x86: Sync 32/64-bit kernel_thread

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1260380084-3707-5-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 13 insertions, 3 deletions

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index bd874d2b6ab1..f2e8b05a4f02 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -211,14 +211,17 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
         regs.si = (unsigned long) fn;
         regs.di = (unsigned long) arg;
 
+#ifdef CONFIG_X86_32
         regs.ds = __USER_DS;
         regs.es = __USER_DS;
         regs.fs = __KERNEL_PERCPU;
         regs.gs = __KERNEL_STACK_CANARY;
+#endif
+
         regs.orig_ax = -1;
         regs.ip = (unsigned long) kernel_thread_helper;
         regs.cs = __KERNEL_CS | get_kernel_rpl();
-        regs.flags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2;
+        regs.flags = X86_EFLAGS_IF | 0x2;
 
         /* Ok, create the new process.. */
         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 00ac66fa5c6b..d49a9094f6f3 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -248,10 +248,17 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
         regs.si = (unsigned long) fn;
         regs.di = (unsigned long) arg;
 
+#ifdef CONFIG_X86_32
+        regs.ds = __USER_DS;
+        regs.es = __USER_DS;
+        regs.fs = __KERNEL_PERCPU;
+        regs.gs = __KERNEL_STACK_CANARY;
+#endif
+
         regs.orig_ax = -1;
         regs.ip = (unsigned long) kernel_thread_helper;
-        regs.cs = __KERNEL_CS;
-        regs.flags = X86_EFLAGS_IF;
+        regs.cs = __KERNEL_CS | get_kernel_rpl();
+        regs.flags = X86_EFLAGS_IF | 0x2;
 
         /* Ok, create the new process.. */
         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);