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[ Upstream commit a2a4d4a6a0bf5eba66f8b0b32502cc20d82715a0 ]
If the load access fault occures in a leaf function (with
CONFIG_FRAME_POINTER=y), when wrong stack trace will be displayed:
[<ffffffff804853c2>] regmap_mmio_read32le+0xe/0x1c
---[ end trace 0000000000000000 ]---
Registers dump:
ra 0xffffffff80485758 <regmap_mmio_read+36>
sp 0xffffffc80200b9a0
fp 0xffffffc80200b9b0
pc 0xffffffff804853ba <regmap_mmio_read32le+6>
Stack dump:
0xffffffc80200b9a0: 0xffffffc80200b9e0 0xffffffc80200b9e0
0xffffffc80200b9b0: 0xffffffff8116d7e8 0x0000000000000100
0xffffffc80200b9c0: 0xffffffd8055b9400 0xffffffd8055b9400
0xffffffc80200b9d0: 0xffffffc80200b9f0 0xffffffff8047c526
0xffffffc80200b9e0: 0xffffffc80200ba30 0xffffffff8047fe9a
The assembler dump of the function preambula:
add sp,sp,-16
sd s0,8(sp)
add s0,sp,16
In the fist stack frame, where ra is not stored on the stack we can
observe:
0(sp) 8(sp)
.---------------------------------------------.
sp->| frame->fp | frame->ra (saved fp) |
|---------------------------------------------|
fp->| .... | .... |
|---------------------------------------------|
| | |
and in the code check is performed:
if (regs && (regs->epc == pc) && (frame->fp & 0x7))
I see no reason to check frame->fp value at all, because it is can be
uninitialized value on the stack. A better way is to check frame->ra to
be an address on the stack. After the stacktrace shows as expect:
[<ffffffff804853c2>] regmap_mmio_read32le+0xe/0x1c
[<ffffffff80485758>] regmap_mmio_read+0x24/0x52
[<ffffffff8047c526>] _regmap_bus_reg_read+0x1a/0x22
[<ffffffff8047fe9a>] _regmap_read+0x5c/0xea
[<ffffffff80480376>] _regmap_update_bits+0x76/0xc0
...
---[ end trace 0000000000000000 ]---
As pointed by Samuel Holland it is incorrect to remove check of the stackframe
entirely.
Changes since v2 [2]:
- Add accidentally forgotten curly brace
Changes since v1 [1]:
- Instead of just dropping frame->fp check, replace it with validation of
frame->ra, which should be a stack address.
- Move frame pointer validation into the separate function.
[1] https://lore.kernel.org/linux-riscv/20240426072701.6463-1-dev.mbstr@gmail.com/
[2] https://lore.kernel.org/linux-riscv/20240521131314.48895-1-dev.mbstr@gmail.com/
Fixes: f766f77a74f5 ("riscv/stacktrace: Fix stack output without ra on the stack top")
Signed-off-by: Matthew Bystrin <dev.mbstr@gmail.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240521191727.62012-1-dev.mbstr@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d14fa1fcf69db9d070e75f1c4425211fa619dfc8 upstream.
childregs represents the registers which are active for the new thread
in user context. For a kernel thread, childregs->gp is never used since
the kernel gp is not touched by switch_to. For a user mode helper, the
gp value can be observed in user space after execve or possibly by other
means.
[From the email thread]
The /* Kernel thread */ comment is somewhat inaccurate in that it is also used
for user_mode_helper threads, which exec a user process, e.g. /sbin/init or
when /proc/sys/kernel/core_pattern is a pipe. Such threads do not have
PF_KTHREAD set and are valid targets for ptrace etc. even before they exec.
childregs is the *user* context during syscall execution and it is observable
from userspace in at least five ways:
1. kernel_execve does not currently clear integer registers, so the starting
register state for PID 1 and other user processes started by the kernel has
sp = user stack, gp = kernel __global_pointer$, all other integer registers
zeroed by the memset in the patch comment.
This is a bug in its own right, but I'm unwilling to bet that it is the only
way to exploit the issue addressed by this patch.
2. ptrace(PTRACE_GETREGSET): you can PTRACE_ATTACH to a user_mode_helper thread
before it execs, but ptrace requires SIGSTOP to be delivered which can only
happen at user/kernel boundaries.
3. /proc/*/task/*/syscall: this is perfectly happy to read pt_regs for
user_mode_helpers before the exec completes, but gp is not one of the
registers it returns.
4. PERF_SAMPLE_REGS_USER: LOCKDOWN_PERF normally prevents access to kernel
addresses via PERF_SAMPLE_REGS_INTR, but due to this bug kernel addresses
are also exposed via PERF_SAMPLE_REGS_USER which is permitted under
LOCKDOWN_PERF. I have not attempted to write exploit code.
5. Much of the tracing infrastructure allows access to user registers. I have
not attempted to determine which forms of tracing allow access to user
registers without already allowing access to kernel registers.
Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Stefan O'Rear <sorear@fastmail.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240327061258.2370291-1-sorear@fastmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 749b94b08005929bbc636df21a23322733166e35 ]
After unloading a module, we must reset the linear mapping permissions,
see the example below:
Before unloading a module:
0xffffaf809d65d000-0xffffaf809d6dc000 0x000000011d65d000 508K PTE . .. .. D A G . . W R V
0xffffaf809d6dc000-0xffffaf809d6dd000 0x000000011d6dc000 4K PTE . .. .. D A G . . . R V
0xffffaf809d6dd000-0xffffaf809d6e1000 0x000000011d6dd000 16K PTE . .. .. D A G . . W R V
0xffffaf809d6e1000-0xffffaf809d6e7000 0x000000011d6e1000 24K PTE . .. .. D A G . X . R V
After unloading a module:
0xffffaf809d65d000-0xffffaf809d6e1000 0x000000011d65d000 528K PTE . .. .. D A G . . W R V
0xffffaf809d6e1000-0xffffaf809d6e7000 0x000000011d6e1000 24K PTE . .. .. D A G . X W R V
The last mapping is not reset and we end up with WX mappings in the linear
mapping.
So add VM_FLUSH_RESET_PERMS to our module_alloc() definition.
Fixes: 0cff8bff7af8 ("riscv: avoid the PIC offset of static percpu data in module beyond 2G limits")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231213134027.155327-2-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 420370f3ae3d3b883813fd3051a38805160b2b9f ]
Otherwise we fall through to vmalloc_to_page() which panics since the
address does not lie in the vmalloc region.
Fixes: 043cb41a85de ("riscv: introduce interfaces to patch kernel code")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231214091926.203439-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 22e0eb04837a63af111fae35a92f7577676b9bc8 ]
This is a backport of a fix that was done in OpenSBI: ec0559eb315b
("lib: sbi_misaligned_ldst: Fix handling of C.SWSP and C.SDSP").
Unlike C.LWSP/C.LDSP, these encodings can be used with the zero
register, so checking that the rs2 field is non-zero is unnecessary.
Additionally, the previous check was incorrect since it was checking
the immediate field of the instruction instead of the rs2 field.
Fixes: 956d705dd279 ("riscv: Unaligned load/store handling for M_MODE")
Signed-off-by: Clément Léger <cleger@rivosinc.com>
Link: https://lore.kernel.org/r/20231103090223.702340-1-cleger@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8cb22bec142624d21bc85ff96b7bad10b6220e6a upstream.
Instructions can write to x0, so we should simulate these instructions
normally.
Currently, the kernel hangs if an instruction who writes to x0 is
simulated.
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Nam Cao <namcaov@gmail.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230829182500.61875-1-namcaov@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 58b1294dd1d65bb62f08dddbf418f954210c2057 ]
thread.bad_cause is saved in arch_uprobe_pre_xol(), it should be restored
in arch_uprobe_{post,abort}_xol() accordingly, otherwise the save operation
is meaningless, this change is similar with x86 and powerpc.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Fixes: 74784081aac8 ("riscv: Add uprobes supported")
Link: https://lore.kernel.org/r/1682214146-3756-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f1581626071c8e37c58c5e8f0b4126b17172a211 upstream.
early_init_dt_verify() is already called in parse_dtb() and since the dtb
address does not change anymore (it is now in the fixmap region), no need
to reset initial_boot_params by calling early_init_dt_verify() again.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230329081932.79831-3-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org # 5.15.x
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef69d2559fe91f23d27a3d6fd640b5641787d22e upstream.
riscv establishes 2 virtual mappings:
- early_pg_dir maps the kernel which allows to discover the system
memory
- swapper_pg_dir installs the final mapping (linear mapping included)
We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this
mapping was not carried over in swapper_pg_dir. It happens that
early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is
setup otherwise we could allocate reserved memory defined in the dtb.
And this function initializes reserved_mem variable with addresses that
lie in the early_pg_dir dtb mapping: when those addresses are reused
with swapper_pg_dir, this mapping does not exist and then we trap.
The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem()
must be called before swapper_pg_dir is set up otherwise we could
allocate in reserved memory defined in the dtb.
So move the dtb mapping in the fixmap region which is established in
early_pg_dir and handed over to swapper_pg_dir.
This patch had to be backported because:
- the documentation for sv57 is not present here (as sv48/57 are not
present)
- handling of sv48/57 is not needed (as not present)
Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap")
Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup")
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org # 5.15.x
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8d736482749f6d350892ef83a7a11d43cd49981e upstream.
In a NOMMU kernel, sigreturn trampolines are generated on the user
stack by setup_rt_frame. Currently, these trampolines are not instruction
fenced, thus their visibility to ifetch is not guaranteed.
This patch adds a flush_icache_range in setup_rt_frame to fix this
problem.
Signed-off-by: Mathis Salmen <mathis.salmen@matsal.de>
Fixes: 6bd33e1ece52 ("riscv: add nommu support")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230406101130.82304-1-mathis.salmen@matsal.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2a8db5ec4a28a0fce822d10224db9471a44b6925 ]
We're currently using stop_machine() to update ftrace & kprobes, which
means that the thread that takes text_mutex during may not be the same
as the thread that eventually patches the code. This isn't actually a
race because the lock is still held (preventing any other concurrent
accesses) and there is only one thread running during stop_machine(),
but it does trigger a lockdep failure.
This patch just elides the lockdep check during stop_machine.
Fixes: c15ac4fd60d5 ("riscv/ftrace: Add dynamic function tracer support")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230303143754.4005217-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 130aee3fd9981297ff9354e5d5609cd59aafbbea ]
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: 76d2a0493a17 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f2913d006fcdb61719635e093d1b5dd0dafecac7 ]
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>
Stable-dep-of: 130aee3fd998 ("riscv: Avoid enabling interrupts in die()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6724a76cff85ee271bbbff42ac527e4643b2ec52 upstream.
Use a temporary register to reduce the size of detour code from 16 bytes to
8 bytes. The previous implementation is from 'commit afc76b8b8011 ("riscv:
Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")'.
Before the patch:
<func_prolog>:
0: REG_S ra, -SZREG(sp)
4: auipc ra, ?
8: jalr ?(ra)
12: REG_L ra, -SZREG(sp)
(func_boddy)
After the patch:
<func_prolog>:
0: auipc t0, ?
4: jalr t0, ?(t0)
(func_boddy)
This patch not just reduces the size of detour code, but also fixes an
important issue:
An Ftrace callback registered with FTRACE_OPS_FL_IPMODIFY flag can
actually change the instruction pointer, e.g. to "replace" the given
kernel function with a new one, which is needed for livepatching, etc.
In this case, the trampoline (ftrace_regs_caller) would not return to
<func_prolog+12> but would rather jump to the new function. So, "REG_L
ra, -SZREG(sp)" would not run and the original return address would not
be restored. The kernel is likely to hang or crash as a result.
This can be easily demonstrated if one tries to "replace", say,
cmdline_proc_show() with a new function with the same signature using
instruction_pointer_set(&fregs->regs, new_func_addr) in the Ftrace
callback.
Link: https://lore.kernel.org/linux-riscv/20221122075440.1165172-1-suagrfillet@gmail.com/
Link: https://lore.kernel.org/linux-riscv/d7d5730b-ebef-68e5-5046-e763e1ee6164@yadro.com/
Co-developed-by: Song Shuai <suagrfillet@gmail.com>
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Evgenii Shatokhin <e.shatokhin@yadro.com>
Reviewed-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/r/20230112090603.1295340-4-guoren@kernel.org
Cc: stable@vger.kernel.org
Fixes: 10626c32e382 ("riscv/ftrace: Add basic support")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8b3b8fbb4896984b5564789a42240e4b3caddb61 ]
Similarly to commit 022eb8ae8b5e ("ARM: 8938/1: kernel: initialize
broadcast hrtimer based clock event device"), RISC-V needs to initiate
hrtimer based broadcast clock event device before C3STOP can be used.
Otherwise, the introduction of C3STOP for the RISC-V arch timer in
commit 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped
during CPU suspend") leaves us without any broadcast timer registered.
This prevents the kernel from entering oneshot mode, which breaks timer
behaviour, for example clock_nanosleep().
A test app that sleeps each cpu for 6, 5, 4, 3 ms respectively, HZ=250
& C3STOP enabled, the sleep times are rounded up to the next jiffy:
== CPU: 1 == == CPU: 2 == == CPU: 3 == == CPU: 4 ==
Mean: 7.974992 Mean: 7.976534 Mean: 7.962591 Mean: 3.952179
Std Dev: 0.154374 Std Dev: 0.156082 Std Dev: 0.171018 Std Dev: 0.076193
Hi: 9.472000 Hi: 10.495000 Hi: 8.864000 Hi: 4.736000
Lo: 6.087000 Lo: 6.380000 Lo: 4.872000 Lo: 3.403000
Samples: 521 Samples: 521 Samples: 521 Samples: 521
Link: https://lore.kernel.org/linux-riscv/YzYTNQRxLr7Q9JR0@spud/
Fixes: 232ccac1bd9b ("clocksource/drivers/riscv: Events are stopped during CPU suspend")
Suggested-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230103141102.772228-2-apatel@ventanamicro.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9c89bb8e327203bc27e09ebd82d8f61ac2ae8b24 ]
This clean up the error/notification messages in kprobes related code.
Basically this defines 'pr_fmt()' macros for each files and update
the messages which describes
- what happened,
- what is the kernel going to do or not do,
- is the kernel fine,
- what can the user do about it.
Also, if the message is not needed (e.g. the function returns unique
error code, or other error message is already shown.) remove it,
and replace the message with WARN_*() macros if suitable.
Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Stable-dep-of: eb7423273cc9 ("riscv: kprobe: Fixup misaligned load text")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cb80242cc679d6397e77d8a964deeb3ff218d2b5 ]
When running kfence_test, I found some testcases failed like this:
# test_out_of_bounds_read: EXPECTATION FAILED at mm/kfence/kfence_test.c:346
Expected report_matches(&expect) to be true, but is false
not ok 1 - test_out_of_bounds_read
The corresponding call-trace is:
BUG: KFENCE: out-of-bounds read in kunit_try_run_case+0x38/0x84
Out-of-bounds read at 0x(____ptrval____) (32B right of kfence-#10):
kunit_try_run_case+0x38/0x84
kunit_generic_run_threadfn_adapter+0x12/0x1e
kthread+0xc8/0xde
ret_from_exception+0x0/0xc
The kfence_test using the first frame of call trace to check whether the
testcase is succeed or not. Commit 6a00ef449370 ("riscv: eliminate
unreliable __builtin_frame_address(1)") skip first frame for all
case, which results the kfence_test failed. Indeed, we only need to skip
the first frame for case (task==NULL || task==current).
With this patch, the call-trace will be:
BUG: KFENCE: out-of-bounds read in test_out_of_bounds_read+0x88/0x19e
Out-of-bounds read at 0x(____ptrval____) (1B left of kfence-#7):
test_out_of_bounds_read+0x88/0x19e
kunit_try_run_case+0x38/0x84
kunit_generic_run_threadfn_adapter+0x12/0x1e
kthread+0xc8/0xde
ret_from_exception+0x0/0xc
Fixes: 6a00ef449370 ("riscv: eliminate unreliable __builtin_frame_address(1)")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Tested-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20221207025038.1022045-1-liushixin2@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 87f48c7ccc73afc78630530d9af51f458f58cab8 ]
The kernel would panic when probed for an illegal position. eg:
(CONFIG_RISCV_ISA_C=n)
echo 'p:hello kernel_clone+0x16 a0=%a0' >> kprobe_events
echo 1 > events/kprobes/hello/enable
cat trace
Kernel panic - not syncing: stack-protector: Kernel stack
is corrupted in: __do_sys_newfstatat+0xb8/0xb8
CPU: 0 PID: 111 Comm: sh Not tainted
6.2.0-rc1-00027-g2d398fe49a4d #490
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff80007268>] dump_backtrace+0x38/0x48
[<ffffffff80c5e83c>] show_stack+0x50/0x68
[<ffffffff80c6da28>] dump_stack_lvl+0x60/0x84
[<ffffffff80c6da6c>] dump_stack+0x20/0x30
[<ffffffff80c5ecf4>] panic+0x160/0x374
[<ffffffff80c6db94>] generic_handle_arch_irq+0x0/0xa8
[<ffffffff802deeb0>] sys_newstat+0x0/0x30
[<ffffffff800158c0>] sys_clone+0x20/0x30
[<ffffffff800039e8>] ret_from_syscall+0x0/0x4
---[ end Kernel panic - not syncing: stack-protector:
Kernel stack is corrupted in: __do_sys_newfstatat+0xb8/0xb8 ]---
That is because the kprobe's ebreak instruction broke the kernel's
original code. The user should guarantee the correction of the probe
position, but it couldn't make the kernel panic.
This patch adds arch_check_kprobe in arch_prepare_kprobe to prevent an
illegal position (Such as the middle of an instruction).
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/r/20230201040604.3390509-1-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream.
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>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b2d473a6019ef9a54b0156ecdb2e0398c9fa6a24 upstream.
In the compressed instruction extension, c.jr, c.jalr, c.mv, and c.add
is encoded the following way (each instruction is 16b):
---+-+-----------+-----------+--
100 0 rs1[4:0]!=0 00000 10 : c.jr
100 1 rs1[4:0]!=0 00000 10 : c.jalr
100 0 rd[4:0]!=0 rs2[4:0]!=0 10 : c.mv
100 1 rd[4:0]!=0 rs2[4:0]!=0 10 : c.add
The following logic is used to decode c.jr and c.jalr:
insn & 0xf007 == 0x8002 => instruction is an c.jr
insn & 0xf007 == 0x9002 => instruction is an c.jalr
When 0xf007 is used to mask the instruction, c.mv can be incorrectly
decoded as c.jr, and c.add as c.jalr.
Correct the decoding by changing the mask from 0xf007 to 0xf07f.
Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230102160748.1307289-1-bjorn@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5c3022e4a616d800cf5f4c3a981d7992179e44a1 upstream.
The 'retp' is a pointer to the return address on the stack, so we
must pass the current return address pointer as the 'retp'
argument to ftrace_push_return_trace(). Not parent function's
return address on the stack.
Fixes: b785ec129bd9 ("riscv/ftrace: Add HAVE_FUNCTION_GRAPH_RET_ADDR_PTR support")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20221109064937.3643993-2-guoren@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b003b3b77d65133a0011ae3b7b255347438c12f6 ]
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: 31da94c25aea ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b17d19a5314a37f7197afd1a0200affd21a7227d ]
If a crash happens on cpu3 and all interrupts are binding on cpu0, the
bad irq routing will cause a crash kernel which can't receive any irq.
Because crash kernel won't clean up all harts' PLIC enable bits in
enable registers. This patch is similar to 9141a003a491 ("ARM: 7316/1:
kexec: EOI active and mask all interrupts in kexec crash path") and
78fd584cdec0 ("arm64: kdump: implement machine_crash_shutdown()"), and
PowerPC also has the same mechanism.
Fixes: fba8a8674f68 ("RISC-V: Add kexec support")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Cc: Nick Kossifidis <mick@ics.forth.gr>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20221020141603.2856206-2-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7e1864332fbc1b993659eab7974da9fe8bf8c128 ]
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: 31da94c25aea ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6fdd5d2f8c2f54b7fad4ff4df2a19542aeaf6102 upstream.
64-bit RISC-V kernels have the kernel image mapped separately to alias
the linear map. The linear map and the kernel image map are documented
as "direct mapping" and "kernel" respectively in [1].
At image load time, the linear map corresponding to the kernel image
is set to PAGE_READ permission, and the kernel image map is set to
PAGE_READ|PAGE_EXEC.
When the initmem is freed, the pages in the linear map should be
restored to PAGE_READ|PAGE_WRITE, whereas the corresponding pages in
the kernel image map should be restored to PAGE_READ, by removing the
PAGE_EXEC permission.
This is not the case. For 64-bit kernels, only the linear map is
restored to its proper page permissions at initmem free, and not the
kernel image map.
In practise this results in that the kernel can potentially jump to
dead __init code, and start executing invalid instructions, without
getting an exception.
Restore the freed initmem properly, by setting both the kernel image
map to the correct permissions.
[1] Documentation/riscv/vm-layout.rst
Fixes: e5c35fa04019 ("riscv: Map the kernel with correct permissions the first time")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Tested-by: Alexandre Ghiti <alex@ghiti.fr>
Link: https://lore.kernel.org/r/20221115090641.258476-1-bjorn@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 74f6bb55c834da6d4bac24f44868202743189b2b upstream.
lkp reported a build error, I tried the config and can reproduce
build error as below:
VDSOLD arch/riscv/kernel/vdso/vdso.so.dbg
ld.lld: error: section .note file range overlaps with .text
>>> .note range is [0x7C8, 0x803]
>>> .text range is [0x800, 0x1993]
ld.lld: error: section .text file range overlaps with .dynamic
>>> .text range is [0x800, 0x1993]
>>> .dynamic range is [0x808, 0x937]
ld.lld: error: section .note virtual address range overlaps with .text
>>> .note range is [0x7C8, 0x803]
>>> .text range is [0x800, 0x1993]
Fix it by setting DISABLE_BRANCH_PROFILING which will disable branch
tracing for vdso, thus avoid useless _ftrace_annotated_branch section
and _ftrace_branch section. Although we can also fix it by removing
the hardcoded .text begin address, but I think that's another story
and should be put into another patch.
Link: https://lore.kernel.org/lkml/202210122123.Cc4FPShJ-lkp@intel.com/#r
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20221102170254.1925-1-jszhang@kernel.org
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 <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fcae44fd36d052e956e69a64642fc03820968d78 ]
Recently, ld.lld moved from '--undefined-version' to
'--no-undefined-version' as the default, which breaks the compat vDSO
build:
ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_gettimeofday' failed: symbol not defined
ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_gettime' failed: symbol not defined
ld.lld: error: version script assignment of 'LINUX_4.15' to symbol '__vdso_clock_getres' failed: symbol not defined
These symbols are not present in the compat vDSO or the regular vDSO for
32-bit but they are unconditionally included in the version section of
the linker script, which is prohibited with '--no-undefined-version'.
Fix this issue by only including the symbols that are actually exported
in the version section of the linker script.
Link: https://github.com/ClangBuiltLinux/linux/issues/1756
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221108171324.3377226-1-nathan@kernel.org/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50e63dd8ed92045eb70a72d7ec725488320fb68b ]
Currently, RISC-V sets up reserved memory using the "early" copy of the
device tree. As a result, when trying to get a reserved memory region
using of_reserved_mem_lookup(), the pointer to reserved memory regions
is using the early, pre-virtual-memory address which causes a kernel
panic when trying to use the buffer's name:
Unable to handle kernel paging request at virtual address 00000000401c31ac
Oops [#1]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc1-00001-g0d9d6953d834 #1
Hardware name: Microchip PolarFire-SoC Icicle Kit (DT)
epc : string+0x4a/0xea
ra : vsnprintf+0x1e4/0x336
epc : ffffffff80335ea0 ra : ffffffff80338936 sp : ffffffff81203be0
gp : ffffffff812e0a98 tp : ffffffff8120de40 t0 : 0000000000000000
t1 : ffffffff81203e28 t2 : 7265736572203a46 s0 : ffffffff81203c20
s1 : ffffffff81203e28 a0 : ffffffff81203d22 a1 : 0000000000000000
a2 : ffffffff81203d08 a3 : 0000000081203d21 a4 : ffffffffffffffff
a5 : 00000000401c31ac a6 : ffff0a00ffffff04 a7 : ffffffffffffffff
s2 : ffffffff81203d08 s3 : ffffffff81203d00 s4 : 0000000000000008
s5 : ffffffff000000ff s6 : 0000000000ffffff s7 : 00000000ffffff00
s8 : ffffffff80d9821a s9 : ffffffff81203d22 s10: 0000000000000002
s11: ffffffff80d9821c t3 : ffffffff812f3617 t4 : ffffffff812f3617
t5 : ffffffff812f3618 t6 : ffffffff81203d08
status: 0000000200000100 badaddr: 00000000401c31ac cause: 000000000000000d
[<ffffffff80338936>] vsnprintf+0x1e4/0x336
[<ffffffff80055ae2>] vprintk_store+0xf6/0x344
[<ffffffff80055d86>] vprintk_emit+0x56/0x192
[<ffffffff80055ed8>] vprintk_default+0x16/0x1e
[<ffffffff800563d2>] vprintk+0x72/0x80
[<ffffffff806813b2>] _printk+0x36/0x50
[<ffffffff8068af48>] print_reserved_mem+0x1c/0x24
[<ffffffff808057ec>] paging_init+0x528/0x5bc
[<ffffffff808031ae>] setup_arch+0xd0/0x592
[<ffffffff8080070e>] start_kernel+0x82/0x73c
early_init_fdt_scan_reserved_mem() takes no arguments as it operates on
initial_boot_params, which is populated by early_init_dt_verify(). On
RISC-V, early_init_dt_verify() is called twice. Once, directly, in
setup_arch() if CONFIG_BUILTIN_DTB is not enabled and once indirectly,
very early in the boot process, by parse_dtb() when it calls
early_init_dt_scan_nodes().
This first call uses dtb_early_va to set initial_boot_params, which is
not usable later in the boot process when
early_init_fdt_scan_reserved_mem() is called. On arm64 for example, the
corresponding call to early_init_dt_scan_nodes() uses fixmap addresses
and doesn't suffer the same fate.
Move early_init_fdt_scan_reserved_mem() further along the boot sequence,
after the direct call to early_init_dt_verify() in setup_arch() so that
the names use the correct virtual memory addresses. The above supposed
that CONFIG_BUILTIN_DTB was not set, but should work equally in the case
where it is - unflatted_and_copy_device_tree() also updates
initial_boot_params.
Reported-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Reported-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/linux-riscv/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/
Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/r/20221107151524.3941467-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50f4dd657a0fcf90aa8da8dc2794a8100ff4c37c ]
Even after commit 89fd4a1df829 ("riscv: jump_label: mark arguments as
const to satisfy asm constraints"), building with CC_OPTIMIZE_FOR_SIZE
+ LLVM=1 can reproduce below build error:
CC arch/riscv/kernel/vdso/vgettimeofday.o
In file included from <built-in>:4:
In file included from lib/vdso/gettimeofday.c:5:
In file included from include/vdso/datapage.h:17:
In file included from include/vdso/processor.h:10:
In file included from arch/riscv/include/asm/vdso/processor.h:7:
In file included from include/linux/jump_label.h:112:
arch/riscv/include/asm/jump_label.h:42:3: error:
invalid operand for inline asm constraint 'i'
" .option push \n\t"
^
1 error generated.
I think the problem is when "-Os" is passed as CFLAGS, it's removed by
"CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os" which is
introduced in commit e05d57dcb8c7 ("riscv: Fixup __vdso_gettimeofday
broke dynamic ftrace"), thus no optimization at all for vgettimeofday.c
arm64 does remove "-Os" as well, but it forces "-O2" after removing
"-Os".
I compared the generated vgettimeofday.o with "-O2" and "-Os",
I think no big performance difference. So let's tell the kbuild not
to remove "-Os" rather than follow arm64 style.
vdso related performance can be improved a lot when building kernel with
CC_OPTIMIZE_FOR_SIZE after this commit, ("-Os" VS no optimization)
Fixes: e05d57dcb8c7 ("riscv: Fixup __vdso_gettimeofday broke dynamic ftrace")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221031182943.2453-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6510c78490c490a6636e48b61eeaa6fb65981f4b ]
thread_struct's s[12] may contain random kernel memory content, which
may be finally leaked to userspace. This is a security hole. Fix it
by clearing the s[12] array in thread_struct when fork.
As for kthread case, it's better to clear the s[12] array as well.
Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20221029113450.4027-1-jszhang@kernel.org
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/CAJF2gTSdVyAaM12T%2B7kXAdRPGS4VyuO08X1c7paE-n4Fr8OtRA@mail.gmail.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 10f6913c548b32ecb73801a16b120e761c6957ea upstream.
When CONFIG_CMDLINE_FORCE is enabled, cmdline provided by
CONFIG_CMDLINE are always used. This allows CONFIG_CMDLINE to be
used regardless of the result of device tree scanning.
This especially fixes the case where a device tree without the
chosen node is supplied to the kernel. In such cases,
early_init_dt_scan would return true. But inside
early_init_dt_scan_chosen, the cmdline won't be updated as there
is no chosen node in the device tree. As a result, CONFIG_CMDLINE
is not copied into boot_command_line even if CONFIG_CMDLINE_FORCE
is enabled. This commit allows properly update boot_command_line
in this situation.
Fixes: 8fd6e05c7463 ("arch: riscv: support kernel command line forcing when no DTB passed")
Signed-off-by: Wenting Zhang <zephray@outlook.com>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/PSBPR04MB399135DFC54928AB958D0638B1829@PSBPR04MB3991.apcprd04.prod.outlook.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9e2e6042a7ec6504fe8e366717afa2f40cf16488 upstream.
Commit 2139619bcad7 ("riscv: mmap with PROT_WRITE but no PROT_READ is
invalid") made mmap() return EINVAL if PROT_WRITE was set wihtout
PROT_READ with the justification that a write-only PTE is considered a
reserved PTE permission bit pattern in the privileged spec. This check
is unnecessary since we let VM_WRITE imply VM_READ on RISC-V, and it is
inconsistent with other architectures that don't support write-only PTEs,
creating a potential software portability issue. Just remove the check
altogether and let PROT_WRITE imply PROT_READ as is the case on other
architectures.
Note that this also allows PROT_WRITE|PROT_EXEC mappings which were
disallowed prior to the aforementioned commit; PROT_READ is implied in
such mappings as well.
Fixes: 2139619bcad7 ("riscv: mmap with PROT_WRITE but no PROT_READ is invalid")
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Andrew Bresticker <abrestic@rivosinc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220915193702.2201018-3-abrestic@rivosinc.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fbd92809997a391f28075f1c8b5ee314c225557c upstream.
RISC-V has no sane defaults to fall back on where there is no cpu-map
in the devicetree.
Without sane defaults, the package, core and thread IDs are all set to
-1. This causes user-visible inaccuracies for tools like hwloc/lstopo
which rely on the sysfs cpu topology files to detect a system's
topology.
On a PolarFire SoC, which should have 4 harts with a thread each,
lstopo currently reports:
Machine (793MB total)
Package L#0
NUMANode L#0 (P#0 793MB)
Core L#0
L1d L#0 (32KB) + L1i L#0 (32KB) + PU L#0 (P#0)
L1d L#1 (32KB) + L1i L#1 (32KB) + PU L#1 (P#1)
L1d L#2 (32KB) + L1i L#2 (32KB) + PU L#2 (P#2)
L1d L#3 (32KB) + L1i L#3 (32KB) + PU L#3 (P#3)
Adding calls to store_cpu_topology() in {boot,smp} hart bringup code
results in the correct topolgy being reported:
Machine (793MB total)
Package L#0
NUMANode L#0 (P#0 793MB)
L1d L#0 (32KB) + L1i L#0 (32KB) + Core L#0 + PU L#0 (P#0)
L1d L#1 (32KB) + L1i L#1 (32KB) + Core L#1 + PU L#1 (P#1)
L1d L#2 (32KB) + L1i L#2 (32KB) + Core L#2 + PU L#2 (P#2)
L1d L#3 (32KB) + L1i L#3 (32KB) + Core L#3 + PU L#3 (P#3)
CC: stable@vger.kernel.org # 456797da792f: arm64: topology: move store_cpu_topology() to shared code
Fixes: 03f11f03dbfe ("RISC-V: Parse cpu topology during boot.")
Reported-by: Brice Goglin <Brice.Goglin@inria.fr>
Link: https://github.com/open-mpi/hwloc/issues/536
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 762df359aa5849e010ef04c3ed79d57588ce17d9 upstream.
riscv has an equivalent of arm bug fixed by 653d48b22166 ("arm: fix
really nasty sigreturn bug"); if signal gets caught by an interrupt that
hits when we have the right value in a0 (-513), *and* another signal
gets delivered upon sigreturn() (e.g. included into the blocked mask for
the first signal and posted while the handler had been running), the
syscall restart logics will see regs->cause equal to EXC_SYSCALL (we are
in a syscall, after all) and a0 already restored to its original value
(-513, which happens to be -ERESTARTNOINTR) and assume that we need to
apply the usual syscall restart logics.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/YxJEiSq%2FCGaL6Gm9@ZenIV/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d951b20b9def73dcc39a5379831525d0d2a537e9 upstream.
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: 31da94c25aea ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3f1901110a89b0e2e13adb2ac8d1a7102879ea98 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2139619bcad7ac44cc8f6f749089120594056613 ]
As mentioned in Table 4.5 in RISC-V spec Volume 2 Section 4.3, write
but not read is "Reserved for future use.". For now, they are not valid.
In the current code, -wx is marked as invalid, but -w- is not marked
as invalid.
This patch refines that judgment.
Reported-by: xctan <xc-tan@outlook.com>
Co-developed-by: dram <dramforever@live.com>
Signed-off-by: dram <dramforever@live.com>
Co-developed-by: Ruizhe Pan <c141028@gmail.com>
Signed-off-by: Ruizhe Pan <c141028@gmail.com>
Signed-off-by: Celeste Liu <coelacanthus@outlook.com>
Link: https://lore.kernel.org/r/PH7PR14MB559464DBDD310E755F5B21E8CEDC9@PH7PR14MB5594.namprd14.prod.outlook.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3dbe5829408bc1586f75b4667ef60e5aab0209c7 upstream.
In riscv the process of uprobe going to clear spie before exec
the origin insn,and set spie after that.But When access the page
which origin insn has been placed a page fault may happen and
irq was disabled in arch_uprobe_pre_xol function,It cause a WARN
as follows.
There is no need to clear/set spie in arch_uprobe_pre/post/abort_xol.
We can just remove it.
[ 31.684157] BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1488
[ 31.684677] in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 76, name: work
[ 31.684929] preempt_count: 0, expected: 0
[ 31.685969] CPU: 2 PID: 76 Comm: work Tainted: G
[ 31.686542] Hardware name: riscv-virtio,qemu (DT)
[ 31.686797] Call Trace:
[ 31.687053] [<ffffffff80006442>] dump_backtrace+0x30/0x38
[ 31.687699] [<ffffffff80812118>] show_stack+0x40/0x4c
[ 31.688141] [<ffffffff8081817a>] dump_stack_lvl+0x44/0x5c
[ 31.688396] [<ffffffff808181aa>] dump_stack+0x18/0x20
[ 31.688653] [<ffffffff8003e454>] __might_resched+0x114/0x122
[ 31.688948] [<ffffffff8003e4b2>] __might_sleep+0x50/0x7a
[ 31.689435] [<ffffffff80822676>] down_read+0x30/0x130
[ 31.689728] [<ffffffff8000b650>] do_page_fault+0x166/x446
[ 31.689997] [<ffffffff80003c0c>] ret_from_exception+0x0/0xc
Fixes: 74784081aac8 ("riscv: Add uprobes supported")
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220721065820.245755-1-zouyipeng@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f2928e224d85e7cc139009ab17cefdfec2df5d11 upstream.
Set pm_power_off to NULL like on all other architectures, check if it
is set in machine_halt() and machine_power_off() and fallback to
default_power_off if no other power driver got registered.
This brings riscv architecture inline with all other architectures,
and allows to reuse exiting power drivers unmodified.
Kernels without legacy SBI v0.1 extensions (CONFIG_RISCV_SBI_V01 is
not set), do not set pm_power_off to sbi_shutdown(). There is no
support for SBI v0.3 system reset extension either. This prevents
using gpio_poweroff on SiFive HiFive Unmatched.
Tested on SiFive HiFive unmatched, with a dtb specifying gpio-poweroff
node and kernel complied without CONFIG_RISCV_SBI_V01.
BugLink: https://bugs.launchpad.net/bugs/1942806
Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Ron Economos <w6rz@comcast.net>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b7fb4d78a6ade6026d9e5cf438c2a46ab962e032 ]
The pointer to buffer loading kernel binaries is in kernel space for
kexec_fil mode, When copy_from_user copies data from pointer to a block
of memory, it checkes that the pointer is in the user space range, on
RISCV-V that is:
static inline bool __access_ok(unsigned long addr, unsigned long size)
{
return size <= TASK_SIZE && addr <= TASK_SIZE - size;
}
and TASK_SIZE is 0x4000000000 for 64-bits, which now causes
copy_from_user to reject the access of the field 'buf' of struct
kexec_segment that is in range [CONFIG_PAGE_OFFSET - VMALLOC_SIZE,
CONFIG_PAGE_OFFSET), is invalid user space pointer.
This patch fixes this issue by skipping access_ok(), use mempcy() instead.
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Link: https://lore.kernel.org/r/20220408100914.150110-3-lizhengyu3@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 630f972d76d6460235e84e1aa034ee06f9c8c3a9 ]
If EFI pages are marked as read-only,
we should remove the _PAGE_WRITE flag.
The current code overwrites an unused value.
Fixes: b91540d52a08b ("RISC-V: Add EFI runtime services")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Link: https://lore.kernel.org/r/20220528014132.91052-1-heinrich.schuchardt@canonical.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 35d33c76d68dfacc330a8eb477b51cc647c5a847 upstream.
Because of the stack canary feature that reads from the current task
structure the stack canary value, the thread pointer register "tp" must
be set before calling any C function from head.S: by chance, setup_vm
and all the functions that it calls does not seem to be part of the
functions where the canary check is done, but in the following commits,
some functions will.
Fixes: f2c9699f65557a31 ("riscv: Add STACKPROTECTOR supported")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
