| Message ID | 20220302023048.6140-2-vincent.chen@sifive.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | RISC-V: add support for restartable sequence | expand |
----- On Mar 1, 2022, at 9:30 PM, Vincent Chen vincent.chen@sifive.com wrote: > Add calls to rseq_signal_deliver() and rseq_syscall() to introduce RSEQ > support. > > 1. Call the rseq_signal_deliver() function to fixup on the pre-signal > frame when a signal is delivered on top of a restartable sequence > critical section. > > 2. Check that system calls are not invoked from within rseq critical > sections by invoking rseq_signal() from ret_from_syscall(). With > CONFIG_DEBUG_RSEQ, such behavior results in termination of the > process with SIGSEGV. > > Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Will it be picked by by riscv maintainers ? Thanks, Mathieu > --- > arch/riscv/Kconfig | 1 + > arch/riscv/kernel/entry.S | 4 ++++ > arch/riscv/kernel/signal.c | 2 ++ > 3 files changed, 7 insertions(+) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 5adcbd9b5e88..67a671b099b6 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -101,6 +101,7 @@ config RISCV > select HAVE_FUNCTION_ARG_ACCESS_API > select HAVE_STACKPROTECTOR > select HAVE_SYSCALL_TRACEPOINTS > + select HAVE_RSEQ > select IRQ_DOMAIN > select IRQ_FORCED_THREADING > select MODULES_USE_ELF_RELA if MODULES > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S > index ed29e9c8f660..56ada2a583fa 100644 > --- a/arch/riscv/kernel/entry.S > +++ b/arch/riscv/kernel/entry.S > @@ -225,6 +225,10 @@ ret_from_syscall: > * (If it was configured with SECCOMP_RET_ERRNO/TRACE) > */ > ret_from_syscall_rejected: > +#ifdef CONFIG_DEBUG_RSEQ > + move a0, sp > + call rseq_syscall > +#endif > /* Trace syscalls, but only if requested by the user. */ > REG_L t0, TASK_TI_FLAGS(tp) > andi t0, t0, _TIF_SYSCALL_WORK > diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c > index c2d5ecbe5526..16da3c3b53a1 100644 > --- a/arch/riscv/kernel/signal.c > +++ b/arch/riscv/kernel/signal.c > @@ -258,6 +258,8 @@ static void handle_signal(struct ksignal *ksig, struct > pt_regs *regs) > } > } > > + rseq_signal_deliver(ksig, regs); > + > /* Set up the stack frame */ > ret = setup_rt_frame(ksig, oldset, regs); > > -- > 2.17.1
On Thu, Mar 3, 2022 at 12:29 AM Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote: > > ----- On Mar 1, 2022, at 9:30 PM, Vincent Chen vincent.chen@sifive.com wrote: > > > Add calls to rseq_signal_deliver() and rseq_syscall() to introduce RSEQ > > support. > > > > 1. Call the rseq_signal_deliver() function to fixup on the pre-signal > > frame when a signal is delivered on top of a restartable sequence > > critical section. > > > > 2. Check that system calls are not invoked from within rseq critical > > sections by invoking rseq_signal() from ret_from_syscall(). With > > CONFIG_DEBUG_RSEQ, such behavior results in termination of the > > process with SIGSEGV. > > > > Signed-off-by: Vincent Chen <vincent.chen@sifive.com> > > Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > > Will it be picked by by riscv maintainers ? > Hi Mathieu, Thank you very much for reviewing it. Yes, I hope it can be picked up by riscv maintainers. Thanks, Vincent > Thanks, > > Mathieu > > > --- > > arch/riscv/Kconfig | 1 + > > arch/riscv/kernel/entry.S | 4 ++++ > > arch/riscv/kernel/signal.c | 2 ++ > > 3 files changed, 7 insertions(+) > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index 5adcbd9b5e88..67a671b099b6 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -101,6 +101,7 @@ config RISCV > > select HAVE_FUNCTION_ARG_ACCESS_API > > select HAVE_STACKPROTECTOR > > select HAVE_SYSCALL_TRACEPOINTS > > + select HAVE_RSEQ > > select IRQ_DOMAIN > > select IRQ_FORCED_THREADING > > select MODULES_USE_ELF_RELA if MODULES > > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S > > index ed29e9c8f660..56ada2a583fa 100644 > > --- a/arch/riscv/kernel/entry.S > > +++ b/arch/riscv/kernel/entry.S > > @@ -225,6 +225,10 @@ ret_from_syscall: > > * (If it was configured with SECCOMP_RET_ERRNO/TRACE) > > */ > > ret_from_syscall_rejected: > > +#ifdef CONFIG_DEBUG_RSEQ > > + move a0, sp > > + call rseq_syscall > > +#endif > > /* Trace syscalls, but only if requested by the user. */ > > REG_L t0, TASK_TI_FLAGS(tp) > > andi t0, t0, _TIF_SYSCALL_WORK > > diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c > > index c2d5ecbe5526..16da3c3b53a1 100644 > > --- a/arch/riscv/kernel/signal.c > > +++ b/arch/riscv/kernel/signal.c > > @@ -258,6 +258,8 @@ static void handle_signal(struct ksignal *ksig, struct > > pt_regs *regs) > > } > > } > > > > + rseq_signal_deliver(ksig, regs); > > + > > /* Set up the stack frame */ > > ret = setup_rt_frame(ksig, oldset, regs); > > > > -- > > 2.17.1 > > -- > Mathieu Desnoyers > EfficiOS Inc. > http://www.efficios.com
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 5adcbd9b5e88..67a671b099b6 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -101,6 +101,7 @@ config RISCV select HAVE_FUNCTION_ARG_ACCESS_API select HAVE_STACKPROTECTOR select HAVE_SYSCALL_TRACEPOINTS + select HAVE_RSEQ select IRQ_DOMAIN select IRQ_FORCED_THREADING select MODULES_USE_ELF_RELA if MODULES diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index ed29e9c8f660..56ada2a583fa 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -225,6 +225,10 @@ ret_from_syscall: * (If it was configured with SECCOMP_RET_ERRNO/TRACE) */ ret_from_syscall_rejected: +#ifdef CONFIG_DEBUG_RSEQ + move a0, sp + call rseq_syscall +#endif /* Trace syscalls, but only if requested by the user. */ REG_L t0, TASK_TI_FLAGS(tp) andi t0, t0, _TIF_SYSCALL_WORK diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index c2d5ecbe5526..16da3c3b53a1 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -258,6 +258,8 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) } } + rseq_signal_deliver(ksig, regs); + /* Set up the stack frame */ ret = setup_rt_frame(ksig, oldset, regs);
Add calls to rseq_signal_deliver() and rseq_syscall() to introduce RSEQ support. 1. Call the rseq_signal_deliver() function to fixup on the pre-signal frame when a signal is delivered on top of a restartable sequence critical section. 2. Check that system calls are not invoked from within rseq critical sections by invoking rseq_signal() from ret_from_syscall(). With CONFIG_DEBUG_RSEQ, such behavior results in termination of the process with SIGSEGV. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> --- arch/riscv/Kconfig | 1 + arch/riscv/kernel/entry.S | 4 ++++ arch/riscv/kernel/signal.c | 2 ++ 3 files changed, 7 insertions(+)