From ea95a6654c3f921849f3541aa856a8806ebf571e Mon Sep 17 00:00:00 2001
From: Robert Morris <rtm@csail.mit.edu>
Date: Fri, 26 Jul 2019 04:53:46 -0400
Subject: [PATCH] trampin -> uservec trampout -> userret

---
 kernel/kernel.ld    |  2 +-
 kernel/proc.c       |  4 ++--
 kernel/proc.h       |  4 ++--
 kernel/trampoline.S | 17 +++++++++--------
 kernel/trap.c       |  4 ++--
 kernel/vm.c         |  4 ++--
 6 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/kernel/kernel.ld b/kernel/kernel.ld
index dec8e4f..0b5e76b 100644
--- a/kernel/kernel.ld
+++ b/kernel/kernel.ld
@@ -12,7 +12,7 @@ SECTIONS
   {
     *(.text)
     . = ALIGN(0x1000);
-    *(trampoline)
+    *(trampsec)
   }
 
   . = ALIGN(0x1000);
diff --git a/kernel/proc.c b/kernel/proc.c
index 48b006f..0dcae00 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -18,7 +18,7 @@ struct spinlock pid_lock;
 extern void forkret(void);
 static void wakeup1(struct proc *chan);
 
-extern char trampout[]; // trampoline.S
+extern char trampoline[]; // trampoline.S
 
 void
 procinit(void)
@@ -159,7 +159,7 @@ proc_pagetable(struct proc *p)
   // only the supervisor uses it, on the way
   // to/from user space, so not PTE_U.
   mappages(pagetable, TRAMPOLINE, PGSIZE,
-           (uint64)trampout, PTE_R | PTE_X);
+           (uint64)trampoline, PTE_R | PTE_X);
 
   // map the trapframe just below TRAMPOLINE, for trampoline.S.
   mappages(pagetable, TRAPFRAME, PGSIZE,
diff --git a/kernel/proc.h b/kernel/proc.h
index d515043..655d79f 100644
--- a/kernel/proc.h
+++ b/kernel/proc.h
@@ -32,10 +32,10 @@ extern struct cpu cpus[NCPU];
 // sits in a page by itself just under the trampoline page in the
 // user page table. not specially mapped in the kernel page table.
 // the sscratch register points here.
-// trampin in trampoline.S saves user registers in the trapframe,
+// uservec in trampoline.S saves user registers in the trapframe,
 // then initializes registers from the trapframe's
 // kernel_sp, kernel_hartid, kernel_satp, and jumps to kernel_trap.
-// usertrapret() and trampout in trampoline.S set up
+// usertrapret() and userret in trampoline.S set up
 // the trapframe's kernel_*, restore user registers from the
 // trapframe, switch to the user page table, and enter user space.
 // the trapframe includes callee-saved user registers like s0-s11 because the
diff --git a/kernel/trampoline.S b/kernel/trampoline.S
index d4066c9..bc31974 100644
--- a/kernel/trampoline.S
+++ b/kernel/trampoline.S
@@ -5,14 +5,15 @@
         # in user and kernel space so that it continues
         # to work when it switches page tables.
 	#
-	# kernel.ld causes trampout to be aligned
+	# kernel.ld causes userret to be aligned
         # to a page boundary.
         #
-.globl usertrap
-	.section trampoline
-.globl trampout
-trampout:
-        # trampout(trapframe, pagetable)
+	.section trampsec
+.globl trampoline
+trampoline:
+.globl userret
+userret:
+        # userret(trapframe, pagetable)
         # switch from kernel to user.
         # usertrapret() calls here.
 	# a0: p->tf in user page table
@@ -67,8 +68,8 @@ trampout:
         sret
 
 .align 4
-.globl trampin
-trampin:    
+.globl uservec
+uservec:    
 	#
         # trap.c set stvec to point here, so
         # user interrupts and exceptions start here,
diff --git a/kernel/trap.c b/kernel/trap.c
index ef2b618..ad2d0f8 100644
--- a/kernel/trap.c
+++ b/kernel/trap.c
@@ -9,7 +9,7 @@
 struct spinlock tickslock;
 uint ticks;
 
-extern char trampout[], trampin[];
+extern char trampoline[], uservec[];
 
 // in kernelvec.S, calls kerneltrap().
 void kernelvec();
@@ -96,7 +96,7 @@ usertrapret(void)
   intr_off();
 
   // send interrupts and exceptions to trampoline.S
-  w_stvec(TRAMPOLINE + (trampin - trampout));
+  w_stvec(TRAMPOLINE + (uservec - trampoline));
 
   // set up values that trampoline.S will need when
   // the process next re-enters the kernel.
diff --git a/kernel/vm.c b/kernel/vm.c
index 33469d1..a1c36ba 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -13,7 +13,7 @@ pagetable_t kernel_pagetable;
 
 extern char etext[];  // kernel.ld sets this to end of kernel code.
 
-extern char trampout[]; // trampoline.S
+extern char trampoline[]; // trampoline.S
 
 /*
  * create a direct-map page table for the kernel and
@@ -46,7 +46,7 @@ kvminit()
 
   // map the trampoline for trap entry/exit to
   // the highest virtual address in the kernel.
-  kvmmap(TRAMPOLINE, (uint64)trampout, PGSIZE, PTE_R | PTE_X);
+  kvmmap(TRAMPOLINE, (uint64)trampoline, PGSIZE, PTE_R | PTE_X);
 }
 
 // Switch h/w page table register to the kernel's page table,