4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Peter Zijlstra <pet...@infradead.org> (cherry picked from commit 1a29b5b7f347a1a9230c1e0af5b37e3e571588ab) Replace the indirect calls with CALL_NOSPEC. Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: David Woodhouse <d...@amazon.co.uk> Cc: Andrea Arcangeli <aarca...@redhat.com> Cc: Andi Kleen <a...@linux.intel.com> Cc: Ashok Raj <ashok....@intel.com> Cc: Greg KH <gre...@linuxfoundation.org> Cc: Jun Nakajima <jun.nakaj...@intel.com> Cc: David Woodhouse <dw...@infradead.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: r...@amazon.de Cc: Dave Hansen <dave.han...@intel.com> Cc: Asit Mallick <asit.k.mall...@intel.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Josh Poimboeuf <jpoim...@redhat.com> Cc: Jason Baron <jba...@akamai.com> Cc: Paolo Bonzini <pbonz...@redhat.com> Cc: Dan Williams <dan.j.willi...@intel.com> Cc: Arjan Van De Ven <arjan.van.de....@intel.com> Cc: Tim Chen <tim.c.c...@linux.intel.com> Link: https://lkml.kernel.org/r/20180125095843.595615...@infradead.org [dwmw2: Use ASM_CALL_CONSTRAINT like upstream, now we have it] Signed-off-by: David Woodhouse <d...@amazon.co.uk> [backport to 4.4] Signed-off-by: Jack Wang <jinpu.w...@profitbricks.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- arch/x86/kvm/emulate.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -26,6 +26,7 @@ #include <asm/kvm_emulate.h> #include <linux/stringify.h> #include <asm/debugreg.h> +#include <asm/nospec-branch.h> #include "x86.h" #include "tss.h" @@ -1000,8 +1001,8 @@ static u8 test_cc(unsigned int condition void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf); flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF; - asm("push %[flags]; popf; call *%[fastop]" - : "=a"(rc) : [fastop]"r"(fop), [flags]"r"(flags)); + asm("push %[flags]; popf; " CALL_NOSPEC + : "=a"(rc) : [thunk_target]"r"(fop), [flags]"r"(flags)); return rc; } @@ -5297,9 +5298,9 @@ static int fastop(struct x86_emulate_ctx ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF; if (!(ctxt->d & ByteOp)) fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE; - asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n" + asm("push %[flags]; popf; " CALL_NOSPEC "; pushf; pop %[flags]\n" : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags), - [fastop]"+S"(fop) + [thunk_target]"+S"(fop) : "c"(ctxt->src2.val)); ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); if (!fop) /* exception is returned in fop variable */
