X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Fthreads%2Fswitch.S;h=244249e07c063594fc3f385937781d22b0bd2371;hb=2b4b1acd2d80945294b8786396251857005c0a81;hp=6cb70aa86e38b8ad85c930376e260ce7ef43cf1d;hpb=575dc45e34db19ee7808c116e93485b37e0df716;p=pintos-anon

diff --git a/src/threads/switch.S b/src/threads/switch.S
index 6cb70aa..244249e 100644
--- a/src/threads/switch.S
+++ b/src/threads/switch.S
@@ -21,7 +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
@@ -33,10 +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