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[ Upstream commit 994af1825a2aa286f4903ff64a1c7378b52defe6 ]
On riscv32, it is possible for the last page in virtual address space
(0xfffff000) to be allocated. This page overlaps with PTR_ERR, so that
shouldn't happen.
There is already some code to ensure memblock won't allocate the last page.
However, buddy allocator is left unchecked.
Fix this by reserving physical memory that would be mapped at virtual
addresses greater than 0xfffff000.
Reported-by: Björn Töpel <bjorn@kernel.org>
Closes: https://lore.kernel.org/linux-riscv/878r1ibpdn.fsf@all.your.base.are.belong.to.us
Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code")
Signed-off-by: Nam Cao <namcao@linutronix.de>
Cc: <stable@vger.kernel.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Link: https://lore.kernel.org/r/20240425115201.3044202-1-namcao@linutronix.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 07aabe8fb6d1ac3163cc74c856521f2ee746270b ]
Try our best to replace the conditional compilation using
"#ifdef CONFIG_64BIT" by a check for "IS_ENABLED(CONFIG_64BIT)", to
simplify the code and to increase compile coverage.
Now we can also remove the __maybe_unused used in max_mapped_addr
declaration.
We also remove the BUG_ON check of mapping the last 4K bytes of the
addressable memory since this is always true for every kernel actually.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Stable-dep-of: 994af1825a2a ("riscv: fix overlap of allocated page and PTR_ERR")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 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>
[ Upstream commit 6065e736f82c817c9a597a31ee67f0ce4628e948 ]
On NOMMU, userspace memory can come from anywhere in physical RAM. The
current definition of TASK_SIZE is wrong if any RAM exists above 4G,
causing spurious failures in the userspace access routines.
Fixes: 6bd33e1ece52 ("riscv: add nommu support")
Fixes: c3f896dcf1e4 ("mm: switch the test_vmalloc module to use __vmalloc_node")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Bo Gan <ganboing@gmail.com>
Link: https://lore.kernel.org/r/20240227003630.3634533-2-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ac88ff6b9d7dea9f0907c86bdae204dde7d5c0e6 ]
When below config items are set, compiler complained:
--------------------
CONFIG_CRASH_CORE=y
CONFIG_KEXEC_CORE=y
CONFIG_CRASH_DUMP=y
......
-----------------------
-------------------------------------------------------------------
arch/riscv/kernel/crash_core.c: In function 'arch_crash_save_vmcoreinfo':
arch/riscv/kernel/crash_core.c:11:58: warning: format '%lx' expects argument of type 'long unsigned int', but argument 2 has type 'int' [-Wformat=]
11 | vmcoreinfo_append_str("NUMBER(VMALLOC_START)=0x%lx\n", VMALLOC_START);
| ~~^
| |
| long unsigned int
| %x
----------------------------------------------------------------------
This is because on riscv macro VMALLOC_START has different type when
CONFIG_MMU is set or unset.
arch/riscv/include/asm/pgtable.h:
--------------------------------------------------
Changing it to _AC(0, UL) in case CONFIG_MMU=n can fix the warning.
Link: https://lkml.kernel.org/r/ZW7OsX4zQRA3mO4+@MiWiFi-R3L-srv
Signed-off-by: Baoquan He <bhe@redhat.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Cc: Eric DeVolder <eric_devolder@yahoo.com>
Cc: Ignat Korchagin <ignat@cloudflare.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: 6065e736f82c ("riscv: Fix TASK_SIZE on 64-bit NOMMU")
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>
commit d080a08b06b6266cc3e0e86c5acfd80db937cb6b upstream.
These macros did not initialize __kr_err, so they could fail even if
the access did not fault.
Cc: stable@vger.kernel.org
Fixes: d464118cdc41 ("riscv: implement __get_kernel_nofault and __put_user_nofault")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240312022030.320789-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a11dd49dcb9376776193e15641f84fcc1e5980c9 ]
Offset vmemmap so that the first page of vmemmap will be mapped
to the first page of physical memory in order to ensure that
vmemmap’s bounds will be respected during
pfn_to_page()/page_to_pfn() operations.
The conversion macros will produce correct SV39/48/57 addresses
for every possible/valid DRAM_BASE inside the physical memory limits.
v2:Address Alex's comments
Suggested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Dimitris Vlachos <dvlachos@ics.forth.gr>
Reported-by: Dimitris Vlachos <dvlachos@ics.forth.gr>
Closes: https://lore.kernel.org/linux-riscv/20240202135030.42265-1-csd4492@csd.uoc.gr
Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem")
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240229191723.32779-1-dvlachos@ics.forth.gr
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a3775634f6da23f5511d0282d7e792cf606e5f3b ]
The opcode definition for c.jalr is
c.jalr c_rs1_n0 1..0=2 15..13=4 12=1 6..2=0
This means funct4 consisting of bit [15:12] is 1001b, so the value is 0x9.
Fixes: edde5584c7ab ("riscv: Add SW single-step support for KDB")
Reported-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu>
Link: https://lore.kernel.org/r/20221223221332.4127602-2-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 64bac5ea17d527872121adddfee869c7a0618f8f ]
The prototype was hidden in an #ifdef on x86, which causes a warning:
kernel/irq_work.c:72:13: error: no previous prototype for 'arch_irq_work_raise' [-Werror=missing-prototypes]
Some architectures have a working prototype, while others don't.
Fix this by providing it in only one place that is always visible.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.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 2f1b0d3d733169eb11680bfa97c266ae5e757148 ]
The RISC-V architecture does not expose sub-registers, and hold all
32-bit values in a sign-extended format [1] [2]:
| The compiler and calling convention maintain an invariant that all
| 32-bit values are held in a sign-extended format in 64-bit
| registers. Even 32-bit unsigned integers extend bit 31 into bits
| 63 through 32. Consequently, conversion between unsigned and
| signed 32-bit integers is a no-op, as is conversion from a signed
| 32-bit integer to a signed 64-bit integer.
While BPF, on the other hand, exposes sub-registers, and use
zero-extension (similar to arm64/x86).
This has led to some subtle bugs, where a BPF JITted program has not
sign-extended the a0 register (return value in RISC-V land), passed
the return value up the kernel, e.g.:
| int from_bpf(void);
|
| long foo(void)
| {
| return from_bpf();
| }
Here, a0 would be 0xffff_ffff, instead of the expected
0xffff_ffff_ffff_ffff.
Internally, the RISC-V JIT uses a5 as a dedicated register for BPF
return values.
Keep a5 zero-extended, but explicitly sign-extend a0 (which is used
outside BPF land). Now that a0 (RISC-V ABI) and a5 (BPF ABI) differs,
a0 is only moved to a5 for non-BPF native calls (BPF_PSEUDO_CALL).
Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://github.com/riscv/riscv-isa-manual/releases/download/riscv-isa-release-056b6ff-2023-10-02/unpriv-isa-asciidoc.pdf # [2]
Link: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/releases/download/draft-20230929-e5c800e661a53efe3c2678d71a306323b60eb13b/riscv-abi.pdf # [2]
Link: https://lore.kernel.org/bpf/20231004120706.52848-2-bjorn@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0fd1fd0104954380477353aea29c347e85dff16d ]
The current emit_call function is not suitable for kernel function call as
it store return value to bpf R0 register. We can separate it out for common
use. Meanwhile, simplify judgment logic, that is, fixed function address
can use jal or auipc+jalr, while the unfixed can use only auipc+jalr.
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/bpf/20230215135205.1411105-3-pulehui@huaweicloud.com
Stable-dep-of: 2f1b0d3d7331 ("riscv, bpf: Sign-extend return values")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4b05b993900dd3eba0fc83ef5c5ddc7d65d786c6 ]
It was reported that the riscv kernel hangs while executing the test
in [1].
Indeed, the test hangs when trying to write a buffer to a file. The
problem is that the riscv implementation of raw_copy_from_user() does not
return the correct number of bytes not written when an exception happens
and is fixed up, instead it always returns the initial size to copy,
even if some bytes were actually copied.
generic_perform_write() pre-faults the user pages and bails out if nothing
can be written, otherwise it will access the userspace buffer: here the
riscv implementation keeps returning it was not able to copy any byte
though the pre-faulting indicates otherwise. So generic_perform_write()
keeps retrying to access the user memory and ends up in an infinite
loop.
Note that before the commit mentioned in [1] that introduced this
regression, it worked because generic_perform_write() would bail out if
only one byte could not be written.
So fix this by returning the number of bytes effectively not written in
__asm_copy_[to|from]_user() and __clear_user(), as it is expected.
Link: https://lore.kernel.org/linux-riscv/20230309151841.bomov6hq3ybyp42a@debian/ [1]
Fixes: ebcbd75e3962 ("riscv: Fix the bug in memory access fixup code")
Reported-by: Bo YU <tsu.yubo@gmail.com>
Closes: https://lore.kernel.org/linux-riscv/20230309151841.bomov6hq3ybyp42a@debian/#t
Reported-by: Aurelien Jarno <aurelien@aurel32.net>
Closes: https://lore.kernel.org/linux-riscv/ZNOnCakhwIeue3yr@aurel32.net/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Link: https://lore.kernel.org/r/20230811150604.1621784-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4eb2eb1b4c0eb07793c240744843498564a67b83 upstream.
Section 2.1 of the Platform Specification [1] states:
Unless otherwise specified by a given I/O device, I/O devices are on
ordering channel 0 (i.e., they are point-to-point strongly ordered).
which is not sufficient to guarantee that a readX() by a hart completes
before a subsequent delay() on the same hart (cf. memory-barriers.txt,
"Kernel I/O barrier effects").
Set the I(nput) bit in __io_ar() to restore the ordering, align inline
comments.
[1] https://github.com/riscv/riscv-platform-specs
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20230803042738.5937-1-parri.andrea@gmail.com
Fixes: fab957c11efe ("RISC-V: Atomic and Locking Code")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b690e266dae2f85f4dfea21fa6a05e3500a51054 ]
lkp reports below sparse warning when building for RV32:
arch/riscv/mm/init.c:1204:48: sparse: warning: cast truncates bits from
constant value (100000000 becomes 0)
IMO, the reason we didn't see this truncates bug in real world is "0"
means MEMBLOCK_ALLOC_ACCESSIBLE in memblock and there's no RV32 HW
with more than 4GB memory.
Fix it anyway to make sparse happy.
Fixes: decf89f86ecd ("riscv: try to allocate crashkern region from 32bit addressible memory")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306080034.SLiCiOMn-lkp@intel.com/
Link: https://lore.kernel.org/r/20230709171036.1906-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c56fb2aab23505bb7160d06097c8de100b82b851 ]
In order to generate the prologue and epilogue, the BPF JIT needs to
know which registers that are clobbered. Therefore, the during
pre-final passes, the prologue is generated after the body of the
program body-prologue-epilogue. Then, in the final pass, a proper
prologue-body-epilogue JITted image is generated.
This scheme has worked most of the time. However, for some large
programs with many jumps, e.g. the test_kmod.sh BPF selftest with
hardening enabled (blinding constants), this has shown to be
incorrect. For the final pass, when the proper prologue-body-epilogue
is generated, the image has not converged. This will lead to that the
final image will have incorrect jump offsets. The following is an
excerpt from an incorrect image:
| ...
| 3b8: 00c50663 beq a0,a2,3c4 <.text+0x3c4>
| 3bc: 0020e317 auipc t1,0x20e
| 3c0: 49630067 jalr zero,1174(t1) # 20e852 <.text+0x20e852>
| ...
| 20e84c: 8796 c.mv a5,t0
| 20e84e: 6422 c.ldsp s0,8(sp) # Epilogue start
| 20e850: 6141 c.addi16sp sp,16
| 20e852: 853e c.mv a0,a5 # Incorrect jump target
| 20e854: 8082 c.jr ra
The image has shrunk, and the epilogue offset is incorrect in the
final pass.
Correct the problem by always generating proper prologue-body-epilogue
outputs, which means that the first pass will only generate the body
to track what registers that are touched.
Fixes: 2353ecc6f91f ("bpf, riscv: add BPF JIT for RV64G")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230710074131.19596-1-bjorn@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3cb70413041fdf028fa1ba3986fd0c6aec9e3dcb ]
Add support for riscv jit to provide bpf_line_info. We need to
consider the prologue offset in ctx->offset, but unlike x86 and
arm64, ctx->offset of riscv does not provide an extra slot for
the prologue, so here we just calculate the len of prologue and
add it to ctx->offset at the end. Both RV64 and RV32 have been
tested.
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220530092815.1112406-3-pulehui@huawei.com
Stable-dep-of: c56fb2aab235 ("riscv, bpf: Fix inconsistent JIT image generation")
Signed-off-by: Sasha Levin <sashal@kernel.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>
[ Upstream commit 99a670b2069c725a7b50318aa681d9cae8f89325 ]
On riscv qemu platform, when add kprobe event on do_sys_open() to show
filename string arg, it just print fault as follow:
echo 'p:myprobe do_sys_open dfd=$arg1 filename=+0($arg2):string flags=$arg3
mode=$arg4' > kprobe_events
bash-166 [000] ...1. 360.195367: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6
bash-166 [000] ...1. 360.219369: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename=(fault) flags=0x8241 mode=0x1b6
bash-191 [000] ...1. 360.378827: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename=(fault) flags=0x98800 mode=0x0
As riscv do not select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE,
the +0($arg2) addr is processed as a kernel address though it is a
userspace address, cause the above filename=(fault) print. So select
ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE to avoid the issue, after that the
kprobe trace is ok as below:
bash-166 [000] ...1. 96.767641: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6
bash-166 [000] ...1. 96.793751: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename="/dev/null" flags=0x8241 mode=0x1b6
bash-177 [000] ...1. 96.962354: myprobe: (do_sys_open+0x0/0x84)
dfd=0xffffffffffffff9c filename="/sys/kernel/debug/tracing/events/kprobes/"
flags=0x98800 mode=0x0
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Fixes: 0ebeea8ca8a4 ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
Link: https://lore.kernel.org/r/20230504072910.3742842-1-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 33d418da6f476b15e4510e0a590062583f63cd36 ]
commit ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap
region") wrongly moved the #ifndef CONFIG_BUILTIN_DTB surrounding the pa
variable definition in create_fdt_early_page_table(), so move it back to
its right place to quiet the following warning:
../arch/riscv/mm/init.c: In function ‘create_fdt_early_page_table’:
../arch/riscv/mm/init.c:925:12: warning: unused variable ‘pa’ [-Wunused-variable]
925 | uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);
Fixes: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230519131311.391960-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This triggers a -Wdeclaration-after-statement as the code has changed a
bit since upstream. It might be better to hoist the whole block up, but
this is a smaller change so I went with it.
arch/riscv/mm/init.c:755:16: warning: mixing declarations and code is a C99 extension [-Wdeclaration-after-statement]
unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT));
^
1 warning generated.
Fixes: bbf94b042155 ("riscv: Move early dtb mapping into the fixmap region")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202304300429.SXZOA5up-lkp@intel.com/
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a15c90b67a662c75f469822a7f95c7aaa049e28f ]
Currently kernel_page_present() function doesn't support huge page
detection causes the function to mistakenly return false to the
hibernation core.
Add huge page detection to the function to solve the problem.
Fixes: 9e953cda5cdf ("riscv: Introduce huge page support for 32/64bit kernel")
Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com>
Reviewed-by: Ley Foon Tan <leyfoon.tan@starfivetech.com>
Reviewed-by: Mason Huo <mason.huo@starfivetech.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230330064321.1008373-4-jeeheng.sia@starfivetech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e4ef93edd4e0b022529303db1915766ff9de450e upstream.
create_fdt_early_page_table() explicitly uses early_pg_dir for
32-bit fdt mapping and the pgdir parameter is redundant here.
So remove it and its caller.
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Fixes: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230426100009.685435-1-suagrfillet@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1b50f956c8fe9082bdee4a9cfd798149c52f7043 upstream.
We used to access the dtb via its linear mapping address but now that the
dtb early mapping was moved in the fixmap region, we can keep using this
address since it is present in swapper_pg_dir, and remove the dtb
relocation.
Note that the relocation was wrong anyway since early_memremap() is
restricted to 256K whereas the maximum fdt size is 2MB.
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/20230329081932.79831-4-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 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>
commit e89c2e815e76471cb507bd95728bf26da7976430 upstream.
There are two related issues that appear in certain combinations with
clang and GNU binutils.
The first occurs when a version of clang that supports zicsr or zifencei
via '-march=' [1] (i.e, >= 17.x) is used in combination with a version
of GNU binutils that do not recognize zicsr and zifencei in the
'-march=' value (i.e., < 2.36):
riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicsr2p0_zifencei2p0: Invalid or unknown z ISA extension: 'zifencei'
riscv64-linux-gnu-ld: failed to merge target specific data of file fs/efivarfs/file.o
riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicsr2p0_zifencei2p0: Invalid or unknown z ISA extension: 'zifencei'
riscv64-linux-gnu-ld: failed to merge target specific data of file fs/efivarfs/super.o
The second occurs when a version of clang that does not support zicsr or
zifencei via '-march=' (i.e., <= 16.x) is used in combination with a
version of GNU as that defaults to a newer ISA base spec, which requires
specifying zicsr and zifencei in the '-march=' value explicitly (i.e, >=
2.38):
../arch/riscv/kernel/kexec_relocate.S: Assembler messages:
../arch/riscv/kernel/kexec_relocate.S:147: Error: unrecognized opcode `fence.i', extension `zifencei' required
clang-12: error: assembler command failed with exit code 1 (use -v to see invocation)
This is the same issue addressed by commit 6df2a016c0c8 ("riscv: fix
build with binutils 2.38") (see [2] for additional information) but
older versions of clang miss out on it because the cc-option check
fails:
clang-12: error: invalid arch name 'rv64imac_zicsr_zifencei', unsupported standard user-level extension 'zicsr'
clang-12: error: invalid arch name 'rv64imac_zicsr_zifencei', unsupported standard user-level extension 'zicsr'
To resolve the first issue, only attempt to add zicsr and zifencei to
the march string when using the GNU assembler 2.38 or newer, which is
when the default ISA spec was updated, requiring these extensions to be
specified explicitly. LLVM implements an older version of the base
specification for all currently released versions, so these instructions
are available as part of the 'i' extension. If LLVM's implementation is
updated in the future, a CONFIG_AS_IS_LLVM condition can be added to
CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI.
To resolve the second issue, use version 2.2 of the base ISA spec when
using an older version of clang that does not support zicsr or zifencei
via '-march=', as that is the spec version most compatible with the one
clang/LLVM implements and avoids the need to specify zicsr and zifencei
explicitly due to still being a part of 'i'.
[1]: 22e199e6af
[2]: https://lore.kernel.org/ZAxT7T9Xy1Fo3d5W@aurel32.net/
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/1808
Co-developed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230313-riscv-zicsr-zifencei-fiasco-v1-1-dd1b7840a551@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9a801afd3eb95e1a89aba17321062df06fb49d98 upstream.
Currently, we pass the CONTEXTID instead of the ASID to the TLB flush
function. We should only take the ASID field to prevent from touching
the reserved bit field.
Fixes: 3f1e782998cd ("riscv: add ASID-based tlbflushing methods")
Signed-off-by: Dylan Jhong <dylan@andestech.com>
Reviewed-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Link: https://lore.kernel.org/r/20230313034906.2401730-1-dylan@andestech.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 61fc1ee8be26bc192d691932b0a67eabee45d12f ]
Increase COMMAND_LINE_SIZE as the current default value is too low
for syzbot kernel command line.
There has been considerable discussion on this patch that has led to a
larger patch set removing COMMAND_LINE_SIZE from the uapi headers on all
ports. That's not quite done yet, but it's gotten far enough we're
confident this is not a uABI change so this is safe.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Link: https://lore.kernel.org/r/20210316193420.904-1-alex@ghiti.fr
[Palmer: it's not uabi]
Link: https://lore.kernel.org/linux-riscv/874b8076-b0d1-4aaa-bcd8-05d523060152@app.fastmail.com/#t
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 82dd33fde0268cc622d3d1ac64971f3f61634142 upstream.
After use_asid_allocator is enabled, the userspace application will
crash by stale TLB entries. Because only using cpumask_clear_cpu without
local_flush_tlb_all couldn't guarantee CPU's TLB entries were fresh.
Then set_mm_asid would cause the user space application to get a stale
value by stale TLB entry, but set_mm_noasid is okay.
Here is the symptom of the bug:
unhandled signal 11 code 0x1 (coredump)
0x0000003fd6d22524 <+4>: auipc s0,0x70
0x0000003fd6d22528 <+8>: ld s0,-148(s0) # 0x3fd6d92490
=> 0x0000003fd6d2252c <+12>: ld a5,0(s0)
(gdb) i r s0
s0 0x8082ed1cc3198b21 0x8082ed1cc3198b21
(gdb) x /2x 0x3fd6d92490
0x3fd6d92490: 0xd80ac8a8 0x0000003f
The core dump file shows that register s0 is wrong, but the value in
memory is correct. Because 'ld s0, -148(s0)' used a stale mapping entry
in TLB and got a wrong result from an incorrect physical address.
When the task ran on CPU0, which loaded/speculative-loaded the value of
address(0x3fd6d92490), then the first version of the mapping entry was
PTWed into CPU0's TLB.
When the task switched from CPU0 to CPU1 (No local_tlb_flush_all here by
asid), it happened to write a value on the address (0x3fd6d92490). It
caused do_page_fault -> wp_page_copy -> ptep_clear_flush ->
ptep_get_and_clear & flush_tlb_page.
The flush_tlb_page used mm_cpumask(mm) to determine which CPUs need TLB
flush, but CPU0 had cleared the CPU0's mm_cpumask in the previous
switch_mm. So we only flushed the CPU1 TLB and set the second version
mapping of the PTE. When the task switched from CPU1 to CPU0 again, CPU0
still used a stale TLB mapping entry which contained a wrong target
physical address. It raised a bug when the task happened to read that
value.
CPU0 CPU1
- switch 'task' in
- read addr (Fill stale mapping
entry into TLB)
- switch 'task' out (no tlb_flush)
- switch 'task' in (no tlb_flush)
- write addr cause pagefault
do_page_fault() (change to
new addr mapping)
wp_page_copy()
ptep_clear_flush()
ptep_get_and_clear()
& flush_tlb_page()
write new value into addr
- switch 'task' out (no tlb_flush)
- switch 'task' in (no tlb_flush)
- read addr again (Use stale
mapping entry in TLB)
get wrong value from old phyical
addr, BUG!
The solution is to keep all CPUs' footmarks of cpumask(mm) in switch_mm,
which could guarantee to invalidate all stale TLB entries during TLB
flush.
Fixes: 65d4b9c53017 ("RISC-V: Implement ASID allocator")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Tested-by: Zong Li <zong.li@sifive.com>
Tested-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Cc: Anup Patel <apatel@ventanamicro.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: stable@vger.kernel.org
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230226150137.1919750-3-geomatsi@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e921050022f1f12d5029d1487a7dfc46cde15523 upstream.
This reverts the remaining bits of commit 4bd1d80efb5a ("riscv: mm:
notify remote harts harts about mmu cache updates").
According to bug reports, suggested approach to fix stale TLB entries
is not sufficient. It needs to be replaced by a more robust solution.
Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates")
Reported-by: Zong Li <zong.li@sifive.com>
Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Cc: stable@vger.kernel.org
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230226150137.1919750-2-geomatsi@gmail.com
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>
commit 416721ff05fddc58ca531b6f069de250301de6e5 upstream.
Commit 21855cac82d3 ("riscv/mm: Prevent kernel module to access user
memory without uaccess routines") added early exits/deaths for page
faults stemming from accesses to user-space without using proper
uaccess routines (where sstatus.SUM is set).
Unfortunatly, this is too strict for some BPF programs, which relies
on BPF exhandler fixups. These BPF programs loads "BTF pointers". A
BTF pointers could either be a valid kernel pointer or NULL, but not a
userspace address.
Resolve the problem by calling the fixup handler in the early exit
path.
Fixes: 21855cac82d3 ("riscv/mm: Prevent kernel module to access user memory without uaccess routines")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230214162515.184827-1-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 9ddfc3cd806081ce1f6c9c2f988cbb031f35d28f upstream.
Runtime code patching must be done at a naturally aligned address, or we
may execute on a partial instruction.
We have encountered problems traced back to static jump functions during
the test. We switched the tracer randomly for every 1~5 seconds on a
dual-core QEMU setup and found the kernel sucking at a static branch
where it jumps to itself.
The reason is that the static branch was 2-byte but not 4-byte aligned.
Then, the kernel would patch the instruction, either J or NOP, with two
half-word stores if the machine does not have efficient unaligned
accesses. Thus, moments exist where half of the NOP mixes with the other
half of the J when transitioning the branch. In our particular case, on
a little-endian machine, the upper half of the NOP was mixed with the
lower part of the J when enabling the branch, resulting in a jump that
jumped to itself. Conversely, it would result in a HINT instruction when
disabling the branch, but it might not be observable.
ARM64 does not have this problem since all instructions must be 4-byte
aligned.
Fixes: ebc00dde8a97 ("riscv: Add jump-label implementation")
Link: https://lore.kernel.org/linux-riscv/20220913094252.3555240-6-andy.chiu@sifive.com/
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230206090440.1255001-1-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>
commit b49f700668fff7565b945dce823def79bff59bb0 upstream.
This is a partial revert of the commit 4bd1d80efb5a ("riscv: mm: notify
remote harts about mmu cache updates"). Original commit included two
loosely related changes serving the same purpose of fixing stale TLB
entries causing user-space application crash:
- introduce deferred per-ASID TLB flush for CPUs not running the task
- switch to per-ASID TLB flush on all CPUs running the task in update_mmu_cache
According to report and discussion in [1], the second part caused a
regression on Renesas RZ/Five SoC. For now restore the old behavior
of the update_mmu_cache.
[1] https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/
Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates")
Reported-by: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com>
Link: trailer, so that it can be parsed with git's trailer functionality?
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230129211818.686557-1-geomatsi@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit eb9be8310c58c166f9fae3b71c0ad9d6741b4897 upstream.
The patchwork automation reported a sparse complaint that
spin_shadow_stack was not declared and should be static:
../arch/riscv/kernel/traps.c:335:15: warning: symbol 'spin_shadow_stack' was not declared. Should it be static?
However, this is used in entry.S and therefore shouldn't be static.
The same applies to the shadow_stack that this pseudo spinlock is
trying to protect, so do like its charge and add a declaration to
thread_info.h
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Fixes: 7e1864332fbc ("riscv: fix race when vmap stack overflow")
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20230210185945.915806-1-conor@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
