Commit fa4b8f84 authored by Brian Gerst's avatar Brian Gerst Committed by H. Peter Anvin

x86, 64-bit: Use user_mode() to determine new stack pointer in copy_thread()

Use user_mode() instead of a magic value for sp to determine when returning
to kernel mode.
Signed-off-by: default avatarBrian Gerst <brgerst@gmail.com>
LKML-Reference: <1260380084-3707-3-git-send-email-brgerst@gmail.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 3bd95dfb
...@@ -254,7 +254,7 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) ...@@ -254,7 +254,7 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
regs.flags = X86_EFLAGS_IF; regs.flags = X86_EFLAGS_IF;
/* Ok, create the new process.. */ /* Ok, create the new process.. */
return do_fork(flags | CLONE_VM | CLONE_UNTRACED, ~0UL, &regs, 0, NULL, NULL); return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
} }
EXPORT_SYMBOL(kernel_thread); EXPORT_SYMBOL(kernel_thread);
...@@ -312,8 +312,9 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, ...@@ -312,8 +312,9 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
*childregs = *regs; *childregs = *regs;
childregs->ax = 0; childregs->ax = 0;
childregs->sp = sp; if (user_mode(regs))
if (sp == ~0UL) childregs->sp = sp;
else
childregs->sp = (unsigned long)childregs; childregs->sp = (unsigned long)childregs;
p->thread.sp = (unsigned long) childregs; p->thread.sp = (unsigned long) childregs;
......
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