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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>
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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>
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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>
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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>
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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: c2c81bb2f691 ("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>
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BUG_ON() uses unlikely in if(), which can be optimized at compile time.
Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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: c22b0bcb1dd02 ("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>
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Now we can set ARCH_HAS_STRICT_MODULE_RWX for MMU riscv platforms, this
is good from security perspective.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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>
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We allocate Non-executable pages, then call bpf_jit_binary_lock_ro()
to enable executable permission after mapping them read-only. This is
to prepare for STRICT_MODULE_RWX in following patch.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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We will drop the executable permissions of the code pages from the
mapping at allocation time soon. Move bpf_jit_alloc_exec() and
bpf_jit_free_exec() to bpf_jit_core.c so that they can be shared by
both RV64I and RV32I.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Luke Nelson <luke.r.nels@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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>
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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>
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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>
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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>
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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>
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This is a preparatory patch for sv48 support that will introduce
dynamic PAGE_OFFSET.
Dynamic PAGE_OFFSET implies that all zones (vmalloc, vmemmap, fixaddr...)
whose addresses depend on PAGE_OFFSET become dynamic and can't be used
to statically initialize the array used by ptdump to identify the
different zones of the vm layout.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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>
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clang prior to 13.0.0 does not support -fpatchable-function-entry for
RISC-V.
clang: error: unsupported option '-fpatchable-function-entry=8' for target 'riscv64-unknown-linux-gnu'
To avoid this error, only select HAVE_DYNAMIC_FTRACE when this option is
not available.
Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")
Link: https://github.com/ClangBuiltLinux/linux/issues/1268
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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>
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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 85602bea297f ("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 c2c81bb2f691 ("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
fe00e50b2db8 ("ARM: 8858/1: vdso: use $(LD) instead of $(CC) to link VDSO")
691efbedc60d ("arm64: vdso: use $(LD) instead of $(CC) to link VDSO")
2ff906994b6c ("MIPS: VDSO: Use $(LD) instead of $(CC) to link VDSO")
2b2a25845d53 ("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>
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For certain SiFive CPUs, "sfence.vma addr" cannot exactly flush addr
from TLB in the particular cases. The details could be found here:
https://sifive.cdn.prismic.io/sifive/167a1a56-03f4-4615-a79e-b2a86153148f_FU740_errata_20210205.pdf
In order to ensure the functionality, this patch uses the Alternative
scheme to replace all "sfence.vma addr" with "sfence.vma" at runtime.
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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>
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Add required ports of the Alternative scheme for SiFive.
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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>
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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>
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When KASAN vmalloc region is populated, there is no userspace process and
the page table in use is swapper_pg_dir, so there is no need to read
SATP. Then we can use the same scheme used by kasan_populate_p*d
functions to go through the page table, which harmonizes the code.
In addition, make use of set_pgd that goes through all unused page table
levels, contrary to p*d_populate functions, which makes this function work
whatever the number of page table levels.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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>
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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>
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FORTIFY_SOURCE could detect various overflows at compile and run time.
ARCH_HAS_FORTIFY_SOURCE means that the architecture can be built and
run with CONFIG_FORTIFY_SOURCE. Select it in RISCV.
See more about this feature from commit 6974f0c4555e
("include/linux/string.h: add the option of fortified string.h functions").
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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The riscv [rv32_]defconfig enabled CONFIG_MEMTEST,
but memtest feature is not supported in RISCV.
Add early_memtest() to support for memtest.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull more RISC-V updates from Palmer Dabbelt:
"A pair of patches that slipped through the cracks:
- enable CPU hotplug in the defconfigs
- some cleanups to setup_bootmem
There's also a single fix for some randconfig build failures:
- make NUMA depend on SMP"
* tag 'riscv-for-linus-5.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
riscv: Cleanup setup_bootmem()
RISC-V: Enable CPU Hotplug in defconfigs
RISC-V: Make NUMA depend on SMP
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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
...
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After the following patches,
commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
commit 1bd14a66ee52 ("RISC-V: Remove any memblock representing unusable memory area")
commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()")
some logic is useless, kill the mem_start/start/end and unneeded code.
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>
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The CPU hotplug support has been tested on QEMU, Spike, and SiFive
Unleashed so let's enable it by default in RV32 and RV64 defconfigs.
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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In theory these are orthogonal, but in practice all NUMA systems are
SMP. NUMA && !SMP doesn't build, everyone else is coupling them, and I
don't really see any value in supporting that configuration.
Fixes: 4f0e8eef772e ("riscv: Add numa support for riscv64 platform")
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Atish Patra <atishp@atishpatra.org>
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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
...
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The kasan functions that populates the shadow regions used to allocate them
page by page and did not take advantage of hugepages, so fix this by
trying to allocate hugepages of 1GB and fallback to 2MB hugepages or 4K
pages in case it fails.
This reduces the page table memory consumption and improves TLB usage,
as shown below:
Before this patch:
---[ Kasan shadow start ]---
0xffffffc000000000-0xffffffc400000000 0x00000000818ef000 16G PTE . A . . . . R V
0xffffffc400000000-0xffffffc447fc0000 0x00000002b7f4f000 1179392K PTE D A . . . W R V
0xffffffc480000000-0xffffffc800000000 0x00000000818ef000 14G PTE . A . . . . R V
---[ Kasan shadow end ]---
After this patch:
---[ Kasan shadow start ]---
0xffffffc000000000-0xffffffc400000000 0x00000000818ef000 16G PTE . A . . . . R V
0xffffffc400000000-0xffffffc440000000 0x0000000240000000 1G PGD D A . . . W R V
0xffffffc440000000-0xffffffc447e00000 0x00000002b7e00000 126M PMD D A . . . W R V
0xffffffc447e00000-0xffffffc447fc0000 0x00000002b818f000 1792K PTE D A . . . W R V
0xffffffc480000000-0xffffffc800000000 0x00000000818ef000 14G PTE . A . . . . R V
---[ Kasan shadow end ]---
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Current population code populates a whole page table without taking care
of what could have been already allocated and without taking into account
possible index in page table, assuming the virtual address to map is always
aligned on the page table size, which, for example, won't be the case when
the kernel will get pushed to the end of the address space.
Address those problems by rewriting the kasan population function,
splitting it into subfunctions for each different page table level.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Instead of hardcoding memory initialization to 0, use KASAN_SHADOW_INIT.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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There is no functional change here, only improvement in code readability
by adding comments to explain where the kasan constants come from and by
replacing hardcoded numerical constant by the corresponding define.
Note that the comments come from arm64.
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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At early boot stage, we have a whole PGDIR to map the kernel, so there
is no need to restrict the early mapping size to 128MB. Removing this
define also allows us to simplify some compile time logic.
This fixes large kernel mappings with a size greater than 128MB, as it
is the case for syzbot kernels whose size was just ~130MB.
Note that on rv64, for now, we are then limited to PGDIR size for early
mapping as we can't use PGD mappings (see [1]). That should be enough
given the relative small size of syzbot kernels compared to PGDIR_SIZE
which is 1GB.
[1] https://lore.kernel.org/lkml/20200603153608.30056-1-alex@ghiti.fr/
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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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: ad5d1122b82f ("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>
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max_low_pfn and min_low_pfn are declared in linux/memblock.h,
and it also is included in arch/riscv/mm/init.c, drop unnecessary
declaration.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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The nommu_k210_defconfig default configuration allows booting a Canaan
Kendryte K210 SoC based boards using an embedded intramfs cpio file.
Modifying this configuration to enable support for the board SD card is
not trivial for all users. To help beginners getting started with these
boards, add the nommu_k210_sdcard_defconfig default configuration file
to set all configuration options necessary to use the board mmc-spi sd
card for the root file system.
This new configuration adds support for the block layer, the mmc-spi
driver and modifies the boot options to specify the rootfs device as
mmcblk0p1 (first partition of the sd card block device). The ext2 file
system is selected by default to encourage its use as that results in
only about 4KB added to the kernel image size. As ext2 does not have
journaling, the boot options specify a read-only mount of the file
system. Similarly to the smaller nommu_k210_defconfig, this new default
configuration disables virtual terminal support to reduce the kernel
image size.
The default device tree selected is unchanged, specifying the simple
"k210_generic" device tree file. The user must change this setting to
specify the device tree suitable for the board being used
(sipeed_maix_bit, sipeed_maix_dock, sipeed_maix_go, sipeed_maixduino or
canaan_kd233).
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Update the Kendryte k210 nommu default configuration file
(nommu_k210_defconfig) to include device drivers for reset, reboot,
I2C, SPI, gpio and LEDs support. Virtual Terminal support is also
disabled as no terminal devices are supported and enabled. Disabling
CONFIG_VT (removing the no longer needed override for
CONFIG_VGA_CONSOLE) reduces the kernel image size by about 65 KB.
This default configuration remains suitable for a system using an
initramfs cpio file linked into the kernel image.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Add the device tree canaan_kd233.dts for the Canaan Kendryte KD233
development board. This device tree enables LEDs, some gpios and
spi/mmc SD card device. The WS2812B RGB LED and the 10 positions rotary
dip switch present on the board are left undefined.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
[Palmer: Remove undocumented microphone entry, along with the use.]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Add the device tree sipeed_maixduino.dts for the SiPeed MAIXDUINO board.
This device tree enables LEDs and spi/mmc SD card device. Additionally,
gpios and i2c are also enabled and mapped to the board header pins as
indicated on the board itself.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
[Palmer: Remove undocumented microphone entry, along with the use.]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Add the device tree sipeed_maix_go.dts for the SiPeed MAIX GO board.
This device tree enables buttons, LEDs, gpio, i2c and spi/mmc SD card
devices.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
[Palmer: Remove undocumented microphone entry, along with the use.]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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Add the device tree sipeed_maix_dock.dts for the SiPeed MAIX DOCK m1
and m1w boards. This device tree enables LEDs, gpio, i2c and spi/mmc
SD card devices.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
[Palmer: Remove undocumented microphone entry, along with the use.]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
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