3.16.56-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: David Woodhouse <dwmw@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Acked-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx> Acked-by: Ingo Molnar <mingo@xxxxxxxxxx> Cc: gnomes@xxxxxxxxxxxxxxxxxxx Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: thomas.lendacky@xxxxxxx Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Jiri Kosina <jikos@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxx> Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxxx> Cc: Paul Turner <pjt@xxxxxxxxxx> Link: https://lkml.kernel.org/r/1515707194-20531-9-git-send-email-dwmw@xxxxxxxxxxxx [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@xxxxxxxxxxxxxxx> --- 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 */