* Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch.
2020-12-04 13:42 [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch Igor Munkin
@ 2020-12-04 14:14 ` Sergey Kaplun
2020-12-04 14:35 ` Igor Munkin
2020-12-04 15:40 ` Sergey Ostanevich
` (2 subsequent siblings)
3 siblings, 1 reply; 9+ messages in thread
From: Sergey Kaplun @ 2020-12-04 14:14 UTC (permalink / raw)
To: Igor Munkin; +Cc: tarantool-patches
Hi, Igor!
Thanks for the patch!
LGTM except the single nit.
On 04.12.20, Igor Munkin wrote:
> From: Mike Pall <mike>
>
> After linking new cframe to the chain KBASEa still stores the address of
> the previous one. If the execution proceeds to <lj_vmeta_call> KBASE
> value (i.e. low 32 bits of the stored address) might be equal to the
> current BASE address value so the execution takes the invalid path. Such
> address clashing occurs only on x86_64 platform with disabled LJ_GC64,
Typo: s/address/address parts/ (considering your message in PR).
> so 64-bit registers have to be compared in x64 build.
>
> NB: Though there is only 32-bit load to restore BASE value prior to the
> comparison, the high 32 bits of RDX are reset to zeros, according to x86
> long mode semantics.
>
> Igor Munkin:
> * backported the original patch to tarantool/luajit repo
> * extended the original commit message with the rationale
>
> For more info and explanation see LuaJIT/LuaJIT#636.
>
> Relates to tarantool/tarantool#4518
> Relates to tarantool/tarantool#4649
>
> Signed-off-by: Igor Munkin <imun@tarantool.org>
> ---
>
> Issues:
> * https://github.com/tarantool/tarantool/issues/4518
> * https://github.com/tarantool/tarantool/issues/4649
> Branch:
> * https://github.com/tarantool/luajit/tree/imun/gh-4518-cmp-64-bit-regs-in-vmeta-call
>
> CI is kinda green, considering C6 EOL and the corresponding failures:
> * https://gitlab.com/tarantool/tarantool/-/pipelines/225349795
>
> @ChangeLog:
> * Fixed address clashing occurring while __call metamethod dispatching
> (gh-4518, gh-4649).
>
> Unfortunately, there is neither test nor reproducer for this failure, so
> we'll know that the patch works only on production installations.
>
> src/vm_x86.dasc | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/src/vm_x86.dasc b/src/vm_x86.dasc
> index 56bee14..d76fbe3 100644
> --- a/src/vm_x86.dasc
> +++ b/src/vm_x86.dasc
> @@ -1374,7 +1374,11 @@ static void build_subroutines(BuildCtx *ctx)
> | mov LFUNC:RB, [RA-8]
> | add NARGS:RD, 1
> | // This is fragile. L->base must not move, KBASE must always be defined.
> + |.if x64
> + | cmp KBASEa, rdx // Continue with CALLT if flag set.
> + |.else
> | cmp KBASE, BASE // Continue with CALLT if flag set.
> + |.endif
> | je ->BC_CALLT_Z
> | mov BASE, RA
> | ins_call // Otherwise call resolved metamethod.
> --
> 2.25.0
>
--
Best regards,
Sergey Kaplun
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch.
2020-12-04 14:14 ` Sergey Kaplun
@ 2020-12-04 14:35 ` Igor Munkin
0 siblings, 0 replies; 9+ messages in thread
From: Igor Munkin @ 2020-12-04 14:35 UTC (permalink / raw)
To: Sergey Kaplun; +Cc: tarantool-patches
Sergey,
Thanks for your review!
On 04.12.20, Sergey Kaplun wrote:
> Hi, Igor!
>
> Thanks for the patch!
> LGTM except the single nit.
Added your tag:
| Reviewed-by: Sergey Kaplun <skaplun@tarantool.org>
>
> On 04.12.20, Igor Munkin wrote:
> > From: Mike Pall <mike>
> >
> > After linking new cframe to the chain KBASEa still stores the address of
> > the previous one. If the execution proceeds to <lj_vmeta_call> KBASE
> > value (i.e. low 32 bits of the stored address) might be equal to the
> > current BASE address value so the execution takes the invalid path. Such
> > address clashing occurs only on x86_64 platform with disabled LJ_GC64,
>
> Typo: s/address/address parts/ (considering your message in PR).
Thanks, fixed.
>
> > so 64-bit registers have to be compared in x64 build.
> >
> > NB: Though there is only 32-bit load to restore BASE value prior to the
> > comparison, the high 32 bits of RDX are reset to zeros, according to x86
> > long mode semantics.
> >
> > Igor Munkin:
> > * backported the original patch to tarantool/luajit repo
> > * extended the original commit message with the rationale
> >
> > For more info and explanation see LuaJIT/LuaJIT#636.
> >
> > Relates to tarantool/tarantool#4518
> > Relates to tarantool/tarantool#4649
> >
> > Signed-off-by: Igor Munkin <imun@tarantool.org>
> > ---
> >
<snipped>
> >
>
> --
> Best regards,
> Sergey Kaplun
--
Best regards,
IM
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch.
2020-12-04 13:42 [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch Igor Munkin
2020-12-04 14:14 ` Sergey Kaplun
@ 2020-12-04 15:40 ` Sergey Ostanevich
2020-12-04 16:22 ` Igor Munkin
2020-12-04 16:24 ` Igor Munkin
2020-12-07 9:37 ` Kirill Yukhin
3 siblings, 1 reply; 9+ messages in thread
From: Sergey Ostanevich @ 2020-12-04 15:40 UTC (permalink / raw)
To: Igor Munkin; +Cc: tarantool-patches
Hi!
Thanks for the patch, LGTM.
Sergos
> On 4 Dec 2020, at 16:42, Igor Munkin <imun@tarantool.org> wrote:
>
> From: Mike Pall <mike>
>
> After linking new cframe to the chain KBASEa still stores the address of
> the previous one. If the execution proceeds to <lj_vmeta_call> KBASE
> value (i.e. low 32 bits of the stored address) might be equal to the
> current BASE address value so the execution takes the invalid path. Such
> address clashing occurs only on x86_64 platform with disabled LJ_GC64,
> so 64-bit registers have to be compared in x64 build.
>
> NB: Though there is only 32-bit load to restore BASE value prior to the
> comparison, the high 32 bits of RDX are reset to zeros, according to x86
> long mode semantics.
>
> Igor Munkin:
> * backported the original patch to tarantool/luajit repo
> * extended the original commit message with the rationale
>
> For more info and explanation see LuaJIT/LuaJIT#636.
>
> Relates to tarantool/tarantool#4518
> Relates to tarantool/tarantool#4649
>
> Signed-off-by: Igor Munkin <imun@tarantool.org>
> ---
>
> Issues:
> * https://github.com/tarantool/tarantool/issues/4518
> * https://github.com/tarantool/tarantool/issues/4649
> Branch:
> * https://github.com/tarantool/luajit/tree/imun/gh-4518-cmp-64-bit-regs-in-vmeta-call
>
> CI is kinda green, considering C6 EOL and the corresponding failures:
> * https://gitlab.com/tarantool/tarantool/-/pipelines/225349795
>
> @ChangeLog:
> * Fixed address clashing occurring while __call metamethod dispatching
> (gh-4518, gh-4649).
>
> Unfortunately, there is neither test nor reproducer for this failure, so
> we'll know that the patch works only on production installations.
>
> src/vm_x86.dasc | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/src/vm_x86.dasc b/src/vm_x86.dasc
> index 56bee14..d76fbe3 100644
> --- a/src/vm_x86.dasc
> +++ b/src/vm_x86.dasc
> @@ -1374,7 +1374,11 @@ static void build_subroutines(BuildCtx *ctx)
> | mov LFUNC:RB, [RA-8]
> | add NARGS:RD, 1
> | // This is fragile. L->base must not move, KBASE must always be defined.
> + |.if x64
> + | cmp KBASEa, rdx // Continue with CALLT if flag set.
> + |.else
> | cmp KBASE, BASE // Continue with CALLT if flag set.
> + |.endif
> | je ->BC_CALLT_Z
> | mov BASE, RA
> | ins_call // Otherwise call resolved metamethod.
> --
> 2.25.0
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch.
2020-12-04 13:42 [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch Igor Munkin
2020-12-04 14:14 ` Sergey Kaplun
2020-12-04 15:40 ` Sergey Ostanevich
@ 2020-12-04 16:24 ` Igor Munkin
2020-12-04 16:46 ` Alexander V. Tikhonov
2020-12-07 9:37 ` Kirill Yukhin
3 siblings, 1 reply; 9+ messages in thread
From: Igor Munkin @ 2020-12-04 16:24 UTC (permalink / raw)
To: Alexander V. Tikhonov; +Cc: tarantool-patches
Sasha,
Could you please confirm whether CI is OK?
On 04.12.20, Igor Munkin wrote:
> From: Mike Pall <mike>
>
> After linking new cframe to the chain KBASEa still stores the address of
> the previous one. If the execution proceeds to <lj_vmeta_call> KBASE
> value (i.e. low 32 bits of the stored address) might be equal to the
> current BASE address value so the execution takes the invalid path. Such
> address clashing occurs only on x86_64 platform with disabled LJ_GC64,
> so 64-bit registers have to be compared in x64 build.
>
> NB: Though there is only 32-bit load to restore BASE value prior to the
> comparison, the high 32 bits of RDX are reset to zeros, according to x86
> long mode semantics.
>
> Igor Munkin:
> * backported the original patch to tarantool/luajit repo
> * extended the original commit message with the rationale
>
> For more info and explanation see LuaJIT/LuaJIT#636.
>
> Relates to tarantool/tarantool#4518
> Relates to tarantool/tarantool#4649
>
> Signed-off-by: Igor Munkin <imun@tarantool.org>
> ---
>
> Issues:
> * https://github.com/tarantool/tarantool/issues/4518
> * https://github.com/tarantool/tarantool/issues/4649
> Branch:
> * https://github.com/tarantool/luajit/tree/imun/gh-4518-cmp-64-bit-regs-in-vmeta-call
>
> CI is kinda green, considering C6 EOL and the corresponding failures:
> * https://gitlab.com/tarantool/tarantool/-/pipelines/225349795
>
> @ChangeLog:
> * Fixed address clashing occurring while __call metamethod dispatching
> (gh-4518, gh-4649).
>
> Unfortunately, there is neither test nor reproducer for this failure, so
> we'll know that the patch works only on production installations.
>
<snipped>
>
--
Best regards,
IM
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch.
2020-12-04 16:24 ` Igor Munkin
@ 2020-12-04 16:46 ` Alexander V. Tikhonov
2020-12-04 17:03 ` Igor Munkin
0 siblings, 1 reply; 9+ messages in thread
From: Alexander V. Tikhonov @ 2020-12-04 16:46 UTC (permalink / raw)
To: Igor Munkin; +Cc: tarantool-patches
Hi Igor, thanks for the patch, as I see no new degradations found [1],
patch LGTM.
[1] - https://gitlab.com/tarantool/tarantool/-/pipelines/225349795
On Fri, Dec 04, 2020 at 07:24:41PM +0300, Igor Munkin wrote:
> Sasha,
>
> Could you please confirm whether CI is OK?
>
> On 04.12.20, Igor Munkin wrote:
> > From: Mike Pall <mike>
> >
> > After linking new cframe to the chain KBASEa still stores the address of
> > the previous one. If the execution proceeds to <lj_vmeta_call> KBASE
> > value (i.e. low 32 bits of the stored address) might be equal to the
> > current BASE address value so the execution takes the invalid path. Such
> > address clashing occurs only on x86_64 platform with disabled LJ_GC64,
> > so 64-bit registers have to be compared in x64 build.
> >
> > NB: Though there is only 32-bit load to restore BASE value prior to the
> > comparison, the high 32 bits of RDX are reset to zeros, according to x86
> > long mode semantics.
> >
> > Igor Munkin:
> > * backported the original patch to tarantool/luajit repo
> > * extended the original commit message with the rationale
> >
> > For more info and explanation see LuaJIT/LuaJIT#636.
> >
> > Relates to tarantool/tarantool#4518
> > Relates to tarantool/tarantool#4649
> >
> > Signed-off-by: Igor Munkin <imun@tarantool.org>
> > ---
> >
> > Issues:
> > * https://github.com/tarantool/tarantool/issues/4518
> > * https://github.com/tarantool/tarantool/issues/4649
> > Branch:
> > * https://github.com/tarantool/luajit/tree/imun/gh-4518-cmp-64-bit-regs-in-vmeta-call
> >
> > CI is kinda green, considering C6 EOL and the corresponding failures:
> > * https://gitlab.com/tarantool/tarantool/-/pipelines/225349795
> >
> > @ChangeLog:
> > * Fixed address clashing occurring while __call metamethod dispatching
> > (gh-4518, gh-4649).
> >
> > Unfortunately, there is neither test nor reproducer for this failure, so
> > we'll know that the patch works only on production installations.
> >
>
> <snipped>
>
> >
>
> --
> Best regards,
> IM
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch.
2020-12-04 16:46 ` Alexander V. Tikhonov
@ 2020-12-04 17:03 ` Igor Munkin
0 siblings, 0 replies; 9+ messages in thread
From: Igor Munkin @ 2020-12-04 17:03 UTC (permalink / raw)
To: Alexander V. Tikhonov; +Cc: tarantool-patches
Sasha,
On 04.12.20, Alexander V. Tikhonov wrote:
> Hi Igor, thanks for the patch, as I see no new degradations found [1],
> patch LGTM.
Great, thanks!
Kirill, please proceed with the patch.
>
> [1] - https://gitlab.com/tarantool/tarantool/-/pipelines/225349795
>
> On Fri, Dec 04, 2020 at 07:24:41PM +0300, Igor Munkin wrote:
> > Sasha,
> >
> > Could you please confirm whether CI is OK?
> >
> > On 04.12.20, Igor Munkin wrote:
> > > From: Mike Pall <mike>
> > >
> > > After linking new cframe to the chain KBASEa still stores the address of
> > > the previous one. If the execution proceeds to <lj_vmeta_call> KBASE
> > > value (i.e. low 32 bits of the stored address) might be equal to the
> > > current BASE address value so the execution takes the invalid path. Such
> > > address clashing occurs only on x86_64 platform with disabled LJ_GC64,
> > > so 64-bit registers have to be compared in x64 build.
> > >
> > > NB: Though there is only 32-bit load to restore BASE value prior to the
> > > comparison, the high 32 bits of RDX are reset to zeros, according to x86
> > > long mode semantics.
> > >
> > > Igor Munkin:
> > > * backported the original patch to tarantool/luajit repo
> > > * extended the original commit message with the rationale
> > >
> > > For more info and explanation see LuaJIT/LuaJIT#636.
> > >
> > > Relates to tarantool/tarantool#4518
> > > Relates to tarantool/tarantool#4649
> > >
> > > Signed-off-by: Igor Munkin <imun@tarantool.org>
> > > ---
> > >
> > > Issues:
> > > * https://github.com/tarantool/tarantool/issues/4518
> > > * https://github.com/tarantool/tarantool/issues/4649
> > > Branch:
> > > * https://github.com/tarantool/luajit/tree/imun/gh-4518-cmp-64-bit-regs-in-vmeta-call
> > >
> > > CI is kinda green, considering C6 EOL and the corresponding failures:
> > > * https://gitlab.com/tarantool/tarantool/-/pipelines/225349795
> > >
> > > @ChangeLog:
> > > * Fixed address clashing occurring while __call metamethod dispatching
> > > (gh-4518, gh-4649).
> > >
> > > Unfortunately, there is neither test nor reproducer for this failure, so
> > > we'll know that the patch works only on production installations.
> > >
> >
> > <snipped>
> >
> > >
> >
> > --
> > Best regards,
> > IM
--
Best regards,
IM
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch.
2020-12-04 13:42 [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch Igor Munkin
` (2 preceding siblings ...)
2020-12-04 16:24 ` Igor Munkin
@ 2020-12-07 9:37 ` Kirill Yukhin
3 siblings, 0 replies; 9+ messages in thread
From: Kirill Yukhin @ 2020-12-07 9:37 UTC (permalink / raw)
To: Igor Munkin; +Cc: tarantool-patches
Hello,
On 04 Dec 16:42, Igor Munkin via Tarantool-patches wrote:
> From: Mike Pall <mike>
>
> After linking new cframe to the chain KBASEa still stores the address of
> the previous one. If the execution proceeds to <lj_vmeta_call> KBASE
> value (i.e. low 32 bits of the stored address) might be equal to the
> current BASE address value so the execution takes the invalid path. Such
> address clashing occurs only on x86_64 platform with disabled LJ_GC64,
> so 64-bit registers have to be compared in x64 build.
>
> NB: Though there is only 32-bit load to restore BASE value prior to the
> comparison, the high 32 bits of RDX are reset to zeros, according to x86
> long mode semantics.
>
> Igor Munkin:
> * backported the original patch to tarantool/luajit repo
> * extended the original commit message with the rationale
>
> For more info and explanation see LuaJIT/LuaJIT#636.
>
> Relates to tarantool/tarantool#4518
> Relates to tarantool/tarantool#4649
>
> Signed-off-by: Igor Munkin <imun@tarantool.org>
I've checked your patch into Tarantool's luakit release branches and
bumped a new version in 1.10, 2.5, 2.6 and master.
--
Regards, Kirill Yukhin
^ permalink raw reply [flat|nested] 9+ messages in thread