start moving towards threads always being in rpc

3 files changed, 10 insertions, 22 deletions

diff --git a/arch/riscv64/kernel/entry.S b/arch/riscv64/kernel/entry.S
index abf3cba..0bc999e 100644
--- a/arch/riscv64/kernel/entry.S
+++ b/arch/riscv64/kernel/entry.S
@@ -107,10 +107,8 @@ handle_exception:
 
 	csrr a0, CSR_SEPC
 	csrr a1, CSR_STVAL
-	/* not really a kernel panic but used for now to signify that something
-	 * happened in userspace that we can't deal with */
 	csrr a2, CSR_SCAUSE
-	call kernel_panic
+	call unhandled_panic
 
 	j	_load_context
 
diff --git a/arch/riscv64/kernel/proc.c b/arch/riscv64/kernel/proc.c
index d3896c1..f012b20 100644
--- a/arch/riscv64/kernel/proc.c
+++ b/arch/riscv64/kernel/proc.c
@@ -42,15 +42,14 @@ void run_init(struct tcb *t, vm_t fdt, vm_t initrd)
 {
 	csr_write(CSR_SSCRATCH, t);
 	csr_write(CSR_SEPC, t->callback);
-	/* gcc gives a warning 'the value of the stack pointer after an asm
-	 * statement must be the same as it was before the statement', so this
-	 * is technically speaking undefined behavior, I think.
-	 *
-	 * Could be fixed with a separate pure asm run_init, but I guess this
-	 * works for now.
-	 */
-	vm_t stack_top = t->thread_stack + t->thread_stack_size;
-	info("jumping to %lx\n", (long)t->callback);
+
+	/* reference main virtual memory */
+	struct tcb *r = get_rproc(t);
+	clone_uvmem(r->proc.vmem, t->rpc.vmem);
+	flush_tlb_all();
+
+	vm_t stack_top = t->rpc_stack - BASE_PAGE_SIZE;
+	info("jumping to %lx with sp = %lx\n", (long)t->callback, stack_top);
 
 	bkl_unlock();
 	riscv_run_init(0, t->tid, SYS_USER_SPAWNED, fdt, initrd, 1, stack_top);
diff --git a/arch/riscv64/kernel/vmem.c b/arch/riscv64/kernel/vmem.c
index 29ec3d5..cf1391e 100644
--- a/arch/riscv64/kernel/vmem.c
+++ b/arch/riscv64/kernel/vmem.c
@@ -538,7 +538,7 @@ vm_t setup_kernel_io(struct vmem *b, vm_t paddr)
 }
 #endif
 
-void clone_uvmem(struct vmem * restrict r, struct vmem * restrict b)
+void clone_uvmem(struct vmem *r, struct vmem *b)
 {
 	size_t i = 0;
 	for (; i < CSTACK_PAGE; ++i) {
@@ -574,20 +574,11 @@ stat_t setup_rpc_stack(struct tcb *t)
 		if (!page)
 			return ERR_OOMEM;
 
-		/* map both into rpc and proc spaces so we can write to the
-		 * current stack frame directly. Especially important when
-		 * returning from an rpc. Technically means that we could leak
-		 * memory if map_vpage() for proc.vmem allocates more and more
-		 * pages, but good enough for now. */
 		if (map_vpage(t->rpc.vmem, page,
 		              RPC_STACK_BASE + BASE_PAGE_SIZE * i,
 		              flags, BASE_PAGE))
 			return ERR_OOMEM;
 
-		if (map_vpage(t->proc.vmem, page,
-		              RPC_STACK_BASE + BASE_PAGE_SIZE * i,
-		              flags, BASE_PAGE))
-			return ERR_OOMEM;
 	}
 
 	/* we allocated a second order page for rpc stack usage */