4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Andi Kleen <[email protected]> commit 7614e913db1f40fff819b36216484dc3808995d4 upstream. Convert all indirect jumps in 32bit irq inline asm code to use non speculative sequences. Signed-off-by: Andi Kleen <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: Arjan van de Ven <[email protected]> Acked-by: Ingo Molnar <[email protected]> Cc: [email protected] Cc: Rik van Riel <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: [email protected] Cc: Peter Zijlstra <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Jiri Kosina <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Kees Cook <[email protected]> Cc: Tim Chen <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Paul Turner <[email protected]> Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: David Woodhouse <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/kernel/irq_32.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -19,6 +19,7 @@ #include <linux/mm.h> #include <asm/apic.h> +#include <asm/nospec-branch.h> #ifdef CONFIG_DEBUG_STACKOVERFLOW @@ -54,11 +55,11 @@ DEFINE_PER_CPU(struct irq_stack *, softi static void call_on_stack(void *func, void *stack) { asm volatile("xchgl %%ebx,%%esp \n" - "call *%%edi \n" + CALL_NOSPEC "movl %%ebx,%%esp \n" : "=b" (stack) : "0" (stack), - "D"(func) + [thunk_target] "D"(func) : "memory", "cc", "edx", "ecx", "eax"); } @@ -94,11 +95,11 @@ static inline int execute_on_irq_stack(i call_on_stack(print_stack_overflow, isp); asm volatile("xchgl %%ebx,%%esp \n" - "call *%%edi \n" + CALL_NOSPEC "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; }
