Leonardo Bras <leobras@redhat.com> says:
I just saw the opportunity of optimizing the helper is_compat_task() by
introducing a compile-time test, and it made possible to remove some
#ifdef's without any loss of performance.
I also saw the possibility of removing the direct check of task flags from
general code, and concentrated it in asm/compat.h by creating a few more
helpers, which in the end helped optimize code.
arch_get_mmap_end() just got a simple improvement and some extra docs.
* b4-shazam-merge:
riscv: Introduce set_compat_task() in asm/compat.h
riscv: Introduce is_compat_thread() into compat.h
riscv: add compile-time test into is_compat_task()
riscv: Replace direct thread flag check with is_compat_task()
riscv: Improve arch_get_mmap_end() macro
Link: https://lore.kernel.org/r/20240103160024.70305-2-leobras@redhat.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
task_user_regset_view() makes use of a function very similar to
is_compat_task(), but pointing to a any thread.
In arm64 asm/compat.h there is a function very similar to that:
is_compat_thread(struct thread_info *thread)
Copy this function to riscv asm/compat.h and make use of it into
task_user_regset_view().
Also, introduce a compile-time test for CONFIG_COMPAT and simplify the
function code by removing the #ifdef.
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20240103160024.70305-6-leobras@redhat.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
User will use its Vector registers only after the kernel really returns
to the userspace. So we can delay restoring Vector registers as long as
we are still running in kernel mode. So, add a thread flag to indicates
the need of restoring Vector and do the restore at the last
arch-specific exit-to-user hook. This save the context restoring cost
when we switch over multiple processes that run V in kernel mode. For
example, if the kernel performs a context swicth from A->B->C, and
returns to C's userspace, then there is no need to restore B's
V-register.
Besides, this also prevents us from repeatedly restoring V context when
executing kernel-mode Vector multiple times.
The cost of this is that we must disable preemption and mark vector as
busy during vstate_{save,restore}. Because then the V context will not
get restored back immediately when a trap-causing context switch happens
in the middle of vstate_{save,restore}.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-5-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This patch add back the ptrace support with the following fix:
- Define NT_RISCV_CSR and re-number NT_RISCV_VECTOR to prevent
conflicting with gdb's NT_RISCV_CSR.
- Use struct __riscv_v_regset_state to handle ptrace requests
Since gdb does not directly include the note description header in
Linux and has already defined NT_RISCV_CSR as 0x900, we decide to
sync with gdb and renumber NT_RISCV_VECTOR to solve and prevent future
conflicts.
Fixes: 0c59922c76 ("riscv: Add ptrace vector support")
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20230825050248.32681-1-andy.chiu@sifive.com
[Palmer: Drop the unused "size" variable in riscv_vr_set().]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
We've found two bugs here: NT_RISCV_VECTOR steps on NT_RISCV_CSR (which
is only for embedded), and we don't have vlenb in the core dumps. Given
that we've have a pair of bugs croup up as part of the GDB review we've
probably got other issues, so let's just cut this for 6.5 and get it
right.
Fixes: 0c59922c76 ("riscv: Add ptrace vector support")
Reviewed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20230816155450.26200-2-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This patch converts riscv to use the generic entry infrastructure from
kernel/entry/*. The generic entry makes maintainers' work easier and
codes more elegant. Here are the changes:
- More clear entry.S with handle_exception and ret_from_exception
- Get rid of complex custom signal implementation
- Move syscall procedure from assembly to C, which is much more
readable.
- Connect ret_from_fork & ret_from_kernel_thread to generic entry.
- Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode
- Use the standard preemption code instead of custom
Suggested-by: Huacai Chen <chenhuacai@kernel.org>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Yipeng Zou <zouyipeng@huawei.com>
Tested-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Link: https://lore.kernel.org/r/20230222033021.983168-5-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
The value of FP registers in the core dump file comes from the
thread.fstate. However, kernel saves the FP registers to the thread.fstate
only before scheduling out the process. If no process switch happens
during the exception handling process, kernel will not have a chance to
save the latest value of FP registers to thread.fstate. It will cause the
value of FP registers in the core dump file may be incorrect. To solve this
problem, this patch force lets kernel save the FP register into the
thread.fstate if the target task_struct equals the current.
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Fixes: b8c8a9590e ("RISC-V: Add FP register ptrace support for gdb.")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
If secure_computing() rejected a system call, we were previously setting
the system call number to -1, to indicate to later code that the syscall
failed. However, if something (e.g. a user notification) was sleeping, and
received a signal, we may set a0 to -ERESTARTSYS and re-try the system call
again.
In this case, seccomp "denies" the syscall (because of the signal), and we
would set a7 to -1, thus losing the value of the system call we want to
restart.
Instead, let's return -1 from do_syscall_trace_enter() to indicate that the
syscall was rejected, so we don't clobber the value in case of -ERESTARTSYS
or whatever.
This commit fixes the user_notification_signal seccomp selftest on riscv to
no longer hang. That test expects the system call to be re-issued after the
signal, and it wasn't due to the above bug. Now that it is, everything
works normally.
Note that in the ptrace (tracer) case, the tracer can set the register
values to whatever they want, so we still need to keep the code that
handles out-of-bounds syscalls. However, we can drop the comment.
We can also drop syscall_set_nr(), since it is no longer used anywhere, and
the code that re-loads the value in a7 because of it.
Reported in: https://lore.kernel.org/bpf/CAEn-LTp=ss0Dfv6J00=rCAy+N78U2AmhqJNjfqjr2FDpPYjxEQ@mail.gmail.com/
Reported-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Pull seccomp updates from Kees Cook:
"Mostly this is implementing the new flag SECCOMP_USER_NOTIF_FLAG_CONTINUE,
but there are cleanups as well.
- implement SECCOMP_USER_NOTIF_FLAG_CONTINUE (Christian Brauner)
- fixes to selftests (Christian Brauner)
- remove secure_computing() argument (Christian Brauner)"
* tag 'seccomp-v5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
seccomp: rework define for SECCOMP_USER_NOTIF_FLAG_CONTINUE
seccomp: fix SECCOMP_USER_NOTIF_FLAG_CONTINUE test
seccomp: simplify secure_computing()
seccomp: test SECCOMP_USER_NOTIF_FLAG_CONTINUE
seccomp: add SECCOMP_USER_NOTIF_FLAG_CONTINUE
seccomp: avoid overflow in implicit constant conversion
Rather than adding prototypes for C functions called only by assembly
code, mark them as __visible. This avoids adding prototypes that will
never be used by the callers. Resolves the following sparse warnings:
arch/riscv/kernel/irq.c:27:29: warning: symbol 'do_IRQ' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:151:6: warning: symbol 'do_syscall_trace_enter' was not declared. Should it be static?
arch/riscv/kernel/ptrace.c:165:6: warning: symbol 'do_syscall_trace_exit' was not declared. Should it be static?
arch/riscv/kernel/signal.c:295:17: warning: symbol 'do_notify_resume' was not declared. Should it be static?
arch/riscv/kernel/traps.c:92:1: warning: symbol 'do_trap_unknown' was not declared. Should it be static?
arch/riscv/kernel/traps.c:94:1: warning: symbol 'do_trap_insn_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:96:1: warning: symbol 'do_trap_insn_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:98:1: warning: symbol 'do_trap_insn_illegal' was not declared. Should it be static?
arch/riscv/kernel/traps.c:100:1: warning: symbol 'do_trap_load_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:102:1: warning: symbol 'do_trap_load_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:104:1: warning: symbol 'do_trap_store_misaligned' was not declared. Should it be static?
arch/riscv/kernel/traps.c:106:1: warning: symbol 'do_trap_store_fault' was not declared. Should it be static?
arch/riscv/kernel/traps.c:108:1: warning: symbol 'do_trap_ecall_u' was not declared. Should it be static?
arch/riscv/kernel/traps.c:110:1: warning: symbol 'do_trap_ecall_s' was not declared. Should it be static?
arch/riscv/kernel/traps.c:112:1: warning: symbol 'do_trap_ecall_m' was not declared. Should it be static?
arch/riscv/kernel/traps.c:124:17: warning: symbol 'do_trap_break' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:136:24: warning: symbol 'smp_callin' was not declared. Should it be static?
Based on a suggestion from Luc Van Oostenryck.
This version includes changes based on feedback from Christoph Hellwig
<hch@lst.de>.
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de> # for do_syscall_trace_*
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 version 2 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
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 97 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Define CREATE_TRACE_POINTS in order to create functions and structures
for the trace events. This is needed if HAVE_SYSCALL_TRACEPOINTS and
CONFIG_FTRACE_SYSCALLS are enabled, otherwise we get linking errors:
[..]
MODPOST vmlinux.o
kernel/trace/trace_syscalls.o: In function `.L0 ':
trace_syscalls.c:(.text+0x1152): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x126c): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x1328): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x14aa): undefined reference to `__tracepoint_sys_enter'
trace_syscalls.c:(.text+0x1684): undefined reference to `__tracepoint_sys_exit'
trace_syscalls.c:(.text+0x17a0): undefined reference to `__tracepoint_sys_exit'
trace_syscalls.c:(.text+0x185c): undefined reference to `__tracepoint_sys_exit'
trace_syscalls.c:(.text+0x19de): undefined reference to `__tracepoint_sys_exit'
arch/riscv/kernel/ptrace.o: In function `.L0 ':
ptrace.c:(.text+0x4dc): undefined reference to `__tracepoint_sys_enter'
ptrace.c:(.text+0x632): undefined reference to `__tracepoint_sys_exit'
make: *** [Makefile:1036: vmlinux] Error 1
Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Fixes: b78002b395b4 ("riscv: add HAVE_SYSCALL_TRACEPOINTS to Kconfig")
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patch adds auditing functions on entry to and exit from every system
call invocation.
Signed-off-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Add a variable and a macro to describe FP registers, assuming only D is
supported. FP code is conditional on CONFIG_FPU. The FP regs and FCSR
are copied separately to avoid copying struct padding. Tested by hand and
with the gdb testsuite.
Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
In riscv_gpr_set, pass regs instead of ®s to user_regset_copyin to fix
gdb segfault.
Signed-off-by: Jim Wilson <jimw@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling. It also contains some generic code that is ABI visible.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
