Mayuresh reported commit 20802d8d47 ("riscv: extable: add a dedicated
uaccess handler") breaks the writev02 test case in LTP. This is due to
the err reg isn't correctly set with the errno(-EFAULT in writev02
case). First of all, the err and zero regs are reg numbers rather than
reg offsets in struct pt_regs; Secondly, regs_set_gpr() should write
the regs when offset isn't zero(zero means epc)
Fix it by correcting regs_set_gpr() logic and passing the correct reg
offset to it.
Reported-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Fixes: 20802d8d47 ("riscv: extable: add a dedicated uaccess handler")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Inspired by commit 2e77a62cb3 ("arm64: extable: add a dedicated
uaccess handler"), do similar to riscv to add a dedicated uaccess
exception handler to update registers in exception context and
subsequently return back into the function which faulted, so we remove
the need for fixups specialized to each faulting instruction.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This is a riscv port of commit d6e2cc5647 ("arm64: extable: add `type`
and `data` fields").
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The var name "fixup" is a bit confusing, since this is a
exception_table_entry. Use "ex" instead to refer to an entire entry.
In subsequent patches we'll use `fixup` to refer to the fixup
field specifically.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The return values of fixup_exception() and riscv_bpf_fixup_exception()
represent a boolean condition rather than an error code, so it's better
to return `bool` rather than `int`.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This is to group riscv related extable related functions signature
into one file.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Similar as other architectures such as arm64, x86 and so on, use
offsets relative to the exception table entry values rather than
absolute addresses for both the exception locationand the fixup.
However, RISCV label difference will actually produce two relocations,
a pair of R_RISCV_ADD32 and R_RISCV_SUB32. Take below simple code for
example:
$ cat test.S
.section .text
1:
nop
.section __ex_table,"a"
.balign 4
.long (1b - .)
.previous
$ riscv64-linux-gnu-gcc -c test.S
$ riscv64-linux-gnu-readelf -r test.o
Relocation section '.rela__ex_table' at offset 0x100 contains 2 entries:
Offset Info Type Sym. Value Sym. Name + Addend
000000000000 000600000023 R_RISCV_ADD32 0000000000000000 .L1^B1 + 0
000000000000 000500000027 R_RISCV_SUB32 0000000000000000 .L0 + 0
The modpost will complain the R_RISCV_SUB32 relocation, so we need to
patch modpost.c to skip this relocation for .rela__ex_table section.
After this patch, the __ex_table section size of defconfig vmlinux is
reduced from 7072 Bytes to 3536 Bytes.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
When a tracing BPF program attempts to read memory without using the
bpf_probe_read() helper, the verifier marks the load instruction with
the BPF_PROBE_MEM flag. Since the riscv JIT does not currently recognize
this flag it falls back to the interpreter.
Add support for BPF_PROBE_MEM, by appending an exception table to the
BPF program. If the load instruction causes a data abort, the fixup
infrastructure finds the exception table and fixes up the fault, by
clearing the destination register and jumping over the faulting
instruction.
A more generic solution would add a "handler" field to the table entry,
like on x86 and s390. The same issue in ARM64 is fixed in 8008342853
("bpf, arm64: Add BPF exception tables").
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Pu Lehui <pulehui@huawei.com>
Tested-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Link: https://lore.kernel.org/bpf/20211027111822.3801679-1-tongtiangen@huawei.com
Many of the privileged CSRs exist in a supervisor and machine version
that are used very similarly. Provide versions of the CSR names and
fields that map to either the S-mode or M-mode variant depending on
a new CONFIG_RISCV_M_MODE kconfig symbol.
Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com>
and Paul Walmsley <paul.walmsley@sifive.com>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip
[paul.walmsley@sifive.com: updated to apply]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not see the file copying or write to the free
software foundation inc
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 12 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190523091651.231300438@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch contains the code that interfaces with ELF objects on RISC-V
systems, the vast majority of which is present to load kernel modules.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Jisheng Zhang