4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: David Woodhouse <[email protected]> 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 <[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: Andi Kleen <[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] [ backport to 4.9, hopefully correct, not tested... - gregkh ] Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/hv/hv.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -31,6 +31,7 @@ #include <linux/clockchips.h> #include <asm/hyperv.h> #include <asm/mshyperv.h> +#include <asm/nospec-branch.h> #include "hyperv_vmbus.h" /* The one and only */ @@ -103,9 +104,10 @@ u64 hv_do_hypercall(u64 control, void *i return (u64)ULLONG_MAX; __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8"); - __asm__ __volatile__("call *%3" : "=a" (hv_status) : + __asm__ __volatile__(CALL_NOSPEC : + "=a" (hv_status) : "c" (control), "d" (input_address), - "m" (hypercall_page)); + THUNK_TARGET(hypercall_page)); return hv_status; @@ -123,11 +125,12 @@ u64 hv_do_hypercall(u64 control, void *i if (!hypercall_page) return (u64)ULLONG_MAX; - __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi), + __asm__ __volatile__ (CALL_NOSPEC : "=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)); + "S"(output_address_lo), + THUNK_TARGET(hypercall_page)); return hv_status_lo | ((u64)hv_status_hi << 32); #endif /* !x86_64 */
