Regression: Fwd: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid

Regression: Fwd: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid

[Dimitri John Ledkov]

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#regzbot ^introduced 2139619bcad7ac44cc8f6f749089120594056613

Over at https://lore.kernel.org/linux-riscv/Yz80ewHKTPI5Rvuz@spud/T/#ebde47064434d4ca4807b4abb8eb39898c48a8de2 it is reported that 2139619bcad7ac44cc8f6f749089120594056613 regresses userspace (openjdk) on riscv64.

This commit has already been released in v6.0 kernel upstream, but has also been included in the stable patch series all the way back to v4.19.y

There is a proposed fix for this at https://lore.kernel.org/linux-riscv/20220915193702.2201018-1-abrestic@rivosinc.com/ which has not yet been merged upstream or in stable series.

Please review and merge above proposed fix, or please revert 2139619bcad7ac44cc8f6f749089120594056613 to stop the regression spreading to all the distributions.

In Ubuntu this regression will be tracked as https://bugs.launchpad.net/bugs/+bug/1992484

-------- Forwarded Message --------
Subject: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid
Date: Thu, 6 Oct 2022 22:20:02 +0300
From: Eva Kotova <nyandarknessgirl@gmail.com>
Reply-To: PH7PR14MB559464DBDD310E755F5B21E8CEDC9@PH7PR14MB5594.namprd14.prod.outlook.com
To: coelacanthus@outlook.com
CC: c141028@gmail.com, dramforever@live.com, linux-riscv@lists.infradead.org, palmer@dabbelt.com, xc-tan@outlook.com

On Tue, 31 May 2022 00:56:52 PDT (-0700), coelacanthus@outlook.com wrote:
> As mentioned in Table 4.5 in RISC-V spec Volume 2 Section 4.3, write
> but not read is "Reserved for future use.". For now, they are not valid.
> In the current code, -wx is marked as invalid, but -w- is not marked
> as invalid.

This patch breaks OpenJDK/Java on RISC-V, as it tries to create a w-only
protective page:

#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 4096 bytes for failed to
allocate memory for PaX check.
# An error report file with more information is saved as:
# /root/hs_err_pid107.log

I bisected to this commit since on Linux 5.19+ java no longer works.
Perhaps some fallback should be implemented, to prevent userspace
breakage. It is currently documented, that at least on i386 PROT_WRITE
mappings imply PROT_READ (See man mmap(2) NOTES), this would be a good
place to start.

Best regards,
Eva

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv


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Re: Regression: Fwd: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid

[Conor Dooley]

On Tue, Oct 11, 2022 at 05:52:13PM +0100, Dimitri John Ledkov wrote:
> #regzbot ^introduced 2139619bcad7ac44cc8f6f749089120594056613
> 
> Over at https://lore.kernel.org/linux-riscv/Yz80ewHKTPI5Rvuz@spud/T/#ebde47064434d4ca4807b4abb8eb39898c48a8de2
> it is reported that 2139619bcad7ac44cc8f6f749089120594056613
> regresses userspace (openjdk) on riscv64.
> 
> This commit has already been released in v6.0 kernel upstream,
> but has also been included in the stable patch series all the
> way back to v4.19.y
> 
> There is a proposed fix for this at
> https://lore.kernel.org/linux-riscv/20220915193702.2201018-1-abrestic@rivosinc.com/
> which has not yet been merged upstream or in stable series.
> 
> Please review and merge above proposed fix, or please revert
> 2139619bcad7ac44cc8f6f749089120594056613 to stop the regression
> spreading to all the distributions.

Out of curiosity, and given the CC list lacks a CC of the maintainer,
who are you actually asking to review and/or merge this?

I'll go bump the fix itself.

Thanks,
Conor.

> 
> In Ubuntu this regression will be tracked as https://bugs.launchpad.net/bugs/+bug/1992484
> 
> -------- Forwarded Message --------
> Subject: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid
> Date: Thu, 6 Oct 2022 22:20:02 +0300
> From: Eva Kotova <nyandarknessgirl@gmail.com>
> Reply-To: PH7PR14MB559464DBDD310E755F5B21E8CEDC9@PH7PR14MB5594.namprd14.prod.outlook.com
> To: coelacanthus@outlook.com
> CC: c141028@gmail.com, dramforever@live.com, linux-riscv@lists.infradead.org, palmer@dabbelt.com, xc-tan@outlook.com
> 
> On Tue, 31 May 2022 00:56:52 PDT (-0700), coelacanthus@outlook.com wrote:
> > As mentioned in Table 4.5 in RISC-V spec Volume 2 Section 4.3, write
> > but not read is "Reserved for future use.". For now, they are not valid.
> > In the current code, -wx is marked as invalid, but -w- is not marked
> > as invalid.
> 
> This patch breaks OpenJDK/Java on RISC-V, as it tries to create a w-only
> protective page:
> 
> #
> # There is insufficient memory for the Java Runtime Environment to continue.
> # Native memory allocation (mmap) failed to map 4096 bytes for failed to
> allocate memory for PaX check.
> # An error report file with more information is saved as:
> # /root/hs_err_pid107.log
> 
> I bisected to this commit since on Linux 5.19+ java no longer works.
> Perhaps some fallback should be implemented, to prevent userspace
> breakage. It is currently documented, that at least on i386 PROT_WRITE
> mappings imply PROT_READ (See man mmap(2) NOTES), this would be a good
> place to start.
> 
> Best regards,
> Eva
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
> 

Re: Regression: Fwd: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid

[Dimitri John Ledkov]

On Tue, 11 Oct 2022 at 17:58, Conor Dooley <conor@kernel.org> wrote:
>
> On Tue, Oct 11, 2022 at 05:52:13PM +0100, Dimitri John Ledkov wrote:
> > #regzbot ^introduced 2139619bcad7ac44cc8f6f749089120594056613
> >
> > Over at https://lore.kernel.org/linux-riscv/Yz80ewHKTPI5Rvuz@spud/T/#ebde47064434d4ca4807b4abb8eb39898c48a8de2
> > it is reported that 2139619bcad7ac44cc8f6f749089120594056613
> > regresses userspace (openjdk) on riscv64.
> >
> > This commit has already been released in v6.0 kernel upstream,
> > but has also been included in the stable patch series all the
> > way back to v4.19.y
> >
> > There is a proposed fix for this at
> > https://lore.kernel.org/linux-riscv/20220915193702.2201018-1-abrestic@rivosinc.com/
> > which has not yet been merged upstream or in stable series.
> >
> > Please review and merge above proposed fix, or please revert
> > 2139619bcad7ac44cc8f6f749089120594056613 to stop the regression
> > spreading to all the distributions.
>
> Out of curiosity, and given the CC list lacks a CC of the maintainer,
> who are you actually asking to review and/or merge this?
>

Good point, this is my first time escalating a regression which is now
in all the stable trees. I guess I should have CC'ed all the M: from
RISC-V in the Maintainers file. Not just the riscv list.

> I'll go bump the fix itself.

Thanks.

>
> Thanks,
> Conor.
>
> >
> > In Ubuntu this regression will be tracked as https://bugs.launchpad.net/bugs/+bug/1992484
> >
> > -------- Forwarded Message --------
> > Subject: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid
> > Date: Thu, 6 Oct 2022 22:20:02 +0300
> > From: Eva Kotova <nyandarknessgirl@gmail.com>
> > Reply-To: PH7PR14MB559464DBDD310E755F5B21E8CEDC9@PH7PR14MB5594.namprd14.prod.outlook.com
> > To: coelacanthus@outlook.com
> > CC: c141028@gmail.com, dramforever@live.com, linux-riscv@lists.infradead.org, palmer@dabbelt.com, xc-tan@outlook.com
> >
> > On Tue, 31 May 2022 00:56:52 PDT (-0700), coelacanthus@outlook.com wrote:
> > > As mentioned in Table 4.5 in RISC-V spec Volume 2 Section 4.3, write
> > > but not read is "Reserved for future use.". For now, they are not valid.
> > > In the current code, -wx is marked as invalid, but -w- is not marked
> > > as invalid.
> >
> > This patch breaks OpenJDK/Java on RISC-V, as it tries to create a w-only
> > protective page:
> >
> > #
> > # There is insufficient memory for the Java Runtime Environment to continue.
> > # Native memory allocation (mmap) failed to map 4096 bytes for failed to
> > allocate memory for PaX check.
> > # An error report file with more information is saved as:
> > # /root/hs_err_pid107.log
> >
> > I bisected to this commit since on Linux 5.19+ java no longer works.
> > Perhaps some fallback should be implemented, to prevent userspace
> > breakage. It is currently documented, that at least on i386 PROT_WRITE
> > mappings imply PROT_READ (See man mmap(2) NOTES), this would be a good
> > place to start.
> >
> > Best regards,
> > Eva
> >
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
> >
>
>
>


-- 
okurrr,

Dimitri

Re: Regression: Fwd: Re: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid #forregzbot

[Thorsten Leemhuis]

[Note: this mail is primarily send for documentation purposes and/or for
regzbot, my Linux kernel regression tracking bot. That's why I removed
most or all folks from the list of recipients, but left any that looked
like a mailing lists. These mails usually contain '#forregzbot' in the
subject, to make them easy to spot and filter out.]

On 11.10.22 18:52, Dimitri John Ledkov wrote:
> #regzbot ^introduced 2139619bcad7ac44cc8f6f749089120594056613

#regzbot fixed-by: 9e2e6042a7ec