---

yaml --- r: 121025 b: refs/heads/master c: 5b3eec0 h: refs/heads/master i: 121023: 1013ccd v: v3
git-mirror · Nov 28, 2008 · 0ec5e04 · 0ec5e04
1 parent a8ecbde
commit 0ec5e04
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Showing 2 changed files with 17 additions and 16 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3bdae4f46445ea7cc9ee031d7ff106fdc6228669
+refs/heads/master: 5b3eec0c80038c8739ccd465b897a35c0dff1cc4
diff --git a/trunk/arch/x86/kernel/entry_64.S b/trunk/arch/x86/kernel/entry_64.S
@@ -361,34 +361,35 @@ ENTRY(save_paranoid)
 END(save_paranoid)
 
 /*
- * A newly forked process directly context switches into this.
+ * A newly forked process directly context switches into this address.
+ *
+ * rdi: prev task we switched from
  */
-/* rdi:	prev */
 ENTRY(ret_from_fork)
 	DEFAULT_FRAME
+
 	push kernel_eflags(%rip)
 	CFI_ADJUST_CFA_OFFSET 8
-	popf				# reset kernel eflags
+	popf					# reset kernel eflags
 	CFI_ADJUST_CFA_OFFSET -8
-	call schedule_tail
+
+	call schedule_tail			# rdi: 'prev' task parameter
+
 	GET_THREAD_INFO(%rcx)
-	testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
+
 	CFI_REMEMBER_STATE
-	jnz rff_trace
-rff_action:
 	RESTORE_REST
-	testl $3,CS-ARGOFFSET(%rsp)	# from kernel_thread?
+
+	testl $3, CS-ARGOFFSET(%rsp)		# from kernel_thread?
 	je   int_ret_from_sys_call
-	testl $_TIF_IA32,TI_flags(%rcx)
+
+	testl $_TIF_IA32, TI_flags(%rcx)	# 32-bit compat task needs IRET
 	jnz  int_ret_from_sys_call
+
 	RESTORE_TOP_OF_STACK %rdi, -ARGOFFSET
-	jmp ret_from_sys_call
+	jmp ret_from_sys_call			# go to the SYSRET fastpath
+
 	CFI_RESTORE_STATE
-rff_trace:
-	movq %rsp,%rdi
-	call syscall_trace_leave
-	GET_THREAD_INFO(%rcx)
-	jmp rff_action
 	CFI_ENDPROC
 END(ret_from_fork)