* [PATCH] x86: fix return value checks of set_guest_{machinecheck, nmi}_trapbounce
@ 2018-05-02 9:02 Jan Beulich
2018-05-02 9:37 ` Andrew Cooper
0 siblings, 1 reply; 3+ messages in thread
From: Jan Beulich @ 2018-05-02 9:02 UTC (permalink / raw)
To: xen-devel; +Cc: Juergen Gross, Andrew Cooper
Commit 0142064421 ("x86/traps: move set_guest_{machine,nmi}_trapbounce")
converted the functions' return types from int to bool without also
correcting the checks in assembly code: The ABI does not guarantee sub-
32-bit return values to be promoted to 32 bits.
Take the liberty and also adjust the number of spaces used in the compat
code, such that both code sequences end up similar (they already are in
the non-compat case).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
This wants backporting to 4.10.
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -74,9 +74,9 @@ compat_process_mce:
testb $1 << VCPU_TRAP_MCE,VCPU_async_exception_mask(%rbx)
jnz .Lcompat_test_guest_nmi
sti
- movb $0,VCPU_mce_pending(%rbx)
- call set_guest_machinecheck_trapbounce
- testl %eax,%eax
+ movb $0, VCPU_mce_pending(%rbx)
+ call set_guest_machinecheck_trapbounce
+ test %al, %al
jz compat_test_all_events
movzbl VCPU_async_exception_mask(%rbx),%edx # save mask for the
movb %dl,VCPU_mce_old_mask(%rbx) # iret hypercall
@@ -88,11 +88,11 @@ compat_process_mce:
/* %rbx: struct vcpu */
compat_process_nmi:
testb $1 << VCPU_TRAP_NMI,VCPU_async_exception_mask(%rbx)
- jnz compat_test_guest_events
+ jnz compat_test_guest_events
sti
- movb $0,VCPU_nmi_pending(%rbx)
+ movb $0, VCPU_nmi_pending(%rbx)
call set_guest_nmi_trapbounce
- testl %eax,%eax
+ test %al, %al
jz compat_test_all_events
movzbl VCPU_async_exception_mask(%rbx),%edx # save mask for the
movb %dl,VCPU_nmi_old_mask(%rbx) # iret hypercall
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -77,7 +77,7 @@ process_mce:
sti
movb $0, VCPU_mce_pending(%rbx)
call set_guest_machinecheck_trapbounce
- test %eax, %eax
+ test %al, %al
jz test_all_events
movzbl VCPU_async_exception_mask(%rbx), %edx # save mask for the
movb %dl, VCPU_mce_old_mask(%rbx) # iret hypercall
@@ -93,7 +93,7 @@ process_nmi:
sti
movb $0, VCPU_nmi_pending(%rbx)
call set_guest_nmi_trapbounce
- test %eax, %eax
+ test %al, %al
jz test_all_events
movzbl VCPU_async_exception_mask(%rbx), %edx # save mask for the
movb %dl, VCPU_nmi_old_mask(%rbx) # iret hypercall
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86: fix return value checks of set_guest_{machinecheck, nmi}_trapbounce
2018-05-02 9:02 [PATCH] x86: fix return value checks of set_guest_{machinecheck, nmi}_trapbounce Jan Beulich
@ 2018-05-02 9:37 ` Andrew Cooper
0 siblings, 0 replies; 3+ messages in thread
From: Andrew Cooper @ 2018-05-02 9:37 UTC (permalink / raw)
To: Jan Beulich, xen-devel; +Cc: Juergen Gross
On 02/05/18 10:02, Jan Beulich wrote:
> Commit 0142064421 ("x86/traps: move set_guest_{machine,nmi}_trapbounce")
> converted the functions' return types from int to bool without also
> correcting the checks in assembly code: The ABI does not guarantee sub-
> 32-bit return values to be promoted to 32 bits.
>
> Take the liberty and also adjust the number of spaces used in the compat
> code, such that both code sequences end up similar (they already are in
> the non-compat case).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
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https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] x86: fix return value checks of set_guest_{machinecheck, nmi}_trapbounce
[not found] <5AE97E9C02000078001C00D5@suse.com>
@ 2018-05-02 10:25 ` Juergen Gross
0 siblings, 0 replies; 3+ messages in thread
From: Juergen Gross @ 2018-05-02 10:25 UTC (permalink / raw)
To: Jan Beulich, xen-devel; +Cc: Andrew Cooper
On 02/05/18 11:02, Jan Beulich wrote:
> Commit 0142064421 ("x86/traps: move set_guest_{machine,nmi}_trapbounce")
> converted the functions' return types from int to bool without also
> correcting the checks in assembly code: The ABI does not guarantee sub-
> 32-bit return values to be promoted to 32 bits.
>
> Take the liberty and also adjust the number of spaces used in the compat
> code, such that both code sequences end up similar (they already are in
> the non-compat case).
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
Release-acked-by: Juergen Gross <jgross@suse.com>
Juergen
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-05-02 9:02 [PATCH] x86: fix return value checks of set_guest_{machinecheck, nmi}_trapbounce Jan Beulich
2018-05-02 9:37 ` Andrew Cooper
[not found] <5AE97E9C02000078001C00D5@suse.com>
2018-05-02 10:25 ` Juergen Gross
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