[PATCH v3 09/13] x86/retpoline/irq32: Convert assembler indirect jumps

[David Woodhouse]

From: Andi Kleen <a...@linux.intel.com>

Convert all indirect jumps in 32bit irq inline asm code to use
non speculative sequences.

Signed-off-by: Andi Kleen <a...@linux.intel.com>
Signed-off-by: David Woodhouse <d...@amazon.co.uk>
---
 arch/x86/kernel/irq_32.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index a83b3346a0e1..e1e58f738c3d 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -20,6 +20,7 @@
 #include <linux/mm.h>
 
 #include <asm/apic.h>
+#include <asm/nospec-branch.h>
 
 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 
@@ -55,11 +56,11 @@ DEFINE_PER_CPU(struct irq_stack *, softirq_stack);
 static void call_on_stack(void *func, void *stack)
 {
        asm volatile("xchgl     %%ebx,%%esp     \n"
-                    "call      *%%edi          \n"
+                    NOSPEC_CALL
                     "movl      %%ebx,%%esp     \n"
                     : "=b" (stack)
                     : "0" (stack),
-                      "D"(func)
+                      [thunk_target] "D"(func)
                     : "memory", "cc", "edx", "ecx", "eax");
 }
 
@@ -95,11 +96,11 @@ static inline int execute_on_irq_stack(int overflow, struct 
irq_desc *desc)
                call_on_stack(print_stack_overflow, isp);
 
        asm volatile("xchgl     %%ebx,%%esp     \n"
-                    "call      *%%edi          \n"
+                    NOSPEC_CALL
                     "movl      %%ebx,%%esp     \n"
                     : "=a" (arg1), "=b" (isp)
                     :  "0" (desc),   "1" (isp),
-                       "D" (desc->handle_irq)
+                       [thunk_target] "D" (desc->handle_irq)
                     : "memory", "cc", "ecx");
        return 1;
 }
-- 
2.14.3