LinuxLists.cc - [PATCH] x86/cpu/vmware: use the full form of inl in VMWARE

2019-10-07 19:22:09

Subject: [PATCH] x86/cpu/vmware: use the full form of inl in VMWARE_PORT

LLVM's assembler doesn't accept the short form inl (%%dx) instruction,
but instead insists on the output register to be explicitly specified:

<inline asm>:1:7: error: invalid operand for instruction
inl (%dx)
^
LLVM ERROR: Error parsing inline asm

Use the full form of the instruction to fix the build.

Signed-off-by: Sami Tolvanen <[email protected]>
---
arch/x86/kernel/cpu/vmware.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 9735139cfdf8..46d732696c1c 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -49,7 +49,7 @@
#define VMWARE_CMD_VCPU_RESERVED 31

#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
- __asm__("inl (%%dx)" : \
+ __asm__("inl (%%dx), %%eax" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \
--
2.23.0.581.g78d2f28ef7-goog

2019-10-07 19:32:31

by Thomas Hellstrom

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Subject: Re: [PATCH] x86/cpu/vmware: use the full form of inl in VMWARE_PORT

On 10/7/19 9:21 PM, Sami Tolvanen wrote:
> LLVM's assembler doesn't accept the short form inl (%%dx) instruction,
> but instead insists on the output register to be explicitly specified:
>
> <inline asm>:1:7: error: invalid operand for instruction
> inl (%dx)
> ^
> LLVM ERROR: Error parsing inline asm
>
> Use the full form of the instruction to fix the build.
>
> Signed-off-by: Sami Tolvanen <[email protected]>

Acked-by: Thomas Hellstrom <[email protected]>

> ---
> arch/x86/kernel/cpu/vmware.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
> index 9735139cfdf8..46d732696c1c 100644
> --- a/arch/x86/kernel/cpu/vmware.c
> +++ b/arch/x86/kernel/cpu/vmware.c
> @@ -49,7 +49,7 @@
> #define VMWARE_CMD_VCPU_RESERVED 31
>
> #define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
> - __asm__("inl (%%dx)" : \
> + __asm__("inl (%%dx), %%eax" : \
> "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
> "a"(VMWARE_HYPERVISOR_MAGIC), \
> "c"(VMWARE_CMD_##cmd), \

2019-10-07 19:58:35

by Nick Desaulniers

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Subject: Re: [PATCH] x86/cpu/vmware: use the full form of inl in VMWARE_PORT

On Mon, Oct 7, 2019 at 12:21 PM 'Sami Tolvanen' via Clang Built Linux
<[email protected]> wrote:
>
> LLVM's assembler doesn't accept the short form inl (%%dx) instruction,
> but instead insists on the output register to be explicitly specified:
>
> <inline asm>:1:7: error: invalid operand for instruction
> inl (%dx)
> ^
> LLVM ERROR: Error parsing inline asm
>
> Use the full form of the instruction to fix the build.
>
> Signed-off-by: Sami Tolvanen <[email protected]>

Thanks Sami, this looks like it addresses:
Link: https://github.com/ClangBuiltLinux/linux/issues/734
Looks like GAS' testsuite has some cases where the second operand is
indeed implicitly %eax if unspecified. (This should still be fixed in
Clang).
Just to triple check that they're equivalent:
$ cat inl.s
inl (%dx)
inl (%dx), %eax
$ as inl.s
$ objdump -d a.out

a.out: file format elf64-x86-64

Disassembly of section .text:

0000000000000000 <.text>:
0: ed in (%dx),%eax
1: ed in (%dx),%eax

Reviewed-by: Nick Desaulniers <[email protected]>

> ---
> arch/x86/kernel/cpu/vmware.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
> index 9735139cfdf8..46d732696c1c 100644
> --- a/arch/x86/kernel/cpu/vmware.c
> +++ b/arch/x86/kernel/cpu/vmware.c
> @@ -49,7 +49,7 @@
> #define VMWARE_CMD_VCPU_RESERVED 31
>
> #define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
> - __asm__("inl (%%dx)" : \
> + __asm__("inl (%%dx), %%eax" : \
> "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
> "a"(VMWARE_HYPERVISOR_MAGIC), \
> "c"(VMWARE_CMD_##cmd), \

--
Thanks,
~Nick Desaulniers

2019-10-08 00:44:59

by Kees Cook

[permalink] [raw]

Subject: Re: [PATCH] x86/cpu/vmware: use the full form of inl in VMWARE_PORT

On Mon, Oct 07, 2019 at 12:21:29PM -0700, Sami Tolvanen wrote:
> LLVM's assembler doesn't accept the short form inl (%%dx) instruction,
> but instead insists on the output register to be explicitly specified:
>
> <inline asm>:1:7: error: invalid operand for instruction
> inl (%dx)
> ^
> LLVM ERROR: Error parsing inline asm
>
> Use the full form of the instruction to fix the build.
>
> Signed-off-by: Sami Tolvanen <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

-Kees

> ---
> arch/x86/kernel/cpu/vmware.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
> index 9735139cfdf8..46d732696c1c 100644
> --- a/arch/x86/kernel/cpu/vmware.c
> +++ b/arch/x86/kernel/cpu/vmware.c
> @@ -49,7 +49,7 @@
> #define VMWARE_CMD_VCPU_RESERVED 31
>
> #define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
> - __asm__("inl (%%dx)" : \
> + __asm__("inl (%%dx), %%eax" : \
> "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
> "a"(VMWARE_HYPERVISOR_MAGIC), \
> "c"(VMWARE_CMD_##cmd), \
> --
> 2.23.0.581.g78d2f28ef7-goog
>

--
Kees Cook

2019-10-08 09:59:55

by tip-bot2 for Jacob Pan

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Subject: [tip: x86/urgent] x86/cpu/vmware: Use the full form of inl in VMWARE_PORT

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: b547c1fa97b030ac50586e8b187571b4a83d154c
Gitweb: https://git.kernel.org/tip/b547c1fa97b030ac50586e8b187571b4a83d154c
Author: Sami Tolvanen <[email protected]>
AuthorDate: Mon, 07 Oct 2019 12:21:29 -07:00
Committer: Borislav Petkov <[email protected]>
CommitterDate: Tue, 08 Oct 2019 11:52:35 +02:00

x86/cpu/vmware: Use the full form of inl in VMWARE_PORT

LLVM's assembler doesn't accept the short form

inl (%%dx)

instruction, but instead insists on the output register to be explicitly
specified:

<inline asm>:1:7: error: invalid operand for instruction
inl (%dx)
^
LLVM ERROR: Error parsing inline asm

Use the full form of the instruction to fix the build.

Signed-off-by: Sami Tolvanen <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Thomas Hellstrom <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: "VMware, Inc." <[email protected]>
Cc: x86-ml <[email protected]>
Link: https://github.com/ClangBuiltLinux/linux/issues/734
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/kernel/cpu/vmware.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 9735139..46d7326 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -49,7 +49,7 @@
#define VMWARE_CMD_VCPU_RESERVED 31

#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
- __asm__("inl (%%dx)" : \
+ __asm__("inl (%%dx), %%eax" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \

2019-10-08 10:01:02

by tip-bot2 for Jacob Pan

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Subject: [tip: x86/urgent] x86/cpu/vmware: Use the full form of inl in VMWARE_PORT

2019-10-08 11:34:16

by tip-bot2 for Jacob Pan

[permalink] [raw]

Subject: [tip: x86/urgent] x86/cpu/vmware: Use the full form of INL in VMWARE_PORT

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: fbcfb8f0270bf24fe348393540b17a7f2ba577d7
Gitweb: https://git.kernel.org/tip/fbcfb8f0270bf24fe348393540b17a7f2ba577d7
Author: Sami Tolvanen <[email protected]>
AuthorDate: Mon, 07 Oct 2019 12:21:29 -07:00
Committer: Ingo Molnar <[email protected]>
CommitterDate: Tue, 08 Oct 2019 13:26:42 +02:00

x86/cpu/vmware: Use the full form of INL in VMWARE_PORT

LLVM's assembler doesn't accept the short form INL instruction:

inl (%%dx)

but instead insists on the output register to be explicitly specified:

<inline asm>:1:7: error: invalid operand for instruction
inl (%dx)
^
LLVM ERROR: Error parsing inline asm

Use the full form of the instruction to fix the build.

Signed-off-by: Sami Tolvanen <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Thomas Hellstrom <[email protected]>
Cc: [email protected]
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: "VMware, Inc." <[email protected]>
Cc: x86-ml <[email protected]>
Link: https://github.com/ClangBuiltLinux/linux/issues/734
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/kernel/cpu/vmware.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 9735139..46d7326 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -49,7 +49,7 @@
#define VMWARE_CMD_VCPU_RESERVED 31

#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
- __asm__("inl (%%dx)" : \
+ __asm__("inl (%%dx), %%eax" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \

2019-10-08 11:34:37

by tip-bot2 for Jacob Pan

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