Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 asm updates from Ingo Molnar:
 "Most of the changes relate to Peter Zijlstra's cleanup of ptregs
  handling, in particular the i386 part is now much simplified and
  standardized - no more partial ptregs stack frames via the esp/ss
  oddity. This simplifies ftrace, kprobes, the unwinder, ptrace, kdump
  and kgdb.

  There's also a CR4 hardening enhancements by Kees Cook, to make the
  generic platform functions such as native_write_cr4() less useful as
  ROP gadgets that disable SMEP/SMAP. Also protect the WP bit of CR0
  against similar attacks.

  The rest is smaller cleanups/fixes"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternatives: Add int3_emulate_call() selftest
  x86/stackframe/32: Allow int3_emulate_push()
  x86/stackframe/32: Provide consistent pt_regs
  x86/stackframe, x86/ftrace: Add pt_regs frame annotations
  x86/stackframe, x86/kprobes: Fix frame pointer annotations
  x86/stackframe: Move ENCODE_FRAME_POINTER to asm/frame.h
  x86/entry/32: Clean up return from interrupt preemption path
  x86/asm: Pin sensitive CR0 bits
  x86/asm: Pin sensitive CR4 bits
  Documentation/x86: Fix path to entry_32.S
  x86/asm: Remove unused TASK_TI_flags from asm-offsets.c

1 files changed, 0 insertions, 29 deletions

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index ee9099061d01..8eb1e58de043 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -155,35 +155,6 @@ static inline bool invalid_selector(u16 value)
 
 #define FLAG_MASK		FLAG_MASK_32
 
-/*
- * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
- * when it traps.  The previous stack will be directly underneath the saved
- * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
- *
- * Now, if the stack is empty, '&regs->sp' is out of range. In this
- * case we try to take the previous stack. To always return a non-null
- * stack pointer we fall back to regs as stack if no previous stack
- * exists.
- *
- * This is valid only for kernel mode traps.
- */
-unsigned long kernel_stack_pointer(struct pt_regs *regs)
-{
-	unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
-	unsigned long sp = (unsigned long)&regs->sp;
-	u32 *prev_esp;
-
-	if (context == (sp & ~(THREAD_SIZE - 1)))
-		return sp;
-
-	prev_esp = (u32 *)(context);
-	if (*prev_esp)
-		return (unsigned long)*prev_esp;
-
-	return (unsigned long)regs;
-}
-EXPORT_SYMBOL_GPL(kernel_stack_pointer);
-
 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
 {
 	BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);