1 files changed, 192 insertions, 28 deletions

diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 9aff9d720590..180d951d3624 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -19,10 +19,14 @@
 #include <asm/signal.h>
 #include <asm/signal32.h>
 #include <asm/switch_to.h>
+#include <asm/vector.h>
 #include <asm/csr.h>
 #include <asm/cacheflush.h>
 
+unsigned long signal_minsigstksz __ro_after_init;
+
 extern u32 __user_rt_sigreturn[2];
+static size_t riscv_v_sc_size __ro_after_init;
 
 #define DEBUG_SIG 0
 
@@ -40,26 +44,13 @@ static long restore_fp_state(struct pt_regs *regs,
 {
 	long err;
 	struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
-	size_t i;
 
 	err = __copy_from_user(&current->thread.fstate, state, sizeof(*state));
 	if (unlikely(err))
 		return err;
 
 	fstate_restore(current, regs);
-
-	/* We support no other extension state at this time. */
-	for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
-		u32 value;
-
-		err = __get_user(value, &sc_fpregs->q.reserved[i]);
-		if (unlikely(err))
-			break;
-		if (value != 0)
-			return -EINVAL;
-	}
-
-	return err;
+	return 0;
 }
 
 static long save_fp_state(struct pt_regs *regs,
@@ -67,52 +58,186 @@ static long save_fp_state(struct pt_regs *regs,
 {
 	long err;
 	struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
-	size_t i;
 
 	fstate_save(current, regs);
 	err = __copy_to_user(state, &current->thread.fstate, sizeof(*state));
+	return err;
+}
+#else
+#define save_fp_state(task, regs) (0)
+#define restore_fp_state(task, regs) (0)
+#endif
+
+#ifdef CONFIG_RISCV_ISA_V
+
+static long save_v_state(struct pt_regs *regs, void __user **sc_vec)
+{
+	struct __riscv_ctx_hdr __user *hdr;
+	struct __sc_riscv_v_state __user *state;
+	void __user *datap;
+	long err;
+
+	hdr = *sc_vec;
+	/* Place state to the user's signal context space after the hdr */
+	state = (struct __sc_riscv_v_state __user *)(hdr + 1);
+	/* Point datap right after the end of __sc_riscv_v_state */
+	datap = state + 1;
+
+	/* datap is designed to be 16 byte aligned for better performance */
+	WARN_ON(unlikely(!IS_ALIGNED((unsigned long)datap, 16)));
+
+	riscv_v_vstate_save(current, regs);
+	/* Copy everything of vstate but datap. */
+	err = __copy_to_user(&state->v_state, &current->thread.vstate,
+			     offsetof(struct __riscv_v_ext_state, datap));
+	/* Copy the pointer datap itself. */
+	err |= __put_user(datap, &state->v_state.datap);
+	/* Copy the whole vector content to user space datap. */
+	err |= __copy_to_user(datap, current->thread.vstate.datap, riscv_v_vsize);
+	/* Copy magic to the user space after saving  all vector conetext */
+	err |= __put_user(RISCV_V_MAGIC, &hdr->magic);
+	err |= __put_user(riscv_v_sc_size, &hdr->size);
 	if (unlikely(err))
 		return err;
 
-	/* We support no other extension state at this time. */
-	for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
-		err = __put_user(0, &sc_fpregs->q.reserved[i]);
-		if (unlikely(err))
-			break;
-	}
+	/* Only progress the sv_vec if everything has done successfully  */
+	*sc_vec += riscv_v_sc_size;
+	return 0;
+}
+
+/*
+ * Restore Vector extension context from the user's signal frame. This function
+ * assumes a valid extension header. So magic and size checking must be done by
+ * the caller.
+ */
+static long __restore_v_state(struct pt_regs *regs, void __user *sc_vec)
+{
+	long err;
+	struct __sc_riscv_v_state __user *state = sc_vec;
+	void __user *datap;
+
+	/* Copy everything of __sc_riscv_v_state except datap. */
+	err = __copy_from_user(&current->thread.vstate, &state->v_state,
+			       offsetof(struct __riscv_v_ext_state, datap));
+	if (unlikely(err))
+		return err;
+
+	/* Copy the pointer datap itself. */
+	err = __get_user(datap, &state->v_state.datap);
+	if (unlikely(err))
+		return err;
+	/*
+	 * Copy the whole vector content from user space datap. Use
+	 * copy_from_user to prevent information leak.
+	 */
+	err = copy_from_user(current->thread.vstate.datap, datap, riscv_v_vsize);
+	if (unlikely(err))
+		return err;
+
+	riscv_v_vstate_restore(current, regs);
 
 	return err;
 }
 #else
-#define save_fp_state(task, regs) (0)
-#define restore_fp_state(task, regs) (0)
+#define save_v_state(task, regs) (0)
+#define __restore_v_state(task, regs) (0)
 #endif
 
 static long restore_sigcontext(struct pt_regs *regs,
 	struct sigcontext __user *sc)
 {
+	void __user *sc_ext_ptr = &sc->sc_extdesc.hdr;
+	__u32 rsvd;
 	long err;
 	/* sc_regs is structured the same as the start of pt_regs */
 	err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs));
+	if (unlikely(err))
+		return err;
+
 	/* Restore the floating-point state. */
-	if (has_fpu())
-		err |= restore_fp_state(regs, &sc->sc_fpregs);
+	if (has_fpu()) {
+		err = restore_fp_state(regs, &sc->sc_fpregs);
+		if (unlikely(err))
+			return err;
+	}
+
+	/* Check the reserved word before extensions parsing */
+	err = __get_user(rsvd, &sc->sc_extdesc.reserved);
+	if (unlikely(err))
+		return err;
+	if (unlikely(rsvd))
+		return -EINVAL;
+
+	while (!err) {
+		__u32 magic, size;
+		struct __riscv_ctx_hdr __user *head = sc_ext_ptr;
+
+		err |= __get_user(magic, &head->magic);
+		err |= __get_user(size, &head->size);
+		if (unlikely(err))
+			return err;
+
+		sc_ext_ptr += sizeof(*head);
+		switch (magic) {
+		case END_MAGIC:
+			if (size != END_HDR_SIZE)
+				return -EINVAL;
+
+			return 0;
+		case RISCV_V_MAGIC:
+			if (!has_vector() || !riscv_v_vstate_query(regs) ||
+			    size != riscv_v_sc_size)
+				return -EINVAL;
+
+			err = __restore_v_state(regs, sc_ext_ptr);
+			break;
+		default:
+			return -EINVAL;
+		}
+		sc_ext_ptr = (void __user *)head + size;
+	}
 	return err;
 }
 
+static size_t get_rt_frame_size(bool cal_all)
+{
+	struct rt_sigframe __user *frame;
+	size_t frame_size;
+	size_t total_context_size = 0;
+
+	frame_size = sizeof(*frame);
+
+	if (has_vector()) {
+		if (cal_all || riscv_v_vstate_query(task_pt_regs(current)))
+			total_context_size += riscv_v_sc_size;
+	}
+	/*
+	 * Preserved a __riscv_ctx_hdr for END signal context header if an
+	 * extension uses __riscv_extra_ext_header
+	 */
+	if (total_context_size)
+		total_context_size += sizeof(struct __riscv_ctx_hdr);
+
+	frame_size += total_context_size;
+
+	frame_size = round_up(frame_size, 16);
+	return frame_size;
+}
+
 SYSCALL_DEFINE0(rt_sigreturn)
 {
 	struct pt_regs *regs = current_pt_regs();
 	struct rt_sigframe __user *frame;
 	struct task_struct *task;
 	sigset_t set;
+	size_t frame_size = get_rt_frame_size(false);
 
 	/* Always make any pending restarted system calls return -EINTR */
 	current->restart_block.fn = do_no_restart_syscall;
 
 	frame = (struct rt_sigframe __user *)regs->sp;
 
-	if (!access_ok(frame, sizeof(*frame)))
+	if (!access_ok(frame, frame_size))
 		goto badframe;
 
 	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
@@ -146,12 +271,23 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
 	struct pt_regs *regs)
 {
 	struct sigcontext __user *sc = &frame->uc.uc_mcontext;
+	struct __riscv_ctx_hdr __user *sc_ext_ptr = &sc->sc_extdesc.hdr;
 	long err;
+
 	/* sc_regs is structured the same as the start of pt_regs */
 	err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs));
 	/* Save the floating-point state. */
 	if (has_fpu())
 		err |= save_fp_state(regs, &sc->sc_fpregs);
+	/* Save the vector state. */
+	if (has_vector() && riscv_v_vstate_query(regs))
+		err |= save_v_state(regs, (void __user **)&sc_ext_ptr);
+	/* Write zero to fp-reserved space and check it on restore_sigcontext */
+	err |= __put_user(0, &sc->sc_extdesc.reserved);
+	/* And put END __riscv_ctx_hdr at the end. */
+	err |= __put_user(END_MAGIC, &sc_ext_ptr->magic);
+	err |= __put_user(END_HDR_SIZE, &sc_ext_ptr->size);
+
 	return err;
 }
 
@@ -175,6 +311,13 @@ static inline void __user *get_sigframe(struct ksignal *ksig,
 	/* Align the stack frame. */
 	sp &= ~0xfUL;
 
+	/*
+	 * Fail if the size of the altstack is not large enough for the
+	 * sigframe construction.
+	 */
+	if (current->sas_ss_size && sp < current->sas_ss_sp)
+		return (void __user __force *)-1UL;
+
 	return (void __user *)sp;
 }
 
@@ -184,9 +327,10 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 	struct rt_sigframe __user *frame;
 	long err = 0;
 	unsigned long __maybe_unused addr;
+	size_t frame_size = get_rt_frame_size(false);
 
-	frame = get_sigframe(ksig, regs, sizeof(*frame));
-	if (!access_ok(frame, sizeof(*frame)))
+	frame = get_sigframe(ksig, regs, frame_size);
+	if (!access_ok(frame, frame_size))
 		return -EFAULT;
 
 	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
@@ -319,3 +463,23 @@ void arch_do_signal_or_restart(struct pt_regs *regs)
 	 */
 	restore_saved_sigmask();
 }
+
+void init_rt_signal_env(void);
+void __init init_rt_signal_env(void)
+{
+	riscv_v_sc_size = sizeof(struct __riscv_ctx_hdr) +
+			  sizeof(struct __sc_riscv_v_state) + riscv_v_vsize;
+	/*
+	 * Determine the stack space required for guaranteed signal delivery.
+	 * The signal_minsigstksz will be populated into the AT_MINSIGSTKSZ entry
+	 * in the auxiliary array at process startup.
+	 */
+	signal_minsigstksz = get_rt_frame_size(true);
+}
+
+#ifdef CONFIG_DYNAMIC_SIGFRAME
+bool sigaltstack_size_valid(size_t ss_size)
+{
+	return ss_size > get_rt_frame_size(false);
+}
+#endif /* CONFIG_DYNAMIC_SIGFRAME */