_trap_load_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:102:1: warning: symbol 'do_trap_load_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:104:1: warning: symbol 'do_trap_store_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:106:1: warning: symbol 'do_trap_store_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:108:1: warning: symbol 'do_trap_ecall_u' was not declared. Should it be static?
arch/riscv/kernel/traps.c:110:1: warning: symbol 'do_trap_ecall_s' was not declared. Should it be static?
arch/riscv/kernel/traps.c:112:1: warning: symbol 'do_trap_ecall_m' was not declared. Should it be static?
arch/riscv/kernel/traps.c:124:17: warning: symbol 'do_trap_break' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:136:24: warning: symbol 'smp_callin' was not declared. Should it be static?

Based on a suggestion from Luc Van Oostenryck.

This version includes changes based on feedback from Christoph Hellwig
<hch@lst.de>.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de> # for do_syscall_trace_*
2019-10-28 00:46:02 -07:00
Paul Walmsley
5ed881bc3a riscv: add missing header file includes
sparse identifies several missing prototypes caused by missing
preprocessor include directives:

arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static?
arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static?
arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static?
arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static?
arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static?
arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static?
arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static?
arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static?
arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static?

Fix by including the appropriate header files in the appropriate
source files.

This patch should have no functional impact.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-10-28 00:46:01 -07:00
Christoph Hellwig
e8f44c50df riscv: cleanup do_trap_break
If we always compile the get_break_insn_length inline function we can
remove the ifdefs and let dead code elimination take care of the warn
branch that is now unreadable because the report_bug stub always
returns BUG_TRAP_TYPE_BUG.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-25 16:32:38 -07:00
Vincent Chen
2f01b78641 riscv: remove the switch statement in do_trap_break()
To make the code more straightforward, replace the switch statement
with an if statement.

Suggested-by: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
[paul.walmsley@sifive.com: cleaned up patch description; updated to
 apply]
Link: https://lore.kernel.org/linux-riscv/20190927224711.GI4700@infradead.org/
Link: https://lore.kernel.org/linux-riscv/CABvJ_xiHJSB7P5QekuLRP=LBPzXXghAfuUpPUYb=a_HbnOQ6BA@mail.gmail.com/
Link: https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/VDCU2WOB6KQISREO4V5DTXEI2M7VOV55/
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-10-14 12:30:28 -07:00