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authorGuo Ren <guoren@linux.alibaba.com>2019-11-05 04:58:33 +0300
committerGuo Ren <guoren@linux.alibaba.com>2020-03-08 15:55:14 +0300
commit9866d141a0977ace974400bf1f793dfc163409ce (patch)
tree44058c31b3030ac4c6ba5836e3f040f7bbc99d2d /arch/csky
parentbfe47f358ad298a1efb9b8f8299a81541d90df87 (diff)
downloadlinux-9866d141a0977ace974400bf1f793dfc163409ce.tar.xz
csky: Add support for restartable sequence
Copied and adapted from vincent's patch, but modified for csky. ref: https://lore.kernel.org/linux-riscv/1572919114-3886-3-git-send-email-vincent.chen@sifive.com/raw Add calls to rseq_signal_deliver(), rseq_handle_notify_resume() and rseq_syscall() to introduce RSEQ support. 1. Call the rseq_handle_notify_resume() function on return to userspace if TIF_NOTIFY_RESUME thread flag is set. 2. 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. 3. 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: Guo Ren <guoren@linux.alibaba.com>
Diffstat (limited to 'arch/csky')
-rw-r--r--arch/csky/Kconfig1
-rw-r--r--arch/csky/kernel/entry.S5
-rw-r--r--arch/csky/kernel/signal.c3
3 files changed, 8 insertions, 1 deletions
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 2dfd3fb07db9..0e9b14367fa8 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -49,6 +49,7 @@ config CSKY
select HAVE_PERF_USER_STACK_DUMP
select HAVE_DMA_CONTIGUOUS
select HAVE_REGS_AND_STACK_ACCESS_API
+ select HAVE_RSEQ
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select MAY_HAVE_SPARSE_IRQ
diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S
index 007706328000..0bde1d9fd277 100644
--- a/arch/csky/kernel/entry.S
+++ b/arch/csky/kernel/entry.S
@@ -128,7 +128,10 @@ tlbop_end 1
ENTRY(csky_systemcall)
SAVE_ALL TRAP0_SIZE
zero_fp
-
+#ifdef CONFIG_RSEQ_DEBUG
+ mov a0, sp
+ jbsr rseq_syscall
+#endif
psrset ee, ie
lrw r11, __NR_syscalls
diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
index 9b1b7c039ddf..3d6b728cbb72 100644
--- a/arch/csky/kernel/signal.c
+++ b/arch/csky/kernel/signal.c
@@ -175,6 +175,8 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
sigset_t *oldset = sigmask_to_save();
int ret;
+ rseq_signal_deliver(ksig, regs);
+
/* Are we from a system call? */
if (in_syscall(regs)) {
/* Avoid additional syscall restarting via ret_from_exception */
@@ -258,5 +260,6 @@ asmlinkage void do_notify_resume(struct pt_regs *regs,
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
+ rseq_handle_notify_resume(NULL, regs);
}
}