| Message ID | 20210921010120.1256762-3-oupton@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | selftests: KVM: Fix some compiler warnings | expand |
On Tue, Sep 21, 2021 at 01:01:20AM +0000, Oliver Upton wrote: > Building steal_time.c for arm64 with clang throws the following: > > >> steal_time.c:130:22: error: value size does not match register size specified by the constraint and modifier [-Werror,-Wasm-operand-widths] > : "=r" (ret) : "r" (func), "r" (arg) : > ^ > >> steal_time.c:130:34: error: value size does not match register size specified by the constraint and modifier [-Werror,-Wasm-operand-widths] > : "=r" (ret) : "r" (func), "r" (arg) : > ^ > > Silence by casting operands to 64 bits. > > Signed-off-by: Oliver Upton <oupton@google.com> > --- > tools/testing/selftests/kvm/steal_time.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c > index ecec30865a74..eb75b31122c5 100644 > --- a/tools/testing/selftests/kvm/steal_time.c > +++ b/tools/testing/selftests/kvm/steal_time.c > @@ -127,7 +127,7 @@ static int64_t smccc(uint32_t func, uint32_t arg) > "mov x1, %2\n" > "hvc #0\n" > "mov %0, x0\n" > - : "=r" (ret) : "r" (func), "r" (arg) : > + : "=r" (ret) : "r" ((uint64_t)func), "r" ((uint64_t)arg) : Actually, I think I'd rather fix this smccc implementation to match the spec, which I think should be done like this diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c index ecec30865a74..7da957259ce4 100644 --- a/tools/testing/selftests/kvm/steal_time.c +++ b/tools/testing/selftests/kvm/steal_time.c @@ -118,12 +118,12 @@ struct st_time { uint64_t st_time; }; -static int64_t smccc(uint32_t func, uint32_t arg) +static int64_t smccc(uint32_t func, uint64_t arg) { unsigned long ret; asm volatile( - "mov x0, %1\n" + "mov w0, %w1\n" "mov x1, %2\n" "hvc #0\n" "mov %0, x0\n" Thanks, drew > "x0", "x1", "x2", "x3"); > > return ret; > -- > 2.33.0.464.g1972c5931b-goog >
On 21/09/21 09:19, Andrew Jones wrote: > On Tue, Sep 21, 2021 at 01:01:20AM +0000, Oliver Upton wrote: >> Building steal_time.c for arm64 with clang throws the following: >> >>>> steal_time.c:130:22: error: value size does not match register size specified by the constraint and modifier [-Werror,-Wasm-operand-widths] >> : "=r" (ret) : "r" (func), "r" (arg) : >> ^ >>>> steal_time.c:130:34: error: value size does not match register size specified by the constraint and modifier [-Werror,-Wasm-operand-widths] >> : "=r" (ret) : "r" (func), "r" (arg) : >> ^ >> >> Silence by casting operands to 64 bits. >> >> Signed-off-by: Oliver Upton <oupton@google.com> >> --- >> tools/testing/selftests/kvm/steal_time.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c >> index ecec30865a74..eb75b31122c5 100644 >> --- a/tools/testing/selftests/kvm/steal_time.c >> +++ b/tools/testing/selftests/kvm/steal_time.c >> @@ -127,7 +127,7 @@ static int64_t smccc(uint32_t func, uint32_t arg) >> "mov x1, %2\n" >> "hvc #0\n" >> "mov %0, x0\n" >> - : "=r" (ret) : "r" (func), "r" (arg) : >> + : "=r" (ret) : "r" ((uint64_t)func), "r" ((uint64_t)arg) : > > Actually, I think I'd rather fix this smccc implementation to match the > spec, which I think should be done like this > > diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c > index ecec30865a74..7da957259ce4 100644 > --- a/tools/testing/selftests/kvm/steal_time.c > +++ b/tools/testing/selftests/kvm/steal_time.c > @@ -118,12 +118,12 @@ struct st_time { > uint64_t st_time; > }; > > -static int64_t smccc(uint32_t func, uint32_t arg) > +static int64_t smccc(uint32_t func, uint64_t arg) > { > unsigned long ret; > > asm volatile( > - "mov x0, %1\n" > + "mov w0, %w1\n" > "mov x1, %2\n" > "hvc #0\n" > "mov %0, x0\n" > Agreed, can you send out a patch? Thanks, Paolo
diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c index ecec30865a74..eb75b31122c5 100644 --- a/tools/testing/selftests/kvm/steal_time.c +++ b/tools/testing/selftests/kvm/steal_time.c @@ -127,7 +127,7 @@ static int64_t smccc(uint32_t func, uint32_t arg) "mov x1, %2\n" "hvc #0\n" "mov %0, x0\n" - : "=r" (ret) : "r" (func), "r" (arg) : + : "=r" (ret) : "r" ((uint64_t)func), "r" ((uint64_t)arg) : "x0", "x1", "x2", "x3"); return ret;