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authorVincent Chen <vincent.chen@sifive.com>2022-03-08 16:32:52 +0800
committerPalmer Dabbelt <palmer@rivosinc.com>2022-03-22 14:45:14 -0700
commit93917ad50972e6298885d81b37b6a8602eb0b188 (patch)
treee723a4f00f052273f81a94723e0664443590f1d0 /arch/riscv
parente783362eb54cd99b2cac8b3a9aeac942e6f6ac07 (diff)
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>
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/Kconfig1
-rw-r--r--arch/riscv/kernel/entry.S4
-rw-r--r--arch/riscv/kernel/signal.c2
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);