[PATCH v2 08/12] x86/retpoline/irq32: Convert assembler indirect jumps

From: Andi Kleen
Date: Wed Jan 03 2018 - 21:02:10 EST


From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

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

Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/irq_32.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index a83b3346a0e1..2dce2fdd2c4e 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/jump-asm.h>

#ifdef CONFIG_DEBUG_STACKOVERFLOW

@@ -55,7 +56,7 @@ 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("%%edi")
"movl %%ebx,%%esp \n"
: "=b" (stack)
: "0" (stack),
@@ -95,7 +96,7 @@ 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("%%edi")
"movl %%ebx,%%esp \n"
: "=a" (arg1), "=b" (isp)
: "0" (desc), "1" (isp),
--
2.14.3