Messages in this thread Patch in this message | | | Date | Fri, 11 Dec 2009 00:45:50 GMT | From | tip-bot for Brian Gerst <> | Subject | [tip:x86/asm] x86, 64-bit: Use user_mode() to determine new stack pointer in copy_thread() |
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Commit-ID: fa4b8f84383ae197e643a46c36bf58ab8dffc95c Gitweb: http://git.kernel.org/tip/fa4b8f84383ae197e643a46c36bf58ab8dffc95c Author: Brian Gerst <brgerst@gmail.com> AuthorDate: Wed, 9 Dec 2009 12:34:41 -0500 Committer: H. Peter Anvin <hpa@zytor.com> CommitDate: Thu, 10 Dec 2009 15:55:30 -0800
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: Brian Gerst <brgerst@gmail.com> LKML-Reference: <1260380084-3707-3-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> --- arch/x86/kernel/process_64.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 92484c2..00ac66f 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -254,7 +254,7 @@ int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) regs.flags = X86_EFLAGS_IF; /* Ok, create the new process.. */ - return do_fork(flags | CLONE_VM | CLONE_UNTRACED, ~0UL, ®s, 0, NULL, NULL); + return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } EXPORT_SYMBOL(kernel_thread); @@ -312,8 +312,9 @@ int copy_thread(unsigned long clone_flags, unsigned long sp, *childregs = *regs; childregs->ax = 0; - childregs->sp = sp; - if (sp == ~0UL) + if (user_mode(regs)) + childregs->sp = sp; + else childregs->sp = (unsigned long)childregs; p->thread.sp = (unsigned long) childregs;
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