3.16.56-rc1 review patch. If anyone has any objections, please let me know.
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From: Andi Kleen ak@linux.intel.com
commit 7614e913db1f40fff819b36216484dc3808995d4 upstream.
Convert all indirect jumps in 32bit irq inline asm code to use non speculative sequences.
Signed-off-by: Andi Kleen ak@linux.intel.com 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: 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/1515707194-20531-12-git-send-email-dwmw@amazon.co.... [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- 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 @@ -20,6 +20,7 @@ #include <linux/mm.h>
#include <asm/apic.h> +#include <asm/nospec-branch.h>
DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); EXPORT_PER_CPU_SYMBOL(irq_stat); @@ -61,11 +62,11 @@ 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"); }
@@ -102,11 +103,11 @@ execute_on_irq_stack(int overflow, struc call_on_stack(print_stack_overflow, isp);
asm volatile("xchgl %%ebx,%%esp \n" - "call *%%edi \n" + CALL_NOSPEC "movl %%ebx,%%esp \n" : "=a" (arg1), "=d" (arg2), "=b" (isp) : "0" (irq), "1" (desc), "2" (isp), - "D" (desc->handle_irq) + [thunk_target] "D" (desc->handle_irq) : "memory", "cc", "ecx"); return 1; }