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Subject[PATCH v5 06/12] x86/retpoline/hyperv: Convert assembler indirect jumps
Date
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>
---
arch/x86/include/asm/mshyperv.h | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 581bb54..6534e57 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -7,6 +7,7 @@
#include <linux/nmi.h>
#include <asm/io.h>
#include <asm/hyperv.h>
+#include <asm/nospec-branch.h>

/*
* The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
@@ -186,10 +187,11 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
return U64_MAX;

__asm__ __volatile__("mov %4, %%r8\n"
- "call *%5"
+ NOSPEC_CALL
: "=a" (hv_status), ASM_CALL_CONSTRAINT,
"+c" (control), "+d" (input_address)
- : "r" (output_address), "m" (hv_hypercall_pg)
+ : "r" (output_address),
+ THUNK_TARGET(hv_hypercall_pg)
: "cc", "memory", "r8", "r9", "r10", "r11");
#else
u32 input_address_hi = upper_32_bits(input_address);
@@ -200,13 +202,13 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
if (!hv_hypercall_pg)
return U64_MAX;

- __asm__ __volatile__("call *%7"
+ __asm__ __volatile__(NOSPEC_CALL
: "=A" (hv_status),
"+c" (input_address_lo), ASM_CALL_CONSTRAINT
: "A" (control),
"b" (input_address_hi),
"D"(output_address_hi), "S"(output_address_lo),
- "m" (hv_hypercall_pg)
+ THUNK_TARGET(hv_hypercall_pg)
: "cc", "memory");
#endif /* !x86_64 */
return hv_status;
@@ -227,10 +229,10 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)

#ifdef CONFIG_X86_64
{
- __asm__ __volatile__("call *%4"
+ __asm__ __volatile__(NOSPEC_CALL
: "=a" (hv_status), ASM_CALL_CONSTRAINT,
"+c" (control), "+d" (input1)
- : "m" (hv_hypercall_pg)
+ : THUNK_TARGET(hv_hypercall_pg)
: "cc", "r8", "r9", "r10", "r11");
}
#else
@@ -238,13 +240,13 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
u32 input1_hi = upper_32_bits(input1);
u32 input1_lo = lower_32_bits(input1);

- __asm__ __volatile__ ("call *%5"
+ __asm__ __volatile__ (NOSPEC_CALL
: "=A"(hv_status),
"+c"(input1_lo),
ASM_CALL_CONSTRAINT
: "A" (control),
"b" (input1_hi),
- "m" (hv_hypercall_pg)
+ THUNK_TARGET(hv_hypercall_pg)
: "cc", "edi", "esi");
}
#endif
--
2.7.4
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