3.16.56-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: David Woodhouse dwmw@amazon.co.uk
commit e70e5892b28c18f517f29ab6e83bd57705104b31 upstream.
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.u... [bwh: Backported to 3.16: - Drop changes to hv_do_fast_hypercall8() - Include earlier updates to the asm constraints - Adjust filename, context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/hv/hv.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)
--- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -29,6 +29,7 @@ #include <linux/version.h> #include <linux/interrupt.h> #include <asm/hyperv.h> +#include <asm/nospec-branch.h> #include "hyperv_vmbus.h"
/* The one and only */ @@ -93,10 +94,13 @@ static u64 do_hypercall(u64 control, voi u64 output_address = (output) ? virt_to_phys(output) : 0; void *hypercall_page = hv_context.hypercall_page;
- __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8"); - __asm__ __volatile__("call *%3" : "=a" (hv_status) : - "c" (control), "d" (input_address), - "m" (hypercall_page)); + __asm__ __volatile__("mov %4, %%r8\n" + CALL_NOSPEC + : "=a" (hv_status), ASM_CALL_CONSTRAINT, + "+c" (control), "+d" (input_address) + : "r" (output_address), + THUNK_TARGET(hypercall_page) + : "cc", "memory", "r8", "r9", "r10", "r11");
return hv_status;
@@ -114,11 +118,14 @@ static u64 do_hypercall(u64 control, voi u32 output_address_lo = output_address & 0xFFFFFFFF; void *hypercall_page = hv_context.hypercall_page;
- __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi), - "=a"(hv_status_lo) : "d" (control_hi), - "a" (control_lo), "b" (input_address_hi), - "c" (input_address_lo), "D"(output_address_hi), - "S"(output_address_lo), "m" (hypercall_page)); + __asm__ __volatile__(CALL_NOSPEC + : "=d" (hv_status_hi), "=a" (hv_status_lo), + "+c" (input_address_lo), ASM_CALL_CONSTRAINT + : "d" (control_hi), "a" (control_lo), + "b" (input_address_hi), + "D"(output_address_hi), "S"(output_address_lo), + THUNK_TARGET(hypercall_page) + : "cc", "memory");
return hv_status_lo | ((u64)hv_status_hi << 32); #endif /* !x86_64 */