X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Fswitch.S;h=244249e07c063594fc3f385937781d22b0bd2371;hb=eb5c6a0f64ab2b0a9efa853fa0ef53822af80047;hp=374da9e4a11cfd64a79816c3d358a177b224ff09;hpb=e5b8483ba96df26aa42ccee127cb9a1d50e67f47;p=pintos-anon

diff --git a/src/threads/switch.S b/src/threads/switch.S
index 374da9e..244249e 100644
--- a/src/threads/switch.S
+++ b/src/threads/switch.S
@@ -12,7 +12,8 @@
 #### restore the registers.  As part of switching stacks we record the
 #### current stack pointer in CUR's thread structure.
 
-.globl switch_threads 
+.globl switch_threads
+.func switch_threads
 switch_threads:
 	# Save caller's register state.
 	#
@@ -20,7 +21,8 @@ switch_threads:
 	# but requires us to preserve %ebx, %ebp, %esi, %edi.  See
 	# [SysV-ABI-386] pages 3-11 and 3-12 for details.
 	#
-	# This stack frame must match the one set up by thread_create().
+	# This stack frame must match the one set up by thread_create()
+	# in size.
 	pushl %ebx
 	pushl %ebp
 	pushl %esi
@@ -32,10 +34,7 @@ switch_threads:
 
 	# Save current stack pointer to old thread's stack, if any.
 	movl SWITCH_CUR(%esp), %eax
-	test %eax, %eax
-	jz 1f
 	movl %esp, (%eax,%edx,1)
-1:
 
 	# Restore stack pointer from new thread's stack.
 	movl SWITCH_NEXT(%esp), %ecx
@@ -47,8 +46,10 @@ switch_threads:
 	popl %ebp
 	popl %ebx
         ret
+.endfunc
 
 .globl switch_entry
+.func switch_entry
 switch_entry:
 	# Discard switch_threads() arguments.
 	addl $8, %esp
@@ -61,3 +62,4 @@ switch_entry:
 
 	# Start thread proper.
 	ret
+.endfunc