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Diffstat (limited to 'arch/riscv/kernel/signal.c')
-rw-r--r--arch/riscv/kernel/signal.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index b7f9a5565c4b..17ba190e84a5 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -17,11 +17,16 @@
#include <asm/switch_to.h>
#include <asm/csr.h>
+extern u32 __user_rt_sigreturn[2];
+
#define DEBUG_SIG 0
struct rt_sigframe {
struct siginfo info;
struct ucontext uc;
+#ifndef CONFIG_MMU
+ u32 sigreturn_code[2];
+#endif
};
#ifdef CONFIG_FPU
@@ -166,7 +171,6 @@ static inline void __user *get_sigframe(struct ksignal *ksig,
return (void __user *)sp;
}
-
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
@@ -189,8 +193,19 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
return -EFAULT;
/* Set up to return from userspace. */
+#ifdef CONFIG_MMU
regs->ra = (unsigned long)VDSO_SYMBOL(
current->mm->context.vdso, rt_sigreturn);
+#else
+ /*
+ * For the nommu case we don't have a VDSO. Instead we push two
+ * instructions to call the rt_sigreturn syscall onto the user stack.
+ */
+ if (copy_to_user(&frame->sigreturn_code, __user_rt_sigreturn,
+ sizeof(frame->sigreturn_code)))
+ return -EFAULT;
+ regs->ra = (unsigned long)&frame->sigreturn_code;
+#endif /* CONFIG_MMU */
/*
* Set up registers for signal handler.