x86/retpoline/hyperv: Convert assembler indirect jumps

Convert all indirect jumps in hyperv inline asm code to use non-speculative
sequences when CONFIG_RETPOLINE is enabled.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-9-git-send-email-dwmw@amazon.co.uk

1 files changed, 10 insertions, 8 deletions

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 581bb54dd464..5119e4b555cc 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -7,6 +7,7 @@
 #include <linux/nmi.h>
 #include <asm/io.h>
 #include <asm/hyperv.h>
+#include <asm/nospec-branch.h>
 
 /*
  * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
@@ -186,10 +187,11 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
                 return U64_MAX;
 
         __asm__ __volatile__("mov %4, %%r8\n"
-                             "call *%5"
+                             CALL_NOSPEC
                              : "=a" (hv_status), ASM_CALL_CONSTRAINT,
                                "+c" (control), "+d" (input_address)
-                             :  "r" (output_address), "m" (hv_hypercall_pg)
+                             :  "r" (output_address),
+                                THUNK_TARGET(hv_hypercall_pg)
                              : "cc", "memory", "r8", "r9", "r10", "r11");
 #else
         u32 input_address_hi = upper_32_bits(input_address);
@@ -200,13 +202,13 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
         if (!hv_hypercall_pg)
                 return U64_MAX;
 
-        __asm__ __volatile__("call *%7"
+        __asm__ __volatile__(CALL_NOSPEC
                              : "=A" (hv_status),
                                "+c" (input_address_lo), ASM_CALL_CONSTRAINT
                              : "A" (control),
                                "b" (input_address_hi),
                                "D"(output_address_hi), "S"(output_address_lo),
-                               "m" (hv_hypercall_pg)
+                               THUNK_TARGET(hv_hypercall_pg)
                              : "cc", "memory");
 #endif /* !x86_64 */
         return hv_status;
@@ -227,10 +229,10 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
 
 #ifdef CONFIG_X86_64
         {
-                __asm__ __volatile__("call *%4"
+                __asm__ __volatile__(CALL_NOSPEC
                                      : "=a" (hv_status), ASM_CALL_CONSTRAINT,
                                        "+c" (control), "+d" (input1)
-                                     : "m" (hv_hypercall_pg)
+                                     : THUNK_TARGET(hv_hypercall_pg)
                                      : "cc", "r8", "r9", "r10", "r11");
         }
 #else
@@ -238,13 +240,13 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
                 u32 input1_hi = upper_32_bits(input1);
                 u32 input1_lo = lower_32_bits(input1);
 
-                __asm__ __volatile__ ("call *%5"
+                __asm__ __volatile__ (CALL_NOSPEC
                                       : "=A"(hv_status),
                                         "+c"(input1_lo),
                                         ASM_CALL_CONSTRAINT
                                       : "A" (control),
                                         "b" (input1_hi),
-                                        "m" (hv_hypercall_pg)
+                                        THUNK_TARGET(hv_hypercall_pg)
                                       : "cc", "edi", "esi");
         }
 #endif