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| author |   Vincent Chen <vincent.chen@sifive.com> | 2022-03-08 16:32:52 +0800 |
|---|---|---|
| committer |   Palmer Dabbelt <palmer@rivosinc.com> | 2022-03-22 14:45:14 -0700 |
| commit | 93917ad50972e6298885d81b37b6a8602eb0b188 (patch) | |
| tree | e723a4f00f052273f81a94723e0664443590f1d0 | |
| parent | Linux 5.17-rc1 (diff) | |
| download | linux-dev-93917ad50972e6298885d81b37b6a8602eb0b188.tar.xz linux-dev-93917ad50972e6298885d81b37b6a8602eb0b188.zip | |
RISC-V: Add support for restartable sequence
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>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| -rw-r--r-- | arch/riscv/Kconfig | 1 | ||||
| -rw-r--r-- | arch/riscv/kernel/entry.S | 4 | ||||
| -rw-r--r-- | arch/riscv/kernel/signal.c | 2 |
3 files changed, 7 insertions, 0 deletions
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); |