From b6032515a058fb02c8c4152c9f055bb3bd462ae2 Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Tue, 12 Feb 2013 23:02:33 -0800
Subject: [PATCH] Fix __pthread_clone and __bionic_clone error handling on x86.

Bug: 3461078
Change-Id: I93c151e27411211dd32717f206745c62c08c21ee
---
 libc/arch-x86/bionic/clone.S | 40 +++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/libc/arch-x86/bionic/clone.S b/libc/arch-x86/bionic/clone.S
index 6f84724c3..e7bc3eec0 100644
--- a/libc/arch-x86/bionic/clone.S
+++ b/libc/arch-x86/bionic/clone.S
@@ -21,27 +21,33 @@ ENTRY(__pthread_clone)
 
         subl    $16, %ecx
         movl    20(%esp), %ebx
+
+        # make system call
         movl    $__NR_clone, %eax
         int     $0x80
-        test    %eax, %eax
-        jns     1f
+
+        cmpl    $0, %eax
+        je      pc_child
+        jg      pc_parent
 
         # an error occurred, set errno and return -1
         negl    %eax
+        pushl   %eax
         call    __set_errno
+        addl    $4, %esp
         orl     $-1, %eax
-        jmp     2f
-
-1:
-        jnz     2f
+        jmp     pc_return
 
+pc_child:
         # we're in the child thread now, call __thread_entry
         # with the appropriate arguments on the child stack
         # we already placed most of them
         call    __thread_entry
         hlt
 
-2:
+pc_parent:
+        # we're the parent; nothing to do.
+pc_return:
         popl    %ecx
         popl    %ebx
         ret
@@ -75,27 +81,33 @@ ENTRY(__bionic_clone)
         movl    24(%esp), %edx
         movl    32(%esp), %esi
         movl    28(%esp), %edi
+
+        # make system call
         movl    $__NR_clone, %eax
         int     $0x80
-        test    %eax, %eax
-        jns     1f
+
+        cmpl    $0, %eax
+        je      bc_child
+        jg      bc_parent
 
         # an error occurred, set errno and return -1
         negl    %eax
+        pushl   %eax
         call    __set_errno
+        addl    $4, %esp
         orl     $-1, %eax
-        jmp     2f
-
-1:
-        jnz     2f
+        jmp     bc_return
 
+bc_child:
         # we're in the child now, call __bionic_clone_entry
         # with the appropriate arguments on the child stack
         # we already placed most of them
         call    __bionic_clone_entry
         hlt
 
-2:
+bc_parent:
+        # we're the parent; nothing to do.
+bc_return:
         popl    %edi
         popl    %esi
         popl    %ebx